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2017-07-12mm, migration: do not trigger OOM killer when migrating memoryMichal Hocko1-1/+1
Page migration (for memory hotplug, soft_offline_page or mbind) needs to allocate a new memory. This can trigger an oom killer if the target memory is depleated. Although quite unlikely, still possible, especially for the memory hotplug (offlining of memoery). Up to now we didn't really have reasonable means to back off. __GFP_NORETRY can fail just too easily and __GFP_THISNODE sticks to a single node and that is not suitable for all callers. But now that we have __GFP_RETRY_MAYFAIL we should use it. It is preferable to fail the migration than disrupt the system by killing some processes. Link: http://lkml.kernel.org/r/20170623085345.11304-7-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alex Belits <alex.belits@cavium.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: David Daney <david.daney@cavium.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: NeilBrown <neilb@suse.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful semanticMichal Hocko3-15/+46
__GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to the page allocator. This has been true but only for allocations requests larger than PAGE_ALLOC_COSTLY_ORDER. It has been always ignored for smaller sizes. This is a bit unfortunate because there is no way to express the same semantic for those requests and they are considered too important to fail so they might end up looping in the page allocator for ever, similarly to GFP_NOFAIL requests. Now that the whole tree has been cleaned up and accidental or misled usage of __GFP_REPEAT flag has been removed for !costly requests we can give the original flag a better name and more importantly a more useful semantic. Let's rename it to __GFP_RETRY_MAYFAIL which tells the user that the allocator would try really hard but there is no promise of a success. This will work independent of the order and overrides the default allocator behavior. Page allocator users have several levels of guarantee vs. cost options (take GFP_KERNEL as an example) - GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_ attempt to free memory at all. The most light weight mode which even doesn't kick the background reclaim. Should be used carefully because it might deplete the memory and the next user might hit the more aggressive reclaim - GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic allocation without any attempt to free memory from the current context but can wake kswapd to reclaim memory if the zone is below the low watermark. Can be used from either atomic contexts or when the request is a performance optimization and there is another fallback for a slow path. - (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) - non sleeping allocation with an expensive fallback so it can access some portion of memory reserves. Usually used from interrupt/bh context with an expensive slow path fallback. - GFP_KERNEL - both background and direct reclaim are allowed and the _default_ page allocator behavior is used. That means that !costly allocation requests are basically nofail but there is no guarantee of that behavior so failures have to be checked properly by callers (e.g. OOM killer victim is allowed to fail currently). - GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior and all allocation requests fail early rather than cause disruptive reclaim (one round of reclaim in this implementation). The OOM killer is not invoked. - GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator behavior and all allocation requests try really hard. The request will fail if the reclaim cannot make any progress. The OOM killer won't be triggered. - GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior and all allocation requests will loop endlessly until they succeed. This might be really dangerous especially for larger orders. Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL because they already had their semantic. No new users are added. __alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if there is no progress and we have already passed the OOM point. This means that all the reclaim opportunities have been exhausted except the most disruptive one (the OOM killer) and a user defined fallback behavior is more sensible than keep retrying in the page allocator. [akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c] [mhocko@suse.com: semantic fix] Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz [mhocko@kernel.org: address other thing spotted by Vlastimil] Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alex Belits <alex.belits@cavium.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: David Daney <david.daney@cavium.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: NeilBrown <neilb@suse.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12random,stackprotect: introduce get_random_canary functionRik van Riel1-0/+21
Patch series "stackprotector: ascii armor the stack canary", v2. Zero out the first byte of the stack canary value on 64 bit systems, in order to mitigate unterminated C string overflows. The null byte both prevents C string functions from reading the canary, and from writing it if the canary value were guessed or obtained through some other means. Reducing the entropy by 8 bits is acceptable on 64-bit systems, which will still have 56 bits of entropy left, but not on 32 bit systems, so the "ascii armor" canary is only implemented on 64-bit systems. Inspired by the "ascii armor" code in execshield and Daniel Micay's linux-hardened tree. Also see https://github.com/thestinger/linux-hardened/ This patch (of 5): Introduce get_random_canary(), which provides a random unsigned long canary value with the first byte zeroed out on 64 bit architectures, in order to mitigate non-terminated C string overflows. The null byte both prevents C string functions from reading the canary, and from writing it if the canary value were guessed or obtained through some other means. Reducing the entropy by 8 bits is acceptable on 64-bit systems, which will still have 56 bits of entropy left, but not on 32 bit systems, so the "ascii armor" canary is only implemented on 64-bit systems. Inspired by the "ascii armor" code in the old execshield patches, and Daniel Micay's linux-hardened tree. Link: http://lkml.kernel.org/r/20170524155751.424-2-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>
2017-07-12include/linux/string.h: add the option of fortified string.h functionsDaniel Micay1-0/+200
This adds support for compiling with a rough equivalent to the glibc _FORTIFY_SOURCE=1 feature, providing compile-time and runtime buffer overflow checks for string.h functions when the compiler determines the size of the source or destination buffer at compile-time. Unlike glibc, it covers buffer reads in addition to writes. GNU C __builtin_*_chk intrinsics are avoided because they would force a much more complex implementation. They aren't designed to detect read overflows and offer no real benefit when using an implementation based on inline checks. Inline checks don't add up to much code size and allow full use of the regular string intrinsics while avoiding the need for a bunch of _chk functions and per-arch assembly to avoid wrapper overhead. This detects various overflows at compile-time in various drivers and some non-x86 core kernel code. There will likely be issues caught in regular use at runtime too. Future improvements left out of initial implementation for simplicity, as it's all quite optional and can be done incrementally: * Some of the fortified string functions (strncpy, strcat), don't yet place a limit on reads from the source based on __builtin_object_size of the source buffer. * Extending coverage