mirror of https://gitee.com/openkylin/linux.git
855 Commits
Author | SHA1 | Message | Date |
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Konstantin Khlebnikov | ca18255185 |
kmemleak: clear stale pointers from task stacks
Kmemleak considers any pointers on task stacks as references. This patch clears newly allocated and reused vmap stacks. Link: http://lkml.kernel.org/r/150728990124.744199.8403409836394318684.stgit@buzz Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Sherry Yang | a1b2289cef |
android: binder: drop lru lock in isolate callback
Drop the global lru lock in isolate callback before calling zap_page_range which calls cond_resched, and re-acquire the global lru lock before returning. Also change return code to LRU_REMOVED_RETRY. Use mmput_async when fail to acquire mmap sem in an atomic context. Fix "BUG: sleeping function called from invalid context" errors when CONFIG_DEBUG_ATOMIC_SLEEP is enabled. Also restore mmput_async, which was initially introduced in commit |
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Linus Torvalds | 7f85565a3f |
selinux/stable-4.14 PR 20170831
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Davidlohr Bueso | a23ba907d5 |
locking/rtmutex: replace top-waiter and pi_waiters leftmost caching
... with the generic rbtree flavor instead. No changes in semantics whatsoever. Link: http://lkml.kernel.org/r/20170719014603.19029-10-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Jérôme Glisse | 133ff0eac9 |
mm/hmm: heterogeneous memory management (HMM for short)
HMM provides 3 separate types of functionality: - Mirroring: synchronize CPU page table and device page table - Device memory: allocating struct page for device memory - Migration: migrating regular memory to device memory This patch introduces some common helpers and definitions to all of those 3 functionality. Link: http://lkml.kernel.org/r/20170817000548.32038-3-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Signed-off-by: Sherry Cheung <SCheung@nvidia.com> Signed-off-by: Subhash Gutti <sgutti@nvidia.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Rik van Riel | d2cd9ede6e |
mm,fork: introduce MADV_WIPEONFORK
Introduce MADV_WIPEONFORK semantics, which result in a VMA being empty in the child process after fork. This differs from MADV_DONTFORK in one important way. If a child process accesses memory that was MADV_WIPEONFORK, it will get zeroes. The address ranges are still valid, they are just empty. If a child process accesses memory that was MADV_DONTFORK, it will get a segmentation fault, since those address ranges are no longer valid in the child after fork. Since MADV_DONTFORK also seems to be used to allow very large programs to fork in systems with strict memory overcommit restrictions, changing the semantics of MADV_DONTFORK might break existing programs. MADV_WIPEONFORK only works on private, anonymous VMAs. The use case is libraries that store or cache information, and want to know that they need to regenerate it in the child process after fork. Examples of this would be: - systemd/pulseaudio API checks (fail after fork) (replacing a getpid check, which is too slow without a PID cache) - PKCS#11 API reinitialization check (mandated by specification) - glibc's upcoming PRNG (reseed after fork) - OpenSSL PRNG (reseed after fork) The security benefits of a forking server having a re-inialized PRNG in every child process are pretty obvious. However, due to libraries having all kinds of internal state, and programs getting compiled with many different versions of each library, it is unreasonable to expect calling programs to re-initialize everything manually after fork. A further complication is the proliferation of clone flags, programs bypassing glibc's functions to call clone directly, and programs calling unshare, causing the glibc pthread_atfork hook to not get called. It would be better to have the kernel take care of this automatically. The patch also adds MADV_KEEPONFORK, to undo the effects of a prior MADV_WIPEONFORK. This is similar to the OpenBSD minherit syscall with MAP_INHERIT_ZERO: https://man.openbsd.org/minherit.2 [akpm@linux-foundation.org: numerically order arch/parisc/include/uapi/asm/mman.h #defines] Link: http://lkml.kernel.org/r/20170811212829.29186-3-riel@redhat.com Signed-off-by: Rik van Riel <riel@redhat.com> Reported-by: Florian Weimer <fweimer@redhat.com> Reported-by: Colm MacCártaigh <colm@allcosts.net> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Kees Cook <keescook@chromium.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Drewry <wad@chromium.org> Cc: <linux-api@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrea Arcangeli | 2129258024 |
mm: oom: let oom_reap_task and exit_mmap run concurrently
This is purely required because exit_aio() may block and exit_mmap() may
never start, if the oom_reap_task cannot start running on a mm with
mm_users == 0.
At the same time if the OOM reaper doesn't wait at all for the memory of
the current OOM candidate to be freed by exit_mmap->unmap_vmas, it would
generate a spurious OOM kill.
If it wasn't because of the exit_aio or similar blocking functions in
the last mmput, it would be enough to change the oom_reap_task() in the
case it finds mm_users == 0, to wait for a timeout or to wait for
__mmput to set MMF_OOM_SKIP itself, but it's not just exit_mmap the
problem here so the concurrency of exit_mmap and oom_reap_task is
apparently warranted.
It's a non standard runtime, exit_mmap() runs without mmap_sem, and
oom_reap_task runs with the mmap_sem for reading as usual (kind of
MADV_DONTNEED).
The race between the two is solved with a combination of
tsk_is_oom_victim() (serialized by task_lock) and MMF_OOM_SKIP
(serialized by a dummy down_write/up_write cycle on the same lines of
the ksm_exit method).
If the oom_reap_task() may be running concurrently during exit_mmap,
exit_mmap will wait it to finish in down_write (before taking down mm
structures that would make the oom_reap_task fail with use after free).
If exit_mmap comes first, oom_reap_task() will skip the mm if
MMF_OOM_SKIP is already set and in turn all memory is already freed and
furthermore the mm data structures may already have been taken down by
free_pgtables.
[aarcange@redhat.com: incremental one liner]
Link: http://lkml.kernel.org/r/20170726164319.GC29716@redhat.com
[rientjes@google.com: remove unused mmput_async]
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708141733130.50317@chino.kir.corp.google.com
[aarcange@redhat.com: microoptimization]
Link: http://lkml.kernel.org/r/20170817171240.GB5066@redhat.com
Link: http://lkml.kernel.org/r/20170726162912.GA29716@redhat.com
Fixes:
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Linus Torvalds | 04759194dc |
arm64 updates for 4.14:
- VMAP_STACK support, allowing the kernel stacks to be allocated in the vmalloc space with a guard page for trapping stack overflows. One of the patches introduces THREAD_ALIGN and changes the generic alloc_thread_stack_node() to use this instead of THREAD_SIZE (no functional change for other architectures) - Contiguous PTE hugetlb support re-enabled (after being reverted a couple of times). We now have the semantics agreed in the generic mm layer together with API improvements so that the architecture code can detect between contiguous and non-contiguous huge PTEs - Initial support for persistent memory on ARM: DC CVAP instruction exposed to user space (HWCAP) and the in-kernel pmem API implemented - raid6 improvements for arm64: faster algorithm for the delta syndrome and implementation of the recovery routines using Neon - FP/SIMD refactoring and removal of support for Neon in interrupt context. This is in preparation for full SVE support - PTE accessors converted from inline asm to cmpxchg so that we can use LSE atomics if available (ARMv8.1) - Perf support for Cortex-A35 and A73 - Non-urgent fixes and cleanups -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEE5RElWfyWxS+3PLO2a9axLQDIXvEFAlmuunYACgkQa9axLQDI XvEH9BAAo8V94GOMkX6HkT+2hjkl7DQ9krjumzmfzLV5AdgHMMzBNozmWKOCzgh0 yaxRcTUju3EyNeKhADr7yLiKDH8fnRPmYEJiVrwfgo7MaPApaCorr7LLIXfPGuxe DTBHw+oxRMjlmaHeATX4PBWfQxAx+vjjhHqv3Qpmvdm4nYqR+0hZomH2BNsu64fk AkSeUCxfCEyzSFIKuQM04M4zhSSZHz1tDxWI0b0RcK73qqEOuYZNkn6qxSKP5J4X b2Y2U8nmxJ5C2fXpDYZaK9shiJ4Vu7X3Ocf/M7hsJzGY5z4dhnmUmxpHROaNiSvo hCx7POYKyAPovps7zMSqcdsujkqOIQO8RHp4zGXx/pIr1RumjIiCY+RGpUYGibvU N4Px5hZNneuHaPZZ+sWjOOdNB28xyzeUp2UK9Bb6uHB+/3xssMAD8Fd/b2ZLnS6a YW3wrZmqA+ckfETsSRibabTs/ayqYHs2SDVwnlDJGtn+4Pw8oQpwGrwokxLQuuw3 uF2sNEPhJz+dcy21q3udYAQE1qOJBlLqTptgP96CHoVqh8X6nYSi5obT7y30ln3n dhpZGOdi6R8YOouxgXS3Wg07pxn444L/VzDw5ku/5DkdryPOZCSRbk/2t8If6oDM 2VD6PCbTx3hsGc7SZ7FdSwIysD2j446u40OMGdH2iLB5jWBwyOM= =vd0/ -----END PGP SIGNATURE----- Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - VMAP_STACK support, allowing the kernel stacks to be allocated in the vmalloc space with a guard page for trapping stack overflows. One of the patches introduces THREAD_ALIGN and changes the generic alloc_thread_stack_node() to use this instead of THREAD_SIZE (no functional change for other architectures) - Contiguous PTE hugetlb support re-enabled (after being reverted a couple of times). We now have the semantics agreed in the generic mm layer together with API improvements so that the architecture code can detect between contiguous and non-contiguous huge PTEs - Initial support for persistent memory on ARM: DC CVAP instruction exposed to user space (HWCAP) and the in-kernel pmem API implemented - raid6 improvements for arm64: faster algorithm for the delta syndrome and implementation of the recovery routines using Neon - FP/SIMD refactoring and removal of support for Neon in interrupt context. This is in preparation for full SVE support - PTE accessors converted from inline asm to cmpxchg so that we can use LSE atomics if available (ARMv8.1) - Perf support for Cortex-A35 and A73 - Non-urgent fixes and cleanups * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (75 commits) arm64: cleanup {COMPAT_,}SET_PERSONALITY() macro arm64: introduce separated bits for mm_context_t flags arm64: hugetlb: Cleanup setup_hugepagesz arm64: Re-enable support for contiguous hugepages arm64: hugetlb: Override set_huge_swap_pte_at() to support contiguous hugepages arm64: hugetlb: Override huge_pte_clear() to support contiguous hugepages arm64: hugetlb: Handle swap entries in huge_pte_offset() for contiguous hugepages arm64: hugetlb: Add break-before-make logic for contiguous entries arm64: hugetlb: Spring clean huge pte accessors arm64: hugetlb: Introduce pte_pgprot helper arm64: hugetlb: set_huge_pte_at Add WARN_ON on !pte_present arm64: kexec: have own crash_smp_send_stop() for crash dump for nonpanic cores arm64: dma-mapping: Mark atomic_pool as __ro_after_init arm64: dma-mapping: Do not pass data to gen_pool_set_algo() arm64: Remove the !CONFIG_ARM64_HW_AFDBM alternative code paths arm64: Ignore hardware dirty bit updates in ptep_set_wrprotect() arm64: Move PTE_RDONLY bit handling out of set_pte_at() kvm: arm64: Convert kvm_set_s2pte_readonly() from inline asm to cmpxchg() arm64: Convert pte handling from inline asm to using (cmp)xchg arm64: neon/efi: Make EFI fpsimd save/restore variables static ... |
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Ingo Molnar | edc2988c54 |
Merge branch 'linus' into locking/core, to fix up conflicts
Conflicts: mm/page_alloc.c Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Eric Biggers | 355627f518 |
mm, uprobes: fix multiple free of ->uprobes_state.xol_area
Commit |
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Eric Biggers | 2b7e8665b4 |
fork: fix incorrect fput of ->exe_file causing use-after-free
Commit |
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Mark Rutland | 48ac3c18cc |
fork: allow arch-override of VMAP stack alignment
In some cases, an architecture might wish its stacks to be aligned to a boundary larger than THREAD_SIZE. For example, using an alignment of double THREAD_SIZE can allow for stack overflows smaller than THREAD_SIZE to be detected by checking a single bit of the stack pointer. This patch allows architectures to override the alignment of VMAP'd stacks, by defining THREAD_ALIGN. Where not defined, this defaults to THREAD_SIZE, as is the case today. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: linux-kernel@vger.kernel.org |
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Ingo Molnar | 040cca3ab2 |
Merge branch 'linus' into locking/core, to resolve conflicts
Conflicts:
include/linux/mm_types.h
mm/huge_memory.c
I removed the smp_mb__before_spinlock() like the following commit does:
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Nadav Amit | 16af97dc5a |
mm: migrate: prevent racy access to tlb_flush_pending
Patch series "fixes of TLB batching races", v6.
