Commit Graph

260 Commits

Author SHA1 Message Date
Mateusz Guzik 1607f09c22 coredump: fix dumping through pipes
The offset in the core file used to be tracked with ->written field of
the coredump_params structure. The field was retired in favour of
file->f_pos.

However, ->f_pos is not maintained for pipes which leads to breakage.

Restore explicit tracking of the offset in coredump_params. Introduce
->pos field for this purpose since ->written was already reused.

Fixes: a008393951 ("get rid of coredump_params->written").

Reported-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-07 22:07:09 -04:00
Linus Torvalds 5d22fc25d4 mm: remove more IS_ERR_VALUE abuses
The do_brk() and vm_brk() return value was "unsigned long" and returned
the starting address on success, and an error value on failure.  The
reasons are entirely historical, and go back to it basically behaving
like the mmap() interface does.

However, nobody actually wanted that interface, and it causes totally
pointless IS_ERR_VALUE() confusion.

What every single caller actually wants is just the simpler integer
return of zero for success and negative error number on failure.

So just convert to that much clearer and more common calling convention,
and get rid of all the IS_ERR_VALUE() uses wrt vm_brk().

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27 15:57:31 -07:00
Michal Hocko ecc2bc8ac0 mm, elf: handle vm_brk error
load_elf_library doesn't handle vm_brk failure although nothing really
indicates it cannot do that because the function is allowed to fail due
to vm_mmap failures already.  This might be not a problem now but later
patch will make vm_brk killable (resp.  mmap_sem for write waiting will
become killable) and so the failure will be more probable.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Linus Torvalds 9e17632c0a Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs cleanups from Al Viro:
 "Assorted cleanups and fixes all over the place"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  coredump: only charge written data against RLIMIT_CORE
  coredump: get rid of coredump_params->written
  ecryptfs_lookup(): try either only encrypted or plaintext name
  ecryptfs: avoid multiple aliases for directories
  bpf: reject invalid names right in ->lookup()
  __d_alloc(): treat NULL name as QSTR("/", 1)
  mtd: switch ubi_open_volume_path() to vfs_stat()
  mtd: switch open_mtd_by_chdev() to use of vfs_stat()
2016-05-18 11:51:59 -07:00
Omar Sandoval a008393951 coredump: get rid of coredump_params->written
cprm->written is redundant with cprm->file->f_pos, so use that instead.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-12 16:55:50 -04:00
Kirill A. Shutemov 09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00
Daniel Cashman 5ef11c35ce mm: ASLR: use get_random_long()
Replace calls to get_random_int() followed by a cast to (unsigned long)
with calls to get_random_long().  Also address shifting bug which, in
case of x86 removed entropy mask for mmap_rnd_bits values > 31 bits.

Signed-off-by: Daniel Cashman <dcashman@android.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nick Kralevich <nnk@google.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Mark Salyzyn <salyzyn@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-27 10:28:52 -08:00
Maciej W. Rozycki eb4bc076ff ELF: Also pass any interpreter's file header to `arch_check_elf'
Also pass any interpreter's file header to `arch_check_elf' so that any
architecture handler can have a look at it if needed.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11478/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-20 00:39:20 +01:00
Linus Torvalds 842cf0b952 Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs update from Al Viro:

 - misc stable fixes

 - trivial kernel-doc and comment fixups

 - remove never-used block_page_mkwrite() wrapper function, and rename
   the function that is _actually_ used to not have double underscores.

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: 9p: cache.h: Add #define of include guard
  vfs: remove stale comment in inode_operations
  vfs: remove unused wrapper block_page_mkwrite()
  binfmt_elf: Correct `arch_check_elf's description
  fs: fix writeback.c kernel-doc warnings
  fs: fix inode.c kernel-doc warning
  fs/pipe.c: return error code rather than 0 in pipe_write()
  fs/pipe.c: preserve alloc_file() error code
  binfmt_elf: Don't clobber passed executable's file header
  FS-Cache: Handle a write to the page immediately beyond the EOF marker
  cachefiles: perform test on s_blocksize when opening cache file.
  FS-Cache: Don't override netfs's primary_index if registering failed
  FS-Cache: Increase reference of parent after registering, netfs success
  debugfs: fix refcount imbalance in start_creating
2015-11-11 09:45:24 -08:00
Maciej W. Rozycki 54d15714f7 binfmt_elf: Correct `arch_check_elf's description
Correct `arch_check_elf's description, mistakenly copied and pasted from
`arch_elf_pt_proc'.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-11 02:19:21 -05:00
Maciej W. Rozycki b582ef5c53 binfmt_elf: Don't clobber passed executable's file header
Do not clobber the buffer space passed from `search_binary_handler' and
originally preloaded by `prepare_binprm' with the executable's file
header by overwriting it with its interpreter's file header.  Instead
keep the buffer space intact and directly use the data structure locally
allocated for the interpreter's file header, fixing a bug introduced in
2.1.14 with loadable module support (linux-mips.org commit beb11695
[Import of Linux/MIPS 2.1.14], predating kernel.org repo's history).
Adjust the amount of data read from the interpreter's file accordingly.

This was not an issue before loadable module support, because back then
`load_elf_binary' was executed only once for a given ELF executable,
whether the function succeeded or failed.

With loadable module support supported and enabled, upon a failure of
`load_elf_binary' -- which may for example be caused by architecture
code rejecting an executable due to a missing hardware feature requested
in the file header -- a module load is attempted and then the function
reexecuted by `search_binary_handler'.  With the executable's file
header replaced with its interpreter's file header the executable can
then be erroneously accepted in this subsequent attempt.

Cc: stable@vger.kernel.org # all the way back
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-11 02:18:07 -05:00
Ross Zwisler 5037835c1f coredump: add DAX filtering for ELF coredumps
Add two new flags to the existing coredump mechanism for ELF files to
allow us to explicitly filter DAX mappings.  This is desirable because
DAX mappings, like hugetlb mappings, have the potential to be very
large.

Update the coredump_filter documentation in
Documentation/filesystems/proc.txt so that it addresses the new DAX
coredump flags.  Also update the documented default value of
coredump_filter to be consistent with the core(5) man page.  The
documentation being updated talks about bit 4, Dump ELF headers, which
is enabled if CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is turned on in the
kernel config.  This kernel config option defaults to "y" if both ELF
binaries and coredump are enabled.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-11-09 13:29:54 -05:00
Linus Torvalds 1dc51b8288 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...
2015-07-04 19:36:06 -07:00
Miklos Szeredi 9bf39ab2ad vfs: add file_path() helper
Turn
	d_path(&file->f_path, ...);
into
	file_path(file, ...);

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:00:05 -04:00
Andrew Morton 2b1d3ae940 fs/binfmt_elf.c:load_elf_binary(): return -EINVAL on zero-length mappings
load_elf_binary() returns `retval', not `error'.