to more string functions like strlcat. * It should be possible to optionally use __builtin_object_size(x, 1) for some functions (C strings) to detect intra-object overflows (like glibc's _FORTIFY_SOURCE=2), but for now this takes the conservative approach to avoid likely compatibility issues. * The compile-time checks should be made available via a separate config option which can be enabled by default (or always enabled) once enough time has passed to get the issues it catches fixed. Kees said: "This is great to have. While it was out-of-tree code, it would have blocked at least CVE-2016-3858 from being exploitable (improper size argument to strlcpy()). I've sent a number of fixes for out-of-bounds-reads that this detected upstream already" [arnd@arndb.de: x86: fix fortified memcpy] Link: http://lkml.kernel.org/r/20170627150047.660360-1-arnd@arndb.de [keescook@chromium.org: avoid panic() in favor of BUG()] Link: http://lkml.kernel.org/r/20170626235122.GA25261@beast [keescook@chromium.org: move from -mm, add ARCH_HAS_FORTIFY_SOURCE, tweak Kconfig help] Link: http://lkml.kernel.org/r/20170526095404.20439-1-danielmicay@gmail.com Link: http://lkml.kernel.org/r/1497903987-21002-8-git-send-email-keescook@chromium.org Signed-off-by: Daniel Micay <danielmicay@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Daniel Axtens <dja@axtens.net> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Chris Metcalf <cmetcalf@ezchip.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>
2017-07-12kernel/watchdog: split up config optionsNicholas Piggin1-9/+20
Split SOFTLOCKUP_DETECTOR from LOCKUP_DETECTOR, and split HARDLOCKUP_DETECTOR_PERF from HARDLOCKUP_DETECTOR. LOCKUP_DETECTOR implies the general boot, sysctl, and programming interfaces for the lockup detectors. An architecture that wants to use a hard lockup detector must define HAVE_HARDLOCKUP_DETECTOR_PERF or HAVE_HARDLOCKUP_DETECTOR_ARCH. Alternatively an arch can define HAVE_NMI_WATCHDOG, which provides the minimum arch_touch_nmi_watchdog, and it otherwise does its own thing and does not implement the LOCKUP_DETECTOR interfaces. sparc is unusual in that it has started to implement some of the interfaces, but not fully yet. It should probably be converted to a full HAVE_HARDLOCKUP_DETECTOR_ARCH. [npiggin@gmail.com: fix] Link: http://lkml.kernel.org/r/20170617223522.66c0ad88@roar.ozlabs.ibm.com Link: http://lkml.kernel.org/r/20170616065715.18390-4-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Don Zickus <dzickus@redhat.com> Reviewed-by: Babu Moger <babu.moger@oracle.com> Tested-by: Babu Moger <babu.moger@oracle.com> [sparc] Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12kernel/watchdog: introduce arch_touch_nmi_watchdog()Nicholas Piggin1-11/+16
For architectures that define HAVE_NMI_WATCHDOG, instead of having them provide the complete touch_nmi_watchdog() function, just have them provide arch_touch_nmi_watchdog(). This gives the generic code more flexibility in implementing this function, and arch implementations don't miss out on touching the softlockup watchdog or other generic details. Link: http://lkml.kernel.org/r/20170616065715.18390-3-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Don Zickus <dzickus@redhat.com> Reviewed-by: Babu Moger <babu.moger@oracle.com> Tested-by: Babu Moger <babu.moger@oracle.com> [sparc] Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12kernel/watchdog: remove unused declarationNicholas Piggin1-3/+0
Patch series "Improve watchdog config for arch watchdogs", v4. A series to make the hardlockup watchdog more easily replaceable by arch code. The last patch provides some justification for why we want to do this (existing sparc watchdog is another that could benefit). This patch (of 5): Remove unused declaration. Link: http://lkml.kernel.org/r/20170616065715.18390-2-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Don Zickus <dzickus@redhat.com> Reviewed-by: Babu Moger <babu.moger@oracle.com> Tested-by: Babu Moger <babu.moger@oracle.com> [sparc] Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12include/linux/sem.h: correctly document sem_ctimeManfred Spraul2-2/+2
sem_ctime is initialized to the semget() time and then updated at every semctl() that changes the array. Thus it does not represent the time of the last change. Especially, semop() calls are only stored in sem_otime, not in sem_ctime. This is already described in ipc/sem.c, I just overlooked that there is a comment in include/linux/sem.h and man semctl(2) as well. So: Correct wrong comments. Link: http://lkml.kernel.org/r/20170515171912.6298-4-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Kees Cook <keescook@chromium.org> Cc: <1vier1@web.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Fabian Frederick <fabf@skynet.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12ipc: merge ipc_rcu and kern_ipc_permManfred Spraul1-0/+3
ipc has two management structures that exist for every id: - struct kern_ipc_perm, it contains e.g. the permissions. - struct ipc_rcu, it contains the rcu head for rcu handling and the refcount. The patch merges both structures. As a bonus, we may save one cacheline, because both structures are cacheline aligned. In addition, it reduces the number of casts, instead most codepaths can use container_of. To simplify code, the ipc_rcu_alloc initializes the allocation to 0. [manfred@colorfullife.com: really include the memset() into ipc_alloc_rcu()] Link: http://lkml.kernel.org/r/564f8612-0601-b267-514f-a9f650ec9b32@colorfullife.com Link: http://lkml.kernel.org/r/20170525185107.12869-3-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12ipc/sem.c: remove sem_base, embed struct semManfred Spraul1-1/+21
sma->sem_base is initialized with sma->sem_base = (struct sem *) &sma[1]; The current code has four problems: - There is an unnecessary pointer dereference - sem_base is not needed. - Alignment for struct sem only works by chance. - The current code causes false positive for static code analysis. - This is a cast between different non-void types, which the future randstruct GCC plugin warns on. And, as bonus, the code size gets smaller: Before: 0 .text 00003770 After: 0 .text 0000374e [manfred@colorfullife.com: s/[0]/[]/, per hch] Link: http://lkml.kernel.org/r/20170525185107.12869-2-manfred@colorfullife.com Link: http://lkml.kernel.org/r/20170515171912.6298-2-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Kees Cook <keescook@chromium.org> Cc: <1vier1@web.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Fabian Frederick <fabf@skynet.be> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12fault-inject: support systematic fault injectionDmitry Vyukov1-0/+1
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>
2017-07-12kcmp: fs/epoll: wrap kcmp code with CONFIG_CHECKPOINT_RESTORECyrill Gorcunov1-0/+2
kcmp syscall is build iif CONFIG_CHECKPOINT_RESTORE is selected, so wrap appropriate helpers in epoll code with the config to build it conditionally. Link: http://lkml.kernel.org/r/20170513083456.GG1881@uranus.lan Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reported-by: Andrew Morton <akpm@linuxfoundation.org> Cc: Andrey Vagin <avagin@openvz.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Jason Baron <jbaron@akamai.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>
2017-07-12kcmp: add KCMP_EPOLL_TFD mode to compare epoll target filesCyrill Gorcunov2-0/+13