It turns out that Linux TLB batching mechanism suffers from various
races. Races that are caused due to batching during reclamation were
recently handled by Mel and this patch-set deals with others. The more
fundamental issue is that concurrent updates of the page-tables allow
for TLB flushes to be batched on one core, while another core changes
the page-tables. This other core may assume a PTE change does not
require a flush based on the updated PTE value, while it is unaware that
TLB flushes are still pending.
This behavior affects KSM (which may result in memory corruption) and
MADV_FREE and MADV_DONTNEED (which may result in incorrect behavior). A
proof-of-concept can easily produce the wrong behavior of MADV_DONTNEED.
Memory corruption in KSM is harder to produce in practice, but was
observed by hacking the kernel and adding a delay before flushing and
replacing the KSM page.
Finally, there is also one memory barrier missing, which may affect
architectures with weak memory model.
This patch (of 7):
Setting and clearing mm->tlb_flush_pending can be performed by multiple
threads, since mmap_sem may only be acquired for read in
task_numa_work(). If this happens, tlb_flush_pending might be cleared
while one of the threads still changes PTEs and batches TLB flushes.
This can lead to the same race between migration and
change_protection_range() that led to the introduction of
tlb_flush_pending. The result of this race was data corruption, which
means that this patch also addresses a theoretically possible data
corruption.
An actual data corruption was not observed, yet the race was was
confirmed by adding assertion to check tlb_flush_pending is not set by
two threads, adding artificial latency in change_protection_range() and
using sysctl to reduce kernel.numa_balancing_scan_delay_ms.
Link: http://lkml.kernel.org/r/20170802000818.4760-2-namit@vmware.com
Fixes:
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Byungchul Park | b09be676e0 |
locking/lockdep: Implement the 'crossrelease' feature
Lockdep is a runtime locking correctness validator that detects and reports a deadlock or its possibility by checking dependencies between locks. It's useful since it does not report just an actual deadlock but also the possibility of a deadlock that has not actually happened yet. That enables problems to be fixed before they affect real systems. However, this facility is only applicable to typical locks, such as spinlocks and mutexes, which are normally released within the context in which they were acquired. However, synchronization primitives like page locks or completions, which are allowed to be released in any context, also create dependencies and can cause a deadlock. So lockdep should track these locks to do a better job. The 'crossrelease' implementation makes these primitives also be tracked. Signed-off-by: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-6-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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James Morris | 53a2ebaaab | sync to Linus v4.13-rc2 for subsystem developers to work against | |
Tetsuo Handa | 3cf2993145 |
LSM: Remove security_task_create() hook.
Since commit
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Rik van Riel | 7cd815bce8 |
fork,random: use get_random_canary() to set tsk->stack_canary
Use the ascii-armor canary to prevent unterminated C string overflows from being able to successfully overwrite the canary, even if they somehow obtain the canary value. Inspired by execshield ascii-armor and Daniel Micay's linux-hardened tree. Link: http://lkml.kernel.org/r/20170524155751.424-3-riel@redhat.com Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Daniel Micay <danielmicay@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Dmitry Vyukov | e41d58185f |
fault-inject: support systematic fault injection
Add /proc/self/task/<current-tid>/fail-nth file that allows failing 0-th, 1-st, 2-nd and so on calls systematically. Excerpt from the added documentation: "Write to this file of integer N makes N-th call in the current task fail (N is 0-based). Read from this file returns a single char 'Y' or 'N' that says if the fault setup with a previous write to this file was injected or not, and disables the fault if it wasn't yet injected. Note that this file enables all types of faults (slab, futex, etc). This setting takes precedence over all other generic settings like probability, interval, times, etc. But per-capability settings (e.g. fail_futex/ignore-private) take precedence over it. This feature is intended for systematic testing of faults in a single system call. See an example below" Why add a new setting: 1. Existing settings are global rather than per-task. So parallel testing is not possible. 2. attr->interval is close but it depends on attr->count which is non reset to 0, so interval does not work as expected. 3. Trying to model this with existing settings requires manipulations of all of probability, interval, times, space, task-filter and unexposed count and per-task make-it-fail files. 4. Existing settings are per-failure-type, and the set of failure types is potentially expanding. 5. make-it-fail can't be changed by unprivileged user and aggressive stress testing better be done from an unprivileged user. Similarly, this would require opening the debugfs files to the unprivileged user, as he would need to reopen at least times file (not possible to pre-open before dropping privs). The proposed interface solves all of the above (see the example). We want to integrate this into syzkaller fuzzer. A prototype has found 10 bugs in kernel in first day of usage: https://groups.google.com/forum/#!searchin/syzkaller/%22FAULT_INJECTION%22%7Csort:relevance I've made the current interface work with all types of our sandboxes. For setuid the secret sauce was prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) to make /proc entries non-root owned. So I am fine with the current version of the code. [akpm@linux-foundation.org: fix build] Link: http://lkml.kernel.org/r/20170328130128.101773-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Christoph Lameter | 112166f88c |
kernel/fork.c: virtually mapped stacks: do not disable interrupts
The reason to disable interrupts seems to be to avoid switching to a different processor while handling per cpu data using individual loads and stores. If we use per cpu RMV primitives we will not have to disable interrupts. Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1705171055130.5898@east.gentwo.org Signed-off-by: Christoph Lameter <cl@linux.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Linus Torvalds | 4fde846ac0 |
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner: "This scheduler update provides: - The (hopefully) final fix for the vtime accounting issues which were around for quite some time - Use types known to user space in UAPI headers to unbreak user space builds - Make load balancing respect the current scheduling domain again instead of evaluating unrelated CPUs" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/headers/uapi: Fix linux/sched/types.h userspace compilation errors sched/fair: Fix load_balance() affinity redo path sched/cputime: Accumulate vtime on top of nsec clocksource sched/cputime: Move the vtime task fields to their own struct sched/cputime: Rename vtime fields sched/cputime: Always set tsk->vtime_snap_whence after accounting vtime vtime, sched/cputime: Remove vtime_account_user() Revert "sched/cputime: Refactor the cputime_adjust() code" |
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Johannes Weiner | ed52be7bfd |
mm: memcontrol: use generic mod_memcg_page_state for kmem pages
The kmem-specific functions do the same thing. Switch and drop. Link: http://lkml.kernel.org/r/20170530181724.27197-5-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Frederic Weisbecker | bac5b6b6b1 |
sched/cputime: Move the vtime task fields to their own struct
We are about to add vtime accumulation fields to the task struct. Let's avoid more bloatification and gather vtime information to their own struct. Tested-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1498756511-11714-5-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Frederic Weisbecker | 60a9ce57e7 |
sched/cputime: Rename vtime fields
The current "snapshot" based naming on vtime fields suggests we record some past event but that's a low level picture of their actual purpose which comes out blurry. The real point of these fields is to run a basic state machine that tracks down cputime entry while switching between contexts. So lets reflect that with more meaningful names. Tested-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1498756511-11714-4-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Linus Torvalds | d024baa58a |
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull kthread fix from Thomas Gleixner: "A single fix which prevents a use after free when kthread fork fails" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kthread: Fix use-after-free if kthread fork fails |
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Vegard Nossum | 4d6501dce0 |
kthread: Fix use-after-free if kthread fork fails
If a kthread forks (e.g. usermodehelper since commit |
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Kirill Tkhai | 3fd3722621 |
pid_ns: Fix race between setns'ed fork() and zap_pid_ns_processes()
Imagine we have a pid namespace and a task from its parent's pid_ns,
which made setns() to the pid namespace. The task is doing fork(),
while the pid namespace's child reaper is dying. We have the race
between them:
Task from parent pid_ns Child reaper
copy_process() ..
alloc_pid() ..
.. zap_pid_ns_processes()
.. disable_pid_allocation()
.. read_lock(&tasklist_lock)
.. iterate over pids in pid_ns
.. kill tasks linked to pids
.. read_unlock(&tasklist_lock)
write_lock_irq(&tasklist_lock); ..
attach_pid(p, PIDTYPE_PID); ..
.. ..
So, just created task p won't receive SIGKILL signal,
and the pid namespace will be in contradictory state.
Only manual kill will help there, but does the userspace
care about this? I suppose, the most users just inject
a task into a pid namespace and wait a SIGCHLD from it.
The patch fixes the problem. It simply checks for
(pid_ns->nr_hashed & PIDNS_HASH_ADDING) in copy_process().
We do it under the tasklist_lock, and can't skip
PIDNS_HASH_ADDING as noted by Oleg:
"zap_pid_ns_processes() does disable_pid_allocation()
and then takes tasklist_lock to kill the whole namespace.
Given that copy_process() checks PIDNS_HASH_ADDING
under write_lock(tasklist) they can't race;
if copy_process() takes this lock first, the new child will
be killed, otherwise copy_process() can't miss
the change in ->nr_hashed."
If allocation is disabled, we just return -ENOMEM
like it's made for such cases in alloc_pid().
v2: Do not move disable_pid_allocation(), do not
introduce a new variable in copy_process() and simplify
the patch as suggested by Oleg Nesterov.
Account the problem with double irq enabling
found by Eric W. Biederman.