Fixes: a87938b2e2 ("fs/binfmt_elf.c: fix bug in loading of PIE binaries")
Reported-by: James Hogan <james.hogan@imgtec.com>
Cc: Michael Davidson <md@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-28 18:25:18 -07:00
Kees Cook 204db6ed17 mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE
The arch_randomize_brk() function is used on several architectures,
even those that don't support ET_DYN ASLR. To avoid bulky extern/#define
tricks, consolidate the support under CONFIG_ARCH_HAS_ELF_RANDOMIZE for
the architectures that support it, while still handling CONFIG_COMPAT_BRK.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Arun Chandran <achandran@mvista.com>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: Min-Hua Chen <orca.chen@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Vineeth Vijayan <vvijayan@mvista.com>
Cc: Jeff Bailey <jeffbailey@google.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Behan Webster <behanw@converseincode.com>
Cc: Ismael Ripoll <iripoll@upv.es>
Cc: Jan-Simon Mller <dl9pf@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:49:05 -07:00
Kees Cook d1fd836dcf mm: split ET_DYN ASLR from mmap ASLR
This fixes the "offset2lib" weakness in ASLR for arm, arm64, mips,
powerpc, and x86.  The problem is that if there is a leak of ASLR from
the executable (ET_DYN), it means a leak of shared library offset as
well (mmap), and vice versa.  Further details and a PoC of this attack
is available here:

  http://cybersecurity.upv.es/attacks/offset2lib/offset2lib.html

With this patch, a PIE linked executable (ET_DYN) has its own ASLR
region:

  $ ./show_mmaps_pie
  54859ccd6000-54859ccd7000 r-xp  ...  /tmp/show_mmaps_pie
  54859ced6000-54859ced7000 r--p  ...  /tmp/show_mmaps_pie
  54859ced7000-54859ced8000 rw-p  ...  /tmp/show_mmaps_pie
  7f75be764000-7f75be91f000 r-xp  ...  /lib/x86_64-linux-gnu/libc.so.6
  7f75be91f000-7f75beb1f000 ---p  ...  /lib/x86_64-linux-gnu/libc.so.6
  7f75beb1f000-7f75beb23000 r--p  ...  /lib/x86_64-linux-gnu/libc.so.6
  7f75beb23000-7f75beb25000 rw-p  ...  /lib/x86_64-linux-gnu/libc.so.6
  7f75beb25000-7f75beb2a000 rw-p  ...
  7f75beb2a000-7f75beb4d000 r-xp  ...  /lib64/ld-linux-x86-64.so.2
  7f75bed45000-7f75bed46000 rw-p  ...
  7f75bed46000-7f75bed47000 r-xp  ...
  7f75bed47000-7f75bed4c000 rw-p  ...
  7f75bed4c000-7f75bed4d000 r--p  ...  /lib64/ld-linux-x86-64.so.2
  7f75bed4d000-7f75bed4e000 rw-p  ...  /lib64/ld-linux-x86-64.so.2
  7f75bed4e000-7f75bed4f000 rw-p  ...
  7fffb3741000-7fffb3762000 rw-p  ...  [stack]
  7fffb377b000-7fffb377d000 r--p  ...  [vvar]
  7fffb377d000-7fffb377f000 r-xp  ...  [vdso]

The change is to add a call the newly created arch_mmap_rnd() into the
ELF loader for handling ET_DYN ASLR in a separate region from mmap ASLR,
as was already done on s390.  Removes CONFIG_BINFMT_ELF_RANDOMIZE_PIE,
which is no longer needed.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Arun Chandran <achandran@mvista.com>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: Min-Hua Chen <orca.chen@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Vineeth Vijayan <vvijayan@mvista.com>
Cc: Jeff Bailey <jeffbailey@google.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Behan Webster <behanw@converseincode.com>
Cc: Ismael Ripoll <iripoll@upv.es>
Cc: Jan-Simon Mller <dl9pf@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:49:05 -07:00
Michael Davidson a87938b2e2 fs/binfmt_elf.c: fix bug in loading of PIE binaries
With CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE enabled, and a normal top-down
address allocation strategy, load_elf_binary() will attempt to map a PIE
binary into an address range immediately below mm->mmap_base.

Unfortunately, load_elf_ binary() does not take account of the need to
allocate sufficient space for the entire binary which means that, while
the first PT_LOAD segment is mapped below mm->mmap_base, the subsequent
PT_LOAD segment(s) end up being mapped above mm->mmap_base into the are
that is supposed to be the "gap" between the stack and the binary.

Since the size of the "gap" on x86_64 is only guaranteed to be 128MB this
means that binaries with large data segments > 128MB can end up mapping
part of their data segment over their stack resulting in corruption of the
stack (and the data segment once the binary starts to run).

Any PIE binary with a data segment > 128MB is vulnerable to this although
address randomization means that the actual gap between the stack and the
end of the binary is normally greater than 128MB.  The larger the data
segment of the binary the higher the probability of failure.

Fix this by calculating the total size of the binary in the same way as
load_elf_interp().

Signed-off-by: Michael Davidson <md@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: 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>
2015-04-14 16:49:04 -07:00
Hector Marco-Gisbert 4e7c22d447 x86, mm/ASLR: Fix stack randomization on 64-bit systems
The issue is that the stack for processes is not properly randomized on
64 bit architectures due to an integer overflow.

The affected function is randomize_stack_top() in file
"fs/binfmt_elf.c":

  static unsigned long randomize_stack_top(unsigned long stack_top)
  {
           unsigned int random_variable = 0;

           if ((current->flags & PF_RANDOMIZE) &&
                   !(current->personality & ADDR_NO_RANDOMIZE)) {
                   random_variable = get_random_int() & STACK_RND_MASK;
                   random_variable <<= PAGE_SHIFT;
           }
           return PAGE_ALIGN(stack_top) + random_variable;
           return PAGE_ALIGN(stack_top) - random_variable;
  }

Note that, it declares the "random_variable" variable as "unsigned int".
Since the result of the shifting operation between STACK_RND_MASK (which
is 0x3fffff on x86_64, 22 bits) and PAGE_SHIFT (which is 12 on x86_64):

	  random_variable <<= PAGE_SHIFT;

then the two leftmost bits are dropped when storing the result in the
"random_variable". This variable shall be at least 34 bits long to hold
the (22+12) result.

These two dropped bits have an impact on the entropy of process stack.
Concretely, the total stack entropy is reduced by four: from 2^28 to
2^30 (One fourth of expected entropy).

This patch restores back the entropy by correcting the types involved
in the operations in the functions randomize_stack_top() and
stack_maxrandom_size().

The successful fix can be tested with:

  $ for i in `seq 1 10`; do cat /proc/self/maps | grep stack; done
  7ffeda566000-7ffeda587000 rw-p 00000000 00:00 0                          [stack]
  7fff5a332000-7fff5a353000 rw-p 00000000 00:00 0                          [stack]
  7ffcdb7a1000-7ffcdb7c2000 rw-p 00000000 00:00 0                          [stack]
  7ffd5e2c4000-7ffd5e2e5000 rw-p 00000000 00:00 0                          [stack]
  ...

Once corrected, the leading bytes should be between 7ffc and 7fff,
rather than always being 7fff.

Signed-off-by: Hector Marco-Gisbert <hecmargi@upv.es>
Signed-off-by: Ismael Ripoll <iripoll@upv.es>
[ Rebased, fixed 80 char bugs, cleaned up commit message, added test example and CVE ]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Fixes: CVE-2015-1593
Link: http://lkml.kernel.org/r/20150214173350.GA18393@www.outflux.net
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-02-19 12:21:36 +01:00
Linus Torvalds c0222ac086 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:
 "This is an unusually large pull request for MIPS - in parts because
  lots of patches missed the 3.18 deadline but primarily because some
  folks opened the flood gates.