With current epoll architecture target files are addressed with file_struct and file descriptor number, where the last is not unique. Moreover files can be transferred from another process via unix socket, added into queue and closed then so we won't find this descriptor in the task fdinfo list. Thus to checkpoint and restore such processes CRIU needs to find out where exactly the target file is present to add it into epoll queue. For this sake one can use kcmp call where some particular target file from the queue is compared with arbitrary file passed as an argument. Because epoll target files can have same file descriptor number but different file_struct a caller should explicitly specify the offset within. To test if some particular file is matching entry inside epoll one have to - fill kcmp_epoll_slot structure with epoll file descriptor, target file number and target file offset (in case if only one target is present then it should be 0) - call kcmp as kcmp(pid1, pid2, KCMP_EPOLL_TFD, fd, &kcmp_epoll_slot) - the kernel fetch file pointer matching file descriptor @fd of pid1 - lookups for file struct in epoll queue of pid2 and returns traditional 0,1,2 result for sorting purpose Link: http://lkml.kernel.org/r/20170424154423.511592110@gmail.com Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Andrey Vagin <avagin@openvz.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Jason Baron <jbaron@akamai.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>
2017-07-12sysctl: add unsigned int range supportLuis R. Rodriguez1-0/+3
To keep parity with regular int interfaces provide the an unsigned int proc_douintvec_minmax() which allows you to specify a range of allowed valid numbers. Adding proc_douintvec_minmax_sysadmin() is easy but we can wait for an actual user for that. Link: http://lkml.kernel.org/r/20170519033554.18592-6-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Kees Cook <keescook@chromium.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12kdump: protect vmcoreinfo data under the crash memoryXunlei Pang2-1/+3
Currently vmcoreinfo data is updated at boot time subsys_initcall(), it has the risk of being modified by some wrong code during system is running. As a result, vmcore dumped may contain the wrong vmcoreinfo. Later on, when using "crash", "makedumpfile", etc utility to parse this vmcore, we probably will get "Segmentation fault" or other unexpected errors. E.g. 1) wrong code overwrites vmcoreinfo_data; 2) further crashes the system; 3) trigger kdump, then we obviously will fail to recognize the crash context correctly due to the corrupted vmcoreinfo. Now except for vmcoreinfo, all the crash data is well protected(including the cpu note which is fully updated in the crash path, thus its correctness is guaranteed). Given that vmcoreinfo data is a large chunk prepared for kdump, we better protect it as well. To solve this, we relocate and copy vmcoreinfo_data to the crash memory when kdump is loading via kexec syscalls. Because the whole crash memory will be protected by existing arch_kexec_protect_crashkres() mechanism, we naturally protect vmcoreinfo_data from write(even read) access under kernel direct mapping after kdump is loaded. Since kdump is usually loaded at the very early stage after boot, we can trust the correctness of the vmcoreinfo data copied. On the other hand, we still need to operate the vmcoreinfo safe copy when crash happens to generate vmcoreinfo_note again, we rely on vmap() to map out a new kernel virtual address and update to use this new one instead in the following crash_save_vmcoreinfo(). BTW, we do not touch vmcoreinfo_note, because it will be fully updated using the protected vmcoreinfo_data after crash which is surely correct just like the cpu crash note. Link: http://lkml.kernel.org/r/1493281021-20737-3-git-send-email-xlpang@redhat.com Signed-off-by: Xunlei Pang <xlpang@redhat.com> Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Young <dyoung@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com> Cc: Juergen Gross <jgross@suse.com> Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12powerpc/fadump: use the correct VMCOREINFO_NOTE_SIZE for phdrXunlei Pang1-1/+0
vmcoreinfo_max_size stands for the vmcoreinfo_data, the correct one we should use is vmcoreinfo_note whose total size is VMCOREINFO_NOTE_SIZE. Like explained in commit 77019967f06b ("kdump: fix exported size of vmcoreinfo note"), it should not affect the actual function, but we better fix it, also this change should be safe and backward compatible. After this, we can get rid of variable vmcoreinfo_max_size, let's use the corresponding macros directly, fewer variables means more safety for vmcoreinfo operation. [xlpang@redhat.com: fix build warning] Link: http://lkml.kernel.org/r/1494830606-27736-1-git-send-email-xlpang@redhat.com Link: http://lkml.kernel.org/r/1493281021-20737-2-git-send-email-xlpang@redhat.com Signed-off-by: Xunlei Pang <xlpang@redhat.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Dave Young <dyoung@redhat.com> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Juergen Gross <jgross@suse.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12kexec: move vmcoreinfo out of the kernel's .bss sectionXunlei Pang1-2/+2
As Eric said, "what we need to do is move the variable vmcoreinfo_note out of the kernel's .bss section. And modify the code to regenerate and keep this information in something like the control page. Definitely something like this needs a page all to itself, and ideally far away from any other kernel data structures. I clearly was not watching closely the data someone decided to keep this silly thing in the kernel's .bss section." This patch allocates extra pages for these vmcoreinfo_XXX variables, one advantage is that it enhances some safety of vmcoreinfo, because vmcoreinfo now is kept far away from other kernel data structures. Link: http://lkml.kernel.org/r/1493281021-20737-1-git-send-email-xlpang@redhat.com Signed-off-by: Xunlei Pang <xlpang@redhat.com> Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Reviewed-by: Juergen Gross <jgross@suse.com> Suggested-by: Eric Biederman <ebiederm@xmission.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Young <dyoung@redhat.com> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com> Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12kernel.h: handle pointers to arrays better in container_of()Ian Abbott1-3/+7
If the first parameter of container_of() is a pointer to a non-const-qualified array type (and the third parameter names a non-const-qualified array member), the local variable __mptr will be defined with a const-qualified array type. In ISO C, these types are incompatible. They work as expected in GNU C, but some versions will issue warnings. For example, GCC 4.9 produces the warning "initialization from incompatible pointer type". Here is an example of where the problem occurs: ------------------------------------------------------- #include <linux/kernel.h> #include <linux/module.h> MODULE_LICENSE("GPL"); struct st { int a; char b[16]; }; static int __init example_init(void) { struct st t = { .a = 101, .b = "hello" }; char (*p)[16] = &t.b; struct st *x = container_of(p, struct st, b); printk(KERN_DEBUG "%p %p\n", (void *)&t, (void *)x); return 0; } static void __exit example_exit(void) { } module_init(example_init); module_exit(example_exit); ------------------------------------------------------- Building the module with gcc-4.9 results in these warnings (where '{m}' is the module source and '{k}' is the kernel source): ------------------------------------------------------- In file included from {m}/example.c:1:0: {m}/example.c: In function `example_init': {k}/include/linux/kernel.h:854:48: warning: initialization from incompatible pointer type const typeof( ((type *)0)->member ) *__mptr = (ptr); \ ^ {m}/example.c:14:17: note: in expansion of macro `container_of' struct st *x = container_of(p, struct st, b); ^ {k}/include/linux/kernel.h:854:48: warning: (near initialization for `x') const typeof( ((type *)0)->member ) *__mptr = (ptr); \ ^ {m}/example.c:14:17: note: in expansion of macro `container_of' struct st *x = container_of(p, struct st, b); ^ ------------------------------------------------------- Replace the type checking performed by the macro to avoid these warnings. Make sure `*(ptr)` either has type compatible with the member, or has type compatible with `void`, ignoring qualifiers. Raise compiler errors if this is not true. This is stronger than the previous behaviour, which only resulted in compiler warnings for a type mismatch. [arnd@arndb.de: fix new warnings for container_of()] Link: http://lkml.kernel.org/r/20170620200940.90557-1-arnd@arndb.de Link: http://lkml.kernel.org/r/20170525120316.24473-7-abbotti@mev.co.uk Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Borislav Petkov <bp@suse.de> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Johannes Berg <johannes.berg@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12include/linux/dcache.h: use unsigned chars in struct name_snapshotStephen Rothwell1-2/+2