Fixes:
|
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Linus Torvalds | 1b84fc1503 |
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull stackprotector fixlet from Ingo Molnar: "A single fix/enhancement to increase stackprotector canary randomness on 64-bit kernels with very little cost" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: stackprotector: Increase the per-task stack canary's random range from 32 bits to 64 bits on 64-bit platforms |
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Linus Torvalds | de4d195308 |
Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar: "The main changes are: - Debloat RCU headers - Parallelize SRCU callback handling (plus overlapping patches) - Improve the performance of Tree SRCU on a CPU-hotplug stress test - Documentation updates - Miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (74 commits) rcu: Open-code the rcu_cblist_n_lazy_cbs() function rcu: Open-code the rcu_cblist_n_cbs() function rcu: Open-code the rcu_cblist_empty() function rcu: Separately compile large rcu_segcblist functions srcu: Debloat the <linux/rcu_segcblist.h> header srcu: Adjust default auto-expediting holdoff srcu: Specify auto-expedite holdoff time srcu: Expedite first synchronize_srcu() when idle srcu: Expedited grace periods with reduced memory contention srcu: Make rcutorture writer stalls print SRCU GP state srcu: Exact tracking of srcu_data structures containing callbacks srcu: Make SRCU be built by default srcu: Fix Kconfig botch when SRCU not selected rcu: Make non-preemptive schedule be Tasks RCU quiescent state srcu: Expedite srcu_schedule_cbs_snp() callback invocation srcu: Parallelize callback handling kvm: Move srcu_struct fields to end of struct kvm rcu: Fix typo in PER_RCU_NODE_PERIOD header comment rcu: Use true/false in assignment to bool rcu: Use bool value directly ... |
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Michal Hocko | 19809c2da2 |
mm, vmalloc: use __GFP_HIGHMEM implicitly
__vmalloc* allows users to provide gfp flags for the underlying allocation. This API is quite popular $ git grep "=[[:space:]]__vmalloc\|return[[:space:]]*__vmalloc" | wc -l 77 The only problem is that many people are not aware that they really want to give __GFP_HIGHMEM along with other flags because there is really no reason to consume precious lowmemory on CONFIG_HIGHMEM systems for pages which are mapped to the kernel vmalloc space. About half of users don't use this flag, though. This signals that we make the API unnecessarily too complex. This patch simply uses __GFP_HIGHMEM implicitly when allocating pages to be mapped to the vmalloc space. Current users which add __GFP_HIGHMEM are simplified and drop the flag. Link: http://lkml.kernel.org/r/20170307141020.29107-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Cristopher Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
Hoeun Ryu | 19659c59af |
fork: free vmapped stacks in cache when cpus are offline
Using virtually mapped stack, kernel stacks are allocated via vmalloc. In the current implementation, two stacks per cpu can be cached when tasks are freed and the cached stacks are used again in task duplications. But the cached stacks may remain unfreed even when cpu are offline. By adding a cpu hotplug callback to free the cached stacks when a cpu goes offline, the pages of the cached stacks are not wasted. Link: http://lkml.kernel.org/r/1487076043-17802-1-git-send-email-hoeun.ryu@gmail.com Signed-off-by: Hoeun Ryu <hoeun.ryu@gmail.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Mateusz Guzik <mguzik@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
Daniel Micay | 5ea30e4e58 |
stackprotector: Increase the per-task stack canary's random range from 32 bits to 64 bits on 64-bit platforms
The stack canary is an 'unsigned long' and should be fully initialized to random data rather than only 32 bits of random data. Signed-off-by: Daniel Micay <danielmicay@gmail.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Arjan van Ven <arjan@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-hardening@lists.openwall.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20170504133209.3053-1-danielmicay@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
|
Linus Torvalds | 0302e28dee |
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris: "Highlights: IMA: - provide ">" and "<" operators for fowner/uid/euid rules KEYS: - add a system blacklist keyring - add KEYCTL_RESTRICT_KEYRING, exposes keyring link restriction functionality to userland via keyctl() LSM: - harden LSM API with __ro_after_init - add prlmit security hook, implement for SELinux - revive security_task_alloc hook TPM: - implement contextual TPM command 'spaces'" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (98 commits) tpm: Fix reference count to main device tpm_tis: convert to using locality callbacks tpm: fix handling of the TPM 2.0 event logs tpm_crb: remove a cruft constant keys: select CONFIG_CRYPTO when selecting DH / KDF apparmor: Make path_max parameter readonly apparmor: fix parameters so that the permission test is bypassed at boot apparmor: fix invalid reference to index variable of iterator line 836 apparmor: use SHASH_DESC_ON_STACK security/apparmor/lsm.c: set debug messages apparmor: fix boolreturn.cocci warnings Smack: Use GFP_KERNEL for smk_netlbl_mls(). smack: fix double free in smack_parse_opts_str() KEYS: add SP800-56A KDF support for DH KEYS: Keyring asymmetric key restrict method with chaining KEYS: Restrict asymmetric key linkage using a specific keychain KEYS: Add a lookup_restriction function for the asymmetric key type KEYS: Add KEYCTL_RESTRICT_KEYRING KEYS: Consistent ordering for __key_link_begin and restrict check KEYS: Add an optional lookup_restriction hook to key_type ... |
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Linus Torvalds | 76f1948a79 |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatch updates from Jiri Kosina: - a per-task consistency model is being added for architectures that support reliable stack dumping (extending this, currently rather trivial set, is currently in the works). This extends the nature of the types of patches that can be applied by live patching infrastructure. The code stems from the design proposal made [1] back in November 2014. It's a hybrid of SUSE's kGraft and RH's kpatch, combining advantages of both: it uses kGraft's per-task consistency and syscall barrier switching combined with kpatch's stack trace switching. There are also a number of fallback options which make it quite flexible. Most of the heavy lifting done by Josh Poimboeuf with help from Miroslav Benes and Petr Mladek [1] https://lkml.kernel.org/r/20141107140458.GA21774@suse.cz - module load time patch optimization from Zhou Chengming - a few assorted small fixes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch: add missing printk newlines livepatch: Cancel transition a safe way for immediate patches livepatch: Reduce the time of finding module symbols livepatch: make klp_mutex proper part of API livepatch: allow removal of a disabled patch livepatch: add /proc/<pid>/patch_state livepatch: change to a per-task consistency model livepatch: store function sizes livepatch: use kstrtobool() in enabled_store() livepatch: move patching functions into patch.c livepatch: remove unnecessary object loaded check livepatch: separate enabled and patched states livepatch/s390: add TIF_PATCH_PENDING thread flag livepatch/s390: reorganize TIF thread flag bits livepatch/powerpc: add TIF_PATCH_PENDING thread flag livepatch/x86: add TIF_PATCH_PENDING thread flag livepatch: create temporary klp_update_patch_state() stub x86/entry: define _TIF_ALLWORK_MASK flags explicitly stacktrace/x86: add function for detecting reliable stack traces |
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Linus Torvalds | 7c8c03bfc7 |
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar: "The main changes in this cycle were: Kernel side changes: - Kprobes and uprobes changes: - Make their trampolines read-only while they are used - Make UPROBES_EVENTS default-y which is the distro practice - Apply misc fixes and robustization to probe point insertion. - add support for AMD IOMMU events - extend hw events on Intel Goldmont CPUs - ... plus misc fixes and updates. Tooling side changes: - support s390 jump instructions in perf annotate (Christian Borntraeger) - vendor hardware events updates (Andi Kleen) - add argument support for SDT events in powerpc (Ravi Bangoria) - beautify the statx syscall arguments in 'perf trace' (Arnaldo Carvalho de Melo) - handle inline functions in callchains (Jin Yao) - enable sorting by srcline as key (Milian Wolff) - add 'brstackinsn' field in 'perf script' to reuse the x86 instruction decoder used in the Intel PT code to study hot paths to samples (Andi Kleen) - add PERF_RECORD_NAMESPACES so that the kernel can record information required to associate samples to namespaces, helping in container problem characterization. (Hari Bathini) - allow sorting by symbol_size in 'perf report' and 'perf top' (Charles Baylis) - in perf stat, make system wide (-a) the default option if no target was specified and one of following conditions is met: - no workload specified (current behaviour) - a workload is specified but all requested events are system wide ones, like uncore ones. (Jiri Olsa) - ... plus lots of other updates, enhancements, cleanups and fixes" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (235 commits) perf tools: Fix the code to strip command name tools arch x86: Sync cpufeatures.h tools arch: Sync arch/x86/lib/memcpy_64.S with the kernel tools: Update asm-generic/mman-common.h copy from the kernel perf tools: Use just forward declarations for struct thread where possible perf tools: Add the right header to obtain PERF_ALIGN() perf tools: Remove poll.h and wait.h from util.h perf tools: Remove string.h, unistd.h and sys/stat.h from util.h perf tools: Remove stale prototypes from builtin.h perf tools: Remove string.h from util.h perf tools: Remove sys/ioctl.h from util.h perf tools: Remove a few more needless includes from util.h perf tools: Include sys/param.h where needed perf callchain: Move callchain specific routines from util.[ch] perf tools: Add compress.h for the *_decompress_to_file() headers perf mem: Fix display of data source snoop indication perf debug: Move dump_stack() and sighandler_dump_stack() to debug.h perf kvm: Make function only used by 'perf kvm' static perf tools: Move timestamp routines from util.h to time-utils.h perf tools: Move units conversion/formatting routines to separate object ... |
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Paul E. McKenney | 5f0d5a3ae7 |
mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU
A group of Linux kernel hackers reported chasing a bug that resulted from their assumption that SLAB_DESTROY_BY_RCU provided an existence guarantee, that is, that no block from such a slab would be reallocated during an RCU read-side critical section. Of course, that is not the case. Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire slab of blocks. However, there is a phrase for this, namely "type safety". This commit therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order to avoid future instances of this sort of confusion. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <linux-mm@kvack.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> [ paulmck: Add comments mentioning the old name, as requested by Eric Dumazet, in order to help people familiar with the old name find the new one. ] Acked-by: David Rientjes <rientjes@google.com> |
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Xunlei Pang | e96a7705e7 |
sched/rtmutex/deadline: Fix a PI crash for deadline tasks
A crash happened while I was playing with deadline PI rtmutex. BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: [<ffffffff810eeb8f>] rt_mutex_get_top_task+0x1f/0x30 PGD 232a75067 PUD 230947067 PMD 0 Oops: 0000 [#1] SMP CPU: 1 PID: 10994 Comm: a.out Not tainted Call Trace: [<ffffffff810b658c>] enqueue_task+0x2c/0x80 [<ffffffff810ba763>] activate_task+0x23/0x30 [<ffffffff810d0ab5>] pull_dl_task+0x1d5/0x260 [<ffffffff810d0be6>] pre_schedule_dl+0x16/0x20 [<ffffffff8164e783>] __schedule+0xd3/0x900 [<ffffffff8164efd9>] schedule+0x29/0x70 [<ffffffff8165035b>] __rt_mutex_slowlock+0x4b/0xc0 [<ffffffff81650501>] rt_mutex_slowlock+0xd1/0x190 [<ffffffff810eeb33>] rt_mutex_timed_lock+0x53/0x60 [<ffffffff810ecbfc>] futex_lock_pi.isra.18+0x28c/0x390 [<ffffffff810ed8b0>] do_futex+0x190/0x5b0 [<ffffffff810edd50>] SyS_futex+0x80/0x180 This is because rt_mutex_enqueue_pi() and rt_mutex_dequeue_pi() are only protected by pi_lock when operating pi waiters, while rt_mutex_get_top_task(), will access them with rq lock held but not holding pi_lock. In order to tackle it, we introduce new "pi_top_task" pointer cached in task_struct, and add new rt_mutex_update_top_task() to update its value, it can be called by rt_mutex_setprio() which held both owner's pi_lock and rq lock. Thus "pi_top_task" can be safely accessed by enqueue_task_dl() under rq lock. Originally-From: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Xunlei Pang <xlpang@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: juri.lelli@arm.com Cc: bigeasy@linutronix.de Cc: mathieu.desnoyers@efficios.com Cc: jdesfossez@efficios.com Cc: bristot@redhat.com Link: http://lkml.kernel.org/r/20170323150216.157682758@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
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Tetsuo Handa | e4e55b47ed |
LSM: Revive security_task_alloc() hook and per "struct task_struct" security blob.