   - Retire the MIPS-specific phys_t with the generic phys_addr_t.
   - Improvments for the backtrace code used by oprofile.
   - Better backtraces on SMP systems.
   - Cleanups for the Octeon platform code.
   - Cleanups and fixes for the Loongson platform code.
   - Cleanups and fixes to the firmware library.
   - Switch ATH79 platform to use the firmware library.
   - Grand overhault to the SEAD3 and Malta interrupt code.
   - Move the GIC interrupt code to drivers/irqchip
   - Lots of GIC cleanups and updates to the GIC code to use modern IRQ
     infrastructures and features of the kernel.
   - OF documentation updates for the GIC bindings
   - Move GIC clocksource driver to drivers/clocksource
   - Merge GIC clocksource driver with clockevent driver.
   - Further updates to bring the GIC clocksource driver up to date.
   - R3000 TLB code cleanups
   - Improvments to the Loongson 3 platform code.
   - Convert pr_warning to pr_warn.
   - Merge a bunch of small lantiq and ralink fixes that have been
     staged/lingering inside the openwrt tree for a while.
   - Update archhelp for IP22/IP32
   - Fix a number of issues for Loongson 1B.
   - New clocksource and clockevent driver for Loongson 1B.
   - Further work on clk handling for Loongson 1B.
   - Platform work for Broadcom BMIPS.
   - Error handling cleanups for TurboChannel.
   - Fixes and optimization to the microMIPS support.
   - Option to disable the FTLB.
   - Dump more relevant information on machine check exception
   - Change binfmt to allow arch to examine PT_*PROC headers
   - Support for new style FPU register model in O32
   - VDSO randomization.
   - BCM47xx cleanups
   - BCM47xx reimplement the way the kernel accesses NVRAM information.
   - Random cleanups
   - Add support for ATH25 platforms
   - Remove pointless locking code in some PCI platforms.
   - Some improvments to EVA support
   - Minor Alchemy cleanup"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (185 commits)
  MIPS: Add MFHC0 and MTHC0 instructions to uasm.
  MIPS: Cosmetic cleanups of page table headers.
  MIPS: Add CP0 macros for extended EntryLo registers
  MIPS: Remove now unused definition of phys_t.
  MIPS: Replace use of phys_t with phys_addr_t.
  MIPS: Replace MIPS-specific 64BIT_PHYS_ADDR with generic PHYS_ADDR_T_64BIT
  PCMCIA: Alchemy Don't select 64BIT_PHYS_ADDR in Kconfig.
  MIPS: lib: memset: Clean up some MIPS{EL,EB} ifdefery
  MIPS: iomap: Use __mem_{read,write}{b,w,l} for MMIO
  MIPS: <asm/types.h> fix indentation.
  MAINTAINERS: Add entry for BMIPS multiplatform kernel
  MIPS: Enable VDSO randomization
  MIPS: Remove a temporary hack for debugging cache flushes in SMTC configuration
  MIPS: Remove declaration of obsolete arch_init_clk_ops()
  MIPS: atomic.h: Reformat to fit in 79 columns
  MIPS: Apply `.insn' to fixup labels throughout
  MIPS: Fix microMIPS LL/SC immediate offsets
  MIPS: Kconfig: Only allow 32-bit microMIPS builds
  MIPS: signal.c: Fix an invalid cast in ISA mode bit handling
  MIPS: mm: Only build one microassembler that is suitable
  ...
2014-12-11 17:56:37 -08:00
Jungseung Lee 52f5592e54 fs/binfmt_elf.c: fix internal inconsistency relating to vma dump size
vma_dump_size() has been used several times on actual dumper and it is
supposed to return the same value for the same vma.  But vma_dump_size()
could return different values for same vma.

The known problem case is concurrent shared memory removal.  If a vma is
used for a shared memory and that shared memory is removed between
writing program header and dumping vma memory, this will result in a
dump file which is internally consistent.

To fix the problem, we set baseline to get dump size and store the size
into vma_filesz and always use the same vma dump size which is stored in
vma_filsz.  The consistnecy with reality is not actually guranteed, but
it's tolerable since that is fully consistent with base line.

Signed-off-by: Jungseung Lee <js07.lee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:12 -08:00
Paul Burton 774c105ed8 binfmt_elf: allow arch code to examine PT_LOPROC ... PT_HIPROC headers
MIPS is introducing new variants of its O32 ABI which differ in their
handling of floating point, in order to enable a gradual transition
towards a world where mips32 binaries can take advantage of new hardware
features only available when configured for certain FP modes. In order
to do this ELF binaries are being augmented with a new section that
indicates, amongst other things, the FP mode requirements of the binary.
The presence & location of such a section is indicated by a program
header in the PT_LOPROC ... PT_HIPROC range.

In order to allow the MIPS architecture code to examine the program
header & section in question, pass all program headers in this range
to an architecture-specific arch_elf_pt_proc function. This function
may return an error if the header is deemed invalid or unsuitable for
the system, in which case that error will be returned from
load_elf_binary and upwards through the execve syscall.

A means is required for the architecture code to make a decision once
it is known that all such headers have been seen, but before it is too
late to return from an execve syscall. For this purpose the
arch_check_elf function is added, and called once, after all PT_LOPROC
to PT_HIPROC headers have been passed to arch_elf_pt_proc but before
the code which invoked execve has been lost. This enables the
architecture code to make a decision based upon all the headers present
in an ELF binary and its interpreter, as is required to forbid
conflicting FP ABI requirements between an ELF & its interpreter.

In order to allow data to be stored throughout the calls to the above
functions, struct arch_elf_state is introduced.

Finally a variant of the SET_PERSONALITY macro is introduced which
accepts a pointer to the struct arch_elf_state, allowing it to act
based upon state observed from the architecture specific program
headers.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7679/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:02 +01:00
Paul Burton a9d9ef133f binfmt_elf: load interpreter program headers earlier
Load the program headers of an ELF interpreter early enough in
load_elf_binary that they can be examined before it's too late to return
an error from an exec syscall. This patch does not perform any such
checking, it merely lays the groundwork for a further patch to do so.

No functional change is intended.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7675/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:02 +01:00
Paul Burton 6a8d38945c binfmt_elf: Hoist ELF program header loading to a function
load_elf_binary & load_elf_interp both load program headers from an ELF
executable in the same way, duplicating the code. This patch introduces
a helper function (load_elf_phdrs) which performs this common task &
calls it from both load_elf_binary & load_elf_interp. In addition to
reducing code duplication, this is part of preparing to load the ELF
interpreter headers earlier such that they can be examined before it's
too late to return an error from an exec syscall.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7676/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:02 +01:00
Al Viro 19d860a140 handle suicide on late failure exits in execve() in search_binary_handler()
... rather than doing that in the guts of ->load_binary().
[updated to fix the bug spotted by Shentino - for SIGSEGV we really need
something stronger than send_sig_info(); again, better do that in one place]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09 02:39:00 -04:00
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
Fabian Frederick b219e25f8d fs/binfmt_elf.c: fix bool assignements
Fix coccinelle warnings.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:21 -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
Alex Thorlton ab0e113f6b exec: kill the unnecessary mm->def_flags setting in load_elf_binary()
load_elf_binary() sets current->mm->def_flags = def_flags and def_flags
is always zero.  Not only this looks strange, this is unnecessary
because mm_init() has already set ->def_flags = 0.

Signed-off-by: Alex Thorlton <athorlton@sgi.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:35:52 -07:00
Josh Triplett 69369a7003 fs, kernel: permit disabling the uselib syscall
uselib hasn't been used since libc5; glibc does not use it.  Support
turning it off.

When disabled, also omit the load_elf_library implementation from
binfmt_elf.c, which only uselib invokes.

bloat-o-meter:
add/remove: 0/4 grow/shrink: 0/1 up/down: 0/-785 (-785)
function                                     old     new   delta
padzero                                       39      36      -3
uselib_flags                                  20       -     -20
sys_uselib                                   168       -    -168
SyS_uselib                                   168       -    -168
load_elf_library                             426       -    -426

The new CONFIG_USELIB defaults to `y'.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:21:05 -07:00
Todor Minchev 7a5f4f1cb0 fs: binfmt_elf: remove unused defines INTERPRETER_NONE and INTERPRETER_ELF
These two defines are unused since the removal of the a.out interpreter
support in the ELF loader in kernel 2.6.25