"kernel.h: handle pointers to arrays better in container_of()" triggers: In file included from include/uapi/linux/stddef.h:1:0, from include/linux/stddef.h:4, from include/uapi/linux/posix_types.h:4, from include/uapi/linux/types.h:13, from include/linux/types.h:5, from include/linux/syscalls.h:71, from fs/dcache.c:17: fs/dcache.c: In function 'release_dentry_name_snapshot': include/linux/compiler.h:542:38: error: call to '__compiletime_assert_305' declared with attribute error: pointer type mismatch in container_of() _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) ^ include/linux/compiler.h:525:4: note: in definition of macro '__compiletime_assert' prefix ## suffix(); \ ^ include/linux/compiler.h:542:2: note: in expansion of macro '_compiletime_assert' _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) ^ include/linux/build_bug.h:46:37: note: in expansion of macro 'compiletime_assert' #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) ^ include/linux/kernel.h:860:2: note: in expansion of macro 'BUILD_BUG_ON_MSG' BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ ^ fs/dcache.c:305:7: note: in expansion of macro 'container_of' p = container_of(name->name, struct external_name, name[0]); Switch name_snapshot to use unsigned chars, matching struct qstr and struct external_name. Link: http://lkml.kernel.org/r/20170710152134.0f78c1e6@canb.auug.org.au Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12Merge branch 'i2c/for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linuxLinus Torvalds4-235/+253
Pull i2c updates from Wolfram Sang: "This pull request contains: - i2c core reorganization. One source file became too monolithic. It is now split up, yet we still have the same named object as the final output. This should ease maintenance. - new drivers: ZTE ZX2967 family, ASPEED 24XX/25XX - designware driver gained slave mode support - xgene-slimpro driver gained ACPI support - bigger overhaul for pca-platform driver - the algo-bit module now supports messages with enforced STOP - slightly bigger than usual set of driver updates and improvements and with much appreciated quality assurance from Andy Shevchenko" * 'i2c/for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (51 commits) i2c: Provide a stub for i2c_detect_slave_mode() i2c: designware: Let slave adapter support be optional i2c: designware: Make HW init functions static i2c: designware: fix spelling mistakes i2c: pca-platform: propagate error from i2c_pca_add_numbered_bus i2c: pca-platform: correctly set algo_data.reset_chip i2c: acpi: Do not create i2c-clients for LNXVIDEO ACPI devices i2c: designware: enable SLAVE in platform module i2c: designware: add SLAVE mode functions i2c: zx2967: drop COMPILE_TEST dependency i2c: zx2967: always use the same device when printing errors i2c: pca-platform: use dev_warn/dev_info instead of printk i2c: pca-platform: use device managed allocations i2c: pca-platform: add devicetree awareness i2c: pca-platform: switch to struct gpio_desc dt-bindings: add bindings for i2c-pca-platform i2c: cadance: fix ctrl/addr reg write order i2c: zx2967: add i2c controller driver for ZTE's zx2967 family dt: bindings: add documentation for zx2967 family i2c controller i2c: algo-bit: add support for I2C_M_STOP ...
2017-07-12Merge tag 'iommu-updates-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommuLinus Torvalds1-0/+20
Pull IOMMU updates from Joerg Roedel: "This update comes with: - Support for lockless operation in the ARM io-pgtable code. This is an important step to solve the scalability problems in the common dma-iommu code for ARM - Some Errata workarounds for ARM SMMU implemenations - Rewrite of the deferred IO/TLB flush code in the AMD IOMMU driver. The code suffered from very high flush rates, with the new implementation the flush rate is down to ~1% of what it was before - Support for amd_iommu=off when booting with kexec. The problem here was that the IOMMU driver bailed out early without disabling the iommu hardware, if it was enabled in the old kernel - The Rockchip IOMMU driver is now available on ARM64 - Align the return value of the iommu_ops->device_group call-backs to not miss error values - Preempt-disable optimizations in the Intel VT-d and common IOVA code to help Linux-RT - Various other small cleanups and fixes" * tag 'iommu-updates-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (60 commits) iommu/vt-d: Constify intel_dma_ops iommu: Warn once when device_group callback returns NULL iommu/omap: Return ERR_PTR in device_group call-back iommu: Return ERR_PTR() values from device_group call-backs iommu/s390: Use iommu_group_get_for_dev() in s390_iommu_add_device() iommu/vt-d: Don't disable preemption while accessing deferred_flush() iommu/iova: Don't disable preempt around this_cpu_ptr() iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #126 iommu/arm-smmu-v3: Enable ACPI based HiSilicon CMD_PREFETCH quirk(erratum 161010701) iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #74 ACPI/IORT: Fixup SMMUv3 resource size for Cavium ThunderX2 SMMUv3 model iommu/arm-smmu-v3, acpi: Add temporary Cavium SMMU-V3 IORT model number definitions iommu/io-pgtable-arm: Use dma_wmb() instead of wmb() when publishing table iommu/io-pgtable: depend on !GENERIC_ATOMIC64 when using COMPILE_TEST with LPAE iommu/arm-smmu-v3: Remove io-pgtable spinlock iommu/arm-smmu: Remove io-pgtable spinlock iommu/io-pgtable-arm-v7s: Support lockless operation iommu/io-pgtable-arm: Support lockless operation iommu/io-pgtable: Introduce explicit coherency iommu/io-pgtable-arm-v7s: Refactor split_blk_unmap ...
2017-07-12Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfsLinus Torvalds1-0/+4
Pull overlayfs updates from Miklos Szeredi: "This work from Amir introduces the inodes index feature, which provides: - hardlinks are not broken on copy up - infrastructure for overlayfs NFS export This also fixes constant st_ino for samefs case for lower hardlinks" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (33 commits) ovl: mark parent impure and restore timestamp on ovl_link_up() ovl: document copying layers restrictions with inodes index ovl: cleanup orphan index entries ovl: persistent overlay inode nlink for indexed inodes ovl: implement index dir copy up ovl: move copy up lock out ovl: rearrange copy up ovl: add flag for upper in ovl_entry ovl: use struct copy_up_ctx as function argument ovl: base tmpfile in workdir too ovl: factor out ovl_copy_up_inode() helper ovl: extract helper to get temp file in copy up ovl: defer upper dir lock to tempfile link ovl: hash overlay non-dir inodes by copy up origin ovl: cleanup bad and stale index entries on mount ovl: lookup index entry for copy up origin ovl: verify index dir matches upper dir ovl: verify upper root dir matches lower root dir ovl: introduce the inodes index dir feature ovl: generalize ovl_create_workdir() ...
