Commit Graph

1619 Commits

Author SHA1 Message Date
David Howells 2b0143b5c9 VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
Kirill A. Shutemov ab676b7d6f pagemap: do not leak physical addresses to non-privileged userspace
As pointed by recent post[1] on exploiting DRAM physical imperfection,
/proc/PID/pagemap exposes sensitive information which can be used to do
attacks.

This disallows anybody without CAP_SYS_ADMIN to read the pagemap.

[1] http://googleprojectzero.blogspot.com/2015/03/exploiting-dram-rowhammer-bug-to-gain.html

[ Eventually we might want to do anything more finegrained, but for now
  this is the simple model.   - Linus ]

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Seaborn <mseaborn@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-03-17 09:31:30 -07:00
Al Viro 7e0e953bb0 procfs: fix race between symlink removals and traversals
use_pde()/unuse_pde() in ->follow_link()/->put_link() resp.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-22 11:43:12 -05:00
Linus Torvalds 50652963ea Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc VFS updates from Al Viro:
 "This cycle a lot of stuff sits on topical branches, so I'll be sending
  more or less one pull request per branch.

  This is the first pile; more to follow in a few.  In this one are
  several misc commits from early in the cycle (before I went for
  separate branches), plus the rework of mntput/dput ordering on umount,
  switching to use of fs_pin instead of convoluted games in
  namespace_unlock()"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  switch the IO-triggering parts of umount to fs_pin
  new fs_pin killing logics
  allow attaching fs_pin to a group not associated with some superblock
  get rid of the second argument of acct_kill()
  take count and rcu_head out of fs_pin
  dcache: let the dentry count go down to zero without taking d_lock
  pull bumping refcount into ->kill()
  kill pin_put()
  mode_t whack-a-mole: chelsio
  file->f_path.dentry is pinned down for as long as the file is open...
  get rid of lustre_dump_dentry()
  gut proc_register() a bit
  kill d_validate()
  ncpfs: get rid of d_validate() nonsense
  selinuxfs: don't open-code d_genocide()
2015-02-17 14:56:45 -08:00
WANG Chao 34b4776429 vmcore: fix PT_NOTE n_namesz, n_descsz overflow issue
When updating PT_NOTE header size (ie.  p_memsz), an overflow issue
happens with the following bogus note entry:

  n_namesz = 0xFFFFFFFF
  n_descsz = 0x0
  n_type   = 0x0

This kind of note entry should be dropped during updating p_memsz.  But
because n_namesz is 32bit, after (n_namesz + 3) & (~3), it's overflow to
0x0, the note entry size looks sane and reserved.

When userspace (eg.  crash utility) is trying to access such bogus note,
it could lead to an unexpected behavior (eg.  crash utility segment fault
because it's reading bogus address).

The source of bogus note hasn't been identified yet.  At least we could
drop the bogus note so user space wouldn't be surprised.

Signed-off-by: WANG Chao <chaowang@redhat.com>
Cc: Dave Anderson <anderson@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Randy Wright <rwright@hp.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Rashika Kheria <rashika.kheria@gmail.com>
Cc: Greg Pearson <greg.pearson@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:52 -08:00
Tejun Heo a0c2e07d6d proc: use %*pb[l] to print bitmaps including cpumasks and nodemasks
printk and friends can now format bitmaps using '%*pb[l]'.  cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:38 -08:00
Andy Shevchenko edc924e023 fs/proc/array.c: convert to use string_escape_str()
Instead of custom approach let's use string_escape_str() to escape a given
string (task_name in this case).

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Rafael Aquini 198d1597cc fs: proc: task_mmu: show page size in /proc/<pid>/numa_maps
The output of /proc/$pid/numa_maps is in terms of number of pages like
anon=22 or dirty=54.  Here's some output:

  7f4680000000 default file=/hugetlb/bigfile anon=50 dirty=50 N0=50
  7f7659600000 default file=/anon_hugepage\040(deleted) anon=50 dirty=50 N0=50
  7fff8d425000 default stack anon=50 dirty=50 N0=50

Looks like we have a stack and a couple of anonymous hugetlbfs
areas page which both use the same amount of memory.  They don't.

The 'bigfile' uses 1GB pages and takes up ~50GB of space.  The
anon_hugepage uses 2MB pages and takes up ~100MB of space while the stack
uses normal 4k pages.  You can go over to smaps to figure out what the
page size _really_ is with KernelPageSize or MMUPageSize.  But, I think
this is a pretty nasty and counterintuitive interface as it stands.

This patch introduces 'kernelpagesize_kB' line element to
/proc/<pid>/numa_maps report file in order to help identifying the size of
pages that are backing memory areas mapped by a given task.  This is
specially useful to help differentiating between HUGE and GIGANTIC page
backed VMAs.

This patch is based on Dave Hansen's proposal and reviewer's follow-ups
taken from the following dicussion threads:
 * https://lkml.org/lkml/2011/9/21/454
 * https://lkml.org/lkml/2014/12/20/66

Signed-off-by: Rafael Aquini <aquini@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Alexander Kuleshov 6bee55f94f fs: proc: use PDE() to get proc_dir_entry
Use the PDE() helper to get proc_dir_entry instead of coding it directly.

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Petr Cermak 695f055936 fs/proc/task_mmu.c: add user-space support for resetting mm->hiwater_rss (peak RSS)
Peak resident size of a process can be reset back to the process's
current rss value by writing "5" to /proc/pid/clear_refs.  The driving
use-case for this would be getting the peak RSS value, which can be
retrieved from the VmHWM field in /proc/pid/status, per benchmark
iteration or test scenario.

[akpm@linux-foundation.org: clarify behaviour in documentation]
Signed-off-by: Petr Cermak <petrcermak@chromium.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Primiano Tucci <primiano@chromium.org>
Cc: Petr Cermak <petrcermak@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Kirill A. Shutemov 7d5b3bfaa2 mm: /proc/pid/clear_refs: avoid split_huge_page()
Currently pagewalker splits all THP pages on any clear_refs request.  It's
not necessary.  We can handle this on PMD level.

One side effect is that soft dirty will potentially see more dirty memory,
since we will mark whole THP page dirty at once.

Sanity checked with CRIU test suite. More testing is required.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:06 -08:00
Naoya Horiguchi 48684a65b4 mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)
walk_page_range() silently skips vma having VM_PFNMAP set, which leads to
undesirable behaviour at client end (who called walk_page_range).  For
example for pagemap_read(), when no callbacks are called against VM_PFNMAP
vma, pagemap_read() may prepare pagemap data for next virtual address
range at wrong index.  That could confuse and/or break userspace
applications.

This patch avoid this misbehavior caused by vma(VM_PFNMAP) like follows:
- for pagemap_read() which has its own ->pte_hole(), call the ->pte_hole()
  over vma(VM_PFNMAP),
- for clear_refs and queue_pages which have their own ->tests_walk,
  just return 1 and skip vma(VM_PFNMAP). This is no problem because
  these are not interested in hole regions,
- for other callers, just skip the vma(VM_PFNMAP) as a default behavior.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Shiraz Hashim <shashim@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:06 -08:00
Naoya Horiguchi d85f4d6d3b numa_maps: remove numa_maps->vma
pagewalk.c can handle vma in itself, so we don't have to pass vma via
walk->private.  And show_numa_map() walks pages on vma basis, so using
walk_page_vma() is preferable.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:06 -08:00
Naoya Horiguchi 632fd60fe4 numa_maps: fix typo in gather_hugetbl_stats
Just doing s/gather_hugetbl_stats/gather_hugetlb_stats/g, this makes code
grep-friendly.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:06 -08:00
Naoya Horiguchi f995ece24d pagemap: use walk->vma instead of calling find_vma()
Page table walker has the information of the current vma in mm_walk, so we
don't have to call find_vma() in each pagemap_(pte|hugetlb)_range() call
any longer.  Currently pagemap_pte_range() does vma loop itself, so this
patch reduces many lines of code.

NULL-vma check is omitted because we assume that we never run these
callbacks on any address outside vma.  And even if it were broken, NULL
pointer dereference would be detected, so we can get enough information
for debugging.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:05 -08:00
Naoya Horiguchi 5c64f52acd clear_refs: remove clear_refs_private->vma and introduce clear_refs_test_walk()
clear_refs_write() has some prechecks to determine if we really walk over
a given vma.  Now we have a test_walk() callback to filter vmas, so let's
utilize it.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:05 -08:00
Naoya Horiguchi 14eb6fdd42 smaps: remove mem_size_stats->vma and use walk_page_vma()
pagewalk.c can handle vma in itself, so we don't have to pass vma via
walk->private.  And show_smap() walks pages on vma basis, so using
walk_page_vma() is preferable.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:05 -08:00
Konstantin Khlebnikov 05fbf357d9 proc/pagemap: walk page tables under pte lock
Lockless access to pte in pagemap_pte_range() might race with page
migration and trigger BUG_ON(!PageLocked()) in migration_entry_to_page():

CPU A (pagemap)                           CPU B (migration)
                                          lock_page()
                                          try_to_unmap(page, TTU_MIGRATION...)
                                               make_migration_entry()
                                               set_pte_at()
<read *pte>
pte_to_pagemap_entry()
                                          remove_migration_ptes()
                                          unlock_page()
    if(is_migration_entry())
        migration_entry_to_page()
            BUG_ON(!PageLocked(page))

Also lockless read might be non-atomic if pte is larger than wordsize.
Other pte walkers (smaps, numa_maps, clear_refs) already lock ptes.

Fixes: 052fb0d635 ("proc: report file/anon bit in /proc/pid/pagemap")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reported-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>	[3.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:05 -08:00
Kirill A. Shutemov dc6c9a35b6 mm: account pmd page tables to the process
Dave noticed that unprivileged process can allocate significant amount of
memory -- >500 MiB on x86_64 -- and stay unnoticed by oom-killer and
memory cgroup.  The trick is to allocate a lot of PMD page tables.  Linux
kernel doesn't account PMD tables to the process, only PTE.

The use-cases below use few tricks to allocate a lot of PMD page tables
while keeping VmRSS and VmPTE low.  oom_score for the process will be 0.

	#include <errno.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <sys/mman.h>
	#include <sys/prctl.h>

	#define PUD_SIZE (1UL << 30)
	#define PMD_SIZE (1UL << 21)

	#define NR_PUD 130000

	int main(void)
	{
		char *addr = NULL;
		unsigned long i;

		prctl(PR_SET_THP_DISABLE);
		for (i = 0; i < NR_PUD ; i++) {
			addr = mmap(addr + PUD_SIZE, PUD_SIZE, PROT_WRITE|PROT_READ,
					MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
			if (addr == MAP_FAILED) {
				perror("mmap");
				break;
			}
			*addr = 'x';
			munmap(addr, PMD_SIZE);
			mmap(addr, PMD_SIZE, PROT_WRITE|PROT_READ,
					MAP_ANONYMOUS|MAP_PRIVATE|MAP_FIXED, -1, 0);
			if (addr == MAP_FAILED)
				perror("re-mmap"), exit(1);
		}
		printf("PID %d consumed %lu KiB in PMD page tables\n",
				getpid(), i * 4096 >> 10);
		return pause();
	}

The patch addresses the issue by account PMD tables to the process the
same way we account PTE.

The main place where PMD tables is accounted is __pmd_alloc() and
free_pmd_range(). But there're few corner cases:

 - HugeTLB can share PMD page tables. The patch handles by accounting
   the table to all processes who share it.

 - x86 PAE pre-allocates few PMD tables on fork.

 - Architectures with FIRST_USER_ADDRESS > 0. We need to adjust sanity
   check on exit(2).

Accounting only happens on configuration where PMD page table's level is
present (PMD is not folded).  As with nr_ptes we use per-mm counter.  The
counter value is used to calculate baseline for badness score by
oom-killer.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: David Rientjes <rientjes@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:04 -08:00
Wang, Yalin 56873f43ab mm:add KPF_ZERO_PAGE flag for /proc/kpageflags
Add KPF_ZERO_PAGE flag for zero_page, so that userspace processes can
detect zero_page in /proc/kpageflags, and then do memory analysis more
accurately.

Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:00 -08:00
Kirill A. Shutemov 1da4b35b00 proc: drop handling non-linear mappings
We have to handle non-linear mappings for /proc/PID/{smaps,clear_refs}
which is unused now.  Let's drop it.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10 14:30:31 -08:00
Al Viro d443b9fd56 gut proc_register() a bit
There are only 3 callers and quite a bit of that thing is executed
exactly in one of those.  Just lift it there...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 23:16:26 -05:00
Linus Torvalds ac88ee3b6c Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq core fix from Thomas Gleixner:
 "A single fix plugging a long standing race between proc/stat and
  proc/interrupts access and freeing of interrupt descriptors"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Prevent proc race against freeing of irq descriptors
2014-12-19 13:26:08 -08:00
Pintu Kumar 47f8f9297d fs/proc/meminfo.c: include cma info in proc/meminfo
This patch include CMA info (CMATotal, CMAFree) in /proc/meminfo.
Currently, in a CMA enabled system, if somebody wants to know the total
CMA size declared, there is no way to tell, other than the dmesg or
/var/log/messages logs.

With this patch we are showing the CMA info as part of meminfo, so that it
can be determined at any point of time.  This will be populated only when
CMA is enabled.

Below is the sample output from a ARM based device with RAM:512MB and CMA:16MB.

  MemTotal:         471172 kB
  MemFree:          111712 kB
  MemAvailable:     271172 kB
  .
  .
  .
  CmaTotal:          16384 kB
  CmaFree:            6144 kB

This patch also fix below checkpatch errors that were found during these changes.

  ERROR: space required after that ',' (ctx:ExV)
  199: FILE: fs/proc/meminfo.c:199:
  +       ,atomic_long_read(&num_poisoned_pages) << (PAGE_SHIFT - 10)
          ^

  ERROR: space required after that ',' (ctx:ExV)
  202: FILE: fs/proc/meminfo.c:202:
  +       ,K(global_page_state(NR_ANON_TRANSPARENT_HUGEPAGES) *
          ^

  ERROR: space required after that ',' (ctx:ExV)
  206: FILE: fs/proc/meminfo.c:206:
  +       ,K(totalcma_pages)
          ^

  total: 3 errors, 0 warnings, 2 checks, 236 lines checked

Signed-off-by: Pintu Kumar <pintu.k@samsung.com>
Signed-off-by: Vishnu Pratap Singh <vishnu.ps@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-18 19:08:10 -08:00
Linus Torvalds 87c31b39ab Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace related fixes from Eric Biederman:
 "As these are bug fixes almost all of thes changes are marked for
  backporting to stable.

  The first change (implicitly adding MNT_NODEV on remount) addresses a
  regression that was created when security issues with unprivileged
  remount were closed.  I go on to update the remount test to make it
  easy to detect if this issue reoccurs.

  Then there are a handful of mount and umount related fixes.

  Then half of the changes deal with the a recently discovered design
  bug in the permission checks of gid_map.  Unix since the beginning has
  allowed setting group permissions on files to less than the user and
  other permissions (aka ---rwx---rwx).  As the unix permission checks
  stop as soon as a group matches, and setgroups allows setting groups
  that can not later be dropped, results in a situtation where it is
  possible to legitimately use a group to assign fewer privileges to a
  process.  Which means dropping a group can increase a processes
  privileges.

  The fix I have adopted is that gid_map is now no longer writable
  without privilege unless the new file /proc/self/setgroups has been
  set to permanently disable setgroups.

  The bulk of user namespace using applications even the applications
  using applications using user namespaces without privilege remain
  unaffected by this change.  Unfortunately this ix breaks a couple user
  space applications, that were relying on the problematic behavior (one
  of which was tools/selftests/mount/unprivileged-remount-test.c).

  To hopefully prevent needing a regression fix on top of my security
  fix I rounded folks who work with the container implementations mostly
  like to be affected and encouraged them to test the changes.

    > So far nothing broke on my libvirt-lxc test bed. :-)
    > Tested with openSUSE 13.2 and libvirt 1.2.9.
    > Tested-by: Richard Weinberger <richard@nod.at>

    > Tested on Fedora20 with libvirt 1.2.11, works fine.
    > Tested-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>

    > Ok, thanks - yes, unprivileged lxc is working fine with your kernels.
    > Just to be sure I was testing the right thing I also tested using
    > my unprivileged nsexec testcases, and they failed on setgroup/setgid
    > as now expected, and succeeded there without your patches.
    > Tested-by: Serge Hallyn <serge.hallyn@ubuntu.com>

    > I tested this with Sandstorm.  It breaks as is and it works if I add
    > the setgroups thing.
    > Tested-by: Andy Lutomirski <luto@amacapital.net> # breaks things as designed :("

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  userns: Unbreak the unprivileged remount tests
  userns; Correct the comment in map_write
  userns: Allow setting gid_maps without privilege when setgroups is disabled
  userns: Add a knob to disable setgroups on a per user namespace basis
  userns: Rename id_map_mutex to userns_state_mutex
  userns: Only allow the creator of the userns unprivileged mappings
  userns: Check euid no fsuid when establishing an unprivileged uid mapping
  userns: Don't allow unprivileged creation of gid mappings
  userns: Don't allow setgroups until a gid mapping has been setablished
  userns: Document what the invariant required for safe unprivileged mappings.
  groups: Consolidate the setgroups permission checks
  mnt: Clear mnt_expire during pivot_root
  mnt: Carefully set CL_UNPRIVILEGED in clone_mnt
  mnt: Move the clear of MNT_LOCKED from copy_tree to it's callers.
  umount: Do not allow unmounting rootfs.
  umount: Disallow unprivileged mount force
  mnt: Update unprivileged remount test
  mnt: Implicitly add MNT_NODEV on remount when it was implicitly added by mount
2014-12-17 12:31:40 -08:00
Linus Torvalds 603ba7e41b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile #2 from Al Viro:
 "Next pile (and there'll be one or two more).

  The large piece in this one is getting rid of /proc/*/ns/* weirdness;
  among other things, it allows to (finally) make nameidata completely
  opaque outside of fs/namei.c, making for easier further cleanups in
  there"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  coda_venus_readdir(): use file_inode()
  fs/namei.c: fold link_path_walk() call into path_init()
  path_init(): don't bother with LOOKUP_PARENT in argument
  fs/namei.c: new helper (path_cleanup())
  path_init(): store the "base" pointer to file in nameidata itself
  make default ->i_fop have ->open() fail with ENXIO
  make nameidata completely opaque outside of fs/namei.c
  kill proc_ns completely
  take the targets of /proc/*/ns/* symlinks to separate fs
  bury struct proc_ns in fs/proc
  copy address of proc_ns_ops into ns_common
  new helpers: ns_alloc_inum/ns_free_inum
  make proc_ns_operations work with struct ns_common * instead of void *
  switch the rest of proc_ns_operations to working with &...->ns
  netns: switch ->get()/->put()/->install()/->inum() to working with &net->ns
  make mntns ->get()/->put()/->install()/->inum() work with &mnt_ns->ns
  common object embedded into various struct ....ns
2014-12-16 15:53:03 -08:00
Thomas Gleixner c291ee6221 genirq: Prevent proc race against freeing of irq descriptors
Since the rework of the sparse interrupt code to actually free the
unused interrupt descriptors there exists a race between the /proc
interfaces to the irq subsystem and the code which frees the interrupt
descriptor.

CPU0				CPU1
				show_interrupts()
				  desc = irq_to_desc(X);
free_desc(desc)
  remove_from_radix_tree();
  kfree(desc);
				  raw_spinlock_irq(&desc->lock);

/proc/interrupts is the only interface which can actively corrupt
kernel memory via the lock access. /proc/stat can only read from freed
memory. Extremly hard to trigger, but possible.

The interfaces in /proc/irq/N/ are not affected by this because the
removal of the proc file is serialized in procfs against concurrent
readers/writers. The removal happens before the descriptor is freed.

For architectures which have CONFIG_SPARSE_IRQ=n this is a non issue
as the descriptor is never freed. It's merely cleared out with the irq
descriptor lock held. So any concurrent proc access will either see
the old correct value or the cleared out ones.

Protect the lookup and access to the irq descriptor in
show_interrupts() with the sparse_irq_lock.

Provide kstat_irqs_usr() which is protecting the lookup and access
with sparse_irq_lock and switch /proc/stat to use it.

Document the existing kstat_irqs interfaces so it's clear that the
caller needs to take care about protection. The users of these
interfaces are either not affected due to SPARSE_IRQ=n or already
protected against removal.

Fixes: 1f5a5b87f7 "genirq: Implement a sane sparse_irq allocator"
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
2014-12-13 13:33:07 +01:00
Eric W. Biederman 9cc46516dd userns: Add a knob to disable setgroups on a per user namespace basis
- Expose the knob to user space through a proc file /proc/<pid>/setgroups

  A value of "deny" means the setgroups system call is disabled in the
  current processes user namespace and can not be enabled in the
  future in this user namespace.

  A value of "allow" means the segtoups system call is enabled.

- Descendant user namespaces inherit the value of setgroups from
  their parents.

- A proc file is used (instead of a sysctl) as sysctls currently do
  not allow checking the permissions at open time.

- Writing to the proc file is restricted to before the gid_map
  for the user namespace is set.

  This ensures that disabling setgroups at a user namespace
  level will never remove the ability to call setgroups
  from a process that already has that ability.

  A process may opt in to the setgroups disable for itself by
  creating, entering and configuring a user namespace or by calling
  setns on an existing user namespace with setgroups disabled.
  Processes without privileges already can not call setgroups so this
  is a noop.  Prodcess with privilege become processes without
  privilege when entering a user namespace and as with any other path
  to dropping privilege they would not have the ability to call
  setgroups.  So this remains within the bounds of what is possible
  without a knob to disable setgroups permanently in a user namespace.

Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2014-12-11 18:06:36 -06:00
Linus Torvalds b6da0076ba Merge branch 'akpm' (patchbomb from Andrew)
Merge first patchbomb from Andrew Morton:
 - a few minor cifs fixes
 - dma-debug upadtes
 - ocfs2
 - slab
 - about half of MM
 - procfs
 - kernel/exit.c
 - panic.c tweaks
 - printk upates
 - lib/ updates
 - checkpatch updates
 - fs/binfmt updates
 - the drivers/rtc tree
 - nilfs
 - kmod fixes
 - more kernel/exit.c
 - various other misc tweaks and fixes

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
  exit: pidns: fix/update the comments in zap_pid_ns_processes()
  exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting
  exit: exit_notify: re-use "dead" list to autoreap current
  exit: reparent: call forget_original_parent() under tasklist_lock
  exit: reparent: avoid find_new_reaper() if no children
  exit: reparent: introduce find_alive_thread()
  exit: reparent: introduce find_child_reaper()
  exit: reparent: document the ->has_child_subreaper checks
  exit: reparent: s/while_each_thread/for_each_thread/ in find_new_reaper()
  exit: reparent: fix the cross-namespace PR_SET_CHILD_SUBREAPER reparenting
  exit: reparent: fix the dead-parent PR_SET_CHILD_SUBREAPER reparenting
  exit: proc: don't try to flush /proc/tgid/task/tgid
  exit: release_task: fix the comment about group leader accounting
  exit: wait: drop tasklist_lock before psig->c* accounting
  exit: wait: don't use zombie->real_parent
  exit: wait: cleanup the ptrace_reparented() checks
  usermodehelper: kill the kmod_thread_locker logic
  usermodehelper: don't use CLONE_VFORK for ____call_usermodehelper()
  fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp
  nilfs2: fix the nilfs_iget() vs. nilfs_new_inode() races
  ...
2014-12-10 18:34:42 -08:00
Al Viro 707c5960f1 Merge branch 'nsfs' into for-next 2014-12-10 21:31:59 -05:00
Al Viro 3d3d35b1e9 kill proc_ns completely
procfs inodes need only the ns_ops part; nsfs inodes don't need it at all

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-10 21:30:57 -05:00
Al Viro e149ed2b80 take the targets of /proc/*/ns/* symlinks to separate fs
New pseudo-filesystem: nsfs.  Targets of /proc/*/ns/* live there now.
It's not mountable (not even registered, so it's not in /proc/filesystems,
etc.).  Files on it *are* bindable - we explicitly permit that in do_loopback().

This stuff lives in fs/nsfs.c now; proc_ns_fget() moved there as well.
get_proc_ns() is a macro now (it's simply returning ->i_private; would
have been an inline, if not for header ordering headache).
proc_ns_inode() is an ex-parrot.  The interface used in procfs is
ns_get_path(path, task, ops) and ns_get_name(buf, size, task, ops).

Dentries and inodes are never hashed; a non-counting reference to dentry
is stashed in ns_common (removed by ->d_prune()) and reused by ns_get_path()
if present.  See ns_get_path()/ns_prune_dentry/nsfs_evict() for details
of that mechanism.

As the result, proc_ns_follow_link() has stopped poking in nd->path.mnt;
it does nd_jump_link() on a consistent <vfsmount,dentry> pair it gets
from ns_get_path().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-10 21:30:20 -05:00
Oleg Nesterov c35a7f18a0 exit: proc: don't try to flush /proc/tgid/task/tgid
proc_flush_task_mnt() always tries to flush task/pid, but this is
pointless if we reap the leader. d_invalidate() is recursive, and
if nothing else the next d_hash_and_lookup(tgid) should fail anyway.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:17 -08:00
Oleg Nesterov abdba6e9ea proc: task_state: ptrace_parent() doesn't need pid_alive() check
p->ptrace != 0 means that release_task(p) was not called, so pid_alive()
buys nothing and we can remove this check.  Other callers already use it
directly without additional checks.

Note: with or without this patch ptrace_parent() can return the pointer to
the freed task, this will be explained/fixed later.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Cc: Sterling Alexander <stalexan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@hack.frob.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Oleg Nesterov b0fafc1111 proc: task_state: move the main seq_printf() outside of rcu_read_lock()
task_state() does seq_printf() under rcu_read_lock(), but this is only
needed for task_tgid_nr_ns() and task_numa_group_id().  We can calculate
tgid/ngid and drop rcu lock.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Cc: Sterling Alexander <stalexan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@hack.frob.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Oleg Nesterov 0f4a0d53f2 proc: task_state: deuglify the max_fds calculation
1. The usage of fdt looks very ugly, it can't be NULL if ->files is
   not NULL. We can use "unsigned int max_fds" instead.