We switched from "struct task_struct"->security to "struct cred"->security in Linux 2.6.29. But not all LSM modules were happy with that change. TOMOYO LSM module is an example which want to use per "struct task_struct" security blob, for TOMOYO's security context is defined based on "struct task_struct" rather than "struct cred". AppArmor LSM module is another example which want to use it, for AppArmor is currently abusing the cred a little bit to store the change_hat and setexeccon info. Although security_task_free() hook was revived in Linux 3.4 because Yama LSM module wanted to release per "struct task_struct" security blob, security_task_alloc() hook and "struct task_struct"->security field were not revived. Nowadays, we are getting proposals of lightweight LSM modules which want to use per "struct task_struct" security blob. We are already allowing multiple concurrent LSM modules (up to one fully armored module which uses "struct cred"->security field or exclusive hooks like security_xfrm_state_pol_flow_match(), plus unlimited number of lightweight modules which do not use "struct cred"->security nor exclusive hooks) as long as they are built into the kernel. But this patch does not implement variable length "struct task_struct"->security field which will become needed when multiple LSM modules want to use "struct task_struct"-> security field. Although it won't be difficult to implement variable length "struct task_struct"->security field, let's think about it after we merged this patch. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: John Johansen <john.johansen@canonical.com> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Tested-by: Djalal Harouni <tixxdz@gmail.com> Acked-by: José Bollo <jobol@nonadev.net> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Eric Paris <eparis@parisplace.org> Cc: Kees Cook <keescook@chromium.org> Cc: James Morris <james.l.morris@oracle.com> Cc: José Bollo <jobol@nonadev.net> Signed-off-by: James Morris <james.l.morris@oracle.com> |
|
Hari Bathini | e422267322 |
perf: Add PERF_RECORD_NAMESPACES to include namespaces related info
With the advert of container technologies like docker, that depend on namespaces for isolation, there is a need for tracing support for namespaces. This patch introduces new PERF_RECORD_NAMESPACES event for recording namespaces related info. By recording info for every namespace, it is left to userspace to take a call on the definition of a container and trace containers by updating perf tool accordingly. Each namespace has a combination of device and inode numbers. Though every namespace has the same device number currently, that may change in future to avoid the need for a namespace of namespaces. Considering such possibility, record both device and inode numbers separately for each namespace. Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Aravinda Prasad <aravinda@linux.vnet.ibm.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Sargun Dhillon <sargun@sargun.me> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/148891929686.25309.2827618988917007768.stgit@hbathini.in.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Josh Poimboeuf | d83a7cb375 |
livepatch: change to a per-task consistency model
Change livepatch to use a basic per-task consistency model. This is the foundation which will eventually enable us to patch those ~10% of security patches which change function or data semantics. This is the biggest remaining piece needed to make livepatch more generally useful. This code stems from the design proposal made by Vojtech [1] in November 2014. It's a hybrid of kGraft and kpatch: it uses kGraft's per-task consistency and syscall barrier switching combined with kpatch's stack trace switching. There are also a number of fallback options which make it quite flexible. Patches are applied on a per-task basis, when the task is deemed safe to switch over. When a patch is enabled, livepatch enters into a transition state where tasks are converging to the patched state. Usually this transition state can complete in a few seconds. The same sequence occurs when a patch is disabled, except the tasks converge from the patched state to the unpatched state. An interrupt handler inherits the patched state of the task it interrupts. The same is true for forked tasks: the child inherits the patched state of the parent. Livepatch uses several complementary approaches to determine when it's safe to patch tasks: 1. The first and most effective approach is stack checking of sleeping tasks. If no affected functions are on the stack of a given task, the task is patched. In most cases this will patch most or all of the tasks on the first try. Otherwise it'll keep trying periodically. This option is only available if the architecture has reliable stacks (HAVE_RELIABLE_STACKTRACE). 2. The second approach, if needed, is kernel exit switching. A task is switched when it returns to user space from a system call, a user space IRQ, or a signal. It's useful in the following cases: a) Patching I/O-bound user tasks which are sleeping on an affected function. In this case you have to send SIGSTOP and SIGCONT to force it to exit the kernel and be patched. b) Patching CPU-bound user tasks. If the task is highly CPU-bound then it will get patched the next time it gets interrupted by an IRQ. c) In the future it could be useful for applying patches for architectures which don't yet have HAVE_RELIABLE_STACKTRACE. In this case you would have to signal most of the tasks on the system. However this isn't supported yet because there's currently no way to patch kthreads without HAVE_RELIABLE_STACKTRACE. 3. For idle "swapper" tasks, since they don't ever exit the kernel, they instead have a klp_update_patch_state() call in the idle loop which allows them to be patched before the CPU enters the idle state. (Note there's not yet such an approach for kthreads.) All the above approaches may be skipped by setting the 'immediate' flag in the 'klp_patch' struct, which will disable per-task consistency and patch all tasks immediately. This can be useful if the patch doesn't change any function or data semantics. Note that, even with this flag set, it's possible that some tasks may still be running with an old version of the function, until that function returns. There's also an 'immediate' flag in the 'klp_func' struct which allows you to specify that certain functions in the patch can be applied without per-task consistency. This might be useful if you want to patch a common function like schedule(), and the function change doesn't need consistency but the rest of the patch does. For architectures which don't have HAVE_RELIABLE_STACKTRACE, the user must set patch->immediate which causes all tasks to be patched immediately. This option should be used with care, only when the patch doesn't change any function or data semantics. In the future, architectures which don't have HAVE_RELIABLE_STACKTRACE may be allowed to use per-task consistency if we can come up with another way to patch kthreads. The /sys/kernel/livepatch/<patch>/transition file shows whether a patch is in transition. Only a single patch (the topmost patch on the stack) can be in transition at a given time. A patch can remain in transition indefinitely, if any of the tasks are stuck in the initial patch state. A transition can be reversed and effectively canceled by writing the opposite value to the /sys/kernel/livepatch/<patch>/enabled file while the transition is in progress. Then all the tasks will attempt to converge back to the original patch state. [1] https://lkml.kernel.org/r/20141107140458.GA21774@suse.cz Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Ingo Molnar <mingo@kernel.org> # for the scheduler changes Signed-off-by: Jiri Kosina <jkosina@suse.cz> |
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Ingo Molnar | 6bfbaa51ed |
sched/headers, RCU: Move rcu_copy_process() from <linux/sched/task.h> to kernel/fork.c
Move rcu_copy_process() into kernel/fork.c, which is the only user of this inline function. This simplifies <linux/sched/task.h> to the level that <linux/sched.h> does not have to be included in it anymore - which change is done in a subsequent patch. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar | 32ef5517c2 |
sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>
Introduce a trivial, mostly empty <linux/sched/cputime.h> header to prepare for the moving of cputime functionality out of sched.h. Update all code that relies on these facilities. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar | 68db0cf106 |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h>
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar | 299300258d |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>
We are going to split <linux/sched/task.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar | 03441a3482 |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/stat.h>
We are going to split <linux/sched/stat.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/stat.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar | 037741a6d4 |
sched/headers: Prepare for the removal of <linux/rtmutex.h> from <linux/sched.h>
Fix up missing #includes in other places that rely on sched.h doing that for them. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar | 6a3827d750 |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/numa_balancing.h>
We are going to split <linux/sched/numa_balancing.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/numa_balancing.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar | 8703e8a465 |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/user.h>
We are going to split <linux/sched/user.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/user.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar | f7ccbae45c |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/coredump.h>
We are going to split <linux/sched/coredump.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/coredump.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar | 6e84f31522 |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h>
We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/mm.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. The APIs that are going to be moved first are: mm_alloc() __mmdrop() mmdrop() mmdrop_async_fn() mmdrop_async() mmget_not_zero() mmput() mmput_async() get_task_mm() mm_access() mm_release() Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar | 4eb5aaa3af |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/autogroup.h>
We are going to split <linux/sched/autogroup.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/autogroup.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar | 780de9dd27 |
sched/headers, cgroups: Remove the threadgroup_change_*() wrappery
threadgroup_change_begin()/end() is a pointless wrapper around cgroup_threadgroup_change_begin()/end(), minus a might_sleep() in the !CONFIG_CGROUPS=y case. Remove the wrappery, move the might_sleep() (the down_read() already has a might_sleep() check). This debloats <linux/sched.h> a bit and simplifies this API. Update all call sites. No change in functionality. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Vegard Nossum | 3fce371bfa |
mm: add new mmget() helper
Apart from adding the helper function itself, the rest of the kernel is converted mechanically using: git grep -l 'atomic_inc.*mm_users' | xargs sed -i 's/atomic_inc(&\(.*\)->mm_users);/mmget\(\1\);/' git grep -l 'atomic_inc.*mm_users' | xargs sed -i 's/atomic_inc(&\(.*\)\.mm_users);/mmget\(\&\1\);/' This is needed for a later patch that hooks into the helper, but might be a worthwhile cleanup on its own. (Michal Hocko provided most of the kerneldoc comment.) Link: http://lkml.kernel.org/r/20161218123229.22952-2-vegard.nossum@oracle.com Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Linus Torvalds | f1ef09fde1 |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace updates from Eric Biederman: "There is a lot here. A lot of these changes result in subtle user visible differences in kernel behavior. I don't expect anything will care but I will revert/fix things immediately if any regressions show up. From Seth Forshee there is a continuation of the work to make the vfs ready for unpriviled mounts. We had thought the previous changes prevented the creation of files outside of s_user_ns of a filesystem, but it turns we missed the O_CREAT path. Ooops. Pavel Tikhomirov and Oleg Nesterov worked together to fix a long standing bug in the implemenation of PR_SET_CHILD_SUBREAPER where only children that are forked after the prctl are considered and not children forked before the prctl. The only known user of this prctl systemd forks all children after the prctl. So no userspace regressions will occur. Holding earlier forked children to the same rules as later forked children creates a semantic that is sane enough to allow checkpoing of processes that use this feature. There is a long delayed change by Nikolay Borisov to limit inotify instances inside a user namespace. Michael Kerrisk extends the API for files used to maniuplate namespaces with two new trivial ioctls to allow discovery of the hierachy and properties of namespaces. Konstantin Khlebnikov with the help of Al Viro adds code that when a network namespace exits purges it's sysctl entries from the dcache. As in some circumstances this could use a lot of memory. Vivek Goyal fixed a bug with stacked filesystems where the permissions on the wrong inode were being checked. I continue previous work on ptracing across exec. Allowing a file to be setuid across exec while being ptraced if the tracer has enough credentials in the user namespace, and if the process has CAP_SETUID in it's own namespace. Proc files for setuid or otherwise undumpable executables are now owned by the root in the user namespace of their mm. Allowing debugging of setuid applications in containers to work better. A bug I introduced with permission checking and automount is now fixed. The big change is to mark the mounts that the kernel initiates as a result of an automount. This allows the permission checks in sget to be safely suppressed for this kind of mount. As the permission check happened when the original filesystem was mounted. Finally a special case in the mount namespace is removed preventing unbounded chains in the mount hash table, and making the semantics simpler which benefits CRIU. The vfs fix along with related work in ima and evm I believe makes us ready to finish developing and merge fully unprivileged mounts of the fuse filesystem. The cleanups of the mount namespace makes discussing how to fix the worst case complexity of umount. The stacked filesystem fixes pave the way for adding multiple mappings for the filesystem uids so that efficient and safer containers can be implemented" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc/sysctl: Don't grab i_lock under sysctl_lock. vfs: Use upper filesystem inode in bprm_fill_uid() proc/sysctl: prune stale dentries during unregistering mnt: Tuck mounts under others instead of creating shadow/side mounts. prctl: propagate has_child_subreaper flag to every descendant introduce the walk_process_tree() helper nsfs: Add an ioctl() to return owner UID of a userns fs: Better permission checking for submounts exit: fix the setns() && PR_SET_CHILD_SUBREAPER interaction vfs: open() with O_CREAT should not create inodes with unknown ids nsfs: Add an ioctl() to return the namespace type proc: Better ownership of files for non-dumpable tasks in user namespaces exec: Remove LSM_UNSAFE_PTRACE_CAP exec: Test the ptracer's saved cred to see if the tracee can gain caps exec: Don't reset euid and egid when the tracee has CAP_SETUID inotify: Convert to using per-namespace limits |
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Pavel Emelyanov | 893e26e61d |
userfaultfd: non-cooperative: Add fork() event
When the mm with uffd-ed vmas fork()-s the respective vmas notify their uffds with the event which contains a descriptor with new uffd. This new descriptor can then be used to get events from the child and populate its mm with data. Note, that there can be different uffd-s controlling different vmas within one mm, so first we should collect all those uffds (and ctx-s) in a list and then notify them all one by one but only once per fork(). The context is created at fork() time but the descriptor, file struct and anon inode object is created at event read time. So some trickery is added to the userfaultfd_ctx_read() to handle the ctx queues' locking vs file creation. Another thing worth noticing is that the task that fork()-s waits for the uffd event to get processed WITHOUT the mmap sem. [aarcange@redhat.com: build warning fix] Link: http://lkml.kernel.org/r/20161216144821.5183-10-aarcange@redhat.com Link: http://lkml.kernel.org/r/20161216144821.5183-9-aarcange@redhat.com Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michael Rapoport <RAPOPORT@il.ibm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Linus Torvalds | 42e1b14b6e |
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar: "The main changes in this cycle were: - Implement wraparound-safe refcount_t and kref_t types based on generic atomic primitives (Peter Zijlstra) - Improve and fix the ww_mutex code (Nicolai Hähnle) - Add self-tests to the ww_mutex code (Chris Wilson) - Optimize percpu-rwsems with the 'rcuwait' mechanism (Davidlohr Bueso) - Micro-optimize the current-task logic all around the core kernel (Davidlohr Bueso) - Tidy up after recent optimizations: remove stale code and APIs, clean up the code (Waiman Long) - ... plus misc fixes, updates and cleanups" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits) fork: Fix task_struct alignment locking/spinlock/debug: Remove spinlock lockup detection code lockdep: Fix incorrect condition to print bug msgs for MAX_LOCKDEP_CHAIN_HLOCKS lkdtm: Convert to refcount_t testing kref: Implement 'struct kref' using refcount_t refcount_t: Introduce a special purpose refcount type sched/wake_q: Clarify queue reinit comment sched/wait, rcuwait: Fix typo in comment locking/mutex: Fix lockdep_assert_held() fail locking/rtmutex: Flip unlikely() branch to likely() in __rt_mutex_slowlock() locking/rwsem: Reinit wake_q after use locking/rwsem: Remove unnecessary atomic_long_t casts jump_labels: Move header guard #endif down where it belongs locking/atomic, kref: Implement kref_put_lock() locking/ww_mutex: Turn off __must_check for now locking/atomic, kref: Avoid more abuse locking/atomic, kref: Use kref_get_unless_zero() more locking/atomic, kref: Kill kref_sub() locking/atomic, kref: Add kref_read() locking/atomic, kref: Add KREF_INIT() ... |
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Linus Torvalds | 828cad8ea0 |
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar: "The main changes in this (fairly busy) cycle were: - There was a class of scheduler bugs related to forgetting to update the rq-clock timestamp which can cause weird and hard to debug problems, so there's a new debug facility for this: which uncovered a whole lot of bugs which convinced us that we want to keep the debug facility. (Peter Zijlstra, Matt Fleming) - Various cputime related updates: eliminate cputime and use u64 nanoseconds directly, simplify and improve the arch interfaces, implement delayed accounting more widely, etc. - (Frederic Weisbecker) - Move code around for better structure plus cleanups (Ingo Molnar) - Move IO schedule accounting deeper into the scheduler plus related changes to improve the situation (Tejun Heo) - ... plus a round of sched/rt and sched/deadline fixes, plus other fixes, updats and cleanups" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (85 commits) sched/core: Remove unlikely() annotation from sched_move_task() sched/autogroup: Rename auto_group.[ch] to autogroup.[ch] sched/topology: Split out scheduler topology code from core.c into topology.c sched/core: Remove unnecessary #include headers sched/rq_clock: Consolidate the ordering of the rq_clock methods delayacct: Include <uapi/linux/taskstats.h> sched/core: Clean up comments sched/rt: Show the 'sched_rr_timeslice' SCHED_RR timeslice tuning knob in milliseconds sched/clock: Add dummy clear_sched_clock_stable() stub function sched/cputime: Remove generic asm headers sched/cputime: Remove unused nsec_to_cputime() s390, sched/cputime: Remove unused cputime definitions powerpc, sched/cputime: Remove unused cputime definitions s390, sched/cputime: Make arch_cpu_idle_time() to return nsecs ia64, sched/cputime: Remove unused cputime definitions ia64: Convert vtime to use nsec units directly ia64, sched/cputime: Move the nsecs based cputime headers to the last arch using it sched/cputime: Remove jiffies based cputime sched/cputime, vtime: Return nsecs instead of cputime_t to account sched/cputime: Complete nsec conversion of tick based accounting ... |
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Peter Zijlstra | 95cb64c1fe |
fork: Fix task_struct alignment
Stupid bug that wrecked the alignment of task_struct and causes WARN()s
in the x86 FPU code on some platforms.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes:
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Pavel Tikhomirov | 749860ce24 |
prctl: propagate has_child_subreaper flag to every descendant
If process forks some children when it has is_child_subreaper
flag enabled they will inherit has_child_subreaper flag - first
group, when is_child_subreaper is disabled forked children will
not inherit it - second group. So child-subreaper does not reparent
all his descendants when their parents die. Having these two
differently behaving groups can lead to confusion. Also it is
a problem for CRIU, as when we restore process tree we need to
somehow determine which descendants belong to which group and
much harder - to put them exactly to these group.