2017-07-11Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds4-29/+84
Pull more block updates from Jens Axboe: "This is a followup for block changes, that didn't make the initial pull request. It's a bit of a mixed bag, this contains: - A followup pull request from Sagi for NVMe. Outside of fixups for NVMe, it also includes a series for ensuring that we properly quiesce hardware queues when browsing live tags. - Set of integrity fixes from Dmitry (mostly), fixing various issues for folks using DIF/DIX. - Fix for a bug introduced in cciss, with the req init changes. From Christoph. - Fix for a bug in BFQ, from Paolo. - Two followup fixes for lightnvm/pblk from Javier. - Depth fix from Ming for blk-mq-sched. - Also from Ming, performance fix for mtip32xx that was introduced with the dynamic initialization of commands" * 'for-linus' of git://git.kernel.dk/linux-block: (44 commits) block: call bio_uninit in bio_endio nvmet: avoid unneeded assignment of submit_bio return value nvme-pci: add module parameter for io queue depth nvme-pci: compile warnings in nvme_alloc_host_mem() nvmet_fc: Accept variable pad lengths on Create Association LS nvme_fc/nvmet_fc: revise Create Association descriptor length lightnvm: pblk: remove unnecessary checks lightnvm: pblk: control I/O flow also on tear down cciss: initialize struct scsi_req null_blk: fix error flow for shared tags during module_init block: Fix __blkdev_issue_zeroout loop nvme-rdma: unconditionally recycle the request mr nvme: split nvme_uninit_ctrl into stop and uninit virtio_blk: quiesce/unquiesce live IO when entering PM states mtip32xx: quiesce request queues to make sure no submissions are inflight nbd: quiesce request queues to make sure no submissions are inflight nvme: kick requeue list when requeueing a request instead of when starting the queues nvme-pci: quiesce/unquiesce admin_q instead of start/stop its hw queues nvme-loop: quiesce/unquiesce admin_q instead of start/stop its hw queues nvme-fc: quiesce/unquiesce admin_q instead of start/stop its hw queues ...
2017-07-11Merge tag 'ceph-for-4.13-rc1' of git://github.com/ceph/ceph-clientLinus Torvalds10-118/+450
Pull ceph updates from Ilya Dryomov: "The main item here is support for v12.y.z ("Luminous") clusters: RESEND_ON_SPLIT, RADOS_BACKOFF, OSDMAP_PG_UPMAP and CRUSH_CHOOSE_ARGS feature bits, and various other changes in the RADOS client protocol. On top of that we have a new fsc mount option to allow supplying fscache uniquifier (similar to NFS) and the usual pile of filesystem fixes from Zheng" * tag 'ceph-for-4.13-rc1' of git://github.com/ceph/ceph-client: (44 commits) libceph: advertise support for NEW_OSDOP_ENCODING and SERVER_LUMINOUS libceph: osd_state is 32 bits wide in luminous crush: remove an obsolete comment crush: crush_init_workspace starts with struct crush_work libceph, crush: per-pool crush_choose_arg_map for crush_do_rule() crush: implement weight and id overrides for straw2 libceph: apply_upmap() libceph: compute actual pgid in ceph_pg_to_up_acting_osds() libceph: pg_upmap[_items] infrastructure libceph: ceph_decode_skip_* helpers libceph: kill __{insert,lookup,remove}_pg_mapping() libceph: introduce and switch to decode_pg_mapping() libceph: don't pass pgid by value libceph: respect RADOS_BACKOFF backoffs libceph: make DEFINE_RB_* helpers more general libceph: avoid unnecessary pi lookups in calc_target() libceph: use target pi for calc_target() calculations libceph: always populate t->target_{oid,oloc} in calc_target() libceph: make sure need_resend targets reflect latest map libceph: delete from need_resend_linger before check_linger_pool_dne() ...
2017-07-11Merge tag 'chrome-platform-for-linus-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platformLinus Torvalds4-4/+208
Pull chrome platform updates from Benson Leung: "Changes in this pull request are around catching up cros_ec with the internal chromeos-kernel versions of cros_ec, cros_ec_lpc, and cros_ec_lightbar. Also, switching maintainership from olof to bleung" * tag 'chrome-platform-for-linus-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform: platform/chrome : Add myself as Maintainer platform/chrome: cros_ec_lightbar - hide unused PM functions cros_ec: Don't signal wake event for non-wake host events cros_ec: Fix deadlock when EC is not responsive at probe cros_ec: Don't return error when checking command version platform/chrome: cros_ec_lightbar - Avoid I2C xfer to EC during suspend platform/chrome: cros_ec_lightbar - Add userspace lightbar control bit to EC platform/chrome: cros_ec_lightbar - Control of suspend/resume lightbar sequence platform/chrome: cros_ec_lightbar - Add lightbar program feature to sysfs platform/chrome: cros_ec_lpc: Add MKBP events support over ACPI platform/chrome: cros_ec_lpc: Add power management ops platform/chrome: cros_ec_lpc: Add support for GOOG004 ACPI device platform/chrome: cros_ec_lpc: Add support for mec1322 EC platform/chrome: cros_ec_lpc: Add R/W helpers to LPC protocol variants mfd: cros_ec: Add support for dumping panic information cros_ec_debugfs: Pass proper struct sizes to cros_ec_cmd_xfer() mfd: cros_ec: add debugfs, console log file mfd: cros_ec: Add EC console read structures definitions mfd: cros_ec: Add helper for event notifier.
2017-07-10Merge branch 'akpm' (patches from Andrew)Linus Torvalds21-137/+302
Merge more updates from Andrew Morton: - most of the rest of MM - KASAN updates - lib/ updates - checkpatch updates - some binfmt_elf changes - various misc bits * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (115 commits) kernel/exit.c: avoid undefined behaviour when calling wait4() kernel/signal.c: avoid undefined behaviour in kill_something_info binfmt_elf: safely increment argv pointers s390: reduce ELF_ET_DYN_BASE powerpc: move ELF_ET_DYN_BASE to 4GB / 4MB arm64: move ELF_ET_DYN_BASE to 4GB / 4MB arm: move ELF_ET_DYN_BASE to 4MB binfmt_elf: use ELF_ET_DYN_BASE only for PIE fs, epoll: short circuit fetching events if thread has been killed checkpatch: improve multi-line alignment test checkpatch: improve macro reuse test checkpatch: change format of --color argument to --color[=WHEN] checkpatch: silence perl 5.26.0 unescaped left brace warnings checkpatch: improve tests for multiple line function definitions checkpatch: remove false warning for commit reference checkpatch: fix stepping through statements with $stat and ctx_statement_block checkpatch: [HLP]LIST_HEAD is also declaration checkpatch: warn when a MAINTAINERS entry isn't [A-Z]:\t checkpatch: improve the unnecessary OOM message test lib/bsearch.c: micro-optimize pivot position calculation ...
