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2017-06-30 Merge tag 'v4.9.35' into linux-linaro-lsk-v4.9Alex Shi
This is the 4.9.35 stable release
2017-06-28Merge branch 'lsk/kdump/for-v4.9' into linux-linaro-lsk-v4.9Alex Shi
2017-06-24mm: fix new crash in unmapped_area_topdown()Hugh Dickins
commit f4cb767d76cf7ee72f97dd76f6cfa6c76a5edc89 upstream. Trinity gets kernel BUG at mm/mmap.c:1963! in about 3 minutes of mmap testing. That's the VM_BUG_ON(gap_end < gap_start) at the end of unmapped_area_topdown(). Linus points out how MAP_FIXED (which does not have to respect our stack guard gap intentions) could result in gap_end below gap_start there. Fix that, and the similar case in its alternative, unmapped_area(). Fixes: 1be7107fbe18 ("mm: larger stack guard gap, between vmas") Reported-by: Dave Jones <davej@codemonkey.org.uk> Debugged-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-24Allow stack to grow up to address space limitHelge Deller
commit bd726c90b6b8ce87602208701b208a208e6d5600 upstream. Fix expand_upwards() on architectures with an upward-growing stack (parisc, metag and partly IA-64) to allow the stack to reliably grow exactly up to the address space limit given by TASK_SIZE. Signed-off-by: Helge Deller <deller@gmx.de> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-24mm: larger stack guard gap, between vmasHugh Dickins
commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream. Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov <oleg@redhat.com> Original-patch-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Tested-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [wt: backport to 4.11: adjust context] [wt: backport to 4.9: adjust context ; kernel doc was not in admin-guide] Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-24swap: cond_resched in swap_cgroup_prepare()Yu Zhao
commit ef70762948dde012146926720b70e79736336764 upstream. I saw need_resched() warnings when swapping on large swapfile (TBs) because continuously allocating many pages in swap_cgroup_prepare() took too long. We already cond_resched when freeing page in swap_cgroup_swapoff(). Do the same for the page allocation. Link: http://lkml.kernel.org/r/20170604200109.17606-1-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-24mm/memory-failure.c: use compound_head() flags for huge pagesJames Morse
commit 7258ae5c5a2ce2f5969e8b18b881be40ab55433d upstream. memory_failure() chooses a recovery action function based on the page flags. For huge pages it uses the tail page flags which don't have anything interesting set, resulting in: > Memory failure: 0x9be3b4: Unknown page state > Memory failure: 0x9be3b4: recovery action for unknown page: Failed Instead, save a copy of the head page's flags if this is a huge page, this means if there are no relevant flags for this tail page, we use the head pages flags instead. This results in the me_huge_page() recovery action being called: > Memory failure: 0x9b7969: recovery action for huge page: Delayed For hugepages that have not yet been allocated, this allows the hugepage to be dequeued. Fixes: 524fca1e7356 ("HWPOISON: fix misjudgement of page_action() for errors on mlocked pages") Link: http://lkml.kernel.org/r/20170524130204.21845-1-james.morse@arm.com Signed-off-by: James Morse <james.morse@arm.com> Tested-by: Punit Agrawal <punit.agrawal@arm.com> Acked-by: Punit Agrawal <punit.agrawal@arm.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-17kasan: respect /proc/sys/kernel/traceoff_on_warningPeter Zijlstra
[ Upstream commit 4f40c6e5627ea73b4e7c615c59631f38cc880885 ] After much waiting I finally reproduced a KASAN issue, only to find my trace-buffer empty of useful information because it got spooled out :/ Make kasan_report honour the /proc/sys/kernel/traceoff_on_warning interface. Link: http://lkml.kernel.org/r/20170125164106.3514-1-aryabinin@virtuozzo.com Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-17shmem: fix sleeping from atomic contextKirill A. Shutemov