To simplify these we can add a propagation of has_child_subreaper
flag on PR_SET_CHILD_SUBREAPER, walking all descendants of child-
subreaper to setup has_child_subreaper flag.
In common cases when process like systemd first sets itself to
be a child-subreaper and only after that forks its services, we will
have zero-length list of descendants to walk. Testing with binary
subtree of 2^15 processes prctl took < 0.007 sec and has shown close
to linear dependency(~0.2 * n * usec) on lower numbers of processes.
Moreover, I doubt someone intentionaly pre-forks the children whitch
should reparent to init before becoming subreaper, because some our
ancestor migh have had is_child_subreaper flag while forking our
sub-tree and our childs will all inherit has_child_subreaper flag,
and we have no way to influence it. And only way to check if we have
no has_child_subreaper flag is to create some childs, kill them and
see where they will reparent to.
Using walk_process_tree helper to walk subtree, thanks to Oleg! Timing
seems to be the same.
Optimize:
a) When descendant already has has_child_subreaper flag all his subtree
has it too already.
* for a) to be true need to move has_child_subreaper inheritance under
the same tasklist_lock with adding task to its ->real_parent->children
as without it process can inherit zero has_child_subreaper, then we
set 1 to it's parent flag, check that parent has no more children, and
only after child with wrong flag is added to the tree.
* Also make these inheritance more clear by using real_parent instead of
current, as on clone(CLONE_PARENT) if current has is_child_subreaper
and real_parent has no is_child_subreaper or has_child_subreaper, child
will have has_child_subreaper flag set without actually having a
subreaper in it's ancestors.
b) When some descendant is child_reaper, it's subtree is in different
pidns from us(original child-subreaper) and processes from other pidns
will never reparent to us.
So we can skip their(a,b) subtree from walk.
v2: switch to walk_process_tree() general helper, move
has_child_subreaper inheritance
v3: remove csr_descendant leftover, change current to real_parent
in has_child_subreaper inheritance
v4: small commit message fix
Fixes:
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Oleg Nesterov | 0f1b92cbdd |
introduce the walk_process_tree() helper
Add the new helper to walk the process tree, the next patch adds a user. Note that it visits the group leaders only, proc_visitor can do for_each_thread itself or we can trivially extend walk_process_tree() to do this. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> |
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Frederic Weisbecker | ebd7e7fc4b |
timers/posix-timers: Convert internals to use nsecs
Use the new nsec based cputime accessors as part of the whole cputime conversion from cputime_t to nsecs. Also convert posix-cpu-timers to use nsec based internal counters to simplify it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-19-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Nicolas Pitre | b18b6a9cef |
timers: Omit POSIX timer stuff from task_struct when disabled
When CONFIG_POSIX_TIMERS is disabled, it is preferable to remove related structures from struct task_struct and struct signal_struct as they won't contain anything useful and shouldn't be relied upon by mistake. Code still referencing those structures is also disabled here. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> |
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Peter Zijlstra | e274795ea7 |
locking/mutex: Fix mutex handoff
While reviewing the ww_mutex patches, I noticed that it was still
possible to (incorrectly) succeed for (incorrect) code like:
mutex_lock(&a);
mutex_lock(&a);
This was possible if the second mutex_lock() would block (as expected)
but then receive a spurious wakeup. At that point it would find itself
at the front of the queue, request a handoff and instantly claim
ownership and continue, since owner would point to itself.
Avoid this scenario and simplify the code by introducing a third low
bit to signal handoff pickup. So once we request handoff, unlock
clears the handoff bit and sets the pickup bit along with the new
owner.
This also removes the need for the .handoff argument to
__mutex_trylock(), since that becomes superfluous with PICKUP.
In order to guarantee enough low bits, ensure task_struct alignment is
at least L1_CACHE_BYTES (which seems a good ideal regardless).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes:
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Linus Torvalds | 7c0f6ba682 |
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Linus Torvalds | 412ac77a9d |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace updates from Eric Biederman: "After a lot of discussion and work we have finally reachanged a basic understanding of what is necessary to make unprivileged mounts safe in the presence of EVM and IMA xattrs which the last commit in this series reflects. While technically it is a revert the comments it adds are important for people not getting confused in the future. Clearing up that confusion allows us to seriously work on unprivileged mounts of fuse in the next development cycle. The rest of the fixes in this set are in the intersection of user namespaces, ptrace, and exec. I started with the first fix which started a feedback cycle of finding additional issues during review and fixing them. Culiminating in a fix for a bug that has been present since at least Linux v1.0. Potentially these fixes were candidates for being merged during the rc cycle, and are certainly backport candidates but enough little things turned up during review and testing that I decided they should be handled as part of the normal development process just to be certain there were not any great surprises when it came time to backport some of these fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: Revert "evm: Translate user/group ids relative to s_user_ns when computing HMAC" exec: Ensure mm->user_ns contains the execed files ptrace: Don't allow accessing an undumpable mm ptrace: Capture the ptracer's creds not PT_PTRACE_CAP mm: Add a user_ns owner to mm_struct and fix ptrace permission checks |
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Linus Torvalds | 7b9dc3f75f |
Power management material for v4.10-rc1
- New cpufreq driver for Broadcom STB SoCs and a Device Tree binding for it (Markus Mayer). - Support for ARM Integrator/AP and Integrator/CP in the generic DT cpufreq driver and elimination of the old Integrator cpufreq driver (Linus Walleij). - Support for the zx296718, r8a7743 and r8a7745, Socionext UniPhier, and PXA SoCs in the the generic DT cpufreq driver (Baoyou Xie, Geert Uytterhoeven, Masahiro Yamada, Robert Jarzmik). - cpufreq core fix to eliminate races that may lead to using inactive policy objects and related cleanups (Rafael Wysocki). - cpufreq schedutil governor update to make it use SCHED_FIFO kernel threads (instead of regular workqueues) for doing delayed work (to reduce the response latency in some cases) and related cleanups (Viresh Kumar). - New cpufreq sysfs attribute for resetting statistics (Markus Mayer). - cpufreq governors fixes and cleanups (Chen Yu, Stratos Karafotis, Viresh Kumar). - Support for using generic cpufreq governors in the intel_pstate driver (Rafael Wysocki). - Support for per-logical-CPU P-state limits and the EPP/EPB (Energy Performance Preference/Energy Performance Bias) knobs in the intel_pstate driver (Srinivas Pandruvada). - New CPU ID for Knights Mill in intel_pstate (Piotr Luc). - intel_pstate driver modification to use the P-state selection algorithm based on CPU load on platforms with the system profile in the ACPI tables set to "mobile" (Srinivas Pandruvada). - intel_pstate driver cleanups (Arnd Bergmann, Rafael Wysocki, Srinivas Pandruvada). - cpufreq powernv driver updates including fast switching support (for the schedutil governor), fixes and cleanus (Akshay Adiga, Andrew Donnellan, Denis Kirjanov). - acpi-cpufreq driver rework to switch it over to the new CPU offline/online state machine (Sebastian Andrzej Siewior). - Assorted cleanups in cpufreq drivers (Wei Yongjun, Prashanth Prakash). - Idle injection rework (to make it use the regular idle path instead of a home-grown custom one) and related powerclamp thermal driver updates (Peter Zijlstra, Jacob Pan, Petr Mladek, Sebastian Andrzej Siewior). - New CPU IDs for Atom Z34xx and Knights Mill in intel_idle (Andy Shevchenko, Piotr Luc). - intel_idle driver cleanups and switch over to using the new CPU offline/online state machine (Anna-Maria Gleixner, Sebastian Andrzej Siewior). - cpuidle DT driver update to support suspend-to-idle properly (Sudeep Holla). - cpuidle core cleanups and misc updates (Daniel Lezcano, Pan Bian, Rafael Wysocki). - Preliminary support for power domains including CPUs in the generic power domains (genpd) framework and related DT bindings (Lina Iyer). - Assorted fixes and cleanups in the generic power domains (genpd) framework (Colin Ian King, Dan Carpenter, Geert Uytterhoeven). - Preliminary support for devices with multiple voltage regulators and related fixes and cleanups in the Operating Performance Points (OPP) library (Viresh Kumar, Masahiro Yamada, Stephen Boyd). - System sleep state selection interface rework to make it easier to support suspend-to-idle as the default system suspend method (Rafael Wysocki). - PM core fixes and cleanups, mostly related to the interactions between the system suspend and runtime PM frameworks (Ulf Hansson, Sahitya Tummala, Tony Lindgren). - Latency tolerance PM QoS framework imorovements (Andrew Lutomirski). - New Knights Mill CPU ID for the Intel RAPL power capping driver (Piotr Luc). - Intel RAPL power capping driver fixes, cleanups and switch over to using the new CPU offline/online state machine (Jacob Pan, Thomas Gleixner, Sebastian Andrzej Siewior). - Fixes and cleanups in the exynos-ppmu, exynos-nocp, rk3399_dmc, rockchip-dfi devfreq drivers and the devfreq core (Axel Lin, Chanwoo Choi, Javier Martinez Canillas, MyungJoo Ham, Viresh Kumar). - Fix for false-positive KASAN warnings during resume from ACPI S3 (suspend-to-RAM) on x86 (Josh Poimboeuf). - Memory map verification during resume from hibernation on x86 to ensure a consistent address space layout (Chen Yu). - Wakeup sources debugging enhancement (Xing Wei). - rockchip-io AVS driver cleanup (Shawn Lin). -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABCAAGBQJYTx4+AAoJEILEb/54YlRx9f8P/2SlNHUENW5qh6FtCw00oC2u UqJerQJ2L38UgbgxbE/0VYblma9rFABDWC1eO2xN2XdcdW5UPBKPVvNcOgNe1Clh gjy3RxZXVpmjfzt2kGfsTLEuGnHqwvx51hTUkeA2LwvkOal45xb8ZESmy8opCtiv iG4LwmPHoxdX5Za5nA9ItFKzxyO1EoyNSnBYAVwALDHxmNOfxEcRevfurASt/0M9 brCCZJA0/sZxeL0lBdy8fNQPIBTUfCoTJG/MtmzGrObJ9wMFvEDfXrVEyZiWs/zA AAZ4kQL77enrIKgrLN8e0G6LzTLHoVcvn38Xjf24dKUqhd7ACBhYcnW+jK3+7EAd gjZ8efObQsiuyK/EDLUNw35tt96CHOqfrQCj2tIwRVvk9EekLqAGXdIndTCr2kYW RpefmP5kMljnm/nQFOVLwMEUQMuVkvUE7EgxADy7DoDmepBFC4ICRDWPye70R2kC 0O1Tn2PAQq4Fd1tyI9TYYz0YQQkRoaRb5rfYUSzbRbeCdsphUopp4Vhsiyn6IcnF XnLbg6pRAat82MoS9n4pfO/VCo8vkErKA8tut9G7TDakkrJoEE7l31PdKW0hP3f6 sBo6xXy6WTeivU/o/i8TbM6K4mA37pBaj78ooIkWLgg5fzRaS2+0xSPVy2H9x1m5 LymHcobCK9rSZ1l208Fe =vhxI -----END PGP SIGNATURE----- Merge tag 'pm-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "Again, cpufreq gets more changes than the other parts this time (one new driver, one old driver less, a bunch of enhancements of the existing code, new CPU IDs, fixes, cleanups) There also are some changes in cpuidle (idle injection rework, a couple of new CPU IDs, online/offline rework in intel_idle, fixes and cleanups), in the generic power domains framework (mostly related to supporting power domains containing CPUs), and in the Operating Performance Points (OPP) library (mostly related to supporting devices with multiple voltage regulators) In addition to that, the system sleep state selection interface is modified to make it easier for distributions with unchanged user space to support suspend-to-idle as the default system suspend method, some issues are fixed in the PM core, the latency