2017-07-10lib/extable.c: use bsearch() library function in search_extable()Thomas Meyer1-2/+3
[thomas@m3y3r.de: v3: fix arch specific implementations] Link: http://lkml.kernel.org/r/1497890858.12931.7.camel@m3y3r.de Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10bitmap: use memcmp optimisation in more situationsMatthew Wilcox1-3/+1
Commit 7dd968163f7c ("bitmap: bitmap_equal memcmp optimization") was rather more restrictive than necessary; we can use memcmp() to implement bitmap_equal() as long as the number of bits can be proved to be a multiple of 8. And architectures other than s390 may be able to make good use of this optimisation. [arnd@arndb.de: fix build: add a memcmp() declaration] Link: http://lkml.kernel.org/r/20170630153908.3439707-1-arnd@arndb.de Link: http://lkml.kernel.org/r/20170628153221.11322-5-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10include/linux/bitmap.h: turn bitmap_set and bitmap_clear into memset when possibleMatthew Wilcox1-0/+6
Several callers have constant 'start' and an 'nbits' that is a multiple of 8, so we can turn them into calls to memset. We don't need the entirety of 'start' and 'nbits' to be constant, we just need to know whether they're divisible by 8. Link: http://lkml.kernel.org/r/20170628153221.11322-4-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10bitmap: optimise bitmap_set and bitmap_clear of a single bitMatthew Wilcox1-3/+20
We have eight users calling bitmap_clear for a single bit and seventeen calling bitmap_set for a single bit. Rather than fix all of them to call __clear_bit or __set_bit, turn bitmap_clear and bitmap_set into inline functions and make this special case efficient. Link: http://lkml.kernel.org/r/20170628153221.11322-3-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10ARM: fix rd_size declarationBart Van Assche1-0/+3
The global variable 'rd_size' is declared as 'int' in source file arch/arm/kernel/atags_parse.c and as 'unsigned long' in drivers/block/brd.c. Fix this inconsistency. Additionally, remove the declarations of rd_image_start, rd_prompt and rd_doload from parse_tag_ramdisk() since these duplicate existing declarations in <linux/initrd.h>. Link: http://lkml.kernel.org/r/20170627065024.12347-1-bart.vanassche@wdc.com Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Cc: Jason Yan <yanaijie@huawei.com> Cc: Zhaohongjiang <zhaohongjiang@huawei.com> Cc: Miao Xie <miaoxie@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10bug: split BUILD_BUG stuff out into <linux/build_bug.h>Ian Abbott2-73/+85
Including <linux/bug.h> pulls in a lot of bloat from <asm/bug.h> and <asm-generic/bug.h> that is not needed to call the BUILD_BUG() family of macros. Split them out into their own header, <linux/build_bug.h>. Also correct some checkpatch.pl errors for the BUILD_BUG_ON_ZERO() and BUILD_BUG_ON_NULL() macros by adding parentheses around the bitfield widths that begin with a minus sign. Link: http://lkml.kernel.org/r/20170525120316.24473-6-abbotti@mev.co.uk Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Acked-by: Michal Nazarewicz <mina86@mina86.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10linux/bug.h: correct "space required before that '-'"Ian Abbott1-2/+2
Correct these checkpatch.pl errors: |ERROR: space required before that '-' (ctx:OxO) |#37: FILE: include/linux/bug.h:37: |+#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) |ERROR: space required before that '-' (ctx:OxO) |#38: FILE: include/linux/bug.h:38: |+#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) I decided to wrap the bitfield expressions that begin with minus signs in parentheses rather than insert spaces before the minus signs. Link: http://lkml.kernel.org/r/20170525120316.24473-5-abbotti@mev.co.uk Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Kees Cook <keescook@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10linux/bug.h: correct "(foo*)" should be "(foo *)"Ian Abbott1-1/+1
Correct this checkpatch.pl error: |ERROR: "(foo*)" should be "(foo *)" |#19: FILE: include/linux/bug.h:19: |+#define BUILD_BUG_ON_NULL(e) ((void*)0) Link: http://lkml.kernel.org/r/20170525120316.24473-4-abbotti@mev.co.uk Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Kees Cook <keescook@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10linux/bug.h: correct formatting of block commentIan Abbott1-4/+6
Correct these checkpatch.pl warnings: |WARNING: Block comments use * on subsequent lines |#34: FILE: include/linux/bug.h:34: |+/* Force a compilation error if condition is true, but also produce a |+ result (of value 0 and type size_t), so the expression can be used |WARNING: Block comments use a trailing */ on a separate line |#36: FILE: include/linux/bug.h:36: |+ aren't permitted). */ Link: http://lkml.kernel.org/r/20170525120316.24473-3-abbotti@mev.co.uk Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Kees Cook <keescook@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10asm-generic/bug.h: declare struct pt_regs; before function prototypeIan Abbott1-0/+1
This series of patches splits BUILD_BUG related macros out of "include/linux/bug.h" into new file "include/linux/build_bug.h" (patch 5), and changes the pointer type checking in the `container_of()` macro to deal with pointers of array type better (patch 6). Patches 1 to 4 are prerequisites. Patches 2, 3, 4, and 5 have been inserted since the previous version of this patch series. Patch 6 here corresponds to v3 and v4's patch 2. Patch 1 was a prerequisite in v3 of this series to avoid a lot of warnings when <linux/bug.h> was included by <linux/kernel.h>. That is no longer relevant for v5 of the series, but I left it in because it was acked by a Arnd Bergmann and Michal Nazarewicz. Patches 2, 3, and 4 are some checkpatch clean-ups on "include/linux/bug.h" before splitting out the BUILD_BUG stuff in patch 5. Patch 5 splits the BUILD_BUG related macros out of "include/linux/bug.h" into new file "include/linux/build_bug.h" because including <linux/bug.h> in "include/linux/kernel.h" would result in build failures due to circular dependencies. Patch 6 changes the pointer type checking by `container_of()` to avoid some incompatible pointer warnings when the dereferenced pointer has array type. 1) asm-generic/bug.h: declare struct pt_regs; before function prototype 2) linux/bug.h: correct formatting of block comment 3) linux/bug.h: correct "(foo*)" should be "(foo *)" 4) linux/bug.h: correct "space required before that '-'" 5) bug: split BUILD_BUG stuff out into <linux/build_bug.h> 6) kernel.h: handle pointers to arrays better in container_of() This patch (of 6): The declaration of `__warn()` has `struct pt_regs *regs` as one of its parameters. This can result in compiler warnings if `struct regs` is not already declared. Add an empty declaration of `struct pt_regs` to avoid the warnings. Link: http://lkml.kernel.org/r/20170525120316.24473-2-abbotti@mev.co.uk Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10mm: disallow early_pfn_to_nid on configurations which do not implement itMichal Hocko1-0/+1
early_pfn_to_nid will return node 0 if both HAVE_ARCH_EARLY_PFN_TO_NID and HAVE_MEMBLOCK_NODE_MAP are disabled. It seems we are safe now because all architectures which support NUMA define one of them (with an exception of alpha which however has CONFIG_NUMA marked as broken) so this works as expected. It can get silently and subtly broken too easily, though. Make sure we fail the compilation if NUMA is enabled and there is no proper implementation for this function. If that ever happens we know that either the specific configuration is invalid and the fix should either disable NUMA or enable one of the above configs. Link: http://lkml.kernel.org/r/20170704075803.15979-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Yang Shi <yang.shi@linaro.org> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10mm: swap: provide lru_add_drain_all_cpuslocked()Thomas Gleixner1-0/+1