2. This also allows to move seq_printf(max_fds) outside of task_lock()
   and join it with the previous seq_printf(). See also the next patch.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Cc: Sterling Alexander <stalexan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@hack.frob.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Oleg Nesterov 4af1036df4 proc: task_state: read cred->group_info outside of task_lock()
task_state() reads cred->group_info under task_lock() because a long ago
it was task_struct->group_info and it was actually protected by
task->alloc_lock.  Today this task_unlock() after rcu_read_unlock() just
adds the confusion, move task_unlock() up.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Cc: Sterling Alexander <stalexan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@hack.frob.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Nicolas Dichtel 2fc1e948e8 fs/proc.c: use rb_entry_safe() instead of rb_entry()
Better to use existing macro that rewriting them.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Debabrata Banerjee b208d54b75 procfs: fix error handling of proc_register()
proc_register() error paths are leaking inodes and directory refcounts.

Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Nicolas Dichtel 710585d492 fs/proc: use a rb tree for the directory entries
When a lot of netdevices are created, one of the bottleneck is the
creation of proc entries.  This serie aims to accelerate this part.

The current implementation for the directories in /proc is using a single
linked list.  This is slow when handling directories with large numbers of
entries (eg netdevice-related entries when lots of tunnels are opened).

This patch replaces this linked list by a red-black tree.

Here are some numbers:

dummy30000.batch contains 30 000 times 'link add type dummy'.

Before the patch:
  $ time ip -b dummy30000.batch
  real    2m31.950s
  user    0m0.440s
  sys     2m21.440s
  $ time rmmod dummy
  real    1m35.764s
  user    0m0.000s
  sys     1m24.088s

After the patch:
  $ time ip -b dummy30000.batch
  real    2m0.874s
  user    0m0.448s
  sys     1m49.720s
  $ time rmmod dummy
  real    1m13.988s
  user    0m0.000s
  sys     1m1.008s

The idea of improving this part was suggested by Thierry Herbelot.

[akpm@linux-foundation.org: initialise proc_root.subdir at compile time]
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Thierry Herbelot <thierry.herbelot@6wind.com>.
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Kirill A. Shutemov c164e038ee mm: fix huge zero page accounting in smaps report
As a small zero page, huge zero page should not be accounted in smaps
report as normal page.

For small pages we rely on vm_normal_page() to filter out zero page, but
vm_normal_page() is not designed to handle pmds.  We only get here due
hackish cast pmd to pte in smaps_pte_range() -- pte and pmd format is not
necessary compatible on each and every architecture.

Let's add separate codepath to handle pmds.  follow_trans_huge_pmd() will
detect huge zero page for us.

We would need pmd_dirty() helper to do this properly.  The patch adds it
to THP-enabled architectures which don't yet have one.

[akpm@linux-foundation.org: use do_div to fix 32-bit build]
Signed-off-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengwei Yin <yfw.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:08 -08:00
Linus Torvalds cbfe0de303 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS changes from Al Viro:
 "First pile out of several (there _definitely_ will be more).  Stuff in
  this one:

   - unification of d_splice_alias()/d_materialize_unique()

   - iov_iter rewrite

   - killing a bunch of ->f_path.dentry users (and f_dentry macro).

     Getting that completed will make life much simpler for
     unionmount/overlayfs, since then we'll be able to limit the places
     sensitive to file _dentry_ to reasonably few.  Which allows to have
     file_inode(file) pointing to inode in a covered layer, with dentry
     pointing to (negative) dentry in union one.

     Still not complete, but much closer now.

   - crapectomy in lustre (dead code removal, mostly)

   - "let's make seq_printf return nothing" preparations

   - assorted cleanups and fixes

  There _definitely_ will be more piles"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  copy_from_iter_nocache()
  new helper: iov_iter_kvec()
  csum_and_copy_..._iter()
  iov_iter.c: handle ITER_KVEC directly
  iov_iter.c: convert copy_to_iter() to iterate_and_advance
  iov_iter.c: convert copy_from_iter() to iterate_and_advance
  iov_iter.c: get rid of bvec_copy_page_{to,from}_iter()
  iov_iter.c: convert iov_iter_zero() to iterate_and_advance
  iov_iter.c: convert iov_iter_get_pages_alloc() to iterate_all_kinds
  iov_iter.c: convert iov_iter_get_pages() to iterate_all_kinds
  iov_iter.c: convert iov_iter_npages() to iterate_all_kinds
  iov_iter.c: iterate_and_advance
  iov_iter.c: macros for iterating over iov_iter
  kill f_dentry macro
  dcache: fix kmemcheck warning in switch_names
  new helper: audit_file()
  nfsd_vfs_write(): use file_inode()
  ncpfs: use file_inode()
  kill f_dentry uses
  lockd: get rid of ->f_path.dentry->d_sb
  ...
2014-12-10 16:10:49 -08:00
Al Viro f77c80142e bury struct proc_ns in fs/proc
a) make get_proc_ns() return a pointer to struct ns_common
b) mirror ns_ops in dentry->d_fsdata of ns dentries, so that
is_mnt_ns_file() could get away with fewer dereferences.

That way struct proc_ns becomes invisible outside of fs/proc/*.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-04 14:34:54 -05:00
Al Viro 33c429405a copy address of proc_ns_ops into ns_common
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-04 14:34:47 -05:00
Al Viro 64964528b2 make proc_ns_operations work with struct ns_common * instead of void *
We can do that now.  And kill ->inum(), while we are at it - all instances
are identical.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-04 14:34:17 -05:00
Al Viro 8ce74dd605 Merge tag 'trace-seq-file-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into for-next
Pull the beginning of seq_file cleanup from Steven:
  "I'm looking to clean up the seq_file code and to eventually merge the
  trace_seq code with seq_file as well, since they basically do the same thing.

  Part of this process is to remove the return code of seq_printf() and friends
  as they are rather inconsistent. It is better to use the new function
  seq_has_overflowed() if you want to stop processing when the buffer
  is full. Note, if the buffer is full, the seq_file code will throw away
  the contents, allocate a bigger buffer, and then call your code again
  to fill in the data. The only thing that breaking out of the function
  early does is to save a little time which is probably never noticed.

  I started with patches from Joe Perches and modified them as well.
  There's many more places that need to be updated before we can convert
  seq_printf() and friends to return void. But this patch set introduces
  the seq_has_overflowed() and does some initial updates."
2014-11-19 13:02:53 -05:00
Al Viro 3aa3377fbc procfs: get rid of ->f_dentry
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-19 13:01:24 -05:00
Qiaowei Ren 4aae7e436f x86, mpx: Introduce VM_MPX to indicate that a VMA is MPX specific
MPX-enabled applications using large swaths of memory can
potentially have large numbers of bounds tables in process
address space to save bounds information. These tables can take
up huge swaths of memory (as much as 80% of the memory on the
system) even if we clean them up aggressively. In the worst-case
scenario, the tables can be 4x the size of the data structure
being tracked. IOW, a 1-page structure can require 4 bounds-table
pages.

Being this huge, our expectation is that folks using MPX are
going to be keen on figuring out how much memory is being
dedicated to it. So we need a way to track memory use for MPX.

If we want to specifically track MPX VMAs we need to be able to
distinguish them from normal VMAs, and keep them from getting
merged with normal VMAs. A new VM_ flag set only on MPX VMAs does
both of those things. With this flag, MPX bounds-table VMAs can
be distinguished from other VMAs, and userspace can also walk
/proc/$pid/smaps to get memory usage for MPX.

In addition to this flag, we also introduce a special ->vm_ops
specific to MPX VMAs (see the patch "add MPX specific mmap
interface"), but currently different ->vm_ops do not by
themselves prevent VMA merging, so we still need this flag.

We understand that VM_ flags are scarce and are open to other
options.

Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-mm@kvack.org
Cc: linux-mips@linux-mips.org
Cc: Dave Hansen <dave@sr71.net>
Link: http://lkml.kernel.org/r/20141114151825.565625B3@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-18 00:58:53 +01:00
Joe Perches a3816ab0e8 fs: Convert show_fdinfo functions to void
seq_printf functions shouldn't really check the return value.
Checking seq_has_overflowed() occasionally is used instead.

Update vfs documentation.

Link: http://lkml.kernel.org/p/e37e6e7b76acbdcc3bb4ab2a57c8f8ca1ae11b9a.1412031505.git.joe@perches.com

Cc: David S. Miller <davem@davemloft.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Joe Perches <joe@perches.com>
[ did a few clean ups ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-05 14:13:23 -05:00
Peter Feiner 64e455079e mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared
For VMAs that don't want write notifications, PTEs created for read faults
have their write bit set.  If the read fault happens after VM_SOFTDIRTY is
cleared, then the PTE's softdirty bit will remain clear after subsequent
writes.

Here's a simple code snippet to demonstrate the bug:

  char* m = mmap(NULL, getpagesize(), PROT_READ | PROT_WRITE,
                 MAP_ANONYMOUS | MAP_SHARED, -1, 0);
  system("echo 4 > /proc/$PPID/clear_refs"); /* clear VM_SOFTDIRTY */
  assert(*m == '\0');     /* new PTE allows write access */
  assert(!soft_dirty(x));
  *m = 'x';               /* should dirty the page */
  assert(soft_dirty(x));  /* fails */

With this patch, write notifications are enabled when VM_SOFTDIRTY is
cleared.  Furthermore, to avoid unnecessary faults, write notifications
are disabled when VM_SOFTDIRTY is set.

As a side effect of enabling and disabling write notifications with
care, this patch fixes a bug in mprotect where vm_page_prot bits set by
drivers were zapped on mprotect.  An analogous bug was fixed in mmap by
commit c9d0bf2414 ("mm: uncached vma support with writenotify").

Signed-off-by: Peter Feiner <pfeiner@google.com>
Reported-by: Peter Feiner <pfeiner@google.com>
Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Jamie Liu <jamieliu@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:28 +02:00
Linus Torvalds 77c688ac87 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "The big thing in this pile is Eric's unmount-on-rmdir series; we
  finally have everything we need for that.  The final piece of prereqs
  is delayed mntput() - now filesystem shutdown always happens on
  shallow stack.

  Other than that, we have several new primitives for iov_iter (Matt
  Wilcox, culled from his XIP-related series) pushing the conversion to
  ->read_iter()/ ->write_iter() a bit more, a bunch of fs/dcache.c
  cleanups and fixes (including the external name refcounting, which
  gives consistent behaviour of d_move() wrt procfs symlinks for long
  and short names alike) and assorted cleanups and fixes all over the
  place.

  This is just the first pile; there's a lot of stuff from various
  people that ought to go in this window.  Starting with
  unionmount/overlayfs mess...  ;-/"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (60 commits)
  fs/file_table.c: Update alloc_file() comment
  vfs: Deduplicate code shared by xattr system calls operating on paths
  reiserfs: remove pointless forward declaration of struct nameidata
  don't need that forward declaration of struct nameidata in dcache.h anymore
  take dname_external() into fs/dcache.c
  let path_init() failures treated the same way as subsequent link_path_walk()
  fix misuses of f_count() in ppp and netlink
  ncpfs: use list_for_each_entry() for d_subdirs walk
  vfs: move getname() from callers to do_mount()
  gfs2_atomic_open(): skip lookups on hashed dentry
  [infiniband] remove pointless assignments
  gadgetfs: saner API for gadgetfs_create_file()
  f_fs: saner API for ffs_sb_create_file()
  jfs: don't hash direct inode
  [s390] remove pointless assignment of ->f_op in vmlogrdr ->open()
  ecryptfs: ->f_op is never NULL
  android: ->f_op is never NULL
  nouveau: __iomem misannotations
  missing annotation in fs/file.c
  fs: namespace: suppress 'may be used uninitialized' warnings
  ...
2014-10-13 11:28:42 +02:00
Linus Torvalds b211e9d7c8 Merge branch 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "Nothing too interesting.  Just a handful of cleanup patches"

* 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  Revert "cgroup: remove redundant variable in cgroup_mount()"
  cgroup: remove redundant variable in cgroup_mount()
  cgroup: fix missing unlock in cgroup_release_agent()
  cgroup: remove CGRP_RELEASABLE flag
  perf/cgroup: Remove perf_put_cgroup()
  cgroup: remove redundant check in cgroup_ino()
  cpuset: simplify proc_cpuset_show()
  cgroup: simplify proc_cgroup_show()
  cgroup: use a per-cgroup work for release agent
  cgroup: remove bogus comments
  cgroup: remove redundant code in cgroup_rmdir()
  cgroup: remove some useless forward declarations
  cgroup: fix a typo in comment.
2014-10-10 07:24:40 -04:00
Konstantin Khlebnikov 09316c09dd mm/balloon_compaction: add vmstat counters and kpageflags bit
Always mark pages with PageBalloon even if balloon compaction is disabled
and expose this mark in /proc/kpageflags as KPF_BALLOON.

Also this patch adds three counters into /proc/vmstat: "balloon_inflate",
"balloon_deflate" and "balloon_migrate".  They accumulate balloon
activity.  Current size of balloon is (balloon_inflate - balloon_deflate)
pages.

All generic balloon code now gathered under option CONFIG_MEMORY_BALLOON.
It should be selected by ballooning driver which wants use this feature.
Currently virtio-balloon is the only user.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:26:01 -04:00
Peter Feiner 81d0fa623c mm: softdirty: unmapped addresses between VMAs are clean
If a /proc/pid/pagemap read spans a [VMA, an unmapped region, then a
VM_SOFTDIRTY VMA], the virtual pages in the unmapped region are reported
as softdirty.  Here's a program to demonstrate the bug:

int main() {
	const uint64_t PAGEMAP_SOFTDIRTY = 1ul << 55;
	uint64_t pme[3];
	int fd = open("/proc/self/pagemap", O_RDONLY);;
	char *m = mmap(NULL, 3 * getpagesize(), PROT_READ,
	               MAP_ANONYMOUS | MAP_SHARED, -1, 0);
	munmap(m + getpagesize(), getpagesize());
	pread(fd, pme, 24, (unsigned long) m / getpagesize() * 8);
	assert(pme[0] & PAGEMAP_SOFTDIRTY);    /* passes */
	assert(!(pme[1] & PAGEMAP_SOFTDIRTY)); /* fails */
	assert(pme[2] & PAGEMAP_SOFTDIRTY);    /* passes */
	return 0;
}

(Note that all pages in new VMAs are softdirty until cleared).

Tested:
	Used the program given above. I'm going to include this code in
	a selftest in the future.

[n-horiguchi@ah.jp.nec.com: prevent pagemap_pte_range() from overrunning]
Signed-off-by: Peter Feiner <pfeiner@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Jamie Liu <jamieliu@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:58 -04:00
Oleg Nesterov 498f237178 mempolicy: fix show_numa_map() vs exec() + do_set_mempolicy() race
9e7814404b "hold task->mempolicy while numa_maps scans." fixed the
race with the exiting task but this is not enough.

The current code assumes that get_vma_policy(task) should either see
task->mempolicy == NULL or it should be equal to ->task_mempolicy saved
by hold_task_mempolicy(), so we can never race with __mpol_put(). But
this can only work if we can't race with do_set_mempolicy(), and thus
we can't race with another do_set_mempolicy() or do_exit() after that.

However, do_set_mempolicy()->down_write(mmap_sem) can not prevent this
race. This task can exec, change it's ->mm, and call do_set_mempolicy()
after that; in this case they take 2 different locks.

Change hold_task_mempolicy() to use get_task_policy(), it never returns
NULL, and change show_numa_map() to use __get_vma_policy() or fall back
to proc_priv->task_mempolicy.

Note: this is the minimal fix, we will cleanup this code later. I think
hold_task_mempolicy() and release_task_mempolicy() should die, we can
move this logic into show_numa_map(). Or we can move get_task_policy()
outside of ->mmap_sem and !CONFIG_NUMA code at least.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:56 -04:00
Baoquan He bf3e269246 fs/proc/kcore.c: don't add modules range to kcore if it's equal to vmcore range
On some ARCHs modules range is eauql to vmalloc range. E.g on i686

	"#define MODULES_VADDR   VMALLOC_START"
	"#define MODULES_END     VMALLOC_END"

This will cause 2 duplicate program segments in /proc/kcore, and no flag
to indicate they are different.  This is confusing.  And usually people
who need check the elf header or read the content of kcore will check
memory ranges.  Two program segments which are the same are unnecessary.

So check if the modules range is equal to vmalloc range.  If so, just skip
adding the modules range.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:50 -04:00
Oleg Nesterov 58cb65487e proc/maps: make vm_is_stack() logic namespace-friendly
- Rename vm_is_stack() to task_of_stack() and change it to return
  "struct task_struct *" rather than the global (and thus wrong in
  general) pid_t.

- Add the new pid_of_stack() helper which calls task_of_stack() and
  uses the right namespace to report the correct pid_t.

  Unfortunately we need to define this helper twice, in task_mmu.c
  and in task_nommu.c. perhaps it makes sense to add fs/proc/util.c
  and move at least pid_of_stack/task_of_stack there to avoid the
  code duplication.

- Change show_map_vma() and show_numa_map() to use the new helper.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:50 -04:00
Oleg Nesterov 2c03376d2d proc/maps: replace proc_maps_private->pid with "struct inode *inode"
m_start() can use get_proc_task() instead, and "struct inode *"
provides more potentially useful info, see the next changes.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:50 -04:00
Oleg Nesterov 47fecca15c fs/proc/task_nommu.c: don't use priv->task->mm
I do not know if CONFIG_PREEMPT/SMP is possible without CONFIG_MMU
but the usage of task->mm in m_stop(). The task can exit/exec before
we take mmap_sem, in this case m_stop() can hit NULL or unlock the
wrong rw_semaphore.

Also, this code uses priv->task != NULL to decide whether we need
up_read/mmput. This is correct, but we will probably kill priv->task.
Change m_start/m_stop to rely on IS_ERR_OR_NULL() like task_mmu.c does.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov 27692cd56e fs/proc/task_nommu.c: shift mm_access() from m_start() to proc_maps_open()
Copy-and-paste the changes from "fs/proc/task_mmu.c: shift mm_access()
from m_start() to proc_maps_open()" into task_nommu.c.

Change maps_open() to initialize priv->mm using proc_mem_open(), m_start()
can rely on atomic_inc_not_zero(mm_users) like task_mmu.c does.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov ce34fddb5b fs/proc/task_nommu.c: change maps_open() to use __seq_open_private()
Cleanup and preparation. maps_open() can use __seq_open_private()
like proc_maps_open() does.

[akpm@linux-foundation.org: deuglify]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov 557c2d8a73 fs/proc/task_mmu.c: update m->version in the main loop in m_start()
Change the main loop in m_start() to update m->version. Mostly for
consistency, but this can help to avoid the same loop if the very
1st ->show() fails due to seq_overflow().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov b8c20a9b85 fs/proc/task_mmu.c: reintroduce m->version logic
Add the "last_addr" optimization back. Like before, every ->show()
method checks !seq_overflow() and sets m->version = vma->vm_start.

However, it also checks that m_next_vma(vma) != NULL, otherwise it
sets m->version = -1 for the lockless "EOF" fast-path in m_start().

m_start() can simply do find_vma() + m_next_vma() if last_addr is
not zero, the code looks clear and simple and this case is clearly
separated from "scan vmas" path.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov ad2a00e4b7 fs/proc/task_mmu.c: introduce m_next_vma() helper
Extract the tail_vma/vm_next calculation from m_next() into the new
trivial helper, m_next_vma().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov 0c255321f8 fs/proc/task_mmu.c: simplify m_start() to make it readable
Now that m->version is gone we can cleanup m_start(). In particular,

  - Remove the "unsigned long" typecast, m->index can't be negative
    or exceed ->map_count. But lets use "unsigned int pos" to make
    it clear that "pos < map_count" is safe.

  - Remove the unnecessary "vma != NULL" check in the main loop. It
    can't be NULL unless we have a vm bug.

  - This also means that "pos < map_count" case can simply return the
    valid vma and avoid "goto" and subsequent checks.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov ebb6cdde1a fs/proc/task_mmu.c: kill the suboptimal and confusing m->version logic
m_start() carefully documents, checks, and sets "m->version = -1" if
we are going to return NULL. The only problem is that we will be never
called again if m_start() returns NULL, so this is simply pointless
and misleading.

Otoh, ->show() methods m->version = 0 if vma == tail_vma and this is
just wrong, we want -1 in this case. And in fact we also want -1 if
->vm_next == NULL and ->tail_vma == NULL.

And it is not used consistently, the "scan vmas" loop in m_start()
should update last_addr too.

Finally, imo the whole "last_addr" logic in m_start() looks horrible.
find_vma(last_addr) is called unconditionally even if we are not going
to use the result. But the main problem is that this code participates
in tail_vma-or-NULL mess, and this looks simply unfixable.

Remove this optimization. We will add it back after some cleanups.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov 0d5f5f45f9 fs/proc/task_mmu.c: shift "priv->task = NULL" from m_start() to m_stop()
1. There is no reason to reset ->tail_vma in m_start(), if we return
   IS_ERR_OR_NULL() it won't be used.

2. m_start() also clears priv->task to ensure that m_stop() won't use
   the stale pointer if we fail before get_task_struct(). But this is
   ugly and confusing, move this initialization in m_stop().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov 23d54837e4 fs/proc/task_mmu.c: cleanup the "tail_vma" horror in m_next()
1. Kill the first "vma != NULL" check. Firstly this is not possible,
   m_next() won't be called if ->start() or the previous ->next()
   returns NULL.

   And if it was possible the 2nd "vma != tail_vma" check is buggy,
   we should not wrongly return ->tail_vma.

2. Make this function readable. The logic is very simple, we should
   return check "vma != tail" once and return "vm_next || tail_vma".

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Oleg Nesterov 59b4bf12d4 fs/proc/task_mmu.c: simplify the vma_stop() logic
m_start() drops ->mmap_sem and does mmput() if it retuns vsyscall
vma. This is because in this case m_stop()->vma_stop() obviously
can't use gate_vma->vm_mm.

Now that we have proc_maps_private->mm we can simplify this logic:

  - Change m_start() to return with ->mmap_sem held unless it returns
    IS_ERR_OR_NULL().

  - Change vma_stop() to use priv->mm and avoid the ugly vma checks,
    this makes "vm_area_struct *vma" unnecessary.

  - This also allows m_start() to use vm_stop().

  - Cleanup m_next() to follow the new locking rule.

    Note: m_stop() looks very ugly, and this temporary uglifies it
    even more. Fixed by the next change.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Oleg Nesterov 29a40ace84 fs/proc/task_mmu.c: shift mm_access() from m_start() to proc_maps_open()
A simple test-case from Kirill Shutemov

	cat /proc/self/maps >/dev/null
	chmod +x /proc/self/net/packet
	exec /proc/self/net/packet

makes lockdep unhappy, cat/exec take seq_file->lock + cred_guard_mutex in
the opposite order.

It's a false positive and probably we should not allow "chmod +x" on proc
files. Still I think that we should avoid mm_access() and cred_guard_mutex
in sys_read() paths, security checking should happen at open time. Besides,
this doesn't even look right if the task changes its ->mm between m_stop()
and m_start().

Add the new "mm_struct *mm" member into struct proc_maps_private and change
proc_maps_open() to initialize it using proc_mem_open(). Change m_start() to
use priv->mm if atomic_inc_not_zero(mm_users) succeeds or return NULL (eof)
otherwise.

The only complication is that proc_maps_open() users should additionally do
mmdrop() in fop->release(), add the new proc_map_release() helper for that.

Note: this is the user-visible change, if the task execs after open("maps")
the new ->mm won't be visible via this file. I hope this is fine, and this
matches /proc/pid/mem bahaviour.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Oleg Nesterov 5381e169e7 proc: introduce proc_mem_open()
Extract the mm_access() code from __mem_open() into the new helper,
proc_mem_open(), the next patch will add another caller.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Oleg Nesterov 4db7d0ee19 fs/proc/task_mmu.c: unify/simplify do_maps_open() and numa_maps_open()
do_maps_open() and numa_maps_open() are overcomplicated, they could use
__seq_open_private().  Plus they do the same, just sizeof(*priv)

Change them to use a new simple helper, proc_maps_open(ops, psize).  This
simplifies the code and allows us to do the next changes.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Oleg Nesterov 46c298cf69 fs/proc/task_mmu.c: don't use task->mm in m_start() and show_*map()
get_gate_vma(priv->task->mm) looks ugly and wrong, task->mm can be NULL or
it can changed by exec right after mm_access().

And in theory this race is not harmless, the task can exec and then later
exit and free the new mm_struct.  In this case get_task_mm(oldmm) can't
help, get_gate_vma(task->mm) can read the freed/unmapped memory.

I think that priv->task should simply die and hold_task_mempolicy() logic
can be simplified.  tail_vma logic asks for cleanups too.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Eric W. Biederman bbd5192412 proc: Update proc_flush_task_mnt to use d_invalidate
Now that d_invalidate always succeeds and flushes mount points use
it in stead of a combination of shrink_dcache_parent and d_drop
in proc_flush_task_mnt.  This removes the danger of a mount point
under /proc/<pid>/... becoming unreachable after the d_drop.

Reviewed-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09 02:38:58 -04:00
Eric W. Biederman c143c2333c vfs: Remove d_drop calls from d_revalidate implementations
Now that d_invalidate always succeeds it is not longer necessary or
desirable to hard code d_drop calls into filesystem specific
d_revalidate implementations.

Remove the unnecessary d_drop calls and rely on d_invalidate
to drop the dentries.  Using d_invalidate ensures that paths
to mount points will not be dropped.

Reviewed-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09 02:38:58 -04:00
Peter Feiner 87e6d49a00 mm: softdirty: addresses before VMAs in PTE holes aren't softdirty
In PTE holes that contain VM_SOFTDIRTY VMAs, unmapped addresses before
VM_SOFTDIRTY VMAs are reported as softdirty by /proc/pid/pagemap.  This
bug was introduced in commit 68b5a65248 ("mm: softdirty: respect
VM_SOFTDIRTY in PTE holes").  That commit made /proc/pid/pagemap look at
VM_SOFTDIRTY in PTE holes but neglected to observe the start of VMAs
returned by find_vma.

Tested:
  Wrote a selftest that creates a PMD-sized VMA then unmaps the first
  page and asserts that the page is not softdirty. I'm going to send the
  pagemap selftest in a later commit.

Signed-off-by: Peter Feiner <pfeiner@google.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Jamie Liu <jamieliu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-09-26 08:10:35 -07:00
Zefan Li 52de4779f2 cpuset: simplify proc_cpuset_show()
Use the ONE macro instead of REG, and we can simplify proc_cpuset_show().

Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-09-18 13:27:23 -04:00
Zefan Li 006f4ac497 cgroup: simplify proc_cgroup_show()
Use the ONE macro instead of REG, and we can simplify proc_cgroup_show().

Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-09-18 13:27:23 -04:00
Linus Torvalds 155134fef2 Revert "proc: Point /proc/{mounts,net} at /proc/thread-self/{mounts,net} instead of /proc/self/{mounts,net}"
This reverts commits 344470cac4 and e813244072.

It turns out that the exact path in the symlink matters, if for somewhat
unfortunate reasons: some apparmor configurations don't allow dhclient
access to the per-thread /proc files.  As reported by Jörg Otte:

  audit: type=1400 audit(1407684227.003:28): apparmor="DENIED"
    operation="open" profile="/sbin/dhclient"
    name="/proc/1540/task/1540/net/dev" pid=1540 comm="dhclient"
    requested_mask="r" denied_mask="r" fsuid=0 ouid=0

so we had better revert this for now.  We might be able to work around
this in practice by only using the per-thread symlinks if the thread
isn't the thread group leader, and if the namespaces differ between
threads (which basically never happens).

We'll see. In the meantime, the revert was made to be intentionally easy.

Reported-by: Jörg Otte <jrg.otte@gmail.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-10 21:24:59 -07:00
Linus Torvalds 77e40aae76 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace updates from Eric Biederman:
 "This is a bunch of small changes built against 3.16-rc6.  The most
  significant change for users is the first patch which makes setns
  drmatically faster by removing unneded rcu handling.

  The next chunk of changes are so that "mount -o remount,.." will not
  allow the user namespace root to drop flags on a mount set by the
  system wide root.  Aks this forces read-only mounts to stay read-only,
  no-dev mounts to stay no-dev, no-suid mounts to stay no-suid, no-exec
  mounts to stay no exec and it prevents unprivileged users from messing
  with a mounts atime settings.  I have included my test case as the
  last patch in this series so people performing backports can verify
  this change works correctly.

  The next change fixes a bug in NFS that was discovered while auditing
  nsproxy users for the first optimization.  Today you can oops the
  kernel by reading /proc/fs/nfsfs/{servers,volumes} if you are clever
  with pid namespaces.  I rebased and fixed the build of the
  !CONFIG_NFS_FS case yesterday when a build bot caught my typo.  Given
  that no one to my knowledge bases anything on my tree fixing the typo
  in place seems more responsible that requiring a typo-fix to be
  backported as well.

  The last change is a small semantic cleanup introducing
  /proc/thread-self and pointing /proc/mounts and /proc/net at it.  This
  prevents several kinds of problemantic corner cases.  It is a
  user-visible change so it has a minute chance of causing regressions
  so the change to /proc/mounts and /proc/net are individual one line
  commits that can be trivially reverted.  Unfortunately I lost and
  could not find the email of the original reporter so he is not
  credited.  From at least one perspective this change to /proc/net is a
  refgression fix to allow pthread /proc/net uses that were broken by
  the introduction of the network namespace"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  proc: Point /proc/mounts at /proc/thread-self/mounts instead of /proc/self/mounts
  proc: Point /proc/net at /proc/thread-self/net instead of /proc/self/net
  proc: Implement /proc/thread-self to point at the directory of the current thread
  proc: Have net show up under /proc/<tgid>/task/<tid>
  NFS: Fix /proc/fs/nfsfs/servers and /proc/fs/nfsfs/volumes
  mnt: Add tests for unprivileged remount cases that have found to be faulty
  mnt: Change the default remount atime from relatime to the existing value
  mnt: Correct permission checks in do_remount
  mnt: Move the test for MNT_LOCK_READONLY from change_mount_flags into do_remount
  mnt: Only change user settable mount flags in remount
  namespaces: Use task_lock and not rcu to protect nsproxy
2014-08-09 17:10:41 -07:00
Joe Perches e5eea0981a sysctl: remove typedef ctl_table
Remove the final user, and the typedef itself.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:24 -07:00
Vitaly Kuznetsov 0692dedcf6 fs/proc/vmcore.c:mmap_vmcore: skip non-ram pages reported by hypervisors
We have a special check in read_vmcore() handler to check if the page was
reported as ram or not by the hypervisor (pfn_is_ram()).  However, when
vmcore is read with mmap() no such check is performed.  That can lead to
unpredictable results, e.g.  when running Xen PVHVM guest memcpy() after
mmap() on /proc/vmcore will hang processing HVMMEM_mmio_dm pages creating
enormous load in both DomU and Dom0.

Fix the issue by mapping each non-ram page to the zero page.  Keep direct
path with remap_oldmem_pfn_range() to avoid looping through all pages on
bare metal.

The issue can also be solved by overriding remap_oldmem_pfn_range() in
xen-specific code, as remap_oldmem_pfn_range() was been designed for.
That, however, would involve non-obvious xen code path for all x86 builds
with CONFIG_XEN_PVHVM=y and would prevent all other hypervisor-specific
code on x86 arch from doing the same override.

[fengguang.wu@intel.com: remap_oldmem_pfn_checked() can be static]
[akpm@linux-foundation.org: clean up layout]
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:23 -07:00
Alexey Dobriyan 8f053ac11f proc: remove INF macro
If you're applying this patch, all /proc/$PID/* files were converted
to seq_file interface and this code became unused.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:23 -07:00
Alexey Dobriyan d962c14483 proc: convert /proc/$PID/hardwall to seq_file interface
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:23 -07:00
Alexey Dobriyan 19aadc98d6 proc: convert /proc/$PID/io to seq_file interface
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:23 -07:00
Alexey Dobriyan 6ba51e3751 proc: convert /proc/$PID/oom_score to seq_file interface
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:23 -07:00
Alexey Dobriyan f6e826ca37 proc: convert /proc/$PID/schedstat to seq_file interface
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:23 -07:00
Alexey Dobriyan edfcd6064f proc: convert /proc/$PID/wchan to seq_file interface
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:23 -07:00
Alexey Dobriyan 2ca66ff70a proc: convert /proc/$PID/cmdline to seq_file interface
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:23 -07:00
Alexey Dobriyan 09d93bd627 proc: convert /proc/$PID/syscall to seq_file interface
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:22 -07:00
Alexey Dobriyan 1c963eb135 proc: convert /proc/$PID/limits to seq_file interface
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:22 -07:00
Alexey Dobriyan f9ea536ef8 proc: convert /proc/$PID/auxv to seq_file interface
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:22 -07:00
Alexey Dobriyan cedbccab8b proc: more "const char *" pointers
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:22 -07:00
Alexey Dobriyan 849d20a128 proc: remove proc_tty_ldisc variable
/proc/tty/ldisc appear to be unused as a directory and
it had been always that way.

But it is userspace visible thing.

Cowardly remove only in-kernel variable holding it.

[akpm@linux-foundation.org: add comment]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:22 -07:00
Alexey Dobriyan 4dcc03fc45 proc: make proc_subdir_lock static
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:22 -07:00
Alexey Dobriyan 335eb53158 proc: faster /proc/$PID lookup
Currently lookup for /proc/$PID first goes through spinlock and whole list
of misc /proc entries only to confirm that, yes, /proc/42 can not possibly
match random proc entry.

List is is several dozens entries long (52 entries on my setup).

None of this is necessary.

Try to convert dentry name to integer first.
If it works, it must be /proc/$PID.
If it doesn't, it must be random proc entry.

Based on patch from Al Viro.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:22 -07:00
Alexey Dobriyan dbcdb50441 proc: add and remove /proc entry create checks
* remove proc_create(NULL, ...) check, let it oops

* warn about proc_create("", ...) and proc_create("very very long name", ...)
  proc code keeps length as u8, no 256+ name length possible

* warn about proc_create("123", ...)
  /proc/$PID and /proc/misc namespaces are separate things,
  but dumb module might create funky a-la $PID entry.

* remove post mortem strchr('/') check
  Triggering it implies either strchr() is buggy or memory corruption.
  It should be VFS check anyway.

In reality, none of these checks will ever trigger,
it is preparation for the next patch.

Based on patch from Al Viro.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:22 -07:00
Fabian Frederick ccf94f1b4a proc: constify seq_operations
proc_uid_seq_operations, proc_gid_seq_operations and
proc_projid_seq_operations are only called in proc_id_map_open with
seq_open as const struct seq_operations so we can constify the 3
structures and update proc_id_map_open prototype.

   text    data     bss     dec     hex filename
   6817     404    1984    9205    23f5 kernel/user_namespace.o-before
   6913     308    1984    9205    23f5 kernel/user_namespace.o-after

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:22 -07:00
Fabian Frederick 108a8a11cb fs/proc/kcore.c: use PAGE_ALIGN instead of ALIGN(PAGE_SIZE)
Use mm.h definition.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:22 -07:00
Peter Feiner 68b5a65248 mm: softdirty: respect VM_SOFTDIRTY in PTE holes
After a VMA is created with the VM_SOFTDIRTY flag set, /proc/pid/pagemap
should report that the VMA's virtual pages are soft-dirty until
VM_SOFTDIRTY is cleared (i.e., by the next write of "4" to
/proc/pid/clear_refs).  However, pagemap ignores the VM_SOFTDIRTY flag
for virtual addresses that fall in PTE holes (i.e., virtual addresses
that don't have a PMD, PUD, or PGD allocated yet).

To observe this bug, use mmap to create a VMA large enough such that
there's a good chance that the VMA will occupy an unused PMD, then test
the soft-dirty bit on its pages.  In practice, I found that a VMA that
covered a PMD's worth of address space was big enough.

This patch adds the necessary VMA lookup to the PTE hole callback in
/proc/pid/pagemap's page walk and sets soft-dirty according to the VMAs'
VM_SOFTDIRTY flag.

Signed-off-by: Peter Feiner <pfeiner@google.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:22 -07:00
Rafael Aquini cc7452b6dc mm: export NR_SHMEM via sysinfo(2) / si_meminfo() interfaces
Historically, we exported shared pages to userspace via sysinfo(2)
sharedram and /proc/meminfo's "MemShared" fields.  With the advent of
tmpfs, from kernel v2.4 onward, that old way for accounting shared mem
was deemed inaccurate and we started to export a hard-coded 0 for
sysinfo.sharedram.  Later on, during the 2.6 timeframe, "MemShared" got
re-introduced to /proc/meminfo re-branded as "Shmem", but we're still
reporting sysinfo.sharedmem as that old hard-coded zero, which makes the
"shared memory" report inconsistent across interfaces.

This patch leverages the addition of explicit accounting for pages used
by shmem/tmpfs -- "4b02108 mm: oom analysis: add shmem vmstat" -- in
order to make the users of sysinfo(2) and si_meminfo*() friends aware of
that vmstat entry and make them report it consistently across the
interfaces, as well to make sysinfo(2) returned data consistent with our
current API documentation states.

Signed-off-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:19 -07:00
Linus Torvalds bb2cbf5e93 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "In this release:

   - PKCS#7 parser for the key management subsystem from David Howells
   - appoint Kees Cook as seccomp maintainer
   - bugfixes and general maintenance across the subsystem"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (94 commits)
  X.509: Need to export x509_request_asymmetric_key()
  netlabel: shorter names for the NetLabel catmap funcs/structs
  netlabel: fix the catmap walking functions
  netlabel: fix the horribly broken catmap functions
  netlabel: fix a problem when setting bits below the previously lowest bit
  PKCS#7: X.509 certificate issuer and subject are mandatory fields in the ASN.1
  tpm: simplify code by using %*phN specifier
  tpm: Provide a generic means to override the chip returned timeouts
  tpm: missing tpm_chip_put in tpm_get_random()
  tpm: Properly clean sysfs entries in error path
  tpm: Add missing tpm_do_selftest to ST33 I2C driver
  PKCS#7: Use x509_request_asymmetric_key()
  Revert "selinux: fix the default socket labeling in sock_graft()"
  X.509: x509_request_asymmetric_keys() doesn't need string length arguments
  PKCS#7: fix sparse non static symbol warning
  KEYS: revert encrypted key change
  ima: add support for measuring and appraising firmware
  firmware_class: perform new LSM checks
  security: introduce kernel_fw_from_file hook
  PKCS#7: Missing inclusion of linux/err.h
  ...
2014-08-06 08:06:39 -07:00
Eric W. Biederman 344470cac4 proc: Point /proc/mounts at /proc/thread-self/mounts instead of /proc/self/mounts
In oddball cases where the thread has a different mount namespace than
the thread group leader or more likely in cases where the thread
remains and the thread group leader has exited this ensures that
/proc/mounts continues to work.

This should not cause any problems but if it does this patch can just
be reverted.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2014-08-04 10:07:15 -07:00
Eric W. Biederman e813244072 proc: Point /proc/net at /proc/thread-self/net instead of /proc/self/net
In oddball cases where the thread has a different network namespace
than the primary thread group leader or more likely in cases where
the thread remains and the thread group leader has exited this
ensures that /proc/net continues to work.

This should not cause any problems but if it does this patch can just
be reverted.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2014-08-04 10:07:13 -07:00
Eric W. Biederman 0097875bd4 proc: Implement /proc/thread-self to point at the directory of the current thread
/proc/thread-self is derived from /proc/self.  /proc/thread-self
points to the directory in proc containing information about the
current thread.

This funtionality has been missing for a long time, and is tricky to
implement in userspace as gettid() is not exported by glibc.  More
importantly this allows fixing defects in /proc/mounts and /proc/net
where in a threaded application today they wind up being empty files
when only the initial pthread has exited, causing problems for other
threads.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2014-08-04 10:07:11 -07:00
Eric W. Biederman 6ba8ed79a3 proc: Have net show up under /proc/<tgid>/task/<tid>
Network namespaces are per task so it make sense for them to show up
in the task directory.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2014-08-04 10:07:08 -07:00
Eric W. Biederman 728dba3a39 namespaces: Use task_lock and not rcu to protect nsproxy
The synchronous syncrhonize_rcu in switch_task_namespaces makes setns
a sufficiently expensive system call that people have complained.

Upon inspect nsproxy no longer needs rcu protection for remote reads.
remote reads are rare.  So optimize for same process reads and write
by switching using rask_lock instead.

This yields a simpler to understand lock, and a faster setns system call.

In particular this fixes a performance regression observed
by Rafael David Tinoco <rafael.tinoco@canonical.com>.

This is effectively a revert of Pavel Emelyanov's commit
cf7b708c8d Make access to task's nsproxy lighter
from 2007.  The race this originialy fixed no longer exists as
do_notify_parent uses task_active_pid_ns(parent) instead of
parent->nsproxy.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2014-07-29 18:08:50 -07:00
Eric Paris 7d8b6c6375 CAPABILITIES: remove undefined caps from all processes
This is effectively a revert of 7b9a7ec565
plus fixing it a different way...

We found, when trying to run an application from an application which
had dropped privs that the kernel does security checks on undefined
capability bits.  This was ESPECIALLY difficult to debug as those
undefined bits are hidden from /proc/$PID/status.

Consider a root application which drops all capabilities from ALL 4
capability sets.  We assume, since the application is going to set
eff/perm/inh from an array that it will clear not only the defined caps
less than CAP_LAST_CAP, but also the higher 28ish bits which are
undefined future capabilities.

The BSET gets cleared differently.  Instead it is cleared one bit at a
time.  The problem here is that in security/commoncap.c::cap_task_prctl()
we actually check the validity of a capability being read.  So any task
which attempts to 'read all things set in bset' followed by 'unset all
things set in bset' will not even attempt to unset the undefined bits
higher than CAP_LAST_CAP.

So the 'parent' will look something like:
CapInh:	0000000000000000
CapPrm:	0000000000000000
CapEff:	0000000000000000
CapBnd:	ffffffc000000000

All of this 'should' be fine.  Given that these are undefined bits that
aren't supposed to have anything to do with permissions.  But they do...

So lets now consider a task which cleared the eff/perm/inh completely
and cleared all of the valid caps in the bset (but not the invalid caps
it couldn't read out of the kernel).  We know that this is exactly what
the libcap-ng library does and what the go capabilities library does.
They both leave you in that above situation if you try to clear all of
you capapabilities from all 4 sets.  If that root task calls execve()
the child task will pick up all caps not blocked by the bset.  The bset
however does not block bits higher than CAP_LAST_CAP.  So now the child
task has bits in eff which are not in the parent.  These are
'meaningless' undefined bits, but still bits which the parent doesn't
have.

The problem is now in cred_cap_issubset() (or any operation which does a
subset test) as the child, while a subset for valid cap bits, is not a
subset for invalid cap bits!  So now we set durring commit creds that
the child is not dumpable.  Given it is 'more priv' than its parent.  It
also means the parent cannot ptrace the child and other stupidity.

The solution here:
1) stop hiding capability bits in status
	This makes debugging easier!

2) stop giving any task undefined capability bits.  it's simple, it you
don't put those invalid bits in CAP_FULL_SET you won't get them in init
and you won't get them in any other task either.
	This fixes the cap_issubset() tests and resulting fallout (which
	made the init task in a docker container untraceable among other
	things)

3) mask out undefined bits when sys_capset() is called as it might use
~0, ~0 to denote 'all capabilities' for backward/forward compatibility.
	This lets 'capsh --caps="all=eip" -- -c /bin/bash' run.

4) mask out undefined bit when we read a file capability off of disk as
again likely all bits are set in the xattr for forward/backward
compatibility.
	This lets 'setcap all+pe /bin/bash; /bin/bash' run

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Andrew G. Morgan <morgan@kernel.org>
Cc: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steve Grubb <sgrubb@redhat.com>
Cc: Dan Walsh <dwalsh@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
2014-07-24 21:53:47 +10:00
Thomas Gleixner 57e0be041d sched: Make task->real_start_time nanoseconds based
Simplify the only user of this data by removing the timespec
conversion.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:18:05 -07:00
Heiko Carstens f74373a5cc /proc/stat: convert to single_open_size()
These two patches are supposed to "fix" failed order-4 memory
allocations which have been observed when reading /proc/stat.  The
problem has been observed on s390 as well as on x86.

To address the problem change the seq_file memory allocations to
fallback to use vmalloc, so that allocations also work if memory is
fragmented.

This approach seems to be simpler and less intrusive than changing
/proc/stat to use an interator.  Also it "fixes" other users as well,
which use seq_file's single_open() interface.

This patch (of 2):

Use seq_file's single_open_size() to preallocate a buffer that is large
enough to hold the whole output, instead of open coding it.  Also
calculate the requested size using the number of online cpus instead of
possible cpus, since the size of the output only depends on the number
of online cpus.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Thorsten Diehl <thorsten.diehl@de.ibm.com>
Cc: Andrea Righi <andrea@betterlinux.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Stefan Bader <stefan.bader@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-07-03 09:21:54 -07:00
Linus Torvalds 3f17ea6dea Merge branch 'next' (accumulated 3.16 merge window patches) into master
Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...
2014-06-08 11:31:16 -07:00
Fabian Frederick a05e16ada4 fs/proc/vmcore.c: remove NULL assignment to static
Static values are automatically initialized to NULL.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06 16:08:12 -07:00
Fabian Frederick 17c2b4ee40 fs/proc/task_mmu.c: replace seq_printf by seq_puts
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06 16:08:12 -07:00
Naoya Horiguchi d4c54919ed mm: add !pte_present() check on existing hugetlb_entry callbacks
The age table walker doesn't check non-present hugetlb entry in common
path, so hugetlb_entry() callbacks must check it.  The reason for this
behavior is that some callers want to handle it in its own way.

[ I think that reason is bogus, btw - it should just do what the regular
  code does, which is to call the "pte_hole()" function for such hugetlb
  entries  - Linus]

However, some callers don't check it now, which causes unpredictable
result, for example when we have a race between migrating hugepage and
reading /proc/pid/numa_maps.  This patch fixes it by adding !pte_present
checks on buggy callbacks.

This bug exists for years and got visible by introducing hugepage
migration.

ChangeLog v2:
- fix if condition (check !pte_present() instead of pte_present())

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: <stable@vger.kernel.org> [3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Backported to 3.15.  Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org> ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06 13:21:16 -07:00
Linus Torvalds a0abcf2e8f Merge branch 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull x86 cdso updates from Peter Anvin:
 "Vdso cleanups and improvements largely from Andy Lutomirski.  This
  makes the vdso a lot less ''special''"

* 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vdso, build: Make LE access macros clearer, host-safe
  x86/vdso, build: Fix cross-compilation from big-endian architectures
  x86/vdso, build: When vdso2c fails, unlink the output
  x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET
  x86, mm: Replace arch_vma_name with vm_ops->name for vsyscalls
  x86, mm: Improve _install_special_mapping and fix x86 vdso naming
  mm, fs: Add vm_ops->name as an alternative to arch_vma_name
  x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET
  x86, vdso: Remove vestiges of VDSO_PRELINK and some outdated comments
  x86, vdso: Move the vvar and hpet mappings next to the 64-bit vDSO
  x86, vdso: Move the 32-bit vdso special pages after the text
  x86, vdso: Reimplement vdso.so preparation in build-time C
  x86, vdso: Move syscall and sysenter setup into kernel/cpu/common.c
  x86, vdso: Clean up 32-bit vs 64-bit vdso params
  x86, mm: Ensure correct alignment of the fixmap
2014-06-05 08:05:29 -07:00
Cyrill Gorcunov c86c97ff42 mm: softdirty: clear VM_SOFTDIRTY flag inside clear_refs_write() instead of clear_soft_dirty()
clear_refs_write() is called earlier than clear_soft_dirty() and it is
more natural to clear VM_SOFTDIRTY (which belongs to VMA entry but not
PTEs) that early instead of clearing it a way deeper inside call chain.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:56 -07:00
Andy Lutomirski 78d683e838 mm, fs: Add vm_ops->name as an alternative to arch_vma_name
arch_vma_name sucks.  It's a silly hack, and it's annoying to
implement correctly.  In fact, AFAICS, even the straightforward x86
implementation is incorrect (I suspect that it breaks if the vdso
mapping is split or gets remapped).

This adds a new vm_ops->name operation that can replace it.  The
followup patches will remove all uses of arch_vma_name on x86,
fixing a couple of annoyances in the process.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2eee21791bb36a0a408c5c2bdb382a9e6a41ca4a.1400538962.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-20 11:36:31 -07:00
Linus Torvalds 5166701b36 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "The first vfs pile, with deep apologies for being very late in this
  window.

  Assorted cleanups and fixes, plus a large preparatory part of iov_iter
  work.  There's a lot more of that, but it'll probably go into the next
  merge window - it *does* shape up nicely, removes a lot of
  boilerplate, gets rid of locking inconsistencie between aio_write and
  splice_write and I hope to get Kent's direct-io rewrite merged into
  the same queue, but some of the stuff after this point is having
  (mostly trivial) conflicts with the things already merged into
  mainline and with some I want more testing.

  This one passes LTP and xfstests without regressions, in addition to
  usual beating.  BTW, readahead02 in ltp syscalls testsuite has started
  giving failures since "mm/readahead.c: fix readahead failure for
  memoryless NUMA nodes and limit readahead pages" - might be a false
  positive, might be a real regression..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  missing bits of "splice: fix racy pipe->buffers uses"
  cifs: fix the race in cifs_writev()
  ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure
  kill generic_file_buffered_write()
  ocfs2_file_aio_write(): switch to generic_perform_write()
  ceph_aio_write(): switch to generic_perform_write()
  xfs_file_buffered_aio_write(): switch to generic_perform_write()
  export generic_perform_write(), start getting rid of generic_file_buffer_write()
  generic_file_direct_write(): get rid of ppos argument
  btrfs_file_aio_write(): get rid of ppos
  kill the 5th argument of generic_file_buffered_write()
  kill the 4th argument of __generic_file_aio_write()
  lustre: don't open-code kernel_recvmsg()
  ocfs2: don't open-code kernel_recvmsg()
  drbd: don't open-code kernel_recvmsg()
  constify blk_rq_map_user_iov() and friends
  lustre: switch to kernel_sendmsg()
  ocfs2: don't open-code kernel_sendmsg()
  take iov_iter stuff to mm/iov_iter.c
  process_vm_access: tidy up a bit
  ...
2014-04-12 14:49:50 -07:00
Linus Torvalds 0b747172dc Merge git://git.infradead.org/users/eparis/audit
Pull audit updates from Eric Paris.

* git://git.infradead.org/users/eparis/audit: (28 commits)
  AUDIT: make audit_is_compat depend on CONFIG_AUDIT_COMPAT_GENERIC
  audit: renumber AUDIT_FEATURE_CHANGE into the 1300 range
  audit: do not cast audit_rule_data pointers pointlesly
  AUDIT: Allow login in non-init namespaces
  audit: define audit_is_compat in kernel internal header
  kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c
  sched: declare pid_alive as inline
  audit: use uapi/linux/audit.h for AUDIT_ARCH declarations
  syscall_get_arch: remove useless function arguments
  audit: remove stray newline from audit_log_execve_info() audit_panic() call
  audit: remove stray newlines from audit_log_lost messages
  audit: include subject in login records
  audit: remove superfluous new- prefix in AUDIT_LOGIN messages
  audit: allow user processes to log from another PID namespace
  audit: anchor all pid references in the initial pid namespace
  audit: convert PPIDs to the inital PID namespace.
  pid: get pid_t ppid of task in init_pid_ns
  audit: rename the misleading audit_get_context() to audit_take_context()
  audit: Add generic compat syscall support
  audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL
  ...
2014-04-12 12:38:53 -07:00
Dave Jones 16caed3196 fault-injection: set bounds on what /proc/self/make-it-fail accepts.
/proc/self/make-it-fail is a boolean, but accepts any number, including
negative ones.  Change variable to unsigned, and cap upper bound at 1.

[akpm@linux-foundation.org: don't make make_it_fail unsigned]
Signed-off-by: Dave Jones <davej@fedoraproject.org>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:10 -07:00
WANG Chao c4082f36fa vmcore: continue vmcore initialization if PT_NOTE is found empty
Currently when an empty PT_NOTE is detected, vmcore initialization
fails.  It sounds too harsh.  Because PT_NOTE could be empty, for
example, one offlined a cpu but never restarted kdump service, and after
crash, PT_NOTE program header is there but no data contains.  It's
better to warn about the empty PT_NOTE and continue to initialise
vmcore.

And ultimately the multiple PT_NOTE are merged into a single one, all
empty PT_NOTE are discarded naturally during the merge.  So empty
PT_NOTE is not visible to user space and vmcore is as good as expected.