Signed-off-by: Todor Minchev <todor@minchev.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:36:58 -08:00
Al Viro afabada957 elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo)
we can't get to do_coredump() if that condition isn't satisfied...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:30 -05:00
Al Viro ec57941e03 constify do_coredump() argument
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:29 -05:00
Al Viro ce39596048 constify copy_siginfo_to_user{,32}()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:29 -05:00
Al Viro 22a8cb8248 new helper: dump_align()
dump_skip to given alignment...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:27 -05:00
Al Viro 9b56d54380 dump_skip(): dump_seek() replacement taking coredump_params
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:26 -05:00
Al Viro 1ad67015e6 binfmt_elf: count notes towards coredump limit
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:25 -05:00
Al Viro cdc3d5627d switch elf_coredump_extra_notes_write() to dump_emit()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:24 -05:00
Al Viro 13046ece96 binfmt_elf: convert writing actual dump pages to dump_emit()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:24 -05:00
Al Viro aa3e7eaf0a switch elf_core_write_extra_data() to dump_emit()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:23 -05:00
Al Viro 506f21c556 switch elf_core_write_extra_phdrs() to dump_emit()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:23 -05:00
Al Viro ecc8c7725e new helper: dump_emit()
dump_write() analog, takes core_dump_params instead of file,
keeps track of the amount written in cprm->written and checks for
cprm->limit.  Start using it in binfmt_elf.c...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:22 -05:00
Al Viro 72c2d53192 file->f_op is never NULL...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24 23:34:54 -04:00
Dan Aloni 7202365696 fs/binfmt_elf.c: prevent a coredump with a large vm_map_count from Oopsing
A high setting of max_map_count, and a process core-dumping with a large
enough vm_map_count could result in an NT_FILE note not being written,
and the kernel crashing immediately later because it has assumed
otherwise.

Reproduction of the oops-causing bug described here:

    https://lkml.org/lkml/2013/8/30/50

Rge ussue originated in commit 2aa362c49c ("coredump: extend core dump
note section to contain file names of mapped file") from Oct 4, 2012.

This patch make that section optional in that case.  fill_files_note()
should signify the error, and also let the info struct in
elf_core_dump() be zero-initialized so that we can check for the
optionally written note.

[akpm@linux-foundation.org: avoid abusing E2BIG, remove a couple of not-really-needed local variables]
[akpm@linux-foundation.org: fix sparse warning]
Signed-off-by: Dan Aloni <alonid@stratoscale.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Reported-by: Martin MOKREJS <mmokrejs@gmail.com>
Tested-by: Martin MOKREJS <mmokrejs@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>
2013-09-30 14:31:01 -07:00
Michel Lespinasse 98d1e64f95 mm: remove free_area_cache
Since all architectures have been converted to use vm_unmapped_area(),
there is no remaining use for the free_area_cache.

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-10 18:11:34 -07:00
Linus Torvalds 5a148af669 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc update from Benjamin Herrenschmidt:
 "The main highlights this time around are:

   - A pile of addition POWER8 bits and nits, such as updated
     performance counter support (Michael Ellerman), new branch history
     buffer support (Anshuman Khandual), base support for the new PCI
     host bridge when not using the hypervisor (Gavin Shan) and other
     random related bits and fixes from various contributors.

   - Some rework of our page table format by Aneesh Kumar which fixes a
     thing or two and paves the way for THP support.  THP itself will
     not make it this time around however.

   - More Freescale updates, including Altivec support on the new e6500
     cores, new PCI controller support, and a pile of new boards support
     and updates.

   - The usual batch of trivial cleanups & fixes"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (156 commits)
  powerpc: Fix build error for book3e
  powerpc: Context switch the new EBB SPRs
  powerpc: Turn on the EBB H/FSCR bits
  powerpc: Replace CPU_FTR_BCTAR with CPU_FTR_ARCH_207S
  powerpc: Setup BHRB instructions facility in HFSCR for POWER8
  powerpc: Fix interrupt range check on debug exception
  powerpc: Update tlbie/tlbiel as per ISA doc
  powerpc: Print page size info during boot
  powerpc: print both base and actual page size on hash failure
  powerpc: Fix hpte_decode to use the correct decoding for page sizes
  powerpc: Decode the pte-lp-encoding bits correctly.
  powerpc: Use encode avpn where we need only avpn values
  powerpc: Reduce PTE table memory wastage
  powerpc: Move the pte free routines from common header
  powerpc: Reduce the PTE_INDEX_SIZE
  powerpc: Switch 16GB and 16MB explicit hugepages to a different page table format
  powerpc: New hugepage directory format
  powerpc: Don't truncate pgd_index wrongly
  powerpc: Don't hard code the size of pte page
  powerpc: Save DAR and DSISR in pt_regs on MCE
  ...
2013-05-02 10:16:16 -07:00
Oleg Nesterov 079148b919 coredump: factor out the setting of PF_DUMPCORE
Cleanup.  Every linux_binfmt->core_dump() sets PF_DUMPCORE, move this into
zap_threads() called by do_coredump().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Neil Horman <nhorman@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:06 -07:00
Jiri Kosina c1d025e22e binfmt_elf: PIE: make PF_RANDOMIZE check comment more accurate
The comment I originally added in commit a3defbe5c3 ("binfmt_elf: fix
PIE execution with randomization disabled") is not really 100% accurate
-- sysctl is not the only way how PF_RANDOMIZE could be forcibly unset
in runtime.

Another option of course is direct modification of personality flags
(i.e.  running through setarch wrapper).

Make the comment more explicit and accurate.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:04 -07:00
Michael Neuling 2171364d1a powerpc: Add HWCAP2 aux entry
We are currently out of free bits in AT_HWCAP. With POWER8, we have
several hardware features that we need to advertise.

Tested on POWER and x86.

Signed-off-by: Michael Neuling <michael@neuling.org>
Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26 16:08:16 +10:00
Naoya Horiguchi 23d9e48213 fs/binfmt_elf.c: fix hugetlb memory check in vma_dump_size()
Documentation/filesystems/proc.txt says about coredump_filter bitmask,

  Note bit 0-4 doesn't effect any hugetlb memory. hugetlb memory are only
  effected by bit 5-6.

However current code can go into the subsequent flag checks of bit 0-4
for vma(VM_HUGETLB). So this patch inserts 'return' and makes it work
as written in the document.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>	[3.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-17 16:10:44 -07:00
Linus Torvalds 8fd5e7a2d9 ImgTec Meta architecture changes for v3.9-rc1
This adds core architecture support for Imagination's Meta processor
 cores, followed by some later miscellaneous arch/metag cleanups and
 fixes which I kept separate to ease review:
 
  - Support for basic Meta 1 (ATP) and Meta 2 (HTP) core architecture
  - A few fixes all over, particularly for symbol prefixes
  - A few privilege protection fixes
  - Several cleanups (setup.c includes, split out a lot of metag_ksyms.c)
  - Fix some missing exports
  - Convert hugetlb to use vm_unmapped_area()
  - Copy device tree to non-init memory
  - Provide dma_get_sgtable()
 
 Signed-off-by: James Hogan <james.hogan@imgtec.com>
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Merge tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag

Pull new ImgTec Meta architecture from James Hogan:
 "This adds core architecture support for Imagination's Meta processor
  cores, followed by some later miscellaneous arch/metag cleanups and
  fixes which I kept separate to ease review:

   - Support for basic Meta 1 (ATP) and Meta 2 (HTP) core architecture
   - A few fixes all over, particularly for symbol prefixes
   - A few privilege protection fixes
   - Several cleanups (setup.c includes, split out a lot of
     metag_ksyms.c)
   - Fix some missing exports
   - Convert hugetlb to use vm_unmapped_area()
   - Copy device tree to non-init memory
   - Provide dma_get_sgtable()"

* tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: (61 commits)
  metag: Provide dma_get_sgtable()
  metag: prom.h: remove declaration of metag_dt_memblock_reserve()
  metag: copy devicetree to non-init memory
  metag: cleanup metag_ksyms.c includes
  metag: move mm/init.c exports out of metag_ksyms.c
  metag: move usercopy.c exports out of metag_ksyms.c
  metag: move setup.c exports out of metag_ksyms.c
  metag: move kick.c exports out of metag_ksyms.c
  metag: move traps.c exports out of metag_ksyms.c
  metag: move irq enable out of irqflags.h on SMP
  genksyms: fix metag symbol prefix on crc symbols
  metag: hugetlb: convert to vm_unmapped_area()
  metag: export clear_page and copy_page
  metag: export metag_code_cache_flush_all
  metag: protect more non-MMU memory regions
  metag: make TXPRIVEXT bits explicit
  metag: kernel/setup.c: sort includes
  perf: Enable building perf tools for Meta
  metag: add boot time LNKGET/LNKSET check
  metag: add __init to metag_cache_probe()
  ...
2013-03-03 12:06:09 -08:00
James Hogan c07380beaf Revert some of "binfmt_elf: cleanups"
The commit "binfmt_elf: cleanups"
(f670d0ecda) removed an ifndef elf_map but
this breaks compilation for metag which does define elf_map.