tolerance PM QoS framework is improved a bit, the Intel RAPL power capping driver is cleaned up and there are some fixes and cleanups in the devfreq subsystem Specifics: - New cpufreq driver for Broadcom STB SoCs and a Device Tree binding for it (Markus Mayer) - Support for ARM Integrator/AP and Integrator/CP in the generic DT cpufreq driver and elimination of the old Integrator cpufreq driver (Linus Walleij) - Support for the zx296718, r8a7743 and r8a7745, Socionext UniPhier, and PXA SoCs in the the generic DT cpufreq driver (Baoyou Xie, Geert Uytterhoeven, Masahiro Yamada, Robert Jarzmik) - cpufreq core fix to eliminate races that may lead to using inactive policy objects and related cleanups (Rafael Wysocki) - cpufreq schedutil governor update to make it use SCHED_FIFO kernel threads (instead of regular workqueues) for doing delayed work (to reduce the response latency in some cases) and related cleanups (Viresh Kumar) - New cpufreq sysfs attribute for resetting statistics (Markus Mayer) - cpufreq governors fixes and cleanups (Chen Yu, Stratos Karafotis, Viresh Kumar) - Support for using generic cpufreq governors in the intel_pstate driver (Rafael Wysocki) - Support for per-logical-CPU P-state limits and the EPP/EPB (Energy Performance Preference/Energy Performance Bias) knobs in the intel_pstate driver (Srinivas Pandruvada) - New CPU ID for Knights Mill in intel_pstate (Piotr Luc) - intel_pstate driver modification to use the P-state selection algorithm based on CPU load on platforms with the system profile in the ACPI tables set to "mobile" (Srinivas Pandruvada) - intel_pstate driver cleanups (Arnd Bergmann, Rafael Wysocki, Srinivas Pandruvada) - cpufreq powernv driver updates including fast switching support (for the schedutil governor), fixes and cleanus (Akshay Adiga, Andrew Donnellan, Denis Kirjanov) - acpi-cpufreq driver rework to switch it over to the new CPU offline/online state machine (Sebastian Andrzej Siewior) - Assorted cleanups in cpufreq drivers (Wei Yongjun, Prashanth Prakash) - Idle injection rework (to make it use the regular idle path instead of a home-grown custom one) and related powerclamp thermal driver updates (Peter Zijlstra, Jacob Pan, Petr Mladek, Sebastian Andrzej Siewior) - New CPU IDs for Atom Z34xx and Knights Mill in intel_idle (Andy Shevchenko, Piotr Luc) - intel_idle driver cleanups and switch over to using the new CPU offline/online state machine (Anna-Maria Gleixner, Sebastian Andrzej Siewior) - cpuidle DT driver update to support suspend-to-idle properly (Sudeep Holla) - cpuidle core cleanups and misc updates (Daniel Lezcano, Pan Bian, Rafael Wysocki) - Preliminary support for power domains including CPUs in the generic power domains (genpd) framework and related DT bindings (Lina Iyer) - Assorted fixes and cleanups in the generic power domains (genpd) framework (Colin Ian King, Dan Carpenter, Geert Uytterhoeven) - Preliminary support for devices with multiple voltage regulators and related fixes and cleanups in the Operating Performance Points (OPP) library (Viresh Kumar, Masahiro Yamada, Stephen Boyd) - System sleep state selection interface rework to make it easier to support suspend-to-idle as the default system suspend method (Rafael Wysocki) - PM core fixes and cleanups, mostly related to the interactions between the system suspend and runtime PM frameworks (Ulf Hansson, Sahitya Tummala, Tony Lindgren) - Latency tolerance PM QoS framework imorovements (Andrew Lutomirski) - New Knights Mill CPU ID for the Intel RAPL power capping driver (Piotr Luc) - Intel RAPL power capping driver fixes, cleanups and switch over to using the new CPU offline/online state machine (Jacob Pan, Thomas Gleixner, Sebastian Andrzej Siewior) - Fixes and cleanups in the exynos-ppmu, exynos-nocp, rk3399_dmc, rockchip-dfi devfreq drivers and the devfreq core (Axel Lin, Chanwoo Choi, Javier Martinez Canillas, MyungJoo Ham, Viresh Kumar) - Fix for false-positive KASAN warnings during resume from ACPI S3 (suspend-to-RAM) on x86 (Josh Poimboeuf) - Memory map verification during resume from hibernation on x86 to ensure a consistent address space layout (Chen Yu) - Wakeup sources debugging enhancement (Xing Wei) - rockchip-io AVS driver cleanup (Shawn Lin)" * tag 'pm-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (127 commits) devfreq: rk3399_dmc: Don't use OPP structures outside of RCU locks devfreq: rk3399_dmc: Remove dangling rcu_read_unlock() devfreq: exynos: Don't use OPP structures outside of RCU locks Documentation: intel_pstate: Document HWP energy/performance hints cpufreq: intel_pstate: Support for energy performance hints with HWP cpufreq: intel_pstate: Add locking around HWP requests PM / sleep: Print active wakeup sources when blocking on wakeup_count reads PM / core: Fix bug in the error handling of async suspend PM / wakeirq: Fix dedicated wakeirq for drivers not using autosuspend PM / Domains: Fix compatible for domain idle state PM / OPP: Don't WARN on multiple calls to dev_pm_opp_set_regulators() PM / OPP: Allow platform specific custom set_opp() callbacks PM / OPP: Separate out _generic_set_opp() PM / OPP: Add infrastructure to manage multiple regulators PM / OPP: Pass struct dev_pm_opp_supply to _set_opp_voltage() PM / OPP: Manage supply's voltage/current in a separate structure PM / OPP: Don't use OPP structure outside of rcu protected section PM / OPP: Reword binding supporting multiple regulators per device PM / OPP: Fix incorrect cpu-supply property in binding cpuidle: Add a kerneldoc comment to cpuidle_use_deepest_state() .. |
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Linus Torvalds | e34bac726d |
Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton: - various misc bits - most of MM (quite a lot of MM material is awaiting the merge of linux-next dependencies) - kasan - printk updates - procfs updates - MAINTAINERS - /lib updates - checkpatch updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (123 commits) init: reduce rootwait polling interval time to 5ms binfmt_elf: use vmalloc() for allocation of vma_filesz checkpatch: don't emit unified-diff error for rename-only patches checkpatch: don't check c99 types like uint8_t under tools checkpatch: avoid multiple line dereferences checkpatch: don't check .pl files, improve absolute path commit log test scripts/checkpatch.pl: fix spelling checkpatch: don't try to get maintained status when --no-tree is given lib/ida: document locking requirements a bit better lib/rbtree.c: fix typo in comment of ____rb_erase_color lib/Kconfig.debug: make CONFIG_STRICT_DEVMEM depend on CONFIG_DEVMEM MAINTAINERS: add drm and drm/i915 irc channels MAINTAINERS: add "C:" for URI for chat where developers hang out MAINTAINERS: add drm and drm/i915 bug filing info MAINTAINERS: add "B:" for URI where to file bugs get_maintainer: look for arbitrary letter prefixes in sections printk: add Kconfig option to set default console loglevel printk/sound: handle more message headers printk/btrfs: handle more message headers printk/kdb: handle more message headers ... |
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Linus Torvalds | 9465d9cc31 |
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner: "The time/timekeeping/timer folks deliver with this update: - Fix a reintroduced signed/unsigned issue and cleanup the whole signed/unsigned mess in the timekeeping core so this wont happen accidentaly again. - Add a new trace clock based on boot time - Prevent injection of random sleep times when PM tracing abuses the RTC for storage - Make posix timers configurable for real tiny systems - Add tracepoints for the alarm timer subsystem so timer based suspend wakeups can be instrumented - The usual pile of fixes and updates to core and drivers" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) timekeeping: Use mul_u64_u32_shr() instead of open coding it timekeeping: Get rid of pointless typecasts timekeeping: Make the conversion call chain consistently unsigned timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversion alarmtimer: Add tracepoints for alarm timers trace: Update documentation for mono, mono_raw and boot clock trace: Add an option for boot clock as trace clock timekeeping: Add a fast and NMI safe boot clock timekeeping/clocksource_cyc2ns: Document intended range limitation timekeeping: Ignore the bogus sleep time if pm_trace is enabled selftests/timers: Fix spelling mistake "Asyncrhonous" -> "Asynchronous" clocksource/drivers/bcm2835_timer: Unmap region obtained by of_iomap clocksource/drivers/arm_arch_timer: Map frame with of_io_request_and_map() arm64: dts: rockchip: Arch counter doesn't tick in system suspend clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspend posix-timers: Make them configurable posix_cpu_timers: Move the add_device_randomness() call to a proper place timer: Move sys_alarm from timer.c to itimer.c ptp_clock: Allow for it to be optional Kconfig: Regenerate *.c_shipped files after previous changes ... |
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Andrey Ryabinin | 0f110a9b95 |
kernel/fork: use vfree_atomic() to free thread stack
vfree() is going to use sleeping lock. Thread stack freed in atomic context, therefore we must use vfree_atomic() here. Link: http://lkml.kernel.org/r/1479474236-4139-6-git-send-email-hch@lst.de Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Joel Fernandes <joelaf@google.com> Cc: Jisheng Zhang <jszhang@marvell.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: John Dias <joaodias@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Oleg Nesterov | 1da5c46fa9 |
kthread: Make struct kthread kmalloc'ed
commit
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Rafael J. Wysocki | 4e28ec3d5f | Merge back earlier cpuidle material for v4.10. | |
Peter Zijlstra | c1de45ca83 |
sched/idle: Add support for tasks that inject idle
Idle injection drivers such as Intel powerclamp and ACPI PAD drivers use realtime tasks to take control of CPU then inject idle. There are two issues with this approach: 1. Low efficiency: injected idle task is treated as busy so sched ticks do not stop during injected idle period, the result of these unwanted wakeups can be ~20% loss in power savings. 2. Idle accounting: injected idle time is presented to user as busy. This patch addresses the issues by introducing a new PF_IDLE flag which allows any given task to be treated as idle task while the flag is set. Therefore, idle injection tasks can run through the normal flow of NOHZ idle enter/exit to get the correct accounting as well as tick stop when possible. The implication is that idle task is then no longer limited to PID == 0. Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
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Eric W. Biederman | bfedb58925 |
mm: Add a user_ns owner to mm_struct and fix ptrace permission checks
During exec dumpable is cleared if the file that is being executed is
not readable by the user executing the file. A bug in
ptrace_may_access allows reading the file if the executable happens to
enter into a subordinate user namespace (aka clone(CLONE_NEWUSER),
unshare(CLONE_NEWUSER), or setns(fd, CLONE_NEWUSER).
This problem is fixed with only necessary userspace breakage by adding
a user namespace owner to mm_struct, captured at the time of exec, so
it is clear in which user namespace CAP_SYS_PTRACE must be present in
to be able to safely give read permission to the executable.
The function ptrace_may_access is modified to verify that the ptracer
has CAP_SYS_ADMIN in task->mm->user_ns instead of task->cred->user_ns.
This ensures that if the task changes it's cred into a subordinate
user namespace it does not become ptraceable.
The function ptrace_attach is modified to only set PT_PTRACE_CAP when
CAP_SYS_PTRACE is held over task->mm->user_ns. The intent of
PT_PTRACE_CAP is to be a flag to note that whatever permission changes
the task might go through the tracer has sufficient permissions for
it not to be an issue. task->cred->user_ns is always the same
as or descendent of mm->user_ns. Which guarantees that having
CAP_SYS_PTRACE over mm->user_ns is the worst case for the tasks
credentials.