Signed-off-by: WANG Chao <chaowang@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Greg Pearson <greg.pearson@hp.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:06 -07:00
Rashika Kheria 82e0703b6c include/linux/crash_dump.h: add vmcore_cleanup() prototype
Eliminate the following warning in proc/vmcore.c:

  fs/proc/vmcore.c:1088:6: warning: no previous prototype for `vmcore_cleanup' [-Wmissing-prototypes]

[akpm@linux-foundation.org: clean up powerpc, remove unneeded EXPORT_SYMBOL]
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:06 -07:00
Oleg Nesterov ad86622b47 wait: swap EXIT_ZOMBIE and EXIT_DEAD to hide EXIT_TRACE from user-space
get_task_state() uses the most significant bit to report the state to
user-space, this means that EXIT_ZOMBIE->EXIT_TRACE->EXIT_DEAD transition
can be noticed via /proc as Z -> X -> Z change.  Note that this was
possible even before EXIT_TRACE was introduced.

This is not really bad but imho it make sense to hide EXIT_TRACE from
user-space completely.  So the patch simply swaps EXIT_ZOMBIE and
EXIT_DEAD, this way EXIT_TRACE will be seen as EXIT_ZOMBIE by user-space.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Michal Schmidt <mschmidt@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:06 -07:00
Djalal Harouni 32ed74a4b9 procfs: make /proc/*/pagemap 0400
The /proc/*/pagemap contain sensitive information and currently its mode
is 0444.  Change this to 0400, so the VFS will prevent unprivileged
processes from getting file descriptors on arbitrary privileged
/proc/*/pagemap files.

This reduces the scope of address space leaking and bypasses by protecting
already running processes.

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:05 -07:00
Djalal Harouni 35a35046e4 procfs: make /proc/*/{stack,syscall,personality} 0400
These procfs files contain sensitive information and currently their
mode is 0444.  Change this to 0400, so the VFS will be able to block
unprivileged processes from getting file descriptors on arbitrary
privileged /proc/*/{stack,syscall,personality} files.

This reduces the scope of ASLR leaking and bypasses by protecting already
running processes.

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:04 -07:00
Monam Agarwal 1c44dbc82f fs/proc/inode.c: use RCU_INIT_POINTER(x, NULL)
Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL)

The rcu_assign_pointer() ensures that the initialization of a structure
is carried out before storing a pointer to that structure.  And in the
case of the NULL pointer, there is no structure to initialize.  So,
rcu_assign_pointer(p, NULL) can be safely converted to
RCU_INIT_POINTER(p, NULL)

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:04 -07:00
Andrey Vagin 49d063cb35 proc: show mnt_id in /proc/pid/fdinfo
Currently we don't have a way how to determing from which mount point
file has been opened.  This information is required for proper dumping
and restoring file descriptos due to presence of mount namespaces.  It's
possible, that two file descriptors are opened using the same paths, but
one fd references mount point from one namespace while the other fd --
from other namespace.

$ ls -l /proc/1/fd/1
lrwx------ 1 root root 64 Mar 19 23:54 /proc/1/fd/1 -> /dev/null

$ cat /proc/1/fdinfo/1
pos:	0
flags:	0100002
mnt_id:	16

$ cat /proc/1/mountinfo | grep ^16
16 32 0:4 / /dev rw,nosuid shared:2 - devtmpfs devtmpfs rw,size=1013356k,nr_inodes=253339,mode=755

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Rob Landley <rob@landley.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:04 -07:00
Luiz Capitulino f0b5664ba7 fs/proc/meminfo: meminfo_proc_show(): fix typo in comment
It should read "reclaimable slab" and not "reclaimable swap".

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:04 -07:00
Davidlohr Bueso 615d6e8756 mm: per-thread vma caching
This patch is a continuation of efforts trying to optimize find_vma(),
avoiding potentially expensive rbtree walks to locate a vma upon faults.
The original approach (https://lkml.org/lkml/2013/11/1/410), where the
largest vma was also cached, ended up being too specific and random,
thus further comparison with other approaches were needed.  There are
two things to consider when dealing with this, the cache hit rate and
the latency of find_vma().  Improving the hit-rate does not necessarily
translate in finding the vma any faster, as the overhead of any fancy
caching schemes can be too high to consider.

We currently cache the last used vma for the whole address space, which
provides a nice optimization, reducing the total cycles in find_vma() by
up to 250%, for workloads with good locality.  On the other hand, this
simple scheme is pretty much useless for workloads with poor locality.
Analyzing ebizzy runs shows that, no matter how many threads are
running, the mmap_cache hit rate is less than 2%, and in many situations
below 1%.

The proposed approach is to replace this scheme with a small per-thread
cache, maximizing hit rates at a very low maintenance cost.
Invalidations are performed by simply bumping up a 32-bit sequence
number.  The only expensive operation is in the rare case of a seq
number overflow, where all caches that share the same address space are
flushed.  Upon a miss, the proposed replacement policy is based on the
page number that contains the virtual address in question.  Concretely,
the following results are seen on an 80 core, 8 socket x86-64 box:

1) System bootup: Most programs are single threaded, so the per-thread
   scheme does improve ~50% hit rate by just adding a few more slots to
   the cache.

+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline       | 50.61%   | 19.90            |
| patched        | 73.45%   | 13.58            |
+----------------+----------+------------------+

2) Kernel build: This one is already pretty good with the current
   approach as we're dealing with good locality.

+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline       | 75.28%   | 11.03            |
| patched        | 88.09%   | 9.31             |
+----------------+----------+------------------+

3) Oracle 11g Data Mining (4k pages): Similar to the kernel build workload.

+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline       | 70.66%   | 17.14            |
| patched        | 91.15%   | 12.57            |
+----------------+----------+------------------+

4) Ebizzy: There's a fair amount of variation from run to run, but this
   approach always shows nearly perfect hit rates, while baseline is just
   about non-existent.  The amounts of cycles can fluctuate between
   anywhere from ~60 to ~116 for the baseline scheme, but this approach
   reduces it considerably.  For instance, with 80 threads:

+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline       | 1.06%    | 91.54            |
| patched        | 99.97%   | 14.18            |
+----------------+----------+------------------+

[akpm@linux-foundation.org: fix nommu build, per Davidlohr]
[akpm@linux-foundation.org: document vmacache_valid() logic]
[akpm@linux-foundation.org: attempt to untangle header files]
[akpm@linux-foundation.org: add vmacache_find() BUG_ON]
[hughd@google.com: add vmacache_valid_mm() (from Oleg)]
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: adjust and enhance comments]
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Tested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:35:53 -07:00
Linus Torvalds 24e7ea3bea Major changes for 3.14 include support for the newly added ZERO_RANGE
and COLLAPSE_RANGE fallocate operations, and scalability improvements
 in the jbd2 layer and in xattr handling when the extended attributes
 spill over into an external block.
 
 Other than that, the usual clean ups and minor bug fixes.
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Major changes for 3.14 include support for the newly added ZERO_RANGE
  and COLLAPSE_RANGE fallocate operations, and scalability improvements
  in the jbd2 layer and in xattr handling when the extended attributes
  spill over into an external block.

  Other than that, the usual clean ups and minor bug fixes"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (42 commits)
  ext4: fix premature freeing of partial clusters split across leaf blocks
  ext4: remove unneeded test of ret variable
  ext4: fix comment typo
  ext4: make ext4_block_zero_page_range static
  ext4: atomically set inode->i_flags in ext4_set_inode_flags()
  ext4: optimize Hurd tests when reading/writing inodes
  ext4: kill i_version support for Hurd-castrated file systems
  ext4: each filesystem creates and uses its own mb_cache
  fs/mbcache.c: doucple the locking of local from global data
  fs/mbcache.c: change block and index hash chain to hlist_bl_node
  ext4: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate
  ext4: refactor ext4_fallocate code
  ext4: Update inode i_size after the preallocation
  ext4: fix partial cluster handling for bigalloc file systems
  ext4: delete path dealloc code in ext4_ext_handle_uninitialized_extents
  ext4: only call sync_filesystm() when remounting read-only
  fs: push sync_filesystem() down to the file system's remount_fs()
  jbd2: improve error messages for inconsistent journal heads
  jbd2: minimize region locked by j_list_lock in jbd2_journal_forget()
  jbd2: minimize region locked by j_list_lock in journal_get_create_access()
  ...
2014-04-04 15:39:39 -07:00
Johannes Weiner 91b0abe36a mm + fs: store shadow entries in page cache
Reclaim will be leaving shadow entries in the page cache radix tree upon
evicting the real page.  As those pages are found from the LRU, an
iput() can lead to the inode being freed concurrently.  At this point,
reclaim must no longer install shadow pages because the inode freeing
code needs to ensure the page tree is really empty.

Add an address_space flag, AS_EXITING, that the inode freeing code sets
under the tree lock before doing the final truncate.  Reclaim will check
for this flag before installing shadow pages.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Metin Doslu <metin@citusdata.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Ozgun Erdogan <ozgun@citusdata.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <klamm@yandex-team.ru>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:21:01 -07:00
Linus Torvalds b9f2b21a32 Devicetree changes for v3.15
Updates to devicetree core code. This branch contains the following notable changes:
 * Add reserved memory binding
 * Make struct device_node a kobject and remove legacy /proc/device-tree
 * ePAPR conformance fixes
 * Update in-kernel DTC copy to version v1.4.0
 * Preparation changes for dynamic device tree overlays
 * minor bug fixes and documentation changes
 
 The most significant change in this branch is the conversion of struct
 device_node to be a kobject that is exposed via sysfs and removal of the
 old /proc/device-tree code. This simplifies the device tree handling
 code and tightens up the lifecycle on device tree nodes.
 
 [updated: added fix for dangling select PROC_DEVICETREE]
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Merge tag 'dt-for-linus' of git://git.secretlab.ca/git/linux

Pull devicetree changes from Grant Likely:
 "Updates to devicetree core code.  This branch contains the following
  notable changes:

   - add reserved memory binding
   - make struct device_node a kobject and remove legacy
     /proc/device-tree
   - ePAPR conformance fixes
   - update in-kernel DTC copy to version v1.4.0
   - preparatory changes for dynamic device tree overlays
   - minor bug fixes and documentation changes

  The most significant change in this branch is the conversion of struct
  device_node to be a kobject that is exposed via sysfs and removal of
  the old /proc/device-tree code.  This simplifies the device tree
  handling code and tightens up the lifecycle on device tree nodes.

  [updated: added fix for dangling select PROC_DEVICETREE]"

* tag 'dt-for-linus' of git://git.secretlab.ca/git/linux: (29 commits)
  dt: Remove dangling "select PROC_DEVICETREE"
  of: Add support for ePAPR "stdout-path" property
  of: device_node kobject lifecycle fixes
  of: only scan for reserved mem when fdt present
  powerpc: add support for reserved memory defined by device tree
  arm64: add support for reserved memory defined by device tree
  of: add missing major vendors
  of: add vendor prefix for SMSC
  of: remove /proc/device-tree
  of/selftest: Add self tests for manipulation of properties
  of: Make device nodes kobjects so they show up in sysfs
  arm: add support for reserved memory defined by device tree
  drivers: of: add support for custom reserved memory drivers
  drivers: of: add initialization code for dynamic reserved memory
  drivers: of: add initialization code for static reserved memory
  of: document bindings for reserved-memory nodes
  Revert "of: fix of_update_property()"
  kbuild: dtbs_install: new make target
  ARM: mvebu: Allows to get the SoC ID even without PCI enabled
  of: Allows to use the PCI translator without the PCI core
  ...
2014-04-02 14:27:15 -07:00
Al Viro 5d826c847b new helper: readlink_copy()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:15 -04:00
Linus Torvalds a21e40877a Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Ingo Molnar:
 "The main purpose is to fix a full dynticks bug related to
  virtualization, where steal time accounting appears to be zero in
  /proc/stat even after a few seconds of competing guests running busy
  loops in a same host CPU.  It's not a regression though as it was
  there since the beginning.

  The other commits are preparatory work to fix the bug and various
  cleanups"

* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arch: Remove stub cputime.h headers
  sched: Remove needless round trip nsecs <-> tick conversion of steal time
  cputime: Fix jiffies based cputime assumption on steal accounting
  cputime: Bring cputime -> nsecs conversion
  cputime: Default implementation of nsecs -> cputime conversion
  cputime: Fix nsecs_to_cputime() return type cast
2014-04-01 10:16:10 -07:00
Grant Likely d88cf7d7b4 Merge remote-tracking branch 'robh/for-next' into devicetree/next 2014-03-31 08:10:55 +01:00
William Roberts 21a6457a79 proc: Update get proc_pid_cmdline() to use mm.h helpers
Re-factor proc_pid_cmdline() to use get_cmdline() helper
from mm.h.

Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Richard Guy Briggs <rgb@redhat.com>

Signed-off-by: William Roberts <wroberts@tresys.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2014-03-20 10:10:26 -04:00
Frederic Weisbecker bfc3f0281e cputime: Default implementation of nsecs -> cputime conversion
The architectures that override cputime_t (s390, ppc) don't provide
any version of nsecs_to_cputime(). Indeed this cputime_t implementation
by backend only happens when CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y under
which the core code doesn't make any use of nsecs_to_cputime().

At least for now.

We are going to make a broader use of it so lets provide a default
version with a per usecs granularity. It should be good enough for most
usecases.

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2014-03-13 15:56:43 +01:00
Theodore Ts'o 02b9984d64 fs: push sync_filesystem() down to the file system's remount_fs()
Previously, the no-op "mount -o mount /dev/xxx" operation when the
file system is already mounted read-write causes an implied,
unconditional syncfs().  This seems pretty stupid, and it's certainly
documented or guaraunteed to do this, nor is it particularly useful,
except in the case where the file system was mounted rw and is getting
remounted read-only.

However, it's possible that there might be some file systems that are
actually depending on this behavior.  In most file systems, it's
probably fine to only call sync_filesystem() when transitioning from
read-write to read-only, and there are some file systems where this is
not needed at all (for example, for a pseudo-filesystem or something
like romfs).

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Jan Kara <jack@suse.cz>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Anders Larsen <al@alarsen.net>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: xfs@oss.sgi.com
Cc: linux-btrfs@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: codalist@coda.cs.cmu.edu
Cc: linux-ext4@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: fuse-devel@lists.sourceforge.net
Cc: cluster-devel@redhat.com
Cc: linux-mtd@lists.infradead.org
Cc: jfs-discussion@lists.sourceforge.net
Cc: linux-nfs@vger.kernel.org
Cc: linux-nilfs@vger.kernel.org
Cc: linux-ntfs-dev@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Cc: reiserfs-devel@vger.kernel.org
2014-03-13 10:14:33 -04:00
Grant Likely 8357041a69 of: remove /proc/device-tree
The same data is now available in sysfs, so we can remove the code
that exports it in /proc and replace it with a symlink to the sysfs
version.

Tested on versatile qemu model and mpc5200 eval board. More testing
would be appreciated.

v5: Fixed up conflicts with mainline changes

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Pantelis Antoniou <panto@antoniou-consulting.com>
2014-03-11 20:48:32 +00:00
Artem Fetishev 70335abb26 fs/proc/base.c: fix GPF in /proc/$PID/map_files
The expected logic of proc_map_files_get_link() is either to return 0
and initialize 'path' or return an error and leave 'path' uninitialized.

By the time dname_to_vma_addr() returns 0 the corresponding vma may have
already be gone.  In this case the path is not initialized but the
return value is still 0.  This results in 'general protection fault'
inside d_path().

Steps to reproduce:

  CONFIG_CHECKPOINT_RESTORE=y

    fd = open(...);
    while (1) {
        mmap(fd, ...);
        munmap(fd, ...);
    }

  ls -la /proc/$PID/map_files

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=68991

Signed-off-by: Artem Fetishev <artem_fetishev@epam.com>
Signed-off-by: Aleksandr Terekhov <aleksandr_terekhov@epam.com>
Reported-by: <wiebittewas@gmail.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-10 17:26:20 -07:00
David Rientjes 668f9abbd4 mm: close PageTail race
Commit bf6bddf192 ("mm: introduce compaction and migration for
ballooned pages") introduces page_count(page) into memory compaction
which dereferences page->first_page if PageTail(page).

This results in a very rare NULL pointer dereference on the
aforementioned page_count(page).  Indeed, anything that does
compound_head(), including page_count() is susceptible to racing with
prep_compound_page() and seeing a NULL or dangling page->first_page
pointer.

This patch uses Andrea's implementation of compound_trans_head() that
deals with such a race and makes it the default compound_head()
implementation.  This includes a read memory barrier that ensures that
if PageTail(head) is true that we return a head page that is neither
NULL nor dangling.  The patch then adds a store memory barrier to
prep_compound_page() to ensure page->first_page is set.

This is the safest way to ensure we see the head page that we are
expecting, PageTail(page) is already in the unlikely() path and the
memory barriers are unfortunately required.

Hugetlbfs is the exception, we don't enforce a store memory barrier
during init since no race is possible.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Holger Kiehl <Holger.Kiehl@dwd.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-04 07:55:47 -08:00
Greg Pearson 38dfac843c vmcore: prevent PT_NOTE p_memsz overflow during header update
Currently, update_note_header_size_elf64() and
update_note_header_size_elf32() will add the size of a PT_NOTE entry to
real_sz even if that causes real_sz to exceeds max_sz.  This patch
corrects the while loop logic in those routines to ensure that does not
happen and prints a warning if a PT_NOTE entry is dropped.  If zero
PT_NOTE entries are found or this condition is encountered because the
only entry was dropped, a warning is printed and an error is returned.

One possible negative side effect of exceeding the max_sz limit is an
allocation failure in merge_note_headers_elf64() or
merge_note_headers_elf32() which would produce console output such as
the following while booting the crash kernel.

  vmalloc: allocation failure: 14076997632 bytes
  swapper/0: page allocation failure: order:0, mode:0x80d2
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.10.0-gbp1 #7
  Call Trace:
    dump_stack+0x19/0x1b
    warn_alloc_failed+0xf0/0x160
    __vmalloc_node_range+0x19e/0x250
    vmalloc_user+0x4c/0x70
    merge_note_headers_elf64.constprop.9+0x116/0x24a
    vmcore_init+0x2d4/0x76c
    do_one_initcall+0xe2/0x190
    kernel_init_freeable+0x17c/0x207
    kernel_init+0xe/0x180
    ret_from_fork+0x7c/0xb0

  Kdump: vmcore not initialized

  kdump: dump target is /dev/sda4
  kdump: saving to /sysroot//var/crash/127.0.0.1-2014.01.28-13:58:52/
  kdump: saving vmcore-dmesg.txt
  Cannot open /proc/vmcore: No such file or directory
  kdump: saving vmcore-dmesg.txt failed
  kdump: saving vmcore
  kdump: saving vmcore failed

This type of failure has been seen on a four socket prototype system
with certain memory configurations.  Most PT_NOTE sections have a single
entry similar to:

  n_namesz = 0x5
  n_descsz = 0x150
  n_type   = 0x1

Occasionally, a second entry is encountered with very large n_namesz and
n_descsz sizes:

  n_namesz = 0x80000008
  n_descsz = 0x510ae163
  n_type   = 0x80000008

Not yet sure of the source of these extra entries, they seem bogus, but
they shouldn't cause crash dump to fail.

Signed-off-by: Greg Pearson <greg.pearson@hp.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-10 16:01:40 -08:00
Oleg Nesterov 185ee40ee7 fs/proc/array.c: change do_task_stat() to use while_each_thread()
Change the remaining next_thread (ab)users to use while_each_thread().

The last user which should be changed is next_tid(), but we can't do this
now.

__exit_signal() and complete_signal() are fine, they actually need
next_thread() logic.

This patch (of 3):

do_task_stat() can use while_each_thread(), no changes in
the compiled code.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Sameer Nanda <snanda@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:37:02 -08:00
Paul Gortmaker abaf3787ac fs/proc: don't use module_init for non-modular core code
PROC_FS is a bool, so this code is either present or absent.  It will
never be modular, so using module_init as an alias for __initcall is
rather misleading.

Fix this up now, so that we can relocate module_init from init.h into
module.h in the future.  If we don't do this, we'd have to add module.h to
obviously non-modular code, and that would be ugly at best.

Note that direct use of __initcall is discouraged, vs.  one of the
priority categorized subgroups.  As __initcall gets mapped onto
device_initcall, our use of fs_initcall (which makes sense for fs code)
will thus change these registrations from level 6-device to level 5-fs
(i.e.  slightly earlier).  However no observable impact of that small
difference has been observed during testing, or is expected.

Also note that this change uncovers a missing semicolon bug in the
registration of vmcore_init as an initcall.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:37:02 -08:00
Dave Jones c1d867a54d fs/proc/proc_devtree.c: remove empty /proc/device-tree when no openfirmware exists.
Distribution kernels might want to build in support for /proc/device-tree
for kernels that might end up running on hardware that doesn't support
openfirmware.  This results in an empty /proc/device-tree existing.
Remove it if the OFW root node doesn't exist.

This situation actually confuses grub2, resulting in install failures.
grub2 sees the /proc/device-tree and picks the wrong install target cf.
http://bzr.savannah.gnu.org/lh/grub/trunk/grub/annotate/4300/util/grub-install.in#L311
grub should be more robust, but still, leaving an empty proc dir seems
pointless.

Addresses https://bugzilla.redhat.com/show_bug.cgi?id=818378.

Signed-off-by: Dave Jones <davej@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:37:01 -08:00
Rui Xiang cdf7e8dded proc: set attributes of pde using accessor functions
Use existing accessors proc_set_user() and proc_set_size() to set
attributes.  Just a cleanup.

Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:37:01 -08:00
Oleg Nesterov 9f6e963f06 proc: fix ->f_pos overflows in first_tid()
1. proc_task_readdir()->first_tid() path truncates f_pos to int, this
   is wrong even on 64bit.

   We could check that f_pos < PID_MAX or even INT_MAX in
   proc_task_readdir(), but this patch simply checks the potential
   overflow in first_tid(), this check is nop on 64bit.  We do not care if
   it was negative and the new unsigned value is huge, all we need to
   ensure is that we never wrongly return !NULL.

2. Remove the 2nd "nr != 0" check before get_nr_threads(),
   nr_threads == 0 is not distinguishable from !pid_task() above.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Sameer Nanda <snanda@chromium.org>
Cc: Sergey Dyasly <dserrg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:37:01 -08:00
Oleg Nesterov d855a4b79f proc: don't (ab)use ->group_leader in proc_task_readdir() paths
proc_task_readdir() does not really need "leader", first_tid() has to
revalidate it anyway.  Just pass proc_pid(inode) to first_tid() instead,
it can do pid_task(PIDTYPE_PID) itself and read ->group_leader only if
necessary.

The patch also extracts the "inode is dead" code from
pid_delete_dentry(dentry) into the new trivial helper,
proc_inode_is_dead(inode), proc_task_readdir() uses it to return -ENOENT
if this dir was removed.

This is a bit racy, but the race is very inlikely and the getdents() after
openndir() can see the empty "." + ".." dir only once.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Sameer Nanda <snanda@chromium.org>
Cc: Sergey Dyasly <dserrg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:37:01 -08:00
Oleg Nesterov c986c14a6a proc: change first_tid() to use while_each_thread() rather than next_thread()
Rerwrite the main loop to use while_each_thread() instead of
next_thread().  We are going to fix or replace while_each_thread(),
next_thread() should be avoided whenever possible.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Sameer Nanda <snanda@chromium.org>
Cc: Sergey Dyasly <dserrg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:37:01 -08:00
Oleg Nesterov 940fe4793a proc: fix the potential use-after-free in first_tid()
proc_task_readdir() verifies that the result of get_proc_task() is
pid_alive() and thus its ->group_leader is fine too.  However this is not
necessarily true after rcu_read_unlock(), we need to recheck this again
after first_tid() does rcu_read_lock().  Otherwise
leader->thread_group.next (used by next_thread()) can be invalid if the
rcu grace period expires in between.

The race is subtle and unlikely, but still it is possible afaics.  To
simplify lets ignore the "likely" case when tid != 0, f_version can be
cleared by proc_task_operations->llseek().

Suppose we have a main thread M and its subthread T.  Suppose that f_pos
== 3, iow first_tid() should return T.  Now suppose that the following
happens between rcu_read_unlock() and rcu_read_lock():

	1. T execs and becomes the new leader. This removes M from
	    ->thread_group but next_thread(M) is still T.

	2. T creates another thread X which does exec as well, T
	   goes away.

	3. X creates another subthread, this increments nr_threads.

	4. first_tid() does next_thread(M) and returns the already
	   dead T.

Note also that we need 2.  and 3.  only because of get_nr_threads() check,
and this check was supposed to be optimization only.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Sameer Nanda <snanda@chromium.org>
Cc: Sergey Dyasly <dserrg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:37:01 -08:00
Oleg Nesterov 74e37200de proc: cleanup/simplify get_task_state/task_state_array
get_task_state() and task_state_array[] look confusing and suboptimal, it
is not clear what it can actually report to user-space and
task_state_array[] blows .data for no reason.

1. state = (tsk->state & TASK_REPORT) | tsk->exit_state is not
   clear. TASK_REPORT is self-documenting but it is not clear
   what ->exit_state can add.

   Move the potential exit_state's (EXIT_ZOMBIE and EXIT_DEAD)
   into TASK_REPORT and use it to calculate the final result.

2. With the change above it is obvious that task_state_array[]
   has the unused entries just to make BUILD_BUG_ON() happy.

   Change this BUILD_BUG_ON() to use TASK_REPORT rather than
   TASK_STATE_MAX and shrink task_state_array[].

3. Turn the "while (state)" loop into fls(state).

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:37:01 -08:00
Naoya Horiguchi e3bba3c3c9 fs/proc/page.c: add PageAnon check to surely detect thp
stable_page_flags() checks !PageHuge && PageTransCompound && PageLRU to
know that a specified page is thp or not.  But sometimes it's not enough
and we fail to detect thp when the thp is on pagevec.  This happens only
for a few seconds after LRU list operations, but it makes it difficult
to control our applications depending on this flag.

So this patch adds another check PageAnon to detect thps on pagevec.  It
might not give the future extensibility for thp pagecache, but it's OK
at least for now.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:36:50 -08:00
Rik van Riel 34e431b0ae /proc/meminfo: provide estimated available memory
Many load balancing and workload placing programs check /proc/meminfo to
estimate how much free memory is available.  They generally do this by
adding up "free" and "cached", which was fine ten years ago, but is
pretty much guaranteed to be wrong today.