This adds the ifndef back in as it was before, but does not affect the
other cleanups made by that patch.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Acked-by: Mikael Pettersson <mikpe@it.uu.se>
2013-03-02 20:09:15 +00:00
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 496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Zhang Yanfei d3330cf08c binfmt_elf: remove unused argument in fill_elf_header
In fill_elf_header(), elf->e_ident[EI_OSABI] is always set to ELF_OSABI,
so remove the unused argument 'osabi'.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.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>
2013-02-21 17:22:26 -08:00
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
Alan Cox 6899e92d65 binfmt_elf: fix corner case kfree of uninitialized data
If elf_core_dump() is called and fill_note_info() fails in the kmalloc()
then it returns 0 but has not yet initialised all the needed fields.  As a
result we do a kfree(randomness) after correctly skipping the thread data.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:19 -08:00
Al Viro 71613c3b87 get rid of pt_regs argument of ->load_binary()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-28 21:53:38 -05:00
Linus Torvalds 42859eea96 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull generic execve() changes from Al Viro:
 "This introduces the generic kernel_thread() and kernel_execve()
  functions, and switches x86, arm, alpha, um and s390 over to them."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits)
  s390: convert to generic kernel_execve()
  s390: switch to generic kernel_thread()
  s390: fold kernel_thread_helper() into ret_from_fork()
  s390: fold execve_tail() into start_thread(), convert to generic sys_execve()
  um: switch to generic kernel_thread()
  x86, um/x86: switch to generic sys_execve and kernel_execve
  x86: split ret_from_fork
  alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  alpha: switch to generic kernel_thread()
  alpha: switch to generic sys_execve()
  arm: get rid of execve wrapper, switch to generic execve() implementation
  arm: optimized current_pt_regs()
  arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]
  generic sys_execve()
  generic kernel_execve()
  new helper: current_pt_regs()
  preparation for generic kernel_thread()
  um: kill thread->forking
  um: let signal_delivered() do SIGTRAP on singlestepping into handler
  ...
2012-10-10 12:02:25 +09:00
Konstantin Khlebnikov 314e51b985 mm: kill vma flag VM_RESERVED and mm->reserved_vm counter
A long time ago, in v2.4, VM_RESERVED kept swapout process off VMA,
currently it lost original meaning but still has some effects:

 | effect                 | alternative flags
-+------------------------+---------------------------------------------
1| account as reserved_vm | VM_IO
2| skip in core dump      | VM_IO, VM_DONTDUMP
3| do not merge or expand | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP
4| do not mlock           | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP

This patch removes reserved_vm counter from mm_struct.  Seems like nobody
cares about it, it does not exported into userspace directly, it only
reduces total_vm showed in proc.

Thus VM_RESERVED can be replaced with VM_IO or pair VM_DONTEXPAND | VM_DONTDUMP.

remap_pfn_range() and io_remap_pfn_range() set VM_IO|VM_DONTEXPAND|VM_DONTDUMP.
remap_vmalloc_range() set VM_DONTEXPAND | VM_DONTDUMP.

[akpm@linux-foundation.org: drivers/vfio/pci/vfio_pci.c fixup]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Venkatesh Pallipadi <venki@google.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 16:22:19 +09:00
Konstantin Khlebnikov 0103bd16fb mm: prepare VM_DONTDUMP for using in drivers
Rename VM_NODUMP into VM_DONTDUMP: this name matches other negative flags:
VM_DONTEXPAND, VM_DONTCOPY.  Currently this flag used only for
sys_madvise.  The next patch will use it for replacing the outdated flag
VM_RESERVED.

Also forbid madvise(MADV_DODUMP) for special kernel mappings VM_SPECIAL
(VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP)

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Venkatesh Pallipadi <venki@google.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 16:22:18 +09:00
Denys Vlasenko 2aa362c49c coredump: extend core dump note section to contain file names of mapped files
This note has the following format:

long count     -- how many files are mapped
long page_size -- units for file_ofs
array of [COUNT] elements of
   long start
   long end
   long file_ofs
followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: "Jonathan M. Foote" <jmfoote@cert.org>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.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>
2012-10-06 03:05:17 +09:00
Denys Vlasenko 49ae4d4b11 coredump: add a new elf note with siginfo of the signal
Existing PRSTATUS note contains only si_signo, si_code, si_errno fields
from the siginfo of the signal which caused core to be dumped.

There are tools which try to analyze crashes for possible security
implications, and they want to use, among other data, si_addr field from
the SIGSEGV.

This patch adds a new elf note, NT_SIGINFO, which contains the complete
siginfo_t of the signal which killed the process.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: "Jonathan M. Foote" <jmfoote@cert.org>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.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>
2012-10-06 03:05:16 +09:00
Denys Vlasenko 5ab1c309b3 coredump: pass siginfo_t* to do_coredump() and below, not merely signr
This is a preparatory patch for the introduction of NT_SIGINFO elf note.

With this patch we pass "siginfo_t *siginfo" instead of "int signr" to
do_coredump() and put it into coredump_params.  It will be used by the
next patch.  Most changes are simple s/signr/siginfo->si_signo/.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: "Jonathan M. Foote" <jmfoote@cert.org>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.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>
2012-10-06 03:05:16 +09:00
Alan Cox 6eec482f47 binfmt_elf: Uninitialized variable
load_elf_interp() has interp_map_addr carefully described as
"uninitialized_var" and marked so as to avoid a warning.  However if you
trace the code it is passed into load_elf_interp and then this value is
checked against NULL.

As this return value isn't used this is actually safe but it freaks
various analysis tools that see un-initialized memory addresses being read
before their value is ever defined.

Set it to NULL as a matter of programming good taste if nothing else

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06 03:05:00 +09:00
Denys Vlasenko f34f9d186d coredump: prevent double-free on an error path in core dumper
In !CORE_DUMP_USE_REGSET case, if elf_note_info_init fails to allocate
memory for info->fields, it frees already allocated stuff and returns
error to its caller, fill_note_info.  Which in turn returns error to its
caller, elf_core_dump.  Which jumps to cleanup label and calls
free_note_info, which will happily try to free all info->fields again.
BOOM.

This is the fix.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Venu Byravarasu <vbyravarasu@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2012-09-26 22:20:21 -04:00
Al Viro 826eba4db0 the only place that needs to include asm/exec.h is linux/binfmts.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-20 09:51:13 -04:00
Al Viro 5a5e4c2eca binfmt_elf: switch elf_map() to vm_mmap/vm_munmap
No reason to hold ->mmap_sem over the sequence

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-30 21:04:55 -04:00
Linus Torvalds 644473e9c6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace enhancements from Eric Biederman:
 "This is a course correction for the user namespace, so that we can
  reach an inexpensive, maintainable, and reasonably complete
  implementation.

  Highlights:
   - Config guards make it impossible to enable the user namespace and
     code that has not been converted to be user namespace safe.

   - Use of the new kuid_t type ensures the if you somehow get past the
     config guards the kernel will encounter type errors if you enable
     user namespaces and attempt to compile in code whose permission
     checks have not been updated to be user namespace safe.