The rework of the cpu hotplug locking unearthed potential deadlocks with the memory hotplug locking code. The solution for these is to rework the memory hotplug locking code as well and take the cpu hotplug lock before the memory hotplug lock in mem_hotplug_begin(), but this will cause a recursive locking of the cpu hotplug lock when the memory hotplug code calls lru_add_drain_all(). Split out the inner workings of lru_add_drain_all() into lru_add_drain_all_cpuslocked() so this function can be invoked from the memory hotplug code with the cpu hotplug lock held. Link: http://lkml.kernel.org/r/20170704093421.419329357@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10mm/list_lru.c: fix list_lru_count_node() to be race freeSahitya Tummala1-0/+1
list_lru_count_node() iterates over all memcgs to get the total number of entries on the node but it can race with memcg_drain_all_list_lrus(), which migrates the entries from a dead cgroup to another. This can return incorrect number of entries from list_lru_count_node(). Fix this by keeping track of entries per node and simply return it in list_lru_count_node(). Link: http://lkml.kernel.org/r/1498707555-30525-1-git-send-email-stummala@codeaurora.org Signed-off-by: Sahitya Tummala <stummala@codeaurora.org> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Alexander Polakov <apolyakov@beget.ru> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10include/linux/backing-dev.h: simplify wb_stat_sumNikolay Borisov1-14/+1
wb_stat_sum() disables interrupts and calls __wb_stat_sum() which eventually calls __percpu_counter_sum(). However, the percpu routine is already irq-safe. Simplify the code a bit by making wb_stat_sum() directly call percpu_counter_sum_positive() and not disable interrupts. Also remove the now-uneeded __wb_stat_sum() which was just a wrapper over percpu_counter_sum_positive(). Link: http://lkml.kernel.org/r/1498230681-29103-1-git-send-email-nborisov@suse.com Signed-off-by: Nikolay Borisov <nborisov@suse.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10include/linux/mmzone.h: remove ancient/ambiguous commentNikolay Borisov1-5/+2
Currently pg_data_t is just a struct which describes a NUMA node memory layout. Let's keep the comment simple and remove ambiguity. Link: http://lkml.kernel.org/r/1498220534-22717-1-git-send-email-nborisov@suse.com Signed-off-by: Nikolay Borisov <nborisov@suse.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>
2017-07-10hugetlb: add support for preferred node to alloc_huge_page_nodemaskMichal Hocko2-3/+4
alloc_huge_page_nodemask tries to allocate from any numa node in the allowed node mask starting from lower numa nodes. This might lead to filling up those low NUMA nodes while others are not used. We can reduce this risk by introducing a concept of the preferred node similar to what we have in the regular page allocator. We will start allocating from the preferred nid and then iterate over all allowed nodes in the zonelist order until we try them all. This is mimicing the page allocator logic except it operates on per-node mempools. dequeue_huge_page_vma already does this so distill the zonelist logic into a more generic dequeue_huge_page_nodemask and use it in alloc_huge_page_nodemask. This will allow us to use proper per numa distance fallback also for alloc_huge_page_node which can use alloc_huge_page_nodemask now and we can get rid of alloc_huge_page_node helper which doesn't have any user anymore. Link: http://lkml.kernel.org/r/20170622193034.28972-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Tested-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10mm, hugetlb: unclutter hugetlb allocation layersMichal Hocko1-1/+1
Patch series "mm, hugetlb: allow proper node fallback dequeue". While working on a hugetlb migration issue addressed in a separate patchset[1] I have noticed that the hugetlb allocations from the preallocated pool are quite subotimal. [1] //lkml.kernel.org/r/20170608074553.22152-1-mhocko@kernel.org There is no fallback mechanism implemented and no notion of preferred node. I have tried to work around it but Vlastimil was right to push back for a more robust solution. It seems that such a solution is to reuse zonelist approach we use for the page alloctor. This series has 3 patches. The first one tries to make hugetlb allocation layers more clear. The second one implements the zonelist hugetlb pool allocation and introduces a preferred node semantic which is used by the migration callbacks. The last patch is a clean up. This patch (of 3): Hugetlb allocation path for fresh huge pages is unnecessarily complex and it mixes different interfaces between layers. __alloc_buddy_huge_page is the central place to perform a new allocation. It checks for the hugetlb overcommit and then relies on __hugetlb_alloc_buddy_huge_page to invoke the page allocator. This is all good except that __alloc_buddy_huge_page pushes vma and address down the callchain and so __hugetlb_alloc_buddy_huge_page has to deal with two different allocation modes - one for memory policy and other node specific (or to make it more obscure node non-specific) requests. This just screams for a reorganization. This patch pulls out all the vma specific handling up to __alloc_buddy_huge_page_with_mpol where it belongs. __alloc_buddy_huge_page will get nodemask argument and __hugetlb_alloc_buddy_huge_page will become a trivial wrapper over the page allocator. In short: __alloc_buddy_huge_page_with_mpol - memory policy handling __alloc_buddy_huge_page - overcommit handling and accounting __hugetlb_alloc_buddy_huge_page - page allocator layer Also note that __hugetlb_alloc_buddy_huge_page and its cpuset retry loop is not really needed because the page allocator already handles the cpusets update. Finally __hugetlb_alloc_buddy_huge_page had a special case for node specific allocations (when no policy is applied and there is a node given). This has relied on __GFP_THISNODE to not fallback to a different node. alloc_huge_page_node is the only caller which relies on this behavior so move the __GFP_THISNODE there. Not only does this remove quite some code it also should make those layers easier to follow and clear wrt responsibilities. Link: http://lkml.kernel.org/r/20170622193034.28972-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Tested-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10mm/oom_kill.c: add tracepoints for oom reaper-related eventsRoman Gushchin1-0/+80
During the debugging of the problem described in https://lkml.org/lkml/2017/5/17/542 and fixed by Tetsuo Handa in https://lkml.org/lkml/2017/5/19/383 , I've found that the existing debug output is not really useful to understand issues related to the oom reaper. So, I assume, that adding some tracepoints might help with debugging of similar issues. Trace the following events: 1) a process is marked as an oom victim, 2) a process is added to the oom reaper list, 3) the oom reaper starts reaping process's mm, 4) the oom reaper finished reaping, 5) the oom reaper skips reaping. How it works in practice? Below is an example which show how the problem mentioned above can be found: one process is added twice to the oom_reaper list: $ cd /sys/kernel/debug/tracing $ echo "oom:mark_victim" > set_event $ echo "oom:wake_reaper" >> set_event $ echo "oom:skip_task_reaping" >> set_event $ echo "oom:start_task_reaping" >> set_event $ echo "oom:finish_task_reaping" >> set_event $ cat trace_pipe allocate-502 [001] .... 91.836405: mark_victim: pid=502 allocate-502 [001] .N.. 91.837356: wake_reaper: pid=502 allocate-502 [000] .N.. 91.871149: wake_reaper: pid=502 oom_reaper-23 [000] .... 91.871177: start_task_reaping: pid=502 oom_reaper-23 [000] .N.. 91.879511: finish_task_reaping: pid=502 oom_reaper-23 [000] .... 91.879580: skip_task_reaping: pid=502 Link: http://lkml.kernel.org/r/20170530185231.GA13412@castle Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10mm: unify new_node_page and alloc_migrate_targetMichal Hocko1-0/+16