It is wrong because Cached includes memory that is not freeable as page
cache, for example shared memory segments, tmpfs, and ramfs, and it does
not include reclaimable slab memory, which can take up a large fraction
of system memory on mostly idle systems with lots of files.

Currently, the amount of memory that is available for a new workload,
without pushing the system into swap, can be estimated from MemFree,
Active(file), Inactive(file), and SReclaimable, as well as the "low"
watermarks from /proc/zoneinfo.

However, this may change in the future, and user space really should not
be expected to know kernel internals to come up with an estimate for the
amount of free memory.

It is more convenient to provide such an estimate in /proc/meminfo.  If
things change in the future, we only have to change it in one place.

Signed-off-by: Rik van Riel <riel@redhat.com>
Reported-by: Erik Mouw <erik.mouw_2@nxp.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21 16:19:43 -08:00
Jan Beulich ae5758a1a7 procfs: also fix proc_reg_get_unmapped_area() for !MMU case
Commit fad1a86e25 ("procfs: call default get_unmapped_area on
MMU-present architectures"), as its title says, took care of only the
MMU case, leaving the !MMU side still in the regressed state (returning
-EIO in all cases where pde->proc_fops->get_unmapped_area is NULL).

From the fad1a86e25 changelog:

 "Commit c4fe244857 ("sparc: fix PCI device proc file mmap(2)") added
  proc_reg_get_unmapped_area in proc_reg_file_ops and
  proc_reg_file_ops_no_compat, by which now mmap always returns EIO if
  get_unmapped_area method is not defined for the target procfs file, which
  causes regression of mmap on /proc/vmcore.

  To address this issue, like get_unmapped_area(), call default
  current->mm->get_unmapped_area on MMU-present architectures if
  pde->proc_fops->get_unmapped_area, i.e.  the one in actual file operation
  in the procfs file, is not defined"

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org>	[3.12.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-12 18:19:26 -08:00
Linus Torvalds 3eaded86ac Merge git://git.infradead.org/users/eparis/audit
Pull audit updates from Eric Paris:
 "Nothing amazing.  Formatting, small bug fixes, couple of fixes where
  we didn't get records due to some old VFS changes, and a change to how
  we collect execve info..."

Fixed conflict in fs/exec.c as per Eric and linux-next.

* git://git.infradead.org/users/eparis/audit: (28 commits)
  audit: fix type of sessionid in audit_set_loginuid()
  audit: call audit_bprm() only once to add AUDIT_EXECVE information
  audit: move audit_aux_data_execve contents into audit_context union
  audit: remove unused envc member of audit_aux_data_execve
  audit: Kill the unused struct audit_aux_data_capset
  audit: do not reject all AUDIT_INODE filter types
  audit: suppress stock memalloc failure warnings since already managed
  audit: log the audit_names record type
  audit: add child record before the create to handle case where create fails
  audit: use given values in tty_audit enable api
  audit: use nlmsg_len() to get message payload length
  audit: use memset instead of trying to initialize field by field
  audit: fix info leak in AUDIT_GET requests
  audit: update AUDIT_INODE filter rule to comparator function
  audit: audit feature to set loginuid immutable
  audit: audit feature to only allow unsetting the loginuid
  audit: allow unsetting the loginuid (with priv)
  audit: remove CONFIG_AUDIT_LOGINUID_IMMUTABLE
  audit: loginuid functions coding style
  selinux: apply selinux checks on new audit message types
  ...
2013-11-21 19:18:14 -08:00
Al Viro b26d4cd385 consolidate simple ->d_delete() instances
Rename simple_delete_dentry() to always_delete_dentry() and export it.
Export simple_dentry_operations, while we are at it, and get rid of
their duplicates

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-15 22:04:17 -05:00
Tetsuo Handa 652586df95 seq_file: remove "%n" usage from seq_file users
All seq_printf() users are using "%n" for calculating padding size,
convert them to use seq_setwidth() / seq_pad() pair.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:20 +09:00
Kirill A. Shutemov cb900f4121 mm, hugetlb: convert hugetlbfs to use split pmd lock
Hugetlb supports multiple page sizes. We use split lock only for PMD
level, but not for PUD.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Alex Thorlton <athorlton@sgi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:14 +09:00
Kirill A. Shutemov bf929152e9 mm, thp: change pmd_trans_huge_lock() to return taken lock
With split ptlock it's important to know which lock
pmd_trans_huge_lock() took.  This patch adds one more parameter to the
function to return the lock.

In most places migration to new api is trivial.  Exception is
move_huge_pmd(): we need to take two locks if pmd tables are different.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Alex Thorlton <athorlton@sgi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:14 +09:00
Kirill A. Shutemov e1f56c89b0 mm: convert mm->nr_ptes to atomic_long_t
With split page table lock for PMD level we can't hold mm->page_table_lock
while updating nr_ptes.

Let's convert it to atomic_long_t to avoid races.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Alex Thorlton <athorlton@sgi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:14 +09:00
Linus Torvalds 5cbb3d216e Merge branch 'akpm' (patches from Andrew Morton)
Merge first patch-bomb from Andrew Morton:
 "Quite a lot of other stuff is banked up awaiting further
  next->mainline merging, but this batch contains:

   - Lots of random misc patches
   - OCFS2
   - Most of MM
   - backlight updates
   - lib/ updates
   - printk updates
   - checkpatch updates
   - epoll tweaking
   - rtc updates
   - hfs
   - hfsplus
   - documentation
   - procfs
   - update gcov to gcc-4.7 format
   - IPC"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (269 commits)
  ipc, msg: fix message length check for negative values
  ipc/util.c: remove unnecessary work pending test
  devpts: plug the memory leak in kill_sb
  ./Makefile: export initial ramdisk compression config option
  init/Kconfig: add option to disable kernel compression
  drivers: w1: make w1_slave::flags long to avoid memory corruption
  drivers/w1/masters/ds1wm.cuse dev_get_platdata()
  drivers/memstick/core/ms_block.c: fix unreachable state in h_msb_read_page()
  drivers/memstick/core/mspro_block.c: fix attributes array allocation
  drivers/pps/clients/pps-gpio.c: remove redundant of_match_ptr
  kernel/panic.c: reduce 1 byte usage for print tainted buffer
  gcov: reuse kbasename helper
  kernel/gcov/fs.c: use pr_warn()
  kernel/module.c: use pr_foo()
  gcov: compile specific gcov implementation based on gcc version
  gcov: add support for gcc 4.7 gcov format
  gcov: move gcov structs definitions to a gcc version specific file
  kernel/taskstats.c: return -ENOMEM when alloc memory fails in add_del_listener()
  kernel/taskstats.c: add nla_nest_cancel() for failure processing between nla_nest_start() and nla_nest_end()
  kernel/sysctl_binary.c: use scnprintf() instead of snprintf()
  ...
2013-11-13 15:45:43 +09:00
Linus Torvalds 9bc9ccd7db Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "All kinds of stuff this time around; some more notable parts:

   - RCU'd vfsmounts handling
   - new primitives for coredump handling
   - files_lock is gone
   - Bruce's delegations handling series
   - exportfs fixes

  plus misc stuff all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (101 commits)
  ecryptfs: ->f_op is never NULL
  locks: break delegations on any attribute modification
  locks: break delegations on link
  locks: break delegations on rename
  locks: helper functions for delegation breaking
  locks: break delegations on unlink
  namei: minor vfs_unlink cleanup
  locks: implement delegations
  locks: introduce new FL_DELEG lock flag
  vfs: take i_mutex on renamed file
  vfs: rename I_MUTEX_QUOTA now that it's not used for quotas
  vfs: don't use PARENT/CHILD lock classes for non-directories
  vfs: pull ext4's double-i_mutex-locking into common code
  exportfs: fix quadratic behavior in filehandle lookup
  exportfs: better variable name
  exportfs: move most of reconnect_path to helper function
  exportfs: eliminate unused "noprogress" counter
  exportfs: stop retrying once we race with rename/remove
  exportfs: clear DISCONNECTED on all parents sooner
  exportfs: more detailed comment for path_reconnect
  ...
2013-11-13 15:34:18 +09:00
Randy Dunlap 1c3fc3e5cc kcore: add Kconfig help text
Under Pseudo filesystems, /proc/kcore support has no help.

Fixes a portion of kernel bugzilla #52671:
  https://bugzilla.kernel.org/show_bug.cgi?id=52671

Thanks for David Howells for the help text.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: <lailavrazda1979@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:33 +09:00
HATAYAMA Daisuke 5721cf84d9 procfs: clean up proc_reg_get_unmapped_area for 80-column limit
Clean up proc_reg_get_unmapped_area due to its 80-column limit
violation.

Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:33 +09:00
Jerome Marchand 00619bcc44 mm: factor commit limit calculation
The same calculation is currently done in three differents places.
Factor that code so future changes has to be made at only one place.

[akpm@linux-foundation.org: uninline vm_commit_limit()]
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:11 +09:00
Naoya Horiguchi ec8e41aec1 /proc/pid/smaps: show VM_SOFTDIRTY flag in VmFlags line
This flag shows that the VMA is "newly created" and thus represents
"dirty" in the task's VM.

You can clear it by "echo 4 > /proc/pid/clear_refs."

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:07 +09:00
David Rientjes 948927ee9e mm, mempolicy: make mpol_to_str robust and always succeed
mpol_to_str() should not fail.  Currently, it either fails because the
string buffer is too small or because a string hasn't been defined for a
mempolicy mode.

If a new mempolicy mode is introduced and no string is defined for it,
just warn and return "unknown".

If the buffer is too small, just truncate the string and return, the
same behavior as snprintf().

This also fixes a bug where there was no NULL-byte termination when doing
*p++ = '=' and *p++ ':' and maxlen has been reached.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Chen Gang <gang.chen@asianux.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:05 +09:00
Xishi Qiu 83285c72e0 mm: use pgdat_end_pfn() to simplify the code in others
Use "pgdat_end_pfn()" instead of "pgdat->node_start_pfn +
pgdat->node_spanned_pages".  Simplify the code, no functional change.

Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:03 +09:00
Linus Torvalds 10d0c9705e DeviceTree updates for 3.13. This is a bit larger pull request than
usual for this cycle with lots of clean-up.
 
 - Cross arch clean-up and consolidation of early DT scanning code.
 - Clean-up and removal of arch prom.h headers. Makes arch specific
   prom.h optional on all but Sparc.
 - Addition of interrupts-extended property for devices connected to
   multiple interrupt controllers.
 - Refactoring of DT interrupt parsing code in preparation for deferred
   probe of interrupts.
 - ARM cpu and cpu topology bindings documentation.
 - Various DT vendor binding documentation updates.
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Merge tag 'devicetree-for-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull devicetree updates from Rob Herring:
 "DeviceTree updates for 3.13.  This is a bit larger pull request than
  usual for this cycle with lots of clean-up.

   - Cross arch clean-up and consolidation of early DT scanning code.
   - Clean-up and removal of arch prom.h headers.  Makes arch specific
     prom.h optional on all but Sparc.
   - Addition of interrupts-extended property for devices connected to
     multiple interrupt controllers.
   - Refactoring of DT interrupt parsing code in preparation for
     deferred probe of interrupts.
   - ARM cpu and cpu topology bindings documentation.
   - Various DT vendor binding documentation updates"

* tag 'devicetree-for-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (82 commits)
  powerpc: add missing explicit OF includes for ppc
  dt/irq: add empty of_irq_count for !OF_IRQ
  dt: disable self-tests for !OF_IRQ
  of: irq: Fix interrupt-map entry matching
  MIPS: Netlogic: replace early_init_devtree() call
  of: Add Panasonic Corporation vendor prefix
  of: Add Chunghwa Picture Tubes Ltd. vendor prefix
  of: Add AU Optronics Corporation vendor prefix
  of/irq: Fix potential buffer overflow
  of/irq: Fix bug in interrupt parsing refactor.
  of: set dma_mask to point to coherent_dma_mask
  of: add vendor prefix for PHYTEC Messtechnik GmbH
  DT: sort vendor-prefixes.txt
  of: Add vendor prefix for Cadence
  of: Add empty for_each_available_child_of_node() macro definition
  arm/versatile: Fix versatile irq specifications.
  of/irq: create interrupts-extended property
  microblaze/pci: Drop PowerPC-ism from irq parsing
  of/irq: Create of_irq_parse_and_map_pci() to consolidate arch code.
  of/irq: Use irq_of_parse_and_map()
  ...
2013-11-12 16:52:17 +09:00
Eric Paris 81407c84ac audit: allow unsetting the loginuid (with priv)
If a task has CAP_AUDIT_CONTROL allow that task to unset their loginuid.
This would allow a child of that task to set their loginuid without
CAP_AUDIT_CONTROL.  Thus when launching a new login daemon, a
priviledged helper would be able to unset the loginuid and then the
daemon, which may be malicious user facing, do not need priv to function
correctly.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:09 -05:00
Ingo Molnar fb10d5b7ef Merge branch 'linus' into sched/core
Resolve cherry-picking conflicts:

Conflicts:
	mm/huge_memory.c
	mm/memory.c
	mm/mprotect.c

See this upstream merge commit for more details:

  52469b4fcd Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-01 08:24:41 +01:00
Al Viro 87dc800be2 new helper: kfree_put_link()
duplicated to hell and back...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24 23:34:49 -04:00
HATAYAMA Daisuke fad1a86e25 procfs: call default get_unmapped_area on MMU-present architectures
Commit c4fe244857 ("sparc: fix PCI device proc file mmap(2)") added
proc_reg_get_unmapped_area in proc_reg_file_ops and
proc_reg_file_ops_no_compat, by which now mmap always returns EIO if
get_unmapped_area method is not defined for the target procfs file,
which causes regression of mmap on /proc/vmcore.

To address this issue, like get_unmapped_area(), call default
current->mm->get_unmapped_area on MMU-present architectures if
pde->proc_fops->get_unmapped_area, i.e.  the one in actual file
operation in the procfs file, is not defined.

Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-16 21:35:53 -07:00
HATAYAMA Daisuke 2cbe3b0af8 procfs: fix unintended truncation of returned mapped address
Currently, proc_reg_get_unmapped_area truncates upper 32-bit of the
mapped virtual address returned from get_unmapped_area method in
pde->proc_fops due to the variable rv of signed integer on x86_64.  This
is too small to have vitual address of unsigned long on x86_64 since on
x86_64, signed integer is of 4 bytes while unsigned long is of 8 bytes.
To fix this issue, use unsigned long instead.

Fixes a regression added in commit c4fe244857 ("sparc: fix PCI device
proc file mmap(2)").

Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-16 21:35:53 -07:00
Cyrill Gorcunov e9cdd6e771 mm: /proc/pid/pagemap: inspect _PAGE_SOFT_DIRTY only on present pages
If a page we are inspecting is in swap we may occasionally report it as
having soft dirty bit (even if it is clean).  The pte_soft_dirty helper
should be called on present pte only.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-16 21:35:52 -07:00
Rob Herring 32df8dca50 of: remove HAVE_ARCH_DEVTREE_FIXUPS
HAVE_ARCH_DEVTREE_FIXUPS appears to always be needed except for sparc,
but it is only used for /proc/device-teee and sparc does not enable
/proc/device-tree. So this option is redundant. Remove the option and
always enable it. This has the side effect of fixing /proc/device-tree
on arches such as arm64 which failed to define this option.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
2013-10-09 20:04:08 -05:00
Mel Gorman e29cf08b05 sched/numa: Report a NUMA task group ID
It is desirable to model from userspace how the scheduler groups tasks
over time. This patch adds an ID to the numa_group and reports it via
/proc/PID/status.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-45-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 14:47:49 +02:00
Kirill A. Shutemov 3cd14fcd3f thp: account anon transparent huge pages into NR_ANON_PAGES
We use NR_ANON_PAGES as base for reporting AnonPages to user.  There's
not much sense in not accounting transparent huge pages there, but add
them on printing to user.

Let's account transparent huge pages in NR_ANON_PAGES in the first place.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Ning Qu <quning@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 15:38:03 -07:00
Michael Holzheu 11e376a3f9 vmcore: enable /proc/vmcore mmap for s390
The patch "s390/vmcore: Implement remap_oldmem_pfn_range for s390" allows
now to use mmap also on s390.

So enable mmap for s390 again.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Jan Willeke <willeke@de.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:14 -07:00
Michael Holzheu 9cb218131d vmcore: introduce remap_oldmem_pfn_range()
For zfcpdump we can't map the HSA storage because it is only available via
a read interface.  Therefore, for the new vmcore mmap feature we have
introduce a new mechanism to create mappings on demand.

This patch introduces a new architecture function remap_oldmem_pfn_range()
that should be used to create mappings with remap_pfn_range() for oldmem
areas that can be directly mapped.  For zfcpdump this is everything
besides of the HSA memory.  For the areas that are not mapped by
remap_oldmem_pfn_range() a generic vmcore a new generic vmcore fault
handler mmap_vmcore_fault() is called.

This handler works as follows:

* Get already available or new page from page cache (find_or_create_page)
* Check if /proc/vmcore page is filled with data (PageUptodate)
* If yes:
  Return that page
* If no:
  Fill page using __vmcore_read(), set PageUptodate, and return page

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Jan Willeke <willeke@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:10 -07:00
Michael Holzheu be8a8d069e vmcore: introduce ELF header in new memory feature
For s390 we want to use /proc/vmcore for our SCSI stand-alone dump
(zfcpdump).  We have support where the first HSA_SIZE bytes are saved into
a hypervisor owned memory area (HSA) before the kdump kernel is booted.
When the kdump kernel starts, it is restricted to use only HSA_SIZE bytes.

The advantages of this mechanism are:

 * No crashkernel memory has to be defined in the old kernel.
 * Early boot problems (before kexec_load has been done) can be dumped
 * Non-Linux systems can be dumped.

We modify the s390 copy_oldmem_page() function to read from the HSA memory
if memory below HSA_SIZE bytes is requested.

Since we cannot use the kexec tool to load the kernel in this scenario,
we have to build the ELF header in the 2nd (kdump/new) kernel.

So with the following patch set we would like to introduce the new
function that the ELF header for /proc/vmcore can be created in the 2nd
kernel memory.

The following steps are done during zfcpdump execution:

1.  Production system crashes
2.  User boots a SCSI disk that has been prepared with the zfcpdump tool
3.  Hypervisor saves CPU state of boot CPU and HSA_SIZE bytes of memory into HSA
4.  Boot loader loads kernel into low memory area
5.  Kernel boots and uses only HSA_SIZE bytes of memory
6.  Kernel saves registers of non-boot CPUs
7.  Kernel does memory detection for dump memory map
8.  Kernel creates ELF header for /proc/vmcore
9.  /proc/vmcore uses this header for initialization
10. The zfcpdump user space reads /proc/vmcore to write dump to SCSI disk
    - copy_oldmem_page() copies from HSA for memory below HSA_SIZE
    - copy_oldmem_page() copies from real memory for memory above HSA_SIZE

Currently for s390 we create the ELF core header in the 2nd kernel with a
small trick.  We relocate the addresses in the ELF header in a way that
for the /proc/vmcore code it seems to be in the 1st kernel (old) memory
and the read_from_oldmem() returns the correct data.  This allows the
/proc/vmcore code to use the ELF header in the 2nd kernel.

This patch:

Exchange the old mechanism with the new and much cleaner function call
override feature that now offcially allows to create the ELF core header
in the 2nd kernel.

To use the new feature the following function have to be defined
by the architecture backend code to read from new memory:

 * elfcorehdr_alloc: Allocate ELF header
 * elfcorehdr_free: Free the memory of the ELF header
 * elfcorehdr_read: Read from ELF header
 * elfcorehdr_read_notes: Read from ELF notes

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Jan Willeke <willeke@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:10 -07:00
Oleg Nesterov 96d0df79f2 proc: make proc_fd_permission() thread-friendly
proc_fd_permission() says "process can still access /proc/self/fd after it
has executed a setuid()", but the "task_pid() = proc_pid() check only
helps if the task is group leader, /proc/self points to
/proc/<leader-pid>.

Change this check to use task_tgid() so that the whole thread group can
access its /proc/self/fd or /proc/<tid-of-sub-thread>/fd.

Notes:
	- CLONE_THREAD does not require CLONE_FILES so task->files
	  can differ, but I don't think this can lead to any security
	  problem. And this matches same_thread_group() in
	  __ptrace_may_access().

	- /proc/self should probably point to /proc/<thread-tid>, but
	  it is too late to change the rules. Perhaps it makes sense
	  to add /proc/thread though.

Test-case:

	void *tfunc(void *arg)
	{
		assert(opendir("/proc/self/fd"));
		return NULL;
	}

	int main(void)
	{
		pthread_t t;
		pthread_create(&t, NULL, tfunc, NULL);
		pthread_join(t, NULL);
		return 0;
	}

fails if, say, this executable is not readable and suid_dumpable = 0.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:03 -07:00
Chen Gang a3c039929d fs/proc/task_mmu.c: check the return value of mpol_to_str()
mpol_to_str() may fail, and not fill the buffer (e.g. -EINVAL), so need
check about it, or buffer may not be zero based, and next seq_printf()
will cause issue.

The failure return need after mpol_cond_put() to match get_vma_policy().

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:03 -07:00
Cyrill Gorcunov d9104d1ca9 mm: track vma changes with VM_SOFTDIRTY bit
Pavel reported that in case if vma area get unmapped and then mapped (or
expanded) in-place, the soft dirty tracker won't be able to recognize this
situation since it works on pte level and ptes are get zapped on unmap,
loosing soft dirty bit of course.

So to resolve this situation we need to track actions on vma level, there
VM_SOFTDIRTY flag comes in.  When new vma area created (or old expanded)
we set this bit, and keep it here until application calls for clearing
soft dirty bit.

Thus when user space application track memory changes now it can detect if
vma area is renewed.

Reported-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:57:56 -07:00
Linus Torvalds c7c4591db6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace changes from Eric Biederman:
 "This is an assorted mishmash of small cleanups, enhancements and bug
  fixes.

  The major theme is user namespace mount restrictions.  nsown_capable
  is killed as it encourages not thinking about details that need to be
  considered.  A very hard to hit pid namespace exiting bug was finally
  tracked and fixed.  A couple of cleanups to the basic namespace
  infrastructure.

  Finally there is an enhancement that makes per user namespace
  capabilities usable as capabilities, and an enhancement that allows
  the per userns root to nice other processes in the user namespace"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  userns:  Kill nsown_capable it makes the wrong thing easy
  capabilities: allow nice if we are privileged
  pidns: Don't have unshare(CLONE_NEWPID) imply CLONE_THREAD
  userns: Allow PR_CAPBSET_DROP in a user namespace.
  namespaces: Simplify copy_namespaces so it is clear what is going on.
  pidns: Fix hang in zap_pid_ns_processes by sending a potentially extra wakeup
  sysfs: Restrict mounting sysfs
  userns: Better restrictions on when proc and sysfs can be mounted
  vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces
  kernel/nsproxy.c: Improving a snippet of code.
  proc: Restrict mounting the proc filesystem
  vfs: Lock in place mounts from more privileged users
2013-09-07 14:35:32 -07:00
Linus Torvalds b14662cae0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
Pull sparc changes from David Miller:
 "Several bug fixes (from Kirill Tkhai, Geery Uytterhoeven, and Alexey
  Dobriyan) and some support for Fujitsu sparc64x chips (from Allen
  Pais)"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Export flush_ptrace_access() (needed by lustre)
  sparc: fix PCI device proc file mmap(2)
  sparc64: Remove RWSEM export leftovers
  sparc64: Fix off by one in trampoline TLB mapping installation loop.
  sparc64: Fix ITLB handler of null page
  esp_scsi: Fix tag state corruption when autosensing.
  sparc64: Fix not SRA'ed %o5 in 32-bit traced syscall
  sparc64: cleanup: Rename ret_from_syscall to ret_from_fork
  sparc32: Fix exit flag passed from traced sys_sigreturn
  sparc64: Fix wrong syscall return value passed to trace_sys_exit()
  support sparc64x chip type in cpumap.c
  cpu hw caps support for sparc64x
2013-09-05 15:28:17 -07:00
Alexey Dobriyan c4fe244857 sparc: fix PCI device proc file mmap(2)
Commit 786d7e1612 "Fix rmmod/read/write races in /proc entries"
must have broken mmapping of PCI device proc files on Sparc.

Notice how it adds wrapper around ->mmap but doesn't do it around ->get_unmapped_area.
Add wrapper around ->get_unmapped_area.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-05 12:12:51 -07:00
Eric W. Biederman e51db73532 userns: Better restrictions on when proc and sysfs can be mounted
Rely on the fact that another flavor of the filesystem is already
mounted and do not rely on state in the user namespace.

Verify that the mounted filesystem is not covered in any significant
way.  I would love to verify that the previously mounted filesystem
has no mounts on top but there are at least the directories
/proc/sys/fs/binfmt_misc and /sys/fs/cgroup/ that exist explicitly
for other filesystems to mount on top of.

Refactor the test into a function named fs_fully_visible and call that
function from the mount routines of proc and sysfs.  This makes this
test local to the filesystems involved and the results current of when
the mounts take place, removing a weird threading of the user
namespace, the mount namespace and the filesystems themselves.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-08-26 19:17:03 -07:00
Eric W. Biederman aee1c13dd0 proc: Restrict mounting the proc filesystem
Don't allow mounting the proc filesystem unless the caller has
CAP_SYS_ADMIN rights over the pid namespace.  The principle here is if
you create or have capabilities over it you can mount it, otherwise
you get to live with what other people have mounted.

Andy pointed out that this is needed to prevent users in a user
namespace from remounting proc and specifying different hidepid and gid
options on already existing proc mounts.

Cc: stable@vger.kernel.org
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-08-26 11:36:58 -07:00
Linus Torvalds 4d4323ea2d Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "Assorted fixes from the last week or so"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  VFS: collect_mounts() should return an ERR_PTR
  bfs: iget_locked() doesn't return an ERR_PTR
  efs: iget_locked() doesn't return an ERR_PTR()
  proc: kill the extra proc_readfd_common()->dir_emit_dots()
  cope with potentially long ->d_dname() output for shmem/hugetlb
2013-08-25 12:25:38 -07:00
Oleg Nesterov a5a1955e0c proc: kill the extra proc_readfd_common()->dir_emit_dots()
proc_readfd_common() does dir_emit_dots() twice in a row,
we need to do this only once.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-08-24 12:10:22 -04:00
Linus Torvalds fd3930f70c proc: more readdir conversion bug-fixes
In the previous commit, Richard Genoud fixed proc_root_readdir(), which
had lost the check for whether all of the non-process /proc entries had
been returned or not.