   - All uids from child user namespaces are mapped into the initial
     user namespace before they are processed.  Removing the need to add
     an additional check to see if the user namespace of the compared
     uids remains the same.

   - With the user namespaces compiled out the performance is as good or
     better than it is today.

   - For most operations absolutely nothing changes performance or
     operationally with the user namespace enabled.

   - The worst case performance I could come up with was timing 1
     billion cache cold stat operations with the user namespace code
     enabled.  This went from 156s to 164s on my laptop (or 156ns to
     164ns per stat operation).

   - (uid_t)-1 and (gid_t)-1 are reserved as an internal error value.
     Most uid/gid setting system calls treat these value specially
     anyway so attempting to use -1 as a uid would likely cause
     entertaining failures in userspace.

   - If setuid is called with a uid that can not be mapped setuid fails.
     I have looked at sendmail, login, ssh and every other program I
     could think of that would call setuid and they all check for and
     handle the case where setuid fails.

   - If stat or a similar system call is called from a context in which
     we can not map a uid we lie and return overflowuid.  The LFS
     experience suggests not lying and returning an error code might be
     better, but the historical precedent with uids is different and I
     can not think of anything that would break by lying about a uid we
     can't map.

   - Capabilities are localized to the current user namespace making it
     safe to give the initial user in a user namespace all capabilities.

  My git tree covers all of the modifications needed to convert the core
  kernel and enough changes to make a system bootable to runlevel 1."

Fix up trivial conflicts due to nearby independent changes in fs/stat.c

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
  userns:  Silence silly gcc warning.
  cred: use correct cred accessor with regards to rcu read lock
  userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq
  userns: Convert cgroup permission checks to use uid_eq
  userns: Convert tmpfs to use kuid and kgid where appropriate
  userns: Convert sysfs to use kgid/kuid where appropriate
  userns: Convert sysctl permission checks to use kuid and kgids.
  userns: Convert proc to use kuid/kgid where appropriate
  userns: Convert ext4 to user kuid/kgid where appropriate
  userns: Convert ext3 to use kuid/kgid where appropriate
  userns: Convert ext2 to use kuid/kgid where appropriate.
  userns: Convert devpts to use kuid/kgid where appropriate
  userns: Convert binary formats to use kuid/kgid where appropriate
  userns: Add negative depends on entries to avoid building code that is userns unsafe
  userns: signal remove unnecessary map_cred_ns
  userns: Teach inode_capable to understand inodes whose uids map to other namespaces.
  userns: Fail exec for suid and sgid binaries with ids outside our user namespace.
  userns: Convert stat to return values mapped from kuids and kgids
  userns: Convert user specfied uids and gids in chown into kuids and kgid
  userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs
  ...
2012-05-23 17:42:39 -07:00
Eric W. Biederman ebc887b278 userns: Convert binary formats to use kuid/kgid where appropriate
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-05-15 14:59:25 -07:00
Linus Torvalds 6be5ceb02e VM: add "vm_mmap()" helper function
This continues the theme started with vm_brk() and vm_munmap():
vm_mmap() does the same thing as do_mmap(), but additionally does the
required VM locking.

This uninlines (and rewrites it to be clearer) do_mmap(), which sadly
duplicates it in mm/mmap.c and mm/nommu.c.  But that way we don't have
to export our internal do_mmap_pgoff() function.

Some day we hopefully don't have to export do_mmap() either, if all
modular users can become the simpler vm_mmap() instead.  We're actually
very close to that already, with the notable exception of the (broken)
use in i810, and a couple of stragglers in binfmt_elf.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-20 17:29:13 -07:00
Linus Torvalds e4eb1ff61b VM: add "vm_brk()" helper function
It does the same thing as "do_brk()", except it handles the VM locking
too.

It turns out that all external callers want that anyway, so we can make
do_brk() static to just mm/mmap.c while at it.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-20 17:28:17 -07:00
Linus Torvalds a591afc01d Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x32 support for x86-64 from Ingo Molnar:
 "This tree introduces the X32 binary format and execution mode for x86:
  32-bit data space binaries using 64-bit instructions and 64-bit kernel
  syscalls.

  This allows applications whose working set fits into a 32 bits address
  space to make use of 64-bit instructions while using a 32-bit address
  space with shorter pointers, more compressed data structures, etc."

Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c}

* 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  x32: Fix alignment fail in struct compat_siginfo
  x32: Fix stupid ia32/x32 inversion in the siginfo format
  x32: Add ptrace for x32
  x32: Switch to a 64-bit clock_t
  x32: Provide separate is_ia32_task() and is_x32_task() predicates
  x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls
  x86/x32: Fix the binutils auto-detect
  x32: Warn and disable rather than error if binutils too old
  x32: Only clear TIF_X32 flag once
  x32: Make sure TS_COMPAT is cleared for x32 tasks
  fs: Remove missed ->fds_bits from cessation use of fd_set structs internally
  fs: Fix close_on_exec pointer in alloc_fdtable
  x32: Drop non-__vdso weak symbols from the x32 VDSO
  x32: Fix coding style violations in the x32 VDSO code
  x32: Add x32 VDSO support
  x32: Allow x32 to be configured
  x32: If configured, add x32 system calls to system call tables
  x32: Handle process creation
  x32: Signal-related system calls
  x86: Add #ifdef CONFIG_COMPAT to <asm/sys_ia32.h>
  ...
2012-03-29 18:12:23 -07:00
Linus Torvalds 0195c00244 Disintegrate and delete asm/system.h
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Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system

Pull "Disintegrate and delete asm/system.h" from David Howells:
 "Here are a bunch of patches to disintegrate asm/system.h into a set of
  separate bits to relieve the problem of circular inclusion
  dependencies.

  I've built all the working defconfigs from all the arches that I can
  and made sure that they don't break.

  The reason for these patches is that I recently encountered a circular
  dependency problem that came about when I produced some patches to
  optimise get_order() by rewriting it to use ilog2().

  This uses bitops - and on the SH arch asm/bitops.h drags in
  asm-generic/get_order.h by a circuituous route involving asm/system.h.

  The main difficulty seems to be asm/system.h.  It holds a number of
  low level bits with no/few dependencies that are commonly used (eg.
  memory barriers) and a number of bits with more dependencies that
  aren't used in many places (eg.  switch_to()).

  These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

        Move memory barriers here.  This already done for MIPS and Alpha.

    (2) asm/switch_to.h

        Move switch_to() and related stuff here.

    (3) asm/exec.h

        Move arch_align_stack() here.  Other process execution related bits
        could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

        Move xchg() and cmpxchg() here as they're full word atomic ops and
        frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

        Move die() and related bits.

    (6) asm/auxvec.h

        Move AT_VECTOR_SIZE_ARCH here.

  Other arch headers are created as needed on a per-arch basis."

Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that.  We'll find out anything that got broken and fix it..

* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
  Delete all instances of asm/system.h
  Remove all #inclusions of asm/system.h
  Add #includes needed to permit the removal of asm/system.h
  Move all declarations of free_initmem() to linux/mm.h
  Disintegrate asm/system.h for OpenRISC
  Split arch_align_stack() out from asm-generic/system.h
  Split the switch_to() wrapper out of asm-generic/system.h
  Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
  Create asm-generic/barrier.h
  Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
  Disintegrate asm/system.h for Xtensa
  Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
  Disintegrate asm/system.h for Tile
  Disintegrate asm/system.h for Sparc
  Disintegrate asm/system.h for SH
  Disintegrate asm/system.h for Score
  Disintegrate asm/system.h for S390
  Disintegrate asm/system.h for PowerPC
  Disintegrate asm/system.h for PA-RISC
  Disintegrate asm/system.h for MN10300
  ...
2012-03-28 15:58:21 -07:00
David Howells 96f951edb1 Add #includes needed to permit the removal of asm/system.h
asm/system.h is a cause of circular dependency problems because it contains
commonly used primitive stuff like barrier definitions and uncommonly used
stuff like switch_to() that might require MMU definitions.

asm/system.h has been disintegrated by this point on all arches into the
following common segments:

 (1) asm/barrier.h

     Moved memory barrier definitions here.