To prevent regressions mm->dumpable and mm->user_ns are not considered
when a task has no mm. As simply failing ptrace_may_attach causes
regressions in privileged applications attempting to read things
such as /proc/<pid>/stat
Cc: stable@vger.kernel.org
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Cyrill Gorcunov <gorcunov@openvz.org>
Fixes:
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Nicolas Pitre | baa73d9e47 |
posix-timers: Make them configurable
Some embedded systems have no use for them. This removes about 25KB from the kernel binary size when configured out. Corresponding syscalls are routed to a stub logging the attempt to use those syscalls which should be enough of a clue if they were disabled without proper consideration. They are: timer_create, timer_gettime: timer_getoverrun, timer_settime, timer_delete, clock_adjtime, setitimer, getitimer, alarm. The clock_settime, clock_gettime, clock_getres and clock_nanosleep syscalls are replaced by simple wrappers compatible with CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only which should cover the vast majority of use cases with very little code. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Michal Marek <mmarek@suse.com> Cc: Edward Cree <ecree@solarflare.com> Link: http://lkml.kernel.org/r/1478841010-28605-7-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
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Stanislaw Gruszka | 40565b5aed |
sched/cputime, powerpc, s390: Make scaled cputime arch specific
Only s390 and powerpc have hardware facilities allowing to measure cputimes scaled by frequency. On all other architectures utimescaled/stimescaled are equal to utime/stime (however they are accounted separately). Remove {u,s}timescaled accounting on all architectures except powerpc and s390, where those values are explicitly accounted in the proper places. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161031162143.GB12646@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Andy Lutomirski | 405c075971 |
fork: Add task stack refcounting sanity check and prevent premature task stack freeing
If something goes wrong with task stack refcounting and a stack refcount hits zero too early, warn and leak it rather than potentially freeing it early (and silently). Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/f29119c783a9680a4b4656e751b6123917ace94b.1477926663.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Linus Torvalds | 9ffc66941d |
This adds a new gcc plugin named "latent_entropy". It is designed to
extract as much possible uncertainty from a running system at boot time as possible, hoping to capitalize on any possible variation in CPU operation (due to runtime data differences, hardware differences, SMP ordering, thermal timing variation, cache behavior, etc). At the very least, this plugin is a much more comprehensive example for how to manipulate kernel code using the gcc plugin internals. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Kees Cook <kees@outflux.net> iQIcBAABCgAGBQJX/BAFAAoJEIly9N/cbcAmzW8QALFbCs7EFFkML+M/M/9d8zEk 1QbUs/z8covJTTT1PjSdw7JUrAMulI3S00owpcQVd/PcWjRPU80QwfsXBgIB0tvC Kub2qxn6Oaf+kTB646zwjFgjdCecw/USJP+90nfcu2+LCnE8ReclKd1aUee+Bnhm iDEUyH2ONIoWq6ta2Z9sA7+E4y2ZgOlmW0iga3Mnf+OcPtLE70fWPoe5E4g9DpYk B+kiPDrD9ql5zsHaEnKG1ldjiAZ1L6Grk8rGgLEXmbOWtTOFmnUhR+raK5NA/RCw MXNuyPay5aYPpqDHFm+OuaWQAiPWfPNWM3Ett4k0d9ZWLixTcD1z68AciExwk7aW SEA8b1Jwbg05ZNYM7NJB6t6suKC4dGPxWzKFOhmBicsh2Ni5f+Az0BQL6q8/V8/4 8UEqDLuFlPJBB50A3z5ngCVeYJKZe8Bg/Swb4zXl6mIzZ9darLzXDEV6ystfPXxJ e1AdBb41WC+O2SAI4l64yyeswkGo3Iw2oMbXG5jmFl6wY/xGp7dWxw7gfnhC6oOh afOT54p2OUDfSAbJaO0IHliWoIdmE5ZYdVYVU9Ek+uWyaIwcXhNmqRg+Uqmo32jf cP5J9x2kF3RdOcbSHXmFp++fU+wkhBtEcjkNpvkjpi4xyA47IWS7lrVBBebrCq9R pa/A7CNQwibIV6YD8+/p =1dUK -----END PGP SIGNATURE----- Merge tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull gcc plugins update from Kees Cook: "This adds a new gcc plugin named "latent_entropy". It is designed to extract as much possible uncertainty from a running system at boot time as possible, hoping to capitalize on any possible variation in CPU operation (due to runtime data differences, hardware differences, SMP ordering, thermal timing variation, cache behavior, etc). At the very least, this plugin is a much more comprehensive example for how to manipulate kernel code using the gcc plugin internals" * tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: latent_entropy: Mark functions with __latent_entropy gcc-plugins: Add latent_entropy plugin |
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Emese Revfy | 0766f788eb |
latent_entropy: Mark functions with __latent_entropy
The __latent_entropy gcc attribute can be used only on functions and variables. If it is on a function then the plugin will instrument it for gathering control-flow entropy. If the attribute is on a variable then the plugin will initialize it with random contents. The variable must be an integer, an integer array type or a structure with integer fields. These specific functions have been selected because they are init functions (to help gather boot-time entropy), are called at unpredictable times, or they have variable loops, each of which provide some level of latent entropy. Signed-off-by: Emese Revfy <re.emese@gmail.com> [kees: expanded commit message] Signed-off-by: Kees Cook <keescook@chromium.org> |
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Emese Revfy | 38addce8b6 |
gcc-plugins: Add latent_entropy plugin
This adds a new gcc plugin named "latent_entropy". It is designed to extract as much possible uncertainty from a running system at boot time as possible, hoping to capitalize on any possible variation in CPU operation (due to runtime data differences, hardware differences, SMP ordering, thermal timing variation, cache behavior, etc). At the very least, this plugin is a much more comprehensive example for how to manipulate kernel code using the gcc plugin internals. The need for very-early boot entropy tends to be very architecture or system design specific, so this plugin is more suited for those sorts of special cases. The existing kernel RNG already attempts to extract entropy from reliable runtime variation, but this plugin takes the idea to a logical extreme by permuting a global variable based on any variation in code execution (e.g. a different value (and permutation function) is used to permute the global based on loop count, case statement, if/then/else branching, etc). To do this, the plugin starts by inserting a local variable in every marked function. The plugin then adds logic so that the value of this variable is modified by randomly chosen operations (add, xor and rol) and random values (gcc generates separate static values for each location at compile time and also injects the stack pointer at runtime). The resulting value depends on the control flow path (e.g., loops and branches taken). Before the function returns, the plugin mixes this local variable into the latent_entropy global variable. The value of this global variable is added to the kernel entropy pool in do_one_initcall() and _do_fork(), though it does not credit any bytes of entropy to the pool; the contents of the global are just used to mix the pool. Additionally, the plugin can pre-initialize arrays with build-time random contents, so that two different kernel builds running on identical hardware will not have the same starting values. Signed-off-by: Emese Revfy <re.emese@gmail.com> [kees: expanded commit message and code comments] Signed-off-by: Kees Cook <keescook@chromium.org> |
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Aaron Lu | 6fcb52a56f |
thp: reduce usage of huge zero page's atomic counter
The global zero page is used to satisfy an anonymous read fault. If THP(Transparent HugePage) is enabled then the global huge zero page is used. The global huge zero page uses an atomic counter for reference counting and is allocated/freed dynamically according to its counter value. CPU time spent on that counter will greatly increase if there are a lot of processes doing anonymous read faults. This patch proposes a way to reduce the access to the global counter so that the CPU load can be reduced accordingly. To do this, a new flag of the mm_struct is introduced: MMF_USED_HUGE_ZERO_PAGE. With this flag, the process only need to touch the global counter in two cases: 1 The first time it uses the global huge zero page; 2 The time when mm_user of its mm_struct reaches zero. Note that right now, the huge zero page is eligible to be freed as soon as its last use goes away. With this patch, the page will not be eligible to be freed until the exit of the last process from which it was ever used. And with the use of mm_user, the kthread is not eligible to use huge zero page either. Since no kthread is using huge zero page today, there is no difference after applying this patch. But if that is not desired, I can change it to when mm_count reaches zero. Case used for test on Haswell EP: usemem -n 72 --readonly -j 0x200000 100G Which spawns 72 processes and each will mmap 100G anonymous space and then do read only access to that space sequentially with a step of 2MB. CPU cycles from perf report for base commit: 54.03% usemem [kernel.kallsyms] [k] get_huge_zero_page CPU cycles from perf report for this commit: 0.11% usemem [kernel.kallsyms] [k] mm_get_huge_zero_page Performance(throughput) of the workload for base commit: 1784430792 Performance(throughput) of the workload for this commit: 4726928591 164% increase. Runtime of the workload for base commit: 707592 us Runtime of the workload for this commit: 303970 us 50% drop. Link: http://lkml.kernel.org/r/fe51a88f-446a-4622-1363-ad1282d71385@intel.com Signed-off-by: Aaron Lu <aaron.lu@intel.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | 862e3073b3 |
mm, oom: get rid of signal_struct::oom_victims
After "oom: keep mm of the killed task available" we can safely detect an oom victim by checking task->signal->oom_mm so we do not need the signal_struct counter anymore so let's get rid of it. This alone wouldn't be sufficient for nommu archs because exit_oom_victim doesn't hide the process from the oom killer anymore. We can, however, mark the mm with a MMF flag in __mmput. We can reuse MMF_OOM_REAPED and rename it to a more generic MMF_OOM_SKIP. Link: http://lkml.kernel.org/r/1472119394-11342-6-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko | 7283094ec3 |
kernel, oom: fix potential pgd_lock deadlock from __mmdrop
Lockdep complains that __mmdrop is not safe from the softirq context:
=================================
[ INFO: inconsistent lock state ]
4.6.0-oomfortification2-00011-geeb3eadeab96-dirty #949 Tainted: G W
---------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
(pgd_lock){+.?...}, at: pgd_free+0x19/0x6b
{SOFTIRQ-ON-W} state was registered at:
__lock_acquire+0xa06/0x196e
lock_acquire+0x139/0x1e1
_raw_spin_lock+0x32/0x41
__change_page_attr_set_clr+0x2a5/0xacd
change_page_attr_set_clr+0x16f/0x32c
set_memory_nx+0x37/0x3a
free_init_pages+0x9e/0xc7
alternative_instructions+0xa2/0xb3
check_bugs+0xe/0x2d
start_kernel+0x3ce/0x3ea
x86_64_start_reservations+0x2a/0x2c
x86_64_start_kernel+0x17a/0x18d
irq event stamp: 105916
hardirqs last enabled at (105916): free_hot_cold_page+0x37e/0x390
hardirqs last disabled at (105915): free_hot_cold_page+0x2c1/0x390
softirqs last enabled at (105878): _local_bh_enable+0x42/0x44
softirqs last disabled at (105879): irq_exit+0x6f/0xd1
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(pgd_lock);
<Interrupt>
lock(pgd_lock);
*** DEADLOCK ***
1 lock held by swapper/1/0:
#0: (rcu_callback){......}, at: rcu_process_callbacks+0x390/0x800
stack backtrace:
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 4.6.0-oomfortification2-00011-geeb3eadeab96-dirty #949
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
Call Trace:
<IRQ>
print_usage_bug.part.25+0x259/0x268
mark_lock+0x381/0x567
__lock_acquire+0x993/0x196e
lock_acquire+0x139/0x1e1
_raw_spin_lock+0x32/0x41
pgd_free+0x19/0x6b
__mmdrop+0x25/0xb9
__put_task_struct+0x103/0x11e
delayed_put_task_struct+0x157/0x15e
rcu_process_callbacks+0x660/0x800
__do_softirq+0x1ec/0x4d5
irq_exit+0x6f/0xd1
smp_apic_timer_interrupt+0x42/0x4d
apic_timer_interrupt+0x8e/0xa0
<EOI>
arch_cpu_idle+0xf/0x11
default_idle_call+0x32/0x34
cpu_startup_entry+0x20c/0x399
start_secondary+0xfe/0x101
More over commit
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Michal Hocko | 26db62f179 |
oom: keep mm of the killed task available
oom_reap_task has to call exit_oom_victim in order to make sure that the
oom vicim will not block the oom killer for ever. This is, however,
opening new problems (e.g oom_killer_disable exclusion - see commit