But that in turn exposed _another_ bug, namely that the original readdir
conversion patch had yet another problem: it had lost the return value
of proc_readdir_de(), so now checking whether it had completed
successfully or not didn't actually work right anyway.

This reinstates the non-zero return for the "end of base entries" that
had also gotten lost in commit f0c3b5093a ("[readdir] convert
procfs").  So now you get all the base entries *and* you get all the
process entries, regardless of getdents buffer size.

(Side note: the Linux "getdents" manual page actually has a nice example
application for testing getdents, which can be easily modified to use
different buffers.  Who knew? Man-pages can be useful)

Reported-by: Emmanuel Benisty <benisty.e@gmail.com>
Reported-by: Marc Dionne <marc.c.dionne@gmail.com>
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-19 16:26:12 -07:00
Richard Genoud 94fc5d9de5 proc: return on proc_readdir error
Commit f0c3b5093a ("[readdir] convert procfs") introduced a bug on the
listing of the proc file-system.  The return value of proc_readdir()
isn't tested anymore in the proc_root_readdir function.

This lead to an "interesting" behaviour when we are using the getdents()
system call with a buffer too small: instead of failing, it returns the
first entries of /proc (enough to fill the given buffer), plus the PID
directories.

This is not triggered on glibc (as getdents is called with a 32KB
buffer), but on uclibc, the buffer size is only 1KB, thus some proc
entries are missing.

See https://lkml.org/lkml/2013/8/12/288 for more background.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-19 09:47:27 -07:00
yonghua zheng 8c8296223f fs/proc/task_mmu.c: fix buffer overflow in add_page_map()
Recently we met quite a lot of random kernel panic issues after enabling
CONFIG_PROC_PAGE_MONITOR.  After debuggind we found this has something
to do with following bug in pagemap:

In struct pagemapread:

  struct pagemapread {
      int pos, len;
      pagemap_entry_t *buffer;
      bool v2;
  };

pos is number of PM_ENTRY_BYTES in buffer, but len is the size of
buffer, it is a mistake to compare pos and len in add_page_map() for
checking buffer is full or not, and this can lead to buffer overflow and
random kernel panic issue.

Correct len to be total number of PM_ENTRY_BYTES in buffer.

[akpm@linux-foundation.org: document pagemapread.pos and .len units, fix PM_ENTRY_BYTES definition]
Signed-off-by: Yonghua Zheng <younghua.zheng@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-13 17:57:50 -07:00
Cyrill Gorcunov 41bb3476b3 mm: save soft-dirty bits on file pages
Andy reported that if file page get reclaimed we lose the soft-dirty bit
if it was there, so save _PAGE_BIT_SOFT_DIRTY bit when page address get
encoded into pte entry.  Thus when #pf happens on such non-present pte
we can restore it back.

Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-13 17:57:48 -07:00
Cyrill Gorcunov 179ef71cbc mm: save soft-dirty bits on swapped pages
Andy Lutomirski reported that if a page with _PAGE_SOFT_DIRTY bit set
get swapped out, the bit is getting lost and no longer available when
pte read back.

To resolve this we introduce _PTE_SWP_SOFT_DIRTY bit which is saved in
pte entry for the page being swapped out.  When such page is to be read
back from a swap cache we check for bit presence and if it's there we
clear it and restore the former _PAGE_SOFT_DIRTY bit back.

One of the problem was to find a place in pte entry where we can save
the _PTE_SWP_SOFT_DIRTY bit while page is in swap.  The _PAGE_PSE was
chosen for that, it doesn't intersect with swap entry format stored in
pte.

Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-13 17:57:47 -07:00
Michael Holzheu 5a74953ff5 s390/kdump: Disable mmap for s390
The kdump mmap patch series (git commit 83086978c6) directly
map the PT_LOADs to memory. On s390 this does not work because the
copy_from_oldmem() function swaps [0,crashkernel size] with
[crashkernel base, crashkernel base+crashkernel size]. The swap
int copy_from_oldmem() was done in order correctly implement /dev/oldmem.

See: http://marc.info/?l=kexec&m=136940802511603&w=2

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-07-18 13:40:18 +02:00
Zhao Hongjiang 30bc30df10 fs/proc/kcore.c: using strlcpy() instead of strncpy()
For NUL terminated string, set '\0' at the end.

Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:02 -07:00
Oleg Nesterov 1d98a5fa11 fs/proc/uptime.c:uptime_proc_show(): use get_monotonic_boottime()
Change uptime_proc_show() to use get_monotonic_boottime() instead of
do_posix_clock_monotonic_gettime() + monotonic_to_bootbased().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Tomas Janousek <tjanouse@redhat.com>
Cc: Tomas Smetana <tsmetana@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:02 -07:00
HATAYAMA Daisuke 83086978c6 vmcore: support mmap() on /proc/vmcore
This patch introduces mmap_vmcore().

Don't permit writable nor executable mapping even with mprotect()
because this mmap() is aimed at reading crash dump memory.  Non-writable
mapping is also requirement of remap_pfn_range() when mapping linear
pages on non-consecutive physical pages; see is_cow_mapping().

Set VM_MIXEDMAP flag to remap memory by remap_pfn_range and by
remap_vmalloc_range_pertial at the same time for a single vma.
do_munmap() can correctly clean partially remapped vma with two
functions in abnormal case.  See zap_pte_range(), vm_normal_page() and
their comments for details.

On x86-32 PAE kernels, mmap() supports at most 16TB memory only.  This
limitation comes from the fact that the third argument of
remap_pfn_range(), pfn, is of 32-bit length on x86-32: unsigned long.

[akpm@linux-foundation.org: use min(), switch to conventional error-unwinding approach]
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Lisa Mitchell <lisa.mitchell@hp.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Tested-by: Maxim Uvarov <muvarov@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:30 -07:00
HATAYAMA Daisuke 591ff71664 vmcore: calculate vmcore file size from buffer size and total size of vmcore objects
The previous patches newly added holes before each chunk of memory and
the holes need to be count in vmcore file size.  There are two ways to
count file size in such a way:

1) suppose m is a poitner to the last vmcore object in vmcore_list.
   Then file size is (m->offset + m->size), or

2) calculate sum of size of buffers for ELF header, program headers,
   ELF note segments and objects in vmcore_list.

Although 1) is more direct and simpler than 2), 2) seems better in that
it reflects internal object structure of /proc/vmcore.  Thus, this patch
changes get_vmcore_size_elf{64, 32} so that it calculates size in the
way of 2).

As a result, both get_vmcore_size_elf{64, 32} have the same definition.
Merge them as get_vmcore_size.

Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Lisa Mitchell <lisa.mitchell@hp.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:30 -07:00
HATAYAMA Daisuke ef9e78fd27 vmcore: allow user process to remap ELF note segment buffer
Now ELF note segment has been copied in the buffer on vmalloc memory.
To allow user process to remap the ELF note segment buffer with
remap_vmalloc_page, the corresponding VM area object has to have
VM_USERMAP flag set.

[akpm@linux-foundation.org: use the conventional comment layout]
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Lisa Mitchell <lisa.mitchell@hp.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:30 -07:00
HATAYAMA Daisuke 087350c9dc vmcore: allocate ELF note segment in the 2nd kernel vmalloc memory
The reasons why we don't allocate ELF note segment in the 1st kernel
(old memory) on page boundary is to keep backward compatibility for old
kernels, and that if doing so, we waste not a little memory due to
round-up operation to fit the memory to page boundary since most of the
buffers are in per-cpu area.

ELF notes are per-cpu, so total size of ELF note segments depends on
number of CPUs.  The current maximum number of CPUs on x86_64 is 5192,
and there's already system with 4192 CPUs in SGI, where total size
amounts to 1MB.  This can be larger in the near future or possibly even
now on another architecture that has larger size of note per a single
cpu.  Thus, to avoid the case where memory allocation for large block
fails, we allocate vmcore objects on vmalloc memory.

This patch adds elfnotes_buf and elfnotes_sz variables to keep pointer
to the ELF note segment buffer and its size.  There's no longer the
vmcore object that corresponds to the ELF note segment in vmcore_list.
Accordingly, read_vmcore() has new case for ELF note segment and
set_vmcore_list_offsets_elf{64,32}() and other helper functions starts
calculating offset from sum of size of ELF headers and size of ELF note
segment.

[akpm@linux-foundation.org: use min(), fix error-path vzalloc() leaks]
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Lisa Mitchell <lisa.mitchell@hp.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:30 -07:00
HATAYAMA Daisuke 7f614cd1e0 vmcore: treat memory chunks referenced by PT_LOAD program header entries in page-size boundary in vmcore_list
Treat memory chunks referenced by PT_LOAD program header entries in
page-size boundary in vmcore_list.  Formally, for each range [start,
end], we set up the corresponding vmcore object in vmcore_list to
[rounddown(start, PAGE_SIZE), roundup(end, PAGE_SIZE)].

This change affects layout of /proc/vmcore.  The gaps generated by the
rearrangement are newly made visible to applications as holes.
Concretely, they are two ranges [rounddown(start, PAGE_SIZE), start] and
[end, roundup(end, PAGE_SIZE)].

Suppose variable m points at a vmcore object in vmcore_list, and
variable phdr points at the program header of PT_LOAD type the variable
m corresponds to.  Then, pictorially:

  m->offset                    +---------------+
                               | hole          |
phdr->p_offset =               +---------------+
  m->offset + (paddr - start)  |               |\
                               | kernel memory | phdr->p_memsz
                               |               |/
                               +---------------+
                               | hole          |
  m->offset + m->size          +---------------+

where m->offset and m->offset + m->size are always page-size aligned.

Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Lisa Mitchell <lisa.mitchell@hp.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:30 -07:00
HATAYAMA Daisuke f2bdacdd59 vmcore: allocate buffer for ELF headers on page-size alignment
Allocate ELF headers on page-size boundary using __get_free_pages()
instead of kmalloc().

Later patch will merge PT_NOTE entries into a single unique one and
decrease the buffer size actually used.  Keep original buffer size in
variable elfcorebuf_sz_orig to kfree the buffer later and actually used
buffer size with rounded up to page-size boundary in variable
elfcorebuf_sz separately.

The size of part of the ELF buffer exported from /proc/vmcore is
elfcorebuf_sz.

The merged, removed PT_NOTE entries, i.e.  the range [elfcorebuf_sz,
elfcorebuf_sz_orig], is filled with 0.

Use size of the ELF headers as an initial offset value in
set_vmcore_list_offsets_elf{64,32} and
process_ptload_program_headers_elf{64,32} in order to indicate that the
offset includes the holes towards the page boundary.

As a result, both set_vmcore_list_offsets_elf{64,32} have the same
definition.  Merge them as set_vmcore_list_offsets.

[akpm@linux-foundation.org: add free_elfcorebuf(), cleanups]
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Lisa Mitchell <lisa.mitchell@hp.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:30 -07:00
HATAYAMA Daisuke b27eb18660 vmcore: clean up read_vmcore()
Rewrite part of read_vmcore() that reads objects in vmcore_list in the
same way as part reading ELF headers, by which some duplicated and
redundant codes are removed.

Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Lisa Mitchell <lisa.mitchell@hp.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:30 -07:00
Pavel Emelyanov 541c237c09 pagemap: prepare to reuse constant bits with page-shift
In order to reuse bits from pagemap entries gracefully, we leave the
entries as is but on pagemap open emit a warning in dmesg, that bits
55-60 are about to change in a couple of releases.  Next, if a user
issues soft-dirty clear command via the clear_refs file (it was disabled
before v3.9) we assume that he's aware of the new pagemap format, note
that fact and report the bits in pagemap in the new manner.

The "migration strategy" looks like this then:

1. existing users are not affected -- they don't touch soft-dirty feature, thus
   see old bits in pagemap, but are warned and have time to fix themselves
2. those who use soft-dirty know about new pagemap format
3. some time soon we get rid of any signs of page-shift in pagemap as well as
   this trick with clear-soft-dirty affecting pagemap format.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:26 -07:00
Pavel Emelyanov 0f8975ec4d mm: soft-dirty bits for user memory changes tracking
The soft-dirty is a bit on a PTE which helps to track which pages a task
writes to.  In order to do this tracking one should

  1. Clear soft-dirty bits from PTEs ("echo 4 > /proc/PID/clear_refs)
  2. Wait some time.
  3. Read soft-dirty bits (55'th in /proc/PID/pagemap2 entries)

To do this tracking, the writable bit is cleared from PTEs when the
soft-dirty bit is.  Thus, after this, when the task tries to modify a
page at some virtual address the #PF occurs and the kernel sets the
soft-dirty bit on the respective PTE.

Note, that although all the task's address space is marked as r/o after
the soft-dirty bits clear, the #PF-s that occur after that are processed
fast.  This is so, since the pages are still mapped to physical memory,
and thus all the kernel does is finds this fact out and puts back
writable, dirty and soft-dirty bits on the PTE.

Another thing to note, is that when mremap moves PTEs they are marked
with soft-dirty as well, since from the user perspective mremap modifies
the virtual memory at mremap's new address.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:26 -07:00
Pavel Emelyanov 2b0a9f0175 pagemap: introduce pagemap_entry_t without pmshift bits
These bits are always constant (== PAGE_SHIFT) and just occupy space in
the entry.  Moreover, in next patch we will need to report one more bit
in the pagemap, but all bits are already busy on it.

That said, describe the pagemap entry that has 6 more free zero bits.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:25 -07:00
Pavel Emelyanov af9de7eb18 clear_refs: introduce private struct for mm_walk
In the next patch the clear-refs-type will be required in
clear_refs_pte_range funciton, so prepare the walk->private to carry
this info.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:25 -07:00
Pavel Emelyanov 040fa02077 clear_refs: sanitize accepted commands declaration
This is the implementation of the soft-dirty bit concept that should
help keep track of changes in user memory, which in turn is very-very
required by the checkpoint-restore project (http://criu.org).

To create a dump of an application(s) we save all the information about
it to files, and the biggest part of such dump is the contents of tasks'
memory.  However, there are usage scenarios where it's not required to
get _all_ the task memory while creating a dump.  For example, when
doing periodical dumps, it's only required to take full memory dump only
at the first step and then take incremental changes of memory.  Another
example is live migration.  We copy all the memory to the destination
node without stopping all tasks, then stop them, check for what pages
has changed, dump it and the rest of the state, then copy it to the
destination node.  This decreases freeze time significantly.

That said, some help from kernel to watch how processes modify the
contents of their memory is required.

The proposal is to track changes with the help of new soft-dirty bit
this way:

1. First do "echo 4 > /proc/$pid/clear_refs".
   At that point kernel clears the soft dirty _and_ the writable bits from all
   ptes of process $pid. From now on every write to any page will result in #pf
   and the subsequent call to pte_mkdirty/pmd_mkdirty, which in turn will set
   the soft dirty flag.

2. Then read the /proc/$pid/pagemap2 and check the soft-dirty bit reported there
   (the 55'th one). If set, the respective pte was written to since last call
   to clear refs.

The soft-dirty bit is the _PAGE_BIT_HIDDEN one.  Although it's used by
kmemcheck, the latter one marks kernel pages with it, while the former
bit is put on user pages so they do not conflict to each other.

This patch:

A new clear-refs type will be added in the next patch, so prepare
code for that.

[akpm@linux-foundation.org: don't assume that sizeof(enum clear_refs_types) == sizeof(int)]
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:25 -07:00
Linus Torvalds da53be12bb Don't pass inode to ->d_hash() and ->d_compare()
Instances either don't look at it at all (the majority of cases) or
only want it to find the superblock (which can be had as dentry->d_sb).
A few cases that want more are actually safe with dentry->d_inode -
the only precaution needed is the check that it hadn't been replaced with
NULL by rmdir() or by overwriting rename(), which case should be simply
treated as cache miss.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:36 +04:00
Al Viro 1df98b8bbc proc_fill_cache(): clean up, get rid of pointless find_inode_number() use
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:19 +04:00
Al Viro c52a47ace7 proc_fill_cache(): just make instantiate_t return int
all instances always return ERR_PTR(-E...) or NULL, anyway

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:18 +04:00
Al Viro db96316487 proc_pid_readdir(): stop wanking with proc_fill_cache() for /proc/self
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:17 +04:00
Al Viro 147ce69974 proc_fill_cache(): kill pointless check
we'd just checked that child->d_inode is non-NULL, for fuck sake!

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:16 +04:00
Al Viro f0c3b5093a [readdir] convert procfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:56:32 +04:00
Kees Cook 637241a900 kmsg: honor dmesg_restrict sysctl on /dev/kmsg
The dmesg_restrict sysctl currently covers the syslog method for access
dmesg, however /dev/kmsg isn't covered by the same protections.  Most
people haven't noticed because util-linux dmesg(1) defaults to using the
syslog method for access in older versions.  With util-linux dmesg(1)
defaults to reading directly from /dev/kmsg.

To fix /dev/kmsg, let's compare the existing interfaces and what they
allow:

 - /proc/kmsg allows:
  - open (SYSLOG_ACTION_OPEN) if CAP_SYSLOG since it uses a destructive
    single-reader interface (SYSLOG_ACTION_READ).
  - everything, after an open.

 - syslog syscall allows:
  - anything, if CAP_SYSLOG.
  - SYSLOG_ACTION_READ_ALL and SYSLOG_ACTION_SIZE_BUFFER, if
    dmesg_restrict==0.
  - nothing else (EPERM).

The use-cases were:
 - dmesg(1) needs to do non-destructive SYSLOG_ACTION_READ_ALLs.
 - sysklog(1) needs to open /proc/kmsg, drop privs, and still issue the
   destructive SYSLOG_ACTION_READs.

AIUI, dmesg(1) is moving to /dev/kmsg, and systemd-journald doesn't
clear the ring buffer.

Based on the comments in devkmsg_llseek, it sounds like actions besides
reading aren't going to be supported by /dev/kmsg (i.e.
SYSLOG_ACTION_CLEAR), so we have a strict subset of the non-destructive
syslog syscall actions.

To this end, move the check as Josh had done, but also rename the
constants to reflect their new uses (SYSLOG_FROM_CALL becomes
SYSLOG_FROM_READER, and SYSLOG_FROM_FILE becomes SYSLOG_FROM_PROC).
SYSLOG_FROM_READER allows non-destructive actions, and SYSLOG_FROM_PROC
allows destructive actions after a capabilities-constrained
SYSLOG_ACTION_OPEN check.

 - /dev/kmsg allows:
  - open if CAP_SYSLOG or dmesg_restrict==0
  - reading/polling, after open

Addresses https://bugzilla.redhat.com/show_bug.cgi?id=903192

[akpm@linux-foundation.org: use pr_warn_once()]
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Christian Kujau <lists@nerdbynature.de>
Tested-by: Josh Boyer <jwboyer@redhat.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-06-12 16:29:44 -07:00
Pavel Tikhomirov 15ef0298de posix-timers: Show clock ID in proc file
Expand information about posix-timers in /proc/<pid>/timers by adding
info about clock, with which the timer was created. I.e. in the forth
line of timer info after "notify:" line go "ClockID: <clock_id>".

Signed-off-by: Pavel Tikhomirov <snorcht@gmail.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Link: http://lkml.kernel.org/r/1368742323-46949-2-git-send-email-snorcht@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-05-28 11:41:14 +02:00
Linus Torvalds 0f47c9423c Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux
Pull slab changes from Pekka Enberg:
 "The bulk of the changes are more slab unification from Christoph.

  There's also few fixes from Aaron, Glauber, and Joonsoo thrown into
  the mix."

* 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux: (24 commits)
  mm, slab_common: Fix bootstrap creation of kmalloc caches
  slab: Return NULL for oversized allocations
  mm: slab: Verify the nodeid passed to ____cache_alloc_node
  slub: tid must be retrieved from the percpu area of the current processor
  slub: Do not dereference NULL pointer in node_match
  slub: add 'likely' macro to inc_slabs_node()
  slub: correct to calculate num of acquired objects in get_partial_node()
  slub: correctly bootstrap boot caches
  mm/sl[au]b: correct allocation type check in kmalloc_slab()
  slab: Fixup CONFIG_PAGE_ALLOC/DEBUG_SLAB_LEAK sections
  slab: Handle ARCH_DMA_MINALIGN correctly
  slab: Common definition for kmem_cache_node
  slab: Rename list3/l3 to node
  slab: Common Kmalloc cache determination
  stat: Use size_t for sizes instead of unsigned
  slab: Common function to create the kmalloc array
  slab: Common definition for the array of kmalloc caches
  slab: Common constants for kmalloc boundaries
  slab: Rename nodelists to node
  slab: Common name for the per node structures
  ...
2013-05-07 08:42:20 -07:00
Pekka Enberg 69df2ac128 Merge branch 'slab/next' into slab/for-linus 2013-05-07 09:19:47 +03:00
Syam Sidhardhan 75fc0cf6af proc_devtree: Replace include linux/module.h with linux/export.h
Since it uses only THIS_MODULE macro, include <linux/export.h>
is the right to go here.

Signed-off-by: Syam Sidhardhan <s.syam@samsung.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-04 15:31:01 -04:00
Linus Torvalds 20b4fb4852 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS updates from Al Viro,

Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).

7kloc removed.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
  don't bother with deferred freeing of fdtables
  proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
  proc: Make the PROC_I() and PDE() macros internal to procfs
  proc: Supply a function to remove a proc entry by PDE
  take cgroup_open() and cpuset_open() to fs/proc/base.c
  ppc: Clean up scanlog
  ppc: Clean up rtas_flash driver somewhat
  hostap: proc: Use remove_proc_subtree()
  drm: proc: Use remove_proc_subtree()
  drm: proc: Use minor->index to label things, not PDE->name
  drm: Constify drm_proc_list[]
  zoran: Don't print proc_dir_entry data in debug
  reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
  proc: Supply an accessor for getting the data from a PDE's parent
  airo: Use remove_proc_subtree()
  rtl8192u: Don't need to save device proc dir PDE
  rtl8187se: Use a dir under /proc/net/r8180/
  proc: Add proc_mkdir_data()
  proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
  proc: Move PDE_NET() to fs/proc/proc_net.c
  ...
2013-05-01 17:51:54 -07:00
David Howells 59d8053f1e proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
Move non-public declarations and definitions from linux/proc_fs.h to
fs/proc/internal.h.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:47 -04:00
David Howells c30480b92c proc: Make the PROC_I() and PDE() macros internal to procfs
Make the PROC_I() and PDE() macros internal to procfs.  This means making
PDE_DATA() out of line.  This could be made more optimal by storing
PDE()->data into inode->i_private.

Also provide a __PDE_DATA() that is inline and internal to procfs.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:47 -04:00
David Howells a8ca16ea7b proc: Supply a function to remove a proc entry by PDE
Supply a function (proc_remove()) to remove a proc entry (and any subtree
rooted there) by proc_dir_entry pointer rather than by name and (optionally)
root dir entry pointer.  This allows us to eliminate all remaining pde->name
accesses outside of procfs.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Grant Likely <grant.likely@linaro.or>
cc: linux-acpi@vger.kernel.org
cc: openipmi-developer@lists.sourceforge.net
cc: devicetree-discuss@lists.ozlabs.org
cc: linux-pci@vger.kernel.org
cc: netdev@vger.kernel.org
cc: netfilter-devel@vger.kernel.org
cc: alsa-devel@alsa-project.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:46 -04:00
Al Viro 8d8b97ba49 take cgroup_open() and cpuset_open() to fs/proc/base.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:46 -04:00
David Howells 4a520d2769 proc: Supply an accessor for getting the data from a PDE's parent
Supply an accessor function for getting the private data from the parent
proc_dir_entry struct of the proc_dir_entry struct associated with an inode.

ReiserFS, for instance, stores the super_block pointer in the proc directory
it makes for that super_block, and a pointer to the respective seq_file show
function in each of the proc files in that directory.

This allows a reduction in the number of file_operations structs, open
functions and seq_operations structs required.  The problem otherwise is that
each show function requires two pieces of data but only has storage for one
per PDE (and this has no release function).

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Jerry Chuang <jerry-chuang@realtek.com>
cc: Maxim Mikityanskiy <maxtram95@gmail.com>
cc: YAMANE Toshiaki <yamanetoshi@gmail.com>
cc: linux-wireless@vger.kernel.org
cc: linux-scsi@vger.kernel.org
cc: devel@driverdev.osuosl.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:42 -04:00
David Howells 270b5ac215 proc: Add proc_mkdir_data()
Add proc_mkdir_data() to allow procfs directories to be created that are
annotated at the time of creation with private data rather than doing this
post-creation.  This means no access is then required to the proc_dir_entry
struct to set this.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Neela Syam Kolli <megaraidlinux@lsi.com>
cc: Jerry Chuang <jerry-chuang@realtek.com>
cc: linux-scsi@vger.kernel.org
cc: devel@driverdev.osuosl.org
cc: linux-wireless@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:41 -04:00
David Howells 34db8aaf0f proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
Move some bits from linux/proc_fs.h to linux/of.h, signal.h and tty.h.

Also move proc_tty_init() and proc_device_tree_init() to fs/proc/internal.h as
they're internal to procfs.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
cc: devicetree-discuss@lists.ozlabs.org
cc: linux-arch@vger.kernel.org
cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Jri Slaby <jslaby@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:40 -04:00
David Howells 4abfd02989 proc: Move PDE_NET() to fs/proc/proc_net.c
Move PDE_NET() to fs/proc/proc_net.c as that's where the only user is.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:40 -04:00
David Howells 0bb80f2405 proc: Split the namespace stuff out into linux/proc_ns.h
Split the proc namespace stuff out into linux/proc_ns.h.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: netdev@vger.kernel.org
cc: Serge E. Hallyn <serge.hallyn@ubuntu.com>
cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:39 -04:00
David Howells c3bef7bcaa proc: Move proc_fd() to fs/proc/fd.h
Move proc_fd() to fs/proc/fd.h.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:39 -04:00
David Howells 1dd704b617 proc: Uninline pid_delete_dentry()
Uninline pid_delete_dentry() as it's only used by three function pointers.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:39 -04:00
David Howells 271a15eabe proc: Supply PDE attribute setting accessor functions
Supply accessor functions to set attributes in proc_dir_entry structs.

The following are supplied: proc_set_size() and proc_set_user().