 (2) asm/cmpxchg.h

     Moved xchg() and cmpxchg() here.  #included in asm/atomic.h.

 (3) asm/bug.h

     Moved die() and similar here.

 (4) asm/exec.h

     Moved arch_align_stack() here.

 (5) asm/elf.h

     Moved AT_VECTOR_SIZE_ARCH here.

 (6) asm/switch_to.h

     Moved switch_to() here.

Signed-off-by: David Howells <dhowells@redhat.com>
2012-03-28 18:30:03 +01:00
Jason Baron accb61fe7b coredump: add VM_NODUMP, MADV_NODUMP, MADV_CLEAR_NODUMP
Since we no longer need the VM_ALWAYSDUMP flag, let's use the freed bit
for 'VM_NODUMP' flag.  The idea is is to add a new madvise() flag:
MADV_DONTDUMP, which can be set by applications to specifically request
memory regions which should not dump core.

The specific application I have in mind is qemu: we can add a flag there
that wouldn't dump all of guest memory when qemu dumps core.  This flag
might also be useful for security sensitive apps that want to absolutely
make sure that parts of memory are not dumped.  To clear the flag use:
MADV_DODUMP.

[akpm@linux-foundation.org: s/MADV_NODUMP/MADV_DONTDUMP/, s/MADV_CLEAR_NODUMP/MADV_DODUMP/, per Roland]
[akpm@linux-foundation.org: fix up the architectures which broke]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Acked-by: Roland McGrath <roland@hack.frob.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:42 -07:00
Jason Baron 909af768e8 coredump: remove VM_ALWAYSDUMP flag
The motivation for this patchset was that I was looking at a way for a
qemu-kvm process, to exclude the guest memory from its core dump, which
can be quite large.  There are already a number of filter flags in
/proc/<pid>/coredump_filter, however, these allow one to specify 'types'
of kernel memory, not specific address ranges (which is needed in this
case).

Since there are no more vma flags available, the first patch eliminates
the need for the 'VM_ALWAYSDUMP' flag.  The flag is used internally by
the kernel to mark vdso and vsyscall pages.  However, it is simple
enough to check if a vma covers a vdso or vsyscall page without the need
for this flag.

The second patch then replaces the 'VM_ALWAYSDUMP' flag with a new
'VM_NODUMP' flag, which can be set by userspace using new madvise flags:
'MADV_DONTDUMP', and unset via 'MADV_DODUMP'.  The core dump filters
continue to work the same as before unless 'MADV_DONTDUMP' is set on the
region.

The qemu code which implements this features is at:

  http://people.redhat.com/~jbaron/qemu-dump/qemu-dump.patch

In my testing the qemu core dump shrunk from 383MB -> 13MB with this
patch.

I also believe that the 'MADV_DONTDUMP' flag might be useful for
security sensitive apps, which might want to select which areas are
dumped.

This patch:

The VM_ALWAYSDUMP flag is currently used by the coredump code to
indicate that a vma is part of a vsyscall or vdso section.  However, we
can determine if a vma is in one these sections by checking it against
the gate_vma and checking for a non-NULL return value from
arch_vma_name().  Thus, freeing a valuable vma bit.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Acked-by: Roland McGrath <roland@hack.frob.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:42 -07:00
Al Viro 19e5109fef take removal of PF_FORKNOEXEC to flush_old_exec()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:51 -04:00
Al Viro 8fc3dc5a3a __register_binfmt() made void
Just don't pass NULL to it - nobody does, anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:46 -04:00
H. Peter Anvin c8e252586f regset: Prevent null pointer reference on readonly regsets
The regset common infrastructure assumed that regsets would always
have .get and .set methods, but not necessarily .active methods.
Unfortunately people have since written regsets without .set methods.

Rather than putting in stub functions everywhere, handle regsets with
null .get or .set methods explicitly.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@hack.frob.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-02 11:38:15 -08:00
H. J. Lu 0953f65d5d elf: Allow core dump-related fields to be overridden
Allow some core dump-related fields to be overridden.  This allows
core dumps to work correctly for x32.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
2012-02-20 12:48:48 -08:00
David Daney e39f560239 fs: binfmt_elf: create Kconfig variable for PIE randomization
Randomization of PIE load address is hard coded in binfmt_elf.c for X86
and ARM.  Create a new Kconfig variable
(CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE) for this and use it instead.  Thus
architecture specific policy is pushed out of the generic binfmt_elf.c and
into the architecture Kconfig files.

X86 and ARM Kconfigs are modified to select the new variable so there is
no change in behavior.  A follow on patch will select it for MIPS too.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 16:30:51 -08:00
Jiri Kosina a3defbe5c3 binfmt_elf: fix PIE execution with randomization disabled
The case of address space randomization being disabled in runtime through
randomize_va_space sysctl is not treated properly in load_elf_binary(),
resulting in SIGKILL coming at exec() time for certain PIE-linked binaries
in case the randomization has been disabled at runtime prior to calling
exec().

Handle the randomize_va_space == 0 case the same way as if we were not
supporting .text randomization at all.

Based on original patch by H.J. Lu and Josh Boyer.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: H.J. Lu <hongjiu.lu@intel.com>
Cc: <stable@kernel.org>
Tested-by: Josh Boyer <jwboyer@redhat.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-02 16:06:58 -07:00
Al Viro 1b5d783c94 consolidate BINPRM_FLAGS_ENFORCE_NONDUMP handling
new helper: would_dump(bprm, file).  Checks if we are allowed to
read the file and if we are not - sets ENFORCE_NODUMP.  Exported,
used in places that previously open-coded the same logics.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:43:10 -04:00
Jiri Kosina 4471a675df brk: COMPAT_BRK: fix detection of randomized brk
5520e89 ("brk: fix min_brk lower bound computation for COMPAT_BRK")
tried to get the whole logic of brk randomization for legacy
(libc5-based) applications finally right.

It turns out that the way to detect whether brk has actually been
randomized in the end or not introduced by that patch still doesn't work
for those binaries, as reported by Geert:

: /sbin/init from my old m68k ramdisk exists prematurely.
:
: Before the patch:
:
: | brk(0x80005c8e)                         = 0x80006000
:
: After the patch:
:
: | brk(0x80005c8e)                         = 0x80005c8e
:
: Old libc5 considers brk() to have failed if the return value is not
: identical to the requested value.

I don't like it, but currently see no better option than a bit flag in
task_struct to catch the CONFIG_COMPAT_BRK && randomize_va_space == 2
case.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-14 16:06:55 -07:00
Linus Torvalds b81a618dcd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  deal with races in /proc/*/{syscall,stack,personality}
  proc: enable writing to /proc/pid/mem
  proc: make check_mem_permission() return an mm_struct on success
  proc: hold cred_guard_mutex in check_mem_permission()
  proc: disable mem_write after exec
  mm: implement access_remote_vm
  mm: factor out main logic of access_process_vm
  mm: use mm_struct to resolve gate vma's in __get_user_pages
  mm: arch: rename in_gate_area_no_task to in_gate_area_no_mm
  mm: arch: make in_gate_area take an mm_struct instead of a task_struct
  mm: arch: make get_gate_vma take an mm_struct instead of a task_struct
  x86: mark associated mm when running a task in 32 bit compatibility mode
  x86: add context tag to mark mm when running a task in 32-bit compatibility mode
  auxv: require the target to be tracable (or yourself)
  close race in /proc/*/environ
  report errors in /proc/*/*map* sanely
  pagemap: close races with suid execve
  make sessionid permissions in /proc/*/task/* match those in /proc/*
  fix leaks in path_lookupat()

Fix up trivial conflicts in fs/proc/base.c
2011-03-23 20:51:42 -07:00
Stephen Wilson 31db58b3ab mm: arch: make get_gate_vma take an mm_struct instead of a task_struct
Morally, the presence of a gate vma is more an attribute of a particular mm than
a particular task.  Moreover, dropping the dependency on task_struct will help
make both existing and future operations on mm's more flexible and convenient.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-23 16:36:54 -04:00
David Daney 1a530a6f23 binfmt_elf: quiet GCC-4.6 'set but not used' warning in load_elf_binary()
With GCC-4.6 we get warnings about things being 'set but not used'.