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Linus Torvalds | 14986a34e1 |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace updates from Eric Biederman: "This set of changes is a number of smaller things that have been overlooked in other development cycles focused on more fundamental change. The devpts changes are small things that were a distraction until we managed to kill off DEVPTS_MULTPLE_INSTANCES. There is an trivial regression fix to autofs for the unprivileged mount changes that went in last cycle. A pair of ioctls has been added by Andrey Vagin making it is possible to discover the relationships between namespaces when referring to them through file descriptors. The big user visible change is starting to add simple resource limits to catch programs that misbehave. With namespaces in general and user namespaces in particular allowing users to use more kinds of resources, it has become important to have something to limit errant programs. Because the purpose of these limits is to catch errant programs the code needs to be inexpensive to use as it always on, and the default limits need to be high enough that well behaved programs on well behaved systems don't encounter them. To this end, after some review I have implemented per user per user namespace limits, and use them to limit the number of namespaces. The limits being per user mean that one user can not exhause the limits of another user. The limits being per user namespace allow contexts where the limit is 0 and security conscious folks can remove from their threat anlysis the code used to manage namespaces (as they have historically done as it root only). At the same time the limits being per user namespace allow other parts of the system to use namespaces. Namespaces are increasingly being used in application sand boxing scenarios so an all or nothing disable for the entire system for the security conscious folks makes increasing use of these sandboxes impossible. There is also added a limit on the maximum number of mounts present in a single mount namespace. It is nontrivial to guess what a reasonable system wide limit on the number of mount structure in the kernel would be, especially as it various based on how a system is using containers. A limit on the number of mounts in a mount namespace however is much easier to understand and set. In most cases in practice only about 1000 mounts are used. Given that some autofs scenarious have the potential to be 30,000 to 50,000 mounts I have set the default limit for the number of mounts at 100,000 which is well above every known set of users but low enough that the mount hash tables don't degrade unreaonsably. These limits are a start. I expect this estabilishes a pattern that other limits for resources that namespaces use will follow. There has been interest in making inotify event limits per user per user namespace as well as interest expressed in making details about what is going on in the kernel more visible" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (28 commits) autofs: Fix automounts by using current_real_cred()->uid mnt: Add a per mount namespace limit on the number of mounts netns: move {inc,dec}_net_namespaces into #ifdef nsfs: Simplify __ns_get_path tools/testing: add a test to check nsfs ioctl-s nsfs: add ioctl to get a parent namespace nsfs: add ioctl to get an owning user namespace for ns file descriptor kernel: add a helper to get an owning user namespace for a namespace devpts: Change the owner of /dev/pts/ptmx to the mounter of /dev/pts devpts: Remove sync_filesystems devpts: Make devpts_kill_sb safe if fsi is NULL devpts: Simplify devpts_mount by using mount_nodev devpts: Move the creation of /dev/pts/ptmx into fill_super devpts: Move parse_mount_options into fill_super userns: When the per user per user namespace limit is reached return ENOSPC userns; Document per user per user namespace limits. mntns: Add a limit on the number of mount namespaces. netns: Add a limit on the number of net namespaces cgroupns: Add a limit on the number of cgroup namespaces ipcns: Add a limit on the number of ipc namespaces ... |
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Andy Lutomirski | ac496bf48d |
fork: Optimize task creation by caching two thread stacks per CPU if CONFIG_VMAP_STACK=y
vmalloc() is a bit slow, and pounding vmalloc()/vfree() will eventually force a global TLB flush. To reduce pressure on them, if CONFIG_VMAP_STACK=y, cache two thread stacks per CPU. This will let us quickly allocate a hopefully cache-hot, TLB-hot stack under heavy forking workloads (shell script style). On my silly pthread_create() benchmark, it saves about 2 µs per pthread_create()+join() with CONFIG_VMAP_STACK=y. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jann Horn <jann@thejh.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/94811d8e3994b2e962f88866290017d498eb069c.1474003868.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Andy Lutomirski | 68f24b08ee |
sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK
We currently keep every task's stack around until the task_struct itself is freed. This means that we keep the stack allocation alive for longer than necessary and that, under load, we free stacks in big batches whenever RCU drops the last task reference. Neither of these is good for reuse of cache-hot memory, and freeing in batches prevents us from usefully caching small numbers of vmalloced stacks. On architectures that have thread_info on the stack, we can't easily change this, but on architectures that set THREAD_INFO_IN_TASK, we can free it as soon as the task is dead. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jann Horn <jann@thejh.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/08ca06cde00ebed0046c5d26cbbf3fbb7ef5b812.1474003868.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar | d4b80afbba |
Merge branch 'linus' into x86/asm, to pick up recent fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Linus Torvalds | b9677faf45 |
Merge branch 'akpm' (patches from Andrew)
Merge fixes from Andrew Morton: "14 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: rapidio/tsi721: fix incorrect detection of address translation condition rapidio/documentation/mport_cdev: add missing parameter description kernel/fork: fix CLONE_CHILD_CLEARTID regression in nscd MAINTAINERS: Vladimir has moved mm, mempolicy: task->mempolicy must be NULL before dropping final reference printk/nmi: avoid direct printk()-s from __printk_nmi_flush() treewide: remove references to the now unnecessary DEFINE_PCI_DEVICE_TABLE drivers/scsi/wd719x.c: remove last declaration using DEFINE_PCI_DEVICE_TABLE mm, vmscan: only allocate and reclaim from zones with pages managed by the buddy allocator lib/test_hash.c: fix warning in preprocessor symbol evaluation lib/test_hash.c: fix warning in two-dimensional array init kconfig: tinyconfig: provide whole choice blocks to avoid warnings kexec: fix double-free when failing to relocate the purgatory mm, oom: prevent premature OOM killer invocation for high order request |
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Michal Hocko | 735f2770a7 |
kernel/fork: fix CLONE_CHILD_CLEARTID regression in nscd
Commit |
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Linus Torvalds | 511a8cdb65 |
Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit
Pull audit fixes from Paul Moore: "Two small patches to fix some bugs with the audit-by-executable functionality we introduced back in v4.3 (both patches are marked for the stable folks)" * 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit: audit: fix exe_file access in audit_exe_compare mm: introduce get_task_exe_file |
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Mateusz Guzik | cd81a9170e |
mm: introduce get_task_exe_file
For more convenient access if one has a pointer to the task. As a minor nit take advantage of the fact that only task lock + rcu are needed to safely grab ->exe_file. This saves mm refcount dance. Use the helper in proc_exe_link. Signed-off-by: Mateusz Guzik <mguzik@redhat.com> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Richard Guy Briggs <rgb@redhat.com> Cc: <stable@vger.kernel.org> # 4.3.x Signed-off-by: Paul Moore <paul@paul-moore.com> |
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Andy Lutomirski | ba14a194a4 |
fork: Add generic vmalloced stack support
If CONFIG_VMAP_STACK=y is selected, kernel stacks are allocated with __vmalloc_node_range(). Grsecurity has had a similar feature (called GRKERNSEC_KSTACKOVERFLOW=y) for a long time. Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/14c07d4fd173a5b117f51e8b939f9f4323e39899.1470907718.git.luto@kernel.org [ Minor edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Balbir Singh | 568ac88821 |
cgroup: reduce read locked section of cgroup_threadgroup_rwsem during fork
cgroup_threadgroup_rwsem is acquired in read mode during process exit and fork. It is also grabbed in write mode during __cgroups_proc_write(). I've recently run into a scenario with lots of memory pressure and OOM and I am beginning to see systemd __switch_to+0x1f8/0x350 __schedule+0x30c/0x990 schedule+0x48/0xc0 percpu_down_write+0x114/0x170 __cgroup_procs_write.isra.12+0xb8/0x3c0 cgroup_file_write+0x74/0x1a0 kernfs_fop_write+0x188/0x200 __vfs_write+0x6c/0xe0 vfs_write+0xc0/0x230 SyS_write+0x6c/0x110 system_call+0x38/0xb4 This thread is waiting on the reader of cgroup_threadgroup_rwsem to exit. The reader itself is under memory pressure and has gone into reclaim after fork. There are times the reader also ends up waiting on oom_lock as well. __switch_to+0x1f8/0x350 __schedule+0x30c/0x990 schedule+0x48/0xc0 jbd2_log_wait_commit+0xd4/0x180 ext4_evict_inode+0x88/0x5c0 evict+0xf8/0x2a0 dispose_list+0x50/0x80 prune_icache_sb+0x6c/0x90 super_cache_scan+0x190/0x210 shrink_slab.part.15+0x22c/0x4c0 shrink_zone+0x288/0x3c0 do_try_to_free_pages+0x1dc/0x590 try_to_free_pages+0xdc/0x260 __alloc_pages_nodemask+0x72c/0xc90 alloc_pages_current+0xb4/0x1a0 page_table_alloc+0xc0/0x170 __pte_alloc+0x58/0x1f0 copy_page_range+0x4ec/0x950 copy_process.isra.5+0x15a0/0x1870 _do_fork+0xa8/0x4b0 ppc_clone+0x8/0xc In the meanwhile, all processes exiting/forking are blocked almost stalling the system. This patch moves the threadgroup_change_begin from before cgroup_fork() to just before cgroup_canfork(). There is no nee to worry about threadgroup changes till the task is actually added to the threadgroup. This avoids having to call reclaim with cgroup_threadgroup_rwsem held. tj: Subject and description edits. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Acked-by: Zefan Li <lizefan@huawei.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org # v4.2+ Signed-off-by: Tejun Heo <tj@kernel.org> |
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Eric W. Biederman | 25f9c0817c |
userns: Generalize the user namespace count into ucount
The same kind of recursive sane default limit and policy countrol that has been implemented for the user namespace is desirable for the other namespaces, so generalize the user namespace refernce count into a ucount. Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
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Eric W. Biederman | f6b2db1a3e |
userns: Make the count of user namespaces per user
Add a structure that is per user and per user ns and use it to hold the count of user namespaces. This makes prevents one user from creating denying service to another user by creating the maximum number of user namespaces. Rename the sysctl export of the maximum count from /proc/sys/userns/max_user_namespaces to /proc/sys/user/max_user_namespaces to reflect that the count is now per user. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
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Eric W. Biederman | b376c3e1b6 |
userns: Add a limit on the number of user namespaces
Export the export the maximum number of user namespaces as /proc/sys/userns/max_user_namespaces. Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
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Andy Lutomirski | efdc949079 |
mm: fix memcg stack accounting for sub-page stacks
We should account for stacks regardless of stack size, and we need to
account in sub-page units if THREAD_SIZE < PAGE_SIZE. Change the units
to kilobytes and Move it into account_kernel_stack().
Fixes:
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Andy Lutomirski | d30dd8be06 |
mm: track NR_KERNEL_STACK in KiB instead of number of stacks
Currently, NR_KERNEL_STACK tracks the number of kernel stacks in a zone. This only makes sense if each kernel stack exists entirely in one zone, and allowing vmapped stacks could break this assumption. Since frv has THREAD_SIZE < PAGE_SIZE, we need to track kernel stack allocations in a unit that divides both THREAD_SIZE and PAGE_SIZE on all architectures. Keep it simple and use KiB. Link: http://lkml.kernel.org/r/083c71e642c5fa5f1b6898902e1b2db7b48940d4.1468523549.git.luto@kernel.org Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vladimir Davydov | 4949148ad4 |
mm: charge/uncharge kmemcg from generic page allocator paths
Currently, to charge a non-slab allocation to kmemcg one has to use alloc_kmem_pages helper with __GFP_ACCOUNT flag. A page allocated with this helper should finally be freed using free_kmem_pages, otherwise it won't be uncharged. This API suits its current users fine, but it turns out to be impossible to use along with page reference counting, i.e. when an allocation is supposed to be freed with put_page, as it is the case with pipe or unix socket buffers. To overcome this limitation, this patch moves charging/uncharging to generic page allocator paths, i.e. to __alloc_pages_nodemask and free_pages_prepare, and zaps alloc/free_kmem_pages helpers. This way, one can use any of the available page allocation functions to get the allocated page charged to kmemcg - it's enough to pass __GFP_ACCOUNT, just like in case of kmalloc and friends. A charged page will be automatically uncharged on free. To make it possible, we need to mark pages charged to kmemcg somehow. To avoid introducing a new page flag, we make use of page->_mapcount for marking such pages. Since pages charged to kmemcg are not supposed to be mapped to userspace, it should work just fine. There are other (ab)users of page->_mapcount - buddy and balloon pages - but we don't conflict with them. In case kmemcg is compiled out or not used at runtime, this patch introduces no overhead to generic page allocator paths. If kmemcg is used, it will be plus one gfp flags check on alloc and plus one page->_mapcount check on free, which shouldn't hurt performance, because the data accessed are hot. Link: http://lkml.kernel.org/r/a9736d856f895bcb465d9f257b54efe32eda6f99.1464079538.git.vdavydov@virtuozzo.com Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michael Ellerman | 9521d39976 |
Fix build break in fork.c when THREAD_SIZE < PAGE_SIZE
Commit |