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
cc: linuxppc-dev@lists.ozlabs.org
cc: linux-media@vger.kernel.org
cc: netdev@vger.kernel.org
cc: linux-wireless@vger.kernel.org
cc: linux-pci@vger.kernel.org
cc: netfilter-devel@vger.kernel.org
cc: alsa-devel@alsa-project.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:18 -04:00
David Rientjes 830e0fc967 fs, proc: truncate /proc/pid/comm writes to first TASK_COMM_LEN bytes
Currently, a write to a procfs file will return the number of bytes
successfully written.  If the actual string is longer than this, the
remainder of the string will not be be written and userspace will
complete the operation by issuing additional write()s.

Hence

	$ echo -n "abcdefghijklmnopqrs" > /proc/self/comm

results in

	$ cat /proc/$$/comm
	pqrs

since the final four bytes were written with a second write() since
TASK_COMM_LEN == 16.  This is obviously an undesired result and not
equivalent to prctl(PR_SET_NAME).  The implementation should not need to
know the definition of TASK_COMM_LEN.

This patch truncates the string to the first TASK_COMM_LEN bytes and
returns the bytes written as the length of the string written so the
second write() is suppressed.

	$ cat /proc/$$/comm
	abcdefghijklmno

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:07 -07:00
Linus Torvalds ab86e974f0 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core timer updates from Ingo Molnar:
 "The main changes in this cycle's merge are:

   - Implement shadow timekeeper to shorten in kernel reader side
     blocking, by Thomas Gleixner.

   - Posix timers enhancements by Pavel Emelyanov:

   - allocate timer ID per process, so that exact timer ID allocations
     can be re-created be checkpoint/restore code.

   - debuggability and tooling (/proc/PID/timers, etc.) improvements.

   - suspend/resume enhancements by Feng Tang: on certain new Intel Atom
     processors (Penwell and Cloverview), there is a feature that the
     TSC won't stop in S3 state, so the TSC value won't be reset to 0
     after resume.  This can be taken advantage of by the generic via
     the CLOCK_SOURCE_SUSPEND_NONSTOP flag: instead of using the RTC to
     recover/approximate sleep time, the main (and precise) clocksource
     can be used.

   - Fix /proc/timer_list for 4096 CPUs by Nathan Zimmer: on so many
     CPUs the file goes beyond 4MB of size and thus the current
     simplistic seqfile approach fails.  Convert /proc/timer_list to a
     proper seq_file with its own iterator.

   - Cleanups and refactorings of the core timekeeping code by John
     Stultz.

   - International Atomic Clock time is managed by the NTP code
     internally currently but not exposed externally.  Separate the TAI
     code out and add CLOCK_TAI support and TAI support to the hrtimer
     and posix-timer code, by John Stultz.

   - Add deep idle support enhacement to the broadcast clockevents core
     timer code, by Daniel Lezcano: add an opt-in CLOCK_EVT_FEAT_DYNIRQ
     clockevents feature (which will be utilized by future clockevents
     driver updates), which allows the use of IRQ affinities to avoid
     spurious wakeups of idle CPUs - the right CPU with an expiring
     timer will be woken.

   - Add new ARM bcm281xx clocksource driver, by Christian Daudt

   - ... various other fixes and cleanups"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  clockevents: Set dummy handler on CPU_DEAD shutdown
  timekeeping: Update tk->cycle_last in resume
  posix-timers: Remove unused variable
  clockevents: Switch into oneshot mode even if broadcast registered late
  timer_list: Convert timer list to be a proper seq_file
  timer_list: Split timer_list_show_tickdevices
  posix-timers: Show sigevent info in proc file
  posix-timers: Introduce /proc/PID/timers file
  posix timers: Allocate timer id per process (v2)
  timekeeping: Make sure to notify hrtimers when TAI offset changes
  hrtimer: Fix ktime_add_ns() overflow on 32bit architectures
  hrtimer: Add expiry time overflow check in hrtimer_interrupt
  timekeeping: Shorten seq_count region
  timekeeping: Implement a shadow timekeeper
  timekeeping: Delay update of clock->cycle_last
  timekeeping: Store cycle_last value in timekeeper struct as well
  ntp: Remove ntp_lock, using the timekeeping locks to protect ntp state
  timekeeping: Simplify tai updating from do_adjtimex
  timekeeping: Hold timekeepering locks in do_adjtimex and hardpps
  timekeeping: Move ADJ_SETOFFSET to top level do_adjtimex()
  ...
2013-04-30 08:15:40 -07:00
Andrew Morton 3c743a7f7b fs/proc/kcore.c: use register_hotmemory_notifier()
Saves an ifdef, no code size changes

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:36 -07:00
Joonsoo Kim db3808c1ba mm, vmalloc: move get_vmalloc_info() to vmalloc.c
Now get_vmalloc_info() is in fs/proc/mmu.c.  There is no reason that this
code must be here and it's implementation needs vmlist_lock and it iterate
a vmlist which may be internal data structure for vmalloc.

It is preferable that vmlist_lock and vmlist is only used in vmalloc.c
for maintainability. So move the code to vmalloc.c

Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Dave Anderson <anderson@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:33 -07:00
David Howells 2f96b8c1d5 proc: Split kcore bits from linux/procfs.h into linux/kcore.h
Split kcore bits from linux/procfs.h into linux/kcore.h.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
cc: linux-mips@linux-mips.org
cc: sparclinux@vger.kernel.org
cc: x86@kernel.org
cc: linux-mm@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-29 15:42:02 -04:00
David Howells 303eb7e2c9 Include missing linux/magic.h inclusions
Include missing linux/magic.h inclusions where the source file is currently
expecting to get magic numbers through linux/proc_fs.h.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-efi@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-29 15:42:01 -04:00
David Howells 0d01ff2583 Include missing linux/slab.h inclusions
Include missing linux/slab.h inclusions where the source file is currently
expecting to get kmalloc() and co. through linux/proc_fs.h.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: linux-s390@vger.kernel.org
cc: sparclinux@vger.kernel.org
cc: linux-efi@vger.kernel.org
cc: linux-mtd@lists.infradead.org
cc: devel@driverdev.osuosl.org
cc: x86@kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-29 15:42:01 -04:00
David Howells 3cb5bf1bf9 proc: Delete create_proc_read_entry()
Delete create_proc_read_entry() as it no longer has any users.

Also delete read_proc_t, write_proc_t, the read_proc member of the
proc_dir_entry struct and the support functions that use them.  This saves a
pointer for every PDE allocated.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-29 15:42:00 -04:00
Thomas Gleixner 6402c7dc2a Merge branch 'linus' into timers/core
Reason: Get upstream fixes before adding conflicting code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-24 20:33:54 +02:00
Pavel Emelyanov 57b8015e07 posix-timers: Show sigevent info in proc file
Previous patch added proc file to list posix timers created by task.
Expand the information provided in this file by adding info about
notification method, with which timers were created. I.e. after
the "ID:" line there go

1. "signal:" line, that shows signal number and sigval bits;
2. "notify:" line, that shows the timer notification method.

Thus the timer entry would looke like this:

ID: 123
signal: 14/0000000000b005d0
notify: signal/pid.732

This information is enough to understand how timer_create() was called
for each particular timer.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Link: http://lkml.kernel.org/r/513DA024.80404@parallels.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-17 20:51:01 +02:00
Pavel Emelyanov 48f6a7a511 posix-timers: Introduce /proc/PID/timers file
Currently kernel doesn't provide any API for getting info about what
posix timers are configured by processes. It's implied, that a process
which configured some timers, knows what it did. However, for external
tools it's impossible to get this information. In particular, this is
critical for checkpoint-restore project to have this info.

Introduce a per-pid proc file with information about posix
timers. Since these timers are shared between threads, this file is
present on tgid level only, no such thing in tid subdirs.

The file format is expected to be the "/proc/<pid>/smaps"-like,
i.e. each timer will occupy seveal lines to allow for future
extending.

Each new timer entry starts with the

ID: <number>

line which is added by this patch.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Link: http://lkml.kernel.org/r/513DA00D.6070009@parallels.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-17 20:51:01 +02:00
Thomas Gleixner f2530dc71c kthread: Prevent unpark race which puts threads on the wrong cpu
The smpboot threads rely on the park/unpark mechanism which binds per
cpu threads on a particular core. Though the functionality is racy:

CPU0	       	 	CPU1  	     	    CPU2
unpark(T)				    wake_up_process(T)
  clear(SHOULD_PARK)	T runs
			leave parkme() due to !SHOULD_PARK  
  bind_to(CPU2)		BUG_ON(wrong CPU)						    

We cannot let the tasks move themself to the target CPU as one of
those tasks is actually the migration thread itself, which requires
that it starts running on the target cpu right away.

The solution to this problem is to prevent wakeups in park mode which
are not from unpark(). That way we can guarantee that the association
of the task to the target cpu is working correctly.

Add a new task state (TASK_PARKED) which prevents other wakeups and
use this state explicitly for the unpark wakeup.

Peter noticed: Also, since the task state is visible to userspace and
all the parked tasks are still in the PID space, its a good hint in ps
and friends that these tasks aren't really there for the moment.

The migration thread has another related issue.

CPU0	      	     	 CPU1
Bring up CPU2
create_thread(T)
park(T)
 wait_for_completion()
			 parkme()
			 complete()
sched_set_stop_task()
			 schedule(TASK_PARKED)

The sched_set_stop_task() call is issued while the task is on the
runqueue of CPU1 and that confuses the hell out of the stop_task class
on that cpu. So we need the same synchronizaion before
sched_set_stop_task().

Reported-by: Dave Jones <davej@redhat.com>
Reported-and-tested-by: Dave Hansen <dave@sr71.net>
Reported-and-tested-by: Borislav Petkov <bp@alien8.de>
Acked-by: Peter Ziljstra <peterz@infradead.org>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: dhillf@gmail.com
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1304091635430.21884@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-12 14:18:43 +02:00
Linus Torvalds e8f2b548de Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "A nasty bug in fs/namespace.c caught by Andrey + a couple of less
  serious unpleasantness - ecryptfs misc device playing hopeless games
  with try_module_get() and palinfo procfs support being...  not quite
  correctly done, to be polite."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  mnt: release locks on error path in do_loopback
  palinfo fixes
  procfs: add proc_remove_subtree()
  ecryptfs: close rmmod race
2013-04-09 12:22:49 -07:00
Al Viro 05c0ae21c0 try a saner locking for pde_opener...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 15:16:52 -04:00
Al Viro ca469f35a8 deal with races between remove_proc_entry() and proc_reg_release()
* serialize the call of ->release() on per-pdeo mutex
* don't remove pdeo from per-pde list until we are through with it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 15:16:51 -04:00
Al Viro 866ad9a747 procfs: preparations for remove_proc_entry() race fixes
* leave ->proc_fops alone; make ->pde_users negative instead
* trim pde_opener
* move relevant code in fs/proc/inode.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 15:16:51 -04:00
David Howells ad147d011f procfs: Clean up huge if-statement in __proc_file_read()
Switch huge if-statement in __proc_file_read() around.  This then puts the
single line loop break immediately after the if-statement and allows us to
de-indent the huge comment and make it take fewer lines.  The code following
the if-statement then follows naturally from the call to dp->read_proc().

Signed-off-by: David Howells <dhowells@redhat.com>
2013-04-09 15:16:50 -04:00
David Howells 80e928f7eb proc: Kill create_proc_entry()
Kill create_proc_entry() in favour of create_proc_read_entry(), proc_create()
and proc_create_data().

Signed-off-by: David Howells <dhowells@redhat.com>
2013-04-09 14:16:39 -04:00
Al Viro d9dda78bad procfs: new helper - PDE_DATA(inode)
The only part of proc_dir_entry the code outside of fs/proc
really cares about is PDE(inode)->data.  Provide a helper
for that; static inline for now, eventually will be moved
to fs/proc, along with the knowledge of struct proc_dir_entry
layout.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:13:32 -04:00
Al Viro ee21ed0afc procfs: kill ->write_proc()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:13:32 -04:00
Al Viro b6cdc73103 procfs: don't allow to use proc_create, create_proc_entry, etc. for directories
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:13:14 -04:00
Al Viro 021ada7dff procfs: switch /proc/self away from proc_dir_entry
Just have it pinned in dcache all along and let procfs ->kill_sb()
drop it before kill_anon_super().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:13:05 -04:00
Al Viro 0ecc833bac mode_t, whack-a-mole at 11...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:13:05 -04:00
Al Viro 8ce584c741 procfs: add proc_remove_subtree()
just what it sounds like; do that only to procfs subtrees you've
created - doing that to something shared with another driver is
not only antisocial, but might cause interesting races with
proc_create() and its ilk.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:09:17 -04:00
Linus Torvalds 2c3de1c2d7 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull userns fixes from Eric W Biederman:
 "The bulk of the changes are fixing the worst consequences of the user
  namespace design oversight in not considering what happens when one
  namespace starts off as a clone of another namespace, as happens with
  the mount namespace.

  The rest of the changes are just plain bug fixes.

  Many thanks to Andy Lutomirski for pointing out many of these issues."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  userns: Restrict when proc and sysfs can be mounted
  ipc: Restrict mounting the mqueue filesystem
  vfs: Carefully propogate mounts across user namespaces
  vfs: Add a mount flag to lock read only bind mounts
  userns:  Don't allow creation if the user is chrooted
  yama:  Better permission check for ptraceme
  pid: Handle the exit of a multi-threaded init.
  scm: Require CAP_SYS_ADMIN over the current pidns to spoof pids.
2013-03-28 13:43:46 -07:00
Eric W. Biederman 87a8ebd637 userns: Restrict when proc and sysfs can be mounted
Only allow unprivileged mounts of proc and sysfs if they are already
mounted when the user namespace is created.

proc and sysfs are interesting because they have content that is
per namespace, and so fresh mounts are needed when new namespaces
are created while at the same time proc and sysfs have content that
is shared between every instance.

Respect the policy of who may see the shared content of proc and sysfs
by only allowing new mounts if there was an existing mount at the time
the user namespace was created.

In practice there are only two interesting cases: proc and sysfs are
mounted at their usual places, proc and sysfs are not mounted at all
(some form of mount namespace jail).

Cc: stable@vger.kernel.org
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-27 07:50:08 -07:00
Linus Torvalds 51f0885e54 vfs,proc: guarantee unique inodes in /proc
Dave Jones found another /proc issue with his Trinity tool: thanks to
the namespace model, we can have multiple /proc dentries that point to
the same inode, aliasing directories in /proc/<pid>/net/ for example.

This ends up being a total disaster, because it acts like hardlinked
directories, and causes locking problems.  We rely on the topological
sort of the inodes pointed to by dentries, and if we have aliased
directories, that odering becomes unreliable.

In short: don't do this.  Multiple dentries with the same (directory)
inode is just a bad idea, and the namespace code should never have
exposed things this way.  But we're kind of stuck with it.

This solves things by just always allocating a new inode during /proc
dentry lookup, instead of using "iget_locked()" to look up existing
inodes by superblock and number.  That actually simplies the code a bit,
at the cost of potentially doing more inode [de]allocations.

That said, the inode lookup wasn't free either (and did a lot of locking
of inodes), so it is probably not that noticeable.  We could easily keep
the old lookup model for non-directory entries, but rather than try to
be excessively clever this just implements the minimal and simplest
workaround for the problem.

Reported-and-tested-by: Dave Jones <davej@redhat.com>
Analyzed-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-22 11:44:04 -07:00
Eric W. Biederman db04dc679b proc: Use nd_jump_link in proc_ns_follow_link
Update proc_ns_follow_link to use nd_jump_link instead of just
manually updating nd.path.dentry.

This fixes the BUG_ON(nd->inode != parent->d_inode) reported by Dave
Jones and reproduced trivially with mkdir /proc/self/ns/uts/a.

Sigh it looks like the VFS change to require use of nd_jump_link
happend while proc_ns_follow_link was baking and since the common case
of proc_ns_follow_link continued to work without problems the need for
making this change was overlooked.

Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-09 00:14:45 -08:00
Zhang Yanfei c2c1b089b4 fs/proc/vmcore.c: put if tests in the top of the while loop to reduce duplication
In read_vmcore() two `if' tests are duplicated.  Change the position of
them could reduce the duplication.  This change does not affect the
behaviour of the function.

[akpm@linux-foundation.org: avoid `if (foo = bar)' thing, use min_t()]
[akpm@linux-foundation.org: s/max_t/min_t/]
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:11 -08:00
Andrew Morton 87ebdc00ee fs/proc: clean up printks
- use pr_foo() throughout

- remove a couple of duplicated KERN_WARNINGs, via WARN(KERN_WARNING "...")

- nuke a few warnings which I've never seen happen, ever.

Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:11 -08:00
Kees Cook e579d2c259 coredump: remove redundant defines for dumpable states
The existing SUID_DUMP_* defines duplicate the newer SUID_DUMPABLE_*
defines introduced in 54b501992d ("coredump: warn about unsafe
suid_dumpable / core_pattern combo").  Remove the new ones, and use the
prior values instead.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Chen Gang <gang.chen@asianux.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@linux.intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: James Morris <james.l.morris@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:11 -08:00
Linus Torvalds d895cb1af1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile (part one) from Al Viro:
 "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
  locking violations, etc.

  The most visible changes here are death of FS_REVAL_DOT (replaced with
  "has ->d_weak_revalidate()") and a new helper getting from struct file
  to inode.  Some bits of preparation to xattr method interface changes.

  Misc patches by various people sent this cycle *and* ocfs2 fixes from
  several cycles ago that should've been upstream right then.

  PS: the next vfs pile will be xattr stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  saner proc_get_inode() calling conventions
  proc: avoid extra pde_put() in proc_fill_super()
  fs: change return values from -EACCES to -EPERM
  fs/exec.c: make bprm_mm_init() static
  ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
  ocfs2: fix possible use-after-free with AIO
  ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
  get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
  target: writev() on single-element vector is pointless
  export kernel_write(), convert open-coded instances
  fs: encode_fh: return FILEID_INVALID if invalid fid_type
  kill f_vfsmnt
  vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
  nfsd: handle vfs_getattr errors in acl protocol
  switch vfs_getattr() to struct path
  default SET_PERSONALITY() in linux/elf.h
  ceph: prepopulate inodes only when request is aborted
  d_hash_and_lookup(): export, switch open-coded instances
  9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
  9p: split dropping the acls from v9fs_set_create_acl()
  ...
2013-02-26 20:16:07 -08:00
Al Viro d3d009cb96 saner proc_get_inode() calling conventions
Make it drop the pde in *all* cases when no new reference to it is
put into an inode - both when an inode had already been set up
(as we were already doing) and when inode allocation has failed.
Makes for simpler logics in callers...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-26 02:46:14 -05:00
Maxim Patlasov 87e0aab37f proc: avoid extra pde_put() in proc_fill_super()
If proc_get_inode() succeeded, but d_make_root() failed, pde_put() for
proc_root will be called twice: the first time due to iput() called from
d_make_root() and the second time directly in the end of
proc_fill_super().

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-26 02:46:14 -05:00
Zhao Hongjiang 4173581876 fs: change return values from -EACCES to -EPERM
According to SUSv3:

[EACCES] Permission denied. An attempt was made to access a file in a way
forbidden by its file access permissions.

[EPERM] Operation not permitted. An attempt was made to perform an operation
limited to processes with appropriate privileges or to the owner of a file
or other resource.

So -EPERM should be returned if capability checks fails.

Strictly speaking this is an API change since the error code user sees is
altered.

Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-26 02:46:14 -05:00
Al Viro 4f522a247b d_hash_and_lookup(): export, switch open-coded instances
* calling conventions change - ERR_PTR() is returned on ->d_hash() errors;
NULL is just for dcache miss now.
* exported, open-coded instances in ncpfs and cifs converted.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-26 02:46:07 -05:00
Shaohua Li 33806f06da swap: make each swap partition have one address_space
When I use several fast SSD to do swap, swapper_space.tree_lock is
heavily contended.  This makes each swap partition have one
address_space to reduce the lock contention.  There is an array of
address_space for swap.  The swap entry type is the index to the array.

In my test with 3 SSD, this increases the swapout throughput 20%.

[akpm@linux-foundation.org: revert unneeded change to  __add_to_swap_cache]
Signed-off-by: Shaohua Li <shli@fusionio.com>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23 17:50:17 -08:00
Xishi Qiu 293c07e31a memory-failure: use num_poisoned_pages instead of mce_bad_pages
Since MCE is an x86 concept, and this code is in mm/, it would be better
to use the name num_poisoned_pages instead of mce_bad_pages.

[akpm@linux-foundation.org: fix mm/sparse.c]
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Suggested-by: Borislav Petkov <bp@alien8.de>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23 17:50:15 -08:00
Al Viro 496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Linus Torvalds 21eaab6d19 tty/serial patches for 3.9-rc1
Here's the big tty/serial driver patches for 3.9-rc1.
 
 More tty port rework and fixes from Jiri here, as well as lots of
 individual serial driver updates and fixes.
 
 All of these have been in the linux-next tree for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial patches from Greg Kroah-Hartman:
 "Here's the big tty/serial driver patches for 3.9-rc1.

  More tty port rework and fixes from Jiri here, as well as lots of
  individual serial driver updates and fixes.

  All of these have been in the linux-next tree for a while."

* tag 'tty-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (140 commits)
  tty: mxser: improve error handling in mxser_probe() and mxser_module_init()
  serial: imx: fix uninitialized variable warning
  serial: tegra: assume CONFIG_OF
  TTY: do not update atime/mtime on read/write
  lguest: select CONFIG_TTY to build properly.
  ARM defconfigs: add missing inclusions of linux/platform_device.h
  fb/exynos: include platform_device.h
  ARM: sa1100/assabet: include platform_device.h directly
  serial: imx: Fix recursive locking bug
  pps: Fix build breakage from decoupling pps from tty
  tty: Remove ancient hardpps()
  pps: Additional cleanups in uart_handle_dcd_change
  pps: Move timestamp read into PPS code proper
  pps: Don't crash the machine when exiting will do
  pps: Fix a use-after free bug when unregistering a source.
  pps: Use pps_lookup_dev to reduce ldisc coupling
  pps: Add pps_lookup_dev() function
  tty: serial: uartlite: Support uartlite on big and little endian systems
  tty: serial: uartlite: Fix sparse and checkpatch warnings
  serial/arc-uart: Miscll DT related updates (Grant's review comments)
  ...

Fix up trivial conflicts, mostly just due to the TTY config option
clashing with the EXPERIMENTAL removal.
2013-02-21 13:41:04 -08:00
Linus Torvalds a0b1c42951 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking update from David Miller:

 1) Checkpoint/restarted TCP sockets now can properly propagate the TCP
    timestamp offset.  From Andrey Vagin.

 2) VMWARE VM VSOCK layer, from Andy King.

 3) Much improved support for virtual functions and SR-IOV in bnx2x,
    from Ariel ELior.

 4) All protocols on ipv4 and ipv6 are now network namespace aware, and
    all the compatability checks for initial-namespace-only protocols is
    removed.  Thanks to Tom Parkin for helping deal with the last major
    holdout, L2TP.

 5) IPV6 support in netpoll and network namespace support in pktgen,
    from Cong Wang.

 6) Multiple Registration Protocol (MRP) and Multiple VLAN Registration
    Protocol (MVRP) support, from David Ward.

 7) Compute packet lengths more accurately in the packet scheduler, from
    Eric Dumazet.

 8) Use per-task page fragment allocator in skb_append_datato_frags(),
    also from Eric Dumazet.

 9) Add support for connection tracking labels in netfilter, from
    Florian Westphal.

10) Fix default multicast group joining on ipv6, and add anti-spoofing
    checks to 6to4 and 6rd.  From Hannes Frederic Sowa.

11) Make ipv4/ipv6 fragmentation memory limits more reasonable in modern
    times, rearrange inet frag datastructures for better cacheline
    locality, and move more operations outside of locking.  From Jesper
    Dangaard Brouer.

12) Instead of strict master <--> slave relationships, allow arbitrary
    scenerios with "upper device lists".  From Jiri Pirko.

13) Improve rate limiting accuracy in TBF and act_police, also from Jiri
    Pirko.

14) Add a BPF filter netfilter match target, from Willem de Bruijn.

15) Orphan and delete a bunch of pre-historic networking drivers from
    Paul Gortmaker.

16) Add TSO support for GRE tunnels, from Pravin B SHelar.  Although
    this still needs some minor bug fixing before it's %100 correct in
    all cases.

17) Handle unresolved IPSEC states like ARP, with a resolution packet
    queue.  From Steffen Klassert.

18) Remove TCP Appropriate Byte Count support (ABC), from Stephen
    Hemminger.  This was long overdue.

19) Support SO_REUSEPORT, from Tom Herbert.

20) Allow locking a socket BPF filter, so that it cannot change after a
    process drops capabilities.

21) Add VLAN filtering to bridge, from Vlad Yasevich.

22) Bring ipv6 on-par with ipv4 and do not cache neighbour entries in
    the ipv6 routes, from YOSHIFUJI Hideaki.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1538 commits)
  ipv6: fix race condition regarding dst->expires and dst->from.
  net: fix a wrong assignment in skb_split()
  ip_gre: remove an extra dst_release()
  ppp: set qdisc_tx_busylock to avoid LOCKDEP splat
  atl1c: restore buffer state
  net: fix a build failure when !CONFIG_PROC_FS
  net: ipv4: fix waring -Wunused-variable
  net: proc: fix build failed when procfs is not configured
  Revert "xen: netback: remove redundant xenvif_put"
  net: move procfs code to net/core/net-procfs.c
  qmi_wwan, cdc-ether: add ADU960S
  bonding: set sysfs device_type to 'bond'
  bonding: fix bond_release_all inconsistencies
  b44: use netdev_alloc_skb_ip_align()
  xen: netback: remove redundant xenvif_put
  net: fec: Do a sanity check on the gpio number
  ip_gre: propogate target device GSO capability to the tunnel device
  ip_gre: allow CSUM capable devices to handle packets
  bonding: Fix initialize after use for 3ad machine state spinlock
  bonding: Fix race condition between bond_enslave() and bond_3ad_update_lacp_rate()
  ...
2013-02-20 18:58:50 -08:00
Gao feng c2399059a3 net: proc: remove proc_net_remove
proc_net_remove has been replaced by remove_proc_entry.
we can remove it now.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-18 14:53:08 -05:00
Gao feng b4278c961a net: proc: remove proc_net_fops_create
proc_net_fops_create has been replaced by proc_create,
we can remove it now.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-18 14:53:08 -05:00
Christoph Lameter 9e5e8deca7 stat: Use size_t for sizes instead of unsigned
On some platforms (such as IA64) the large page size may results in
slab allocations to be allowed of numbers that do not fit in 32 bit.