In load_elf_binary() this can happen with reloc_func_desc if ELF_PLAT_INIT
is defined, but doesn't use the reloc_func_desc argument.

Quiet the warning/error by marking reloc_func_desc as __maybe_unused.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:15 -07:00
Mikael Pettersson f670d0ecda binfmt_elf: cleanups
This cleans up a few bits in binfmt_elf.c and binfmts.h:

- the hasvdso field in struct linux_binfmt is unused, so remove it and
  the only initialization of it

- the elf_map CPP symbol is not defined anywhere in the kernel, so
  remove an unnecessary #ifndef elf_map

- reduce excessive indentation in elf_format's initializer

- add missing spaces, remove extraneous spaces

No functional changes, but tested on x86 (32 and 64 bit), powerpc (32 and
64 bit), sparc64, arm, and alpha.

Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:12 -08:00
Nicolas Pitre e4eab08d60 ARM: 6342/1: fix ASLR of PIE executables
Since commits 990cb8acf2 and cc92c28b2d, it is possible to have full
address space layout randomization (ASLR) on ARM.  Except that one small
change was missing for ASLR of PIE executables.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-08 10:02:53 +01:00
Masami Hiramatsu 30736a4d43 coredump: pass mm->flags as a coredump parameter for consistency
Pass mm->flags as a coredump parameter for consistency.

 ---
1787         if (mm->core_state || !get_dumpable(mm)) {  <- (1)
1788                 up_write(&mm->mmap_sem);
1789                 put_cred(cred);
1790                 goto fail;
1791         }
1792
[...]
1798         if (get_dumpable(mm) == 2) {    /* Setuid core dump mode */ <-(2)
1799                 flag = O_EXCL;          /* Stop rewrite attacks */
1800                 cred->fsuid = 0;        /* Dump root private */
1801         }
 ---

Since dumpable bits are not protected by lock, there is a chance to change
these bits between (1) and (2).

To solve this issue, this patch copies mm->flags to
coredump_params.mm_flags at the beginning of do_coredump() and uses it
instead of get_dumpable() while dumping core.

This copy is also passed to binfmt->core_dump, since elf*_core_dump() uses
dump_filter bits in mm->flags.

[akpm@linux-foundation.org: fix merge]
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 11:26:46 -08:00
Daisuke HATAYAMA 8d9032bbe4 elf coredump: add extended numbering support
The current ELF dumper implementation can produce broken corefiles if
program headers exceed 65535.  This number is determined by the number of
vmas which the process have.  In particular, some extreme programs may use
more than 65535 vmas.  (If you google max_map_count, you can find some
users facing this problem.) This kind of program never be able to generate
correct coredumps.

This patch implements ``extended numbering'' that uses sh_info field of
the first section header instead of e_phnum field in order to represent
upto 4294967295 vmas.

This is supported by
AMD64-ABI(http://www.x86-64.org/documentation.html) and
Solaris(http://docs.sun.com/app/docs/doc/817-1984/).
Of course, we are preparing patches for gdb and binutils.

Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 11:26:46 -08:00
Daisuke HATAYAMA 93eb211e6c elf coredump: make offset calculation process and writing process explicit
By the next patch, elf_core_dump() and elf_fdpic_core_dump() will support
extended numbering and so will produce the corefiles with section header
table in a special case.

The problem is the process of writing a file header offset of the section
header table into e_shoff field of the ELF header.  ELF header is
positioned at the beginning of the corefile, while section header at the
end.  So, we need to take which of the following ways:

 1. Seek backward to retry writing operation for ELF header
    after writing process for a whole part

 2. Make offset calculation process and writing process
    totally sequential

The clause 1.  is not always possible: one cannot assume that file system
supports seek function.  Consider the no_llseek case.

Therefore, this patch adopts the clause 2.

Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 11:26:46 -08:00
Daisuke HATAYAMA 1fcccbac89 elf coredump: replace ELF_CORE_EXTRA_* macros by functions
elf_core_dump() and elf_fdpic_core_dump() use #ifdef and the corresponding
macro for hiding _multiline_ logics in functions.  This patch removes
#ifdef and replaces ELF_CORE_EXTRA_* by corresponding functions.  For
architectures not implemeonting ELF_CORE_EXTRA_*, we use weak functions in
order to reduce a range of modification.

This cleanup is for my next patches, but I think this cleanup itself is
worth doing regardless of my firnal purpose.

Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 11:26:45 -08:00
Daisuke HATAYAMA 088e7af73a coredump: move dump_write() and dump_seek() into a header file
My next patch will replace ELF_CORE_EXTRA_* macros by functions, putting
them into other newly created *.c files.  Then, each files will contain
dump_write(), where each pair of binfmt_*.c and elfcore.c should be the
same.  So, this patch moves them into a header file with dump_seek().
Also, the patch deletes confusing DUMP_WRITE macros in each files.

Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 11:26:45 -08:00
Linus Torvalds 221af7f87b Split 'flush_old_exec' into two functions
'flush_old_exec()' is the point of no return when doing an execve(), and
it is pretty badly misnamed.  It doesn't just flush the old executable
environment, it also starts up the new one.

Which is very inconvenient for things like setting up the new
personality, because we want the new personality to affect the starting
of the new environment, but at the same time we do _not_ want the new
personality to take effect if flushing the old one fails.

As a result, the x86-64 '32-bit' personality is actually done using this
insane "I'm going to change the ABI, but I haven't done it yet" bit
(TIF_ABI_PENDING), with SET_PERSONALITY() not actually setting the
personality, but just the "pending" bit, so that "flush_thread()" can do
the actual personality magic.

This patch in no way changes any of that insanity, but it does split the
'flush_old_exec()' function up into a preparatory part that can fail
(still called flush_old_exec()), and a new part that will actually set
up the new exec environment (setup_new_exec()).  All callers are changed
to trivially comply with the new world order.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-29 08:22:01 -08:00
Masami Hiramatsu f6151dfea2 mm: introduce coredump parameter structure
Introduce coredump parameter data structure (struct coredump_params) to
simplify binfmt->core_dump() arguments.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-17 15:45:31 -08:00
Christoph Hellwig 698ba7b5a3 elf: kill USE_ELF_CORE_DUMP
Currently all architectures but microblaze unconditionally define
USE_ELF_CORE_DUMP.  The microblaze omission seems like an error to me, so
let's kill this ifdef and make sure we are the same everywhere.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: <linux-arch@vger.kernel.org>
Cc: Michal Simek <michal.simek@petalogix.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:12 -08:00
André Goddard Rosa af901ca181 tree-wide: fix assorted typos all over the place
That is "success", "unknown", "through", "performance", "[re|un]mapping"
, "access", "default", "reasonable", "[con]currently", "temperature"
, "channel", "[un]used", "application", "example","hierarchy", "therefore"
, "[over|under]flow", "contiguous", "threshold", "enough" and others.

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-12-04 15:39:55 +01:00
Amerigo Wang 0cf062d0ff elf: clean up fill_note_info()
Introduce a helper function elf_note_info_init() to help fill_note_info()
to do initializations, also fix the potential memory leaks.

[akpm@linux-foundation.org: remove NUM_NOTES]
Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24 07:21:01 -07:00