Commit 394e31d2ceb4 ("mem-hotplug: alloc new page from a nearest neighbor node when mem-offline") has duplicated a large part of alloc_migrate_target with some hotplug specific special casing. To be more precise it tried to enfore the allocation from a different node than the original page. As a result the two function diverged in their shared logic, e.g. the hugetlb allocation strategy. Let's unify the two and express different NUMA requirements by the given nodemask. new_node_page will simply exclude the node it doesn't care about and alloc_migrate_target will use all the available nodes. alloc_migrate_target will then learn to migrate hugetlb pages more sanely and use preallocated pool when possible. Please note that alloc_migrate_target used to call alloc_page resp. alloc_pages_current so the memory policy of the current context which is quite strange when we consider that it is used in the context of alloc_contig_range which just tries to migrate pages which stand in the way. Link: http://lkml.kernel.org/r/20170608074553.22152-4-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: zhong jiang <zhongjiang@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10hugetlb, memory_hotplug: prefer to use reserved pages for migrationMichal Hocko1-0/+2
new_node_page will try to use the origin's next NUMA node as the migration destination for hugetlb pages. If such a node doesn't have any preallocated pool it falls back to __alloc_buddy_huge_page_no_mpol to allocate a surplus page instead. This is quite subotpimal for any configuration when hugetlb pages are no distributed to all NUMA nodes evenly. Say we have a hotplugable node 4 and spare hugetlb pages are node 0 /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages:10000 /sys/devices/system/node/node1/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node2/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node3/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node4/hugepages/hugepages-2048kB/nr_hugepages:10000 /sys/devices/system/node/node5/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node6/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node7/hugepages/hugepages-2048kB/nr_hugepages:0 Now we consume the whole pool on node 4 and try to offline this node. All the allocated pages should be moved to node0 which has enough preallocated pages to hold them. With the current implementation offlining very likely fails because hugetlb allocations during runtime are much less reliable. Fix this by reusing the nodemask which excludes migration source and try to find a first node which has a page in the preallocated pool first and fall back to __alloc_buddy_huge_page_no_mpol only when the whole pool is consumed. [akpm@linux-foundation.org: remove bogus arg from alloc_huge_page_nodemask() stub] Link: http://lkml.kernel.org/r/20170608074553.22152-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: zhong jiang <zhongjiang@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10include/linux/page_ref.h: ensure page_ref_unfreeze is ordered against prior accessesWill Deacon1-0/+1
page_ref_freeze and page_ref_unfreeze are designed to be used as a pair, wrapping a critical section where struct pages can be modified without having to worry about consistency for a concurrent fast-GUP. Whilst page_ref_freeze has full barrier semantics due to its use of atomic_cmpxchg, page_ref_unfreeze is implemented using atomic_set, which doesn't provide any barrier semantics and allows the operation to be reordered with respect to page modifications in the critical section. This patch ensures that page_ref_unfreeze is ordered after any critical section updates, by invoking smp_mb() prior to the atomic_set. Link: http://lkml.kernel.org/r/1497349722-6731-3-git-send-email-will.deacon@arm.com Signed-off-by: Will Deacon <will.deacon@arm.com> Acked-by: Steve Capper <steve.capper@arm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10mm: always enable thp for dax mappingsDan Williams3-5/+11
The madvise policy for transparent huge pages is meant to avoid unwanted allocations of transparent huge pages. It allows a policy of disabling the extra memory pressure and effort to arrange for a huge page when it is not needed. DAX by definition never incurs this overhead since it is statically allocated. The policy choice makes even less sense for device-dax which tries to guarantee a given tlb-fault size. Specifically, the following setting: echo never > /sys/kernel/mm/transparent_hugepage/enabled ...violates that guarantee and silently disables all device-dax instances with a 2M or 1G alignment. So, let's avoid that non-obvious side effect by force enabling thp for dax mappings in all cases. It is worth noting that the reason this uses vma_is_dax(), and the resulting header include changes, is that previous attempts to add a VM_DAX flag were NAKd. Link: http://lkml.kernel.org/r/149739531127.20686.15813586620597484283.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@lst.de> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10mm: improve readability of transparent_hugepage_enabled()Dan Williams1-12/+29
Turn the macro into a static inline and rewrite the condition checks for better readability in preparation for adding another condition. [ross.zwisler@linux.intel.com: fix logic to make conversion equivalent] [akpm@linux-foundation.org: resolve vs mm-make-pr_set_thp_disable-immediately-active.patch] [akpm@linux-foundation.org: include coredump.h for MMF_DISABLE_THP] Link: http://lkml.kernel.org/r/149739530612.20686.14760671150202647861.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10oom, trace: remove ENUM evaluation of COMPACTION_FEEDBACKSteven Rostedt (VMware)1-1/+1
After enabling CONFIG_TRACE_ENUM_MAP_FILE (which will soon be renamed to CONFIG_TRACE_EVAL_MAP_FILE), I am able to examine the enums that have been evaluated: # cat /sys/kernel/debug/tracing/enum_map (which will soon be renamed to eval_map) And it showed some interesting results: [..] ZONE_MOVABLE 3 (oom) ZONE_NORMAL 2 (oom) ZONE_DMA32 1 (oom) ZONE_DMA 0 (oom) 3 3 (oom) 2 2 (oom) 1 1 (oom) COMPACT_PRIO_ASYNC 2 (oom) COMPACT_PRIO_SYNC_LIGHT 1 (oom) COMPACT_PRIO_SYNC_FULL 0 (oom) [..] ZONE_DMA 0 (vmscan) 3 3 (vmscan) 2 2 (vmscan) 1 1 (vmscan) COMPACT_PRIO_ASYNC 2 (vmscan) [..] ZONE_DMA 0 (kmem) 3 3 (kmem) 2 2 (kmem) 1 1 (kmem) COMPACT_PRIO_ASYNC 2 (kmem) [..] ZONE_DMA 0 (compaction) 3 3 (compaction) 2 2 (compaction) 1 1 (compaction) COMPACT_PRIO_ASYNC 2 (compaction) [..] The name within the parenthesis are the trace systems that the enum/eval maps are associated with. When there's a number evaluated to another number, that tells me that the TRACE_DEFINE_ENUM() was used on a #define and not an enum. As #defines get converted normally, they are not needed to be evaluated. Each of the above trace systems with the number to number evaluation included the file include/trace/events/mmflags.h which has: /* High-level compaction status feedback */ #define COMPACTION_FAILED 1 #define COMPACTION_WITHDRAWN 2 #define COMPACTION_PROGRESS 3 [..] #define COMPACTION_FEEDBACK \ EM(COMPACTION_FAILED, "failed") \ EM(COMPACTION_WITHDRAWN, "withdrawn") \ EMe(COMPACTION_PROGRESS, "progress") Which is still needed for the __print_symbolic() usage in the trace_event. But it is not needed to be evaluated. Removing the evaluation part removes the unnecessary evaluations of numbers to numbers. Link: http://lkml.kernel.org/r/20170615074944.7be9a647@gandalf.local.home Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>