Acked-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2013-02-01 12:32:08 +02:00
Frederic Weisbecker 6fac4829ce cputime: Use accessors to read task cputime stats
This is in preparation for the full dynticks feature. While
remotely reading the cputime of a task running in a full
dynticks CPU, we'll need to do some extra-computation. This
way we can account the time it spent tickless in userspace
since its last cputime snapshot.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-01-27 19:23:31 +01:00
Joe Millenbach 4f73bc4dd3 tty: Added a CONFIG_TTY option to allow removal of TTY
The option allows you to remove TTY and compile without errors. This
saves space on systems that won't support TTY interfaces anyway.
bloat-o-meter output is below.

The bulk of this patch consists of Kconfig changes adding "depends on
TTY" to various serial devices and similar drivers that require the TTY
layer.  Ideally, these dependencies would occur on a common intermediate
symbol such as SERIO, but most drivers "select SERIO" rather than
"depends on SERIO", and "select" does not respect dependencies.

bloat-o-meter output comparing our previous minimal to new minimal by
removing TTY.  The list is filtered to not show removed entries with awk
'$3 != "-"' as the list was very long.

add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350)
function                                     old     new   delta
chr_dev_init                                 166     170      +4
allow_signal                                  80      82      +2
static.__warned                              143     142      -1
disallow_signal                               63      62      -1
__set_special_pids                            95      94      -1
unregister_console                           126     121      -5
start_kernel                                 546     541      -5
register_console                             593     588      -5
copy_from_user                                45      40      -5
sys_setsid                                   128     120      -8
sys_vhangup                                   32      19     -13
do_exit                                     1543    1526     -17
bitmap_zero                                   60      40     -20
arch_local_irq_save                          137     117     -20
release_task                                 674     652     -22
static.spin_unlock_irqrestore                308     260     -48

Signed-off-by: Joe Millenbach <jmillenbach@gmail.com>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-18 16:15:27 -08:00
Hugh Dickins a7a88b2373 mempolicy: remove arg from mpol_parse_str, mpol_to_str
Remove the unused argument (formerly no_context) from mpol_parse_str()
and from mpol_to_str().

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-02 09:27:10 -08:00
Eric W. Biederman dfb2ea45be proc: Allow proc_free_inum to be called from any context
While testing the pid namespace code I hit this nasty warning.

[  176.262617] ------------[ cut here ]------------
[  176.263388] WARNING: at /home/eric/projects/linux/linux-userns-devel/kernel/softirq.c:160 local_bh_enable_ip+0x7a/0xa0()
[  176.265145] Hardware name: Bochs
[  176.265677] Modules linked in:
[  176.266341] Pid: 742, comm: bash Not tainted 3.7.0userns+ #18
[  176.266564] Call Trace:
[  176.266564]  [<ffffffff810a539f>] warn_slowpath_common+0x7f/0xc0
[  176.266564]  [<ffffffff810a53fa>] warn_slowpath_null+0x1a/0x20
[  176.266564]  [<ffffffff810ad9ea>] local_bh_enable_ip+0x7a/0xa0
[  176.266564]  [<ffffffff819308c9>] _raw_spin_unlock_bh+0x19/0x20
[  176.266564]  [<ffffffff8123dbda>] proc_free_inum+0x3a/0x50
[  176.266564]  [<ffffffff8111d0dc>] free_pid_ns+0x1c/0x80
[  176.266564]  [<ffffffff8111d195>] put_pid_ns+0x35/0x50
[  176.266564]  [<ffffffff810c608a>] put_pid+0x4a/0x60
[  176.266564]  [<ffffffff8146b177>] tty_ioctl+0x717/0xc10
[  176.266564]  [<ffffffff810aa4d5>] ? wait_consider_task+0x855/0xb90
[  176.266564]  [<ffffffff81086bf9>] ? default_spin_lock_flags+0x9/0x10
[  176.266564]  [<ffffffff810cab0a>] ? remove_wait_queue+0x5a/0x70
[  176.266564]  [<ffffffff811e37e8>] do_vfs_ioctl+0x98/0x550
[  176.266564]  [<ffffffff810b8a0f>] ? recalc_sigpending+0x1f/0x60
[  176.266564]  [<ffffffff810b9127>] ? __set_task_blocked+0x37/0x80
[  176.266564]  [<ffffffff810ab95b>] ? sys_wait4+0xab/0xf0
[  176.266564]  [<ffffffff811e3d31>] sys_ioctl+0x91/0xb0
[  176.266564]  [<ffffffff810a95f0>] ? task_stopped_code+0x50/0x50
[  176.266564]  [<ffffffff81939199>] system_call_fastpath+0x16/0x1b
[  176.266564] ---[ end trace 387af88219ad6143 ]---

It turns out that spin_unlock_bh(proc_inum_lock) is not safe when
put_pid is called with another spinlock held and irqs disabled.

For now take the easy path and use spin_lock_irqsave(proc_inum_lock)
in proc_free_inum and spin_loc_irq in proc_alloc_inum(proc_inum_lock).

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-12-25 16:23:12 -08:00
Linus Torvalds 4c9a44aebe Merge branch 'akpm' (Andrew's patch-bomb)
Merge the rest of Andrew's patches for -rc1:
 "A bunch of fixes and misc missed-out-on things.

  That'll do for -rc1.  I still have a batch of IPC patches which still
  have a possible bug report which I'm chasing down."

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (25 commits)
  keys: use keyring_alloc() to create module signing keyring
  keys: fix unreachable code
  sendfile: allows bypassing of notifier events
  SGI-XP: handle non-fatal traps
  fat: fix incorrect function comment
  Documentation: ABI: remove testing/sysfs-devices-node
  proc: fix inconsistent lock state
  linux/kernel.h: fix DIV_ROUND_CLOSEST with unsigned divisors
  memcg: don't register hotcpu notifier from ->css_alloc()
  checkpatch: warn on uapi #includes that #include <uapi/...
  revert "rtc: recycle id when unloading a rtc driver"
  mm: clean up transparent hugepage sysfs error messages
  hfsplus: add error message for the case of failure of sync fs in delayed_sync_fs() method
  hfsplus: rework processing of hfs_btree_write() returned error
  hfsplus: rework processing errors in hfsplus_free_extents()
  hfsplus: avoid crash on failed block map free
  kcmp: include linux/ptrace.h
  drivers/rtc/rtc-imxdi.c: must include <linux/spinlock.h>
  mm: cma: WARN if freed memory is still in use
  exec: do not leave bprm->interp on stack
  ...
2012-12-20 20:00:43 -08:00
Xiaotian Feng ee297209bf proc: fix inconsistent lock state
Lockdep found an inconsistent lock state when rcu is processing delayed
work in softirq.  Currently, kernel is using spin_lock/spin_unlock to
protect proc_inum_ida, but proc_free_inum is called by rcu in softirq
context.

Use spin_lock_bh/spin_unlock_bh fix following lockdep warning.

  =================================
  [ INFO: inconsistent lock state ]
  3.7.0 #36 Not tainted
  ---------------------------------
  inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
  swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
   (proc_inum_lock){+.?...}, at: proc_free_inum+0x1c/0x50
  {SOFTIRQ-ON-W} state was registered at:
     __lock_acquire+0x8ae/0xca0
     lock_acquire+0x199/0x200
     _raw_spin_lock+0x41/0x50
     proc_alloc_inum+0x4c/0xd0
     alloc_mnt_ns+0x49/0xc0
     create_mnt_ns+0x25/0x70
     mnt_init+0x161/0x1c7
     vfs_caches_init+0x107/0x11a
     start_kernel+0x348/0x38c
     x86_64_start_reservations+0x131/0x136
     x86_64_start_kernel+0x103/0x112
  irq event stamp: 2993422
  hardirqs last  enabled at (2993422):  _raw_spin_unlock_irqrestore+0x55/0x80
  hardirqs last disabled at (2993421):  _raw_spin_lock_irqsave+0x29/0x70
  softirqs last  enabled at (2993394):  _local_bh_enable+0x13/0x20
  softirqs last disabled at (2993395):  call_softirq+0x1c/0x30

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(proc_inum_lock);
    <Interrupt>
      lock(proc_inum_lock);

   *** DEADLOCK ***

  no locks held by swapper/1/0.

  stack backtrace:
  Pid: 0, comm: swapper/1 Not tainted 3.7.0 #36
  Call Trace:
   <IRQ>  [<ffffffff810a40f1>] ? vprintk_emit+0x471/0x510
    print_usage_bug+0x2a5/0x2c0
    mark_lock+0x33b/0x5e0
    __lock_acquire+0x813/0xca0
    lock_acquire+0x199/0x200
    _raw_spin_lock+0x41/0x50
    proc_free_inum+0x1c/0x50
    free_pid_ns+0x1c/0x50
    put_pid_ns+0x2e/0x50
    put_pid+0x4a/0x60
    delayed_put_pid+0x12/0x20
    rcu_process_callbacks+0x462/0x790
    __do_softirq+0x1b4/0x3b0
    call_softirq+0x1c/0x30
    do_softirq+0x59/0xd0
    irq_exit+0x54/0xd0
    smp_apic_timer_interrupt+0x95/0xa3
    apic_timer_interrupt+0x72/0x80
    cpuidle_enter_tk+0x10/0x20
    cpuidle_enter_state+0x17/0x50
    cpuidle_idle_call+0x287/0x520
    cpu_idle+0xba/0x130
    start_secondary+0x2b3/0x2bc

Signed-off-by: Xiaotian Feng <dannyfeng@tencent.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-20 17:40:20 -08:00
Marco Stornelli 46f6955710 procfs: drop vmtruncate
Removed vmtruncate

Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-20 14:00:01 -05:00
Linus Torvalds 848b81415c Merge branch 'akpm' (Andrew's patch-bomb)
Merge misc patches from Andrew Morton:
 "Incoming:

   - lots of misc stuff

   - backlight tree updates

   - lib/ updates

   - Oleg's percpu-rwsem changes

   - checkpatch

   - rtc

   - aoe

   - more checkpoint/restart support

  I still have a pile of MM stuff pending - Pekka should be merging
  later today after which that is good to go.  A number of other things
  are twiddling thumbs awaiting maintainer merges."

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (180 commits)
  scatterlist: don't BUG when we can trivially return a proper error.
  docs: update documentation about /proc/<pid>/fdinfo/<fd> fanotify output
  fs, fanotify: add @mflags field to fanotify output
  docs: add documentation about /proc/<pid>/fdinfo/<fd> output
  fs, notify: add procfs fdinfo helper
  fs, exportfs: add exportfs_encode_inode_fh() helper
  fs, exportfs: escape nil dereference if no s_export_op present
  fs, epoll: add procfs fdinfo helper
  fs, eventfd: add procfs fdinfo helper
  procfs: add ability to plug in auxiliary fdinfo providers
  tools/testing/selftests/kcmp/kcmp_test.c: print reason for failure in kcmp_test
  breakpoint selftests: print failure status instead of cause make error
  kcmp selftests: print fail status instead of cause make error
  kcmp selftests: make run_tests fix
  mem-hotplug selftests: print failure status instead of cause make error
  cpu-hotplug selftests: print failure status instead of cause make error
  mqueue selftests: print failure status instead of cause make error
  vm selftests: print failure status instead of cause make error
  ubifs: use prandom_bytes
  mtd: nandsim: use prandom_bytes
  ...
2012-12-17 20:58:12 -08:00
Cyrill Gorcunov 138d22b586 fs, epoll: add procfs fdinfo helper
This allows us to print out eventpoll target file descriptor, events and
data, the /proc/pid/fdinfo/fd consists of

 | pos:	0
 | flags:	02
 | tfd:        5 events:       1d data: ffffffffffffffff enabled: 1

[avagin@: fix for unitialized ret variable]

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:27 -08:00
Cyrill Gorcunov 55985dd72a procfs: add ability to plug in auxiliary fdinfo providers
This patch brings ability to print out auxiliary data associated with
file in procfs interface /proc/pid/fdinfo/fd.

In particular further patches make eventfd, evenpoll, signalfd and
fsnotify to print additional information complete enough to restore
these objects after checkpoint.

To simplify the code we add show_fdinfo callback inside struct
file_operations (as Al and Pavel are proposing).

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:27 -08:00
Artem Bityutskiy 8d238027b8 proc: pid/status: show all supplementary groups
We display a list of supplementary group for each process in
/proc/<pid>/status.  However, we show only the first 32 groups, not all of
them.

Although this is rare, but sometimes processes do have more than 32
supplementary groups, and this kernel limitation breaks user-space apps
that rely on the group list in /proc/<pid>/status.

Number 32 comes from the internal NGROUPS_SMALL macro which defines the
length for the internal kernel "small" groups buffer.  There is no
apparent reason to limit to this value.

This patch removes the 32 groups printing limit.

The Linux kernel limits the amount of supplementary groups by NGROUPS_MAX,
which is currently set to 65536.  And this is the maximum count of groups
we may possibly print.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:23 -08:00
Kees Cook 2f4b3bf6b2 /proc/pid/status: add "Seccomp" field
It is currently impossible to examine the state of seccomp for a given
process.  While attaching with gdb and attempting "call
prctl(PR_GET_SECCOMP,...)" will work with some situations, it is not
reliable.  If the process is in seccomp mode 1, this query will kill the
process (prctl not allowed), if the process is in mode 2 with prctl not
allowed, it will similarly be killed, and in weird cases, if prctl is
filtered to return errno 0, it can look like seccomp is disabled.

When reviewing the state of running processes, there should be a way to
externally examine the seccomp mode.  ("Did this build of Chrome end up
using seccomp?" "Did my distro ship ssh with seccomp enabled?")

This adds the "Seccomp" line to /proc/$pid/status.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: James Morris <jmorris@namei.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:22 -08:00
Cyrill Gorcunov 834f82e2aa procfs: add VmFlags field in smaps output
During c/r sessions we've found that there is no way at the moment to
fetch some VMA associated flags, such as mlock() and madvise().

This leads us to a problem -- we don't know if we should call for mlock()
and/or madvise() after restore on the vma area we're bringing back to
life.

This patch intorduces a new field into "smaps" output called VmFlags,
where all set flags associated with the particular VMA is shown as two
letter mnemonics.

[ Strictly speaking for c/r we only need mlock/madvise bits but it has been
  said that providing just a few flags looks somehow inconsistent.  So all
  flags are here now. ]

This feature is made available on CONFIG_CHECKPOINT_RESTORE=n kernels, as
other applications may start to use these fields.

The data is encoded in a somewhat awkward two letters mnemonic form, to
encourage userspace to be prepared for fields being added or removed in
the future.

[a.p.zijlstra@chello.nl: props to use for_each_set_bit]
[sfr@canb.auug.org.au: props to use array instead of struct]
[akpm@linux-foundation.org: overall redesign and simplification]
[akpm@linux-foundation.org: remove unneeded braces per sfr, avoid using bloaty for_each_set_bit()]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:22 -08:00
Andrew Vagin 7b9a7ec565 proc: don't show nonexistent capabilities
Without this patch it is really hard to interpret a bounding set, if
CAP_LAST_CAP is unknown for a current kernel.

Non-existant capabilities can not be deleted from a bounding set with help
of prctl.

E.g.: Here are two examples without/with this patch.

  CapBnd:	ffffffe0fdecffff
  CapBnd:	00000000fdecffff

I suggest to hide non-existent capabilities. Here is two reasons.
* It's logically and easier for using.
* It helps to checkpoint-restore capabilities of tasks, because tasks
can be restored on another kernel, where CAP_LAST_CAP is bigger.

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Cc: Andrew G. Morgan <morgan@kernel.org>
Reviewed-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:22 -08:00
Andy Shevchenko f9a00e8738 procfs: use kbasename()
[yongjun_wei@trendmicro.com.cn: remove duplicated include]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:17 -08:00
Linus Torvalds 6a2b60b17b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace changes from Eric Biederman:
 "While small this set of changes is very significant with respect to
  containers in general and user namespaces in particular.  The user
  space interface is now complete.

  This set of changes adds support for unprivileged users to create user
  namespaces and as a user namespace root to create other namespaces.
  The tyranny of supporting suid root preventing unprivileged users from
  using cool new kernel features is broken.

  This set of changes completes the work on setns, adding support for
  the pid, user, mount namespaces.

  This set of changes includes a bunch of basic pid namespace
  cleanups/simplifications.  Of particular significance is the rework of
  the pid namespace cleanup so it no longer requires sending out
  tendrils into all kinds of unexpected cleanup paths for operation.  At
  least one case of broken error handling is fixed by this cleanup.

  The files under /proc/<pid>/ns/ have been converted from regular files
  to magic symlinks which prevents incorrect caching by the VFS,
  ensuring the files always refer to the namespace the process is
  currently using and ensuring that the ptrace_mayaccess permission
  checks are always applied.

  The files under /proc/<pid>/ns/ have been given stable inode numbers
  so it is now possible to see if different processes share the same
  namespaces.

  Through the David Miller's net tree are changes to relax many of the
  permission checks in the networking stack to allowing the user
  namespace root to usefully use the networking stack.  Similar changes
  for the mount namespace and the pid namespace are coming through my
  tree.

  Two small changes to add user namespace support were commited here adn
  in David Miller's -net tree so that I could complete the work on the
  /proc/<pid>/ns/ files in this tree.

  Work remains to make it safe to build user namespaces and 9p, afs,
  ceph, cifs, coda, gfs2, ncpfs, nfs, nfsd, ocfs2, and xfs so the
  Kconfig guard remains in place preventing that user namespaces from
  being built when any of those filesystems are enabled.

  Future design work remains to allow root users outside of the initial
  user namespace to mount more than just /proc and /sys."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (38 commits)
  proc: Usable inode numbers for the namespace file descriptors.
  proc: Fix the namespace inode permission checks.
  proc: Generalize proc inode allocation
  userns: Allow unprivilged mounts of proc and sysfs
  userns: For /proc/self/{uid,gid}_map derive the lower userns from the struct file
  procfs: Print task uids and gids in the userns that opened the proc file
  userns: Implement unshare of the user namespace
  userns: Implent proc namespace operations
  userns: Kill task_user_ns
  userns: Make create_new_namespaces take a user_ns parameter
  userns: Allow unprivileged use of setns.
  userns: Allow unprivileged users to create new namespaces
  userns: Allow setting a userns mapping to your current uid.
  userns: Allow chown and setgid preservation
  userns: Allow unprivileged users to create user namespaces.
  userns: Ignore suid and sgid on binaries if the uid or gid can not be mapped
  userns: fix return value on mntns_install() failure
  vfs: Allow unprivileged manipulation of the mount namespace.
  vfs: Only support slave subtrees across different user namespaces
  vfs: Add a user namespace reference from struct mnt_namespace
  ...
2012-12-17 15:44:47 -08:00
Linus Torvalds f6e858a00a Merge branch 'akpm' (Andrew's patch-bomb)
Merge misc VM changes from Andrew Morton:
 "The rest of most-of-MM.  The other MM bits await a slab merge.

  This patch includes the addition of a huge zero_page.  Not a
  performance boost but it an save large amounts of physical memory in
  some situations.

  Also a bunch of Fujitsu engineers are working on memory hotplug.
  Which, as it turns out, was badly broken.  About half of their patches
  are included here; the remainder are 3.8 material."

However, this merge disables CONFIG_MOVABLE_NODE, which was totally
broken.  We don't add new features with "default y", nor do we add
Kconfig questions that are incomprehensible to most people without any
help text.  Does the feature even make sense without compaction or
memory hotplug?

* akpm: (54 commits)
  mm/bootmem.c: remove unused wrapper function reserve_bootmem_generic()
  mm/memory.c: remove unused code from do_wp_page()
  asm-generic, mm: pgtable: consolidate zero page helpers
  mm/hugetlb.c: fix warning on freeing hwpoisoned hugepage
  hwpoison, hugetlbfs: fix RSS-counter warning
  hwpoison, hugetlbfs: fix "bad pmd" warning in unmapping hwpoisoned hugepage
  mm: protect against concurrent vma expansion
  memcg: do not check for mm in __mem_cgroup_count_vm_event
  tmpfs: support SEEK_DATA and SEEK_HOLE (reprise)
  mm: provide more accurate estimation of pages occupied by memmap
  fs/buffer.c: remove redundant initialization in alloc_page_buffers()
  fs/buffer.c: do not inline exported function
  writeback: fix a typo in comment
  mm: introduce new field "managed_pages" to struct zone
  mm, oom: remove statically defined arch functions of same name
  mm, oom: remove redundant sleep in pagefault oom handler
  mm, oom: cleanup pagefault oom handler
  memory_hotplug: allow online/offline memory to result movable node
  numa: add CONFIG_MOVABLE_NODE for movable-dedicated node
  mm, memcg: avoid unnecessary function call when memcg is disabled
  ...
2012-12-13 13:11:15 -08:00
Linus Torvalds 6be35c700f Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking changes from David Miller:

1) Allow to dump, monitor, and change the bridge multicast database
   using netlink.  From Cong Wang.

2) RFC 5961 TCP blind data injection attack mitigation, from Eric
   Dumazet.

3) Networking user namespace support from Eric W. Biederman.

4) tuntap/virtio-net multiqueue support by Jason Wang.

5) Support for checksum offload of encapsulated packets (basically,
   tunneled traffic can still be checksummed by HW).  From Joseph
   Gasparakis.

6) Allow BPF filter access to VLAN tags, from Eric Dumazet and
   Daniel Borkmann.

7) Bridge port parameters over netlink and BPDU blocking support
   from Stephen Hemminger.

8) Improve data access patterns during inet socket demux by rearranging
   socket layout, from Eric Dumazet.

9) TIPC protocol updates and cleanups from Ying Xue, Paul Gortmaker, and
   Jon Maloy.

10) Update TCP socket hash sizing to be more in line with current day
    realities.  The existing heurstics were choosen a decade ago.
    From Eric Dumazet.

11) Fix races, queue bloat, and excessive wakeups in ATM and
    associated drivers, from Krzysztof Mazur and David Woodhouse.

12) Support DOVE (Distributed Overlay Virtual Ethernet) extensions
    in VXLAN driver, from David Stevens.

13) Add "oops_only" mode to netconsole, from Amerigo Wang.

14) Support set and query of VEB/VEPA bridge mode via PF_BRIDGE, also
    allow DCB netlink to work on namespaces other than the initial
    namespace.  From John Fastabend.

15) Support PTP in the Tigon3 driver, from Matt Carlson.

16) tun/vhost zero copy fixes and improvements, plus turn it on
    by default, from Michael S. Tsirkin.

17) Support per-association statistics in SCTP, from Michele
    Baldessari.

And many, many, driver updates, cleanups, and improvements.  Too
numerous to mention individually.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1722 commits)
  net/mlx4_en: Add support for destination MAC in steering rules
  net/mlx4_en: Use generic etherdevice.h functions.
  net: ethtool: Add destination MAC address to flow steering API
  bridge: add support of adding and deleting mdb entries
  bridge: notify mdb changes via netlink
  ndisc: Unexport ndisc_{build,send}_skb().
  uapi: add missing netconf.h to export list
  pkt_sched: avoid requeues if possible
  solos-pci: fix double-free of TX skb in DMA mode
  bnx2: Fix accidental reversions.
  bna: Driver Version Updated to 3.1.2.1
  bna: Firmware update
  bna: Add RX State
  bna: Rx Page Based Allocation
  bna: TX Intr Coalescing Fix
  bna: Tx and Rx Optimizations
  bna: Code Cleanup and Enhancements
  ath9k: check pdata variable before dereferencing it
  ath5k: RX timestamp is reported at end of frame
  ath9k_htc: RX timestamp is reported at end of frame
  ...
2012-12-12 18:07:07 -08:00
Lai Jiangshan 4ff1b2c293 procfs: use N_MEMORY instead N_HIGH_MEMORY
N_HIGH_MEMORY stands for the nodes that has normal or high memory.
N_MEMORY stands for the nodes that has any memory.

The code here need to handle with the nodes which have memory, we should
use N_MEMORY instead.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Lin Feng <linfeng@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-12 17:38:32 -08:00
Kirill A. Shutemov e180377f1a thp: change split_huge_page_pmd() interface
Pass vma instead of mm and add address parameter.

In most cases we already have vma on the stack. We provides
split_huge_page_pmd_mm() for few cases when we have mm, but not vma.

This change is preparation to huge zero pmd splitting implementation.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-12 17:38:31 -08:00
Linus Torvalds f57d54bab6 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "The biggest change affects group scheduling: we now track the runnable
  average on a per-task entity basis, allowing a smoother, exponential
  decay average based load/weight estimation instead of the previous
  binary on-the-runqueue/off-the-runqueue load weight method.

  This will inevitably disturb workloads that were in some sort of
  borderline balancing state or unstable equilibrium, so an eye has to
  be kept on regressions.

  For that reason the new load average is only limited to group
  scheduling (shares distribution) at the moment (which was also hurting
  the most from the prior, crude weight calculation and whose scheduling
  quality wins most from this change) - but we plan to extend this to
  regular SMP balancing as well in the future, which will simplify and
  speed up things a bit.

  Other changes involve ongoing preparatory work to extend NOHZ to the
  scheduler as well, eventually allowing completely irq-free user-space
  execution."

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  Revert "sched/autogroup: Fix crash on reboot when autogroup is disabled"
  cputime: Comment cputime's adjusting code
  cputime: Consolidate cputime adjustment code
  cputime: Rename thread_group_times to thread_group_cputime_adjusted
  cputime: Move thread_group_cputime() to sched code
  vtime: Warn if irqs aren't disabled on system time accounting APIs
  vtime: No need to disable irqs on vtime_account()
  vtime: Consolidate a bit the ctx switch code
  vtime: Explicitly account pending user time on process tick
  vtime: Remove the underscore prefix invasion
  sched/autogroup: Fix crash on reboot when autogroup is disabled
  cputime: Separate irqtime accounting from generic vtime
  cputime: Specialize irq vtime hooks
  kvm: Directly account vtime to system on guest switch
  vtime: Make vtime_account_system() irqsafe
  vtime: Gather vtime declarations to their own header file
  sched: Describe CFS load-balancer
  sched: Introduce temporary FAIR_GROUP_SCHED dependency for load-tracking
  sched: Make __update_entity_runnable_avg() fast
  sched: Update_cfs_shares at period edge
  ...
2012-12-11 18:21:38 -08:00