[ Upstream commit 253fd0f02040a19c6fe80e4171659fa3482a422d ] Syzkaller fuzzer managed to trigger this: BUG: sleeping function called from invalid context at mm/shmem.c:852 in_atomic(): 1, irqs_disabled(): 0, pid: 529, name: khugepaged 3 locks held by khugepaged/529: #0: (shrinker_rwsem){++++..}, at: [<ffffffff818d7ef1>] shrink_slab.part.59+0x121/0xd30 mm/vmscan.c:451 #1: (&type->s_umount_key#29){++++..}, at: [<ffffffff81a63630>] trylock_super+0x20/0x100 fs/super.c:392 #2: (&(&sbinfo->shrinklist_lock)->rlock){+.+.-.}, at: [<ffffffff818fd83e>] spin_lock include/linux/spinlock.h:302 [inline] #2: (&(&sbinfo->shrinklist_lock)->rlock){+.+.-.}, at: [<ffffffff818fd83e>] shmem_unused_huge_shrink+0x28e/0x1490 mm/shmem.c:427 CPU: 2 PID: 529 Comm: khugepaged Not tainted 4.10.0-rc5+ #201 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: shmem_undo_range+0xb20/0x2710 mm/shmem.c:852 shmem_truncate_range+0x27/0xa0 mm/shmem.c:939 shmem_evict_inode+0x35f/0xca0 mm/shmem.c:1030 evict+0x46e/0x980 fs/inode.c:553 iput_final fs/inode.c:1515 [inline] iput+0x589/0xb20 fs/inode.c:1542 shmem_unused_huge_shrink+0xbad/0x1490 mm/shmem.c:446 shmem_unused_huge_scan+0x10c/0x170 mm/shmem.c:512 super_cache_scan+0x376/0x450 fs/super.c:106 do_shrink_slab mm/vmscan.c:378 [inline] shrink_slab.part.59+0x543/0xd30 mm/vmscan.c:481 shrink_slab mm/vmscan.c:2592 [inline] shrink_node+0x2c7/0x870 mm/vmscan.c:2592 shrink_zones mm/vmscan.c:2734 [inline] do_try_to_free_pages+0x369/0xc80 mm/vmscan.c:2776 try_to_free_pages+0x3c6/0x900 mm/vmscan.c:2982 __perform_reclaim mm/page_alloc.c:3301 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:3322 [inline] __alloc_pages_slowpath+0xa24/0x1c30 mm/page_alloc.c:3683 __alloc_pages_nodemask+0x544/0xae0 mm/page_alloc.c:3848 __alloc_pages include/linux/gfp.h:426 [inline] __alloc_pages_node include/linux/gfp.h:439 [inline] khugepaged_alloc_page+0xc2/0x1b0 mm/khugepaged.c:750 collapse_huge_page+0x182/0x1fe0 mm/khugepaged.c:955 khugepaged_scan_pmd+0xfdf/0x12a0 mm/khugepaged.c:1208 khugepaged_scan_mm_slot mm/khugepaged.c:1727 [inline] khugepaged_do_scan mm/khugepaged.c:1808 [inline] khugepaged+0xe9b/0x1590 mm/khugepaged.c:1853 kthread+0x326/0x3f0 kernel/kthread.c:227 ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430 The iput() from atomic context was a bad idea: if after igrab() somebody else calls iput() and we left with the last inode reference, our iput() would lead to inode eviction and therefore sleeping. This patch should fix the situation. Link: http://lkml.kernel.org/r/20170131093141.GA15899@node.shutemov.name Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14fs: add i_blocksize()Fabian Frederick
commit 93407472a21b82f39c955ea7787e5bc7da100642 upstream. Replace all 1 << inode->i_blkbits and (1 << inode->i_blkbits) in fs branch. This patch also fixes multiple checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' Thanks to Andrew Morton for suggesting more appropriate function instead of macro. [geliangtang@gmail.com: truncate: use i_blocksize()] Link: http://lkml.kernel.org/r/9c8b2cd83c8f5653805d43debde9fa8817e02fc4.1484895804.git.geliangtang@gmail.com Link: http://lkml.kernel.org/r/1481319905-10126-1-git-send-email-fabf@skynet.be Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-08memblock: add memblock_cap_memory_range()AKASHI Takahiro
Add memblock_cap_memory_range() which will remove all the memblock regions except the memory range specified in the arguments. In addition, rework is done on memblock_mem_limit_remove_map() to re-implement it using memblock_cap_memory_range(). This function, like memblock_mem_limit_remove_map(), will not remove memblocks with MEMMAP_NOMAP attribute as they may be mapped and accessed later as "device memory." See the commit a571d4eb55d8 ("mm/memblock.c: add new infrastructure to address the mem limit issue"). This function is used, in a succeeding patch in the series of arm64 kdump suuport, to limit the range of usable memory, or System RAM, on crash dump kernel. (Please note that "mem=" parameter is of little use for this purpose.) Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Dennis Chen <dennis.chen@arm.com> Cc: linux-mm@kvack.org Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-06-08memblock: add memblock_clear_nomap()AKASHI Takahiro
This function, with a combination of memblock_mark_nomap(), will be used in a later kdump patch for arm64 when it temporarily isolates some range of memory from the other memory blocks in order to create a specific kernel mapping at boot time. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-06-07mm/slub.c: trace free objects at KERN_INFODaniel Thompson
commit aa2efd5ea4041754da4046c3d2e7edaac9526258 upstream. Currently when trace is enabled (e.g. slub_debug=T,kmalloc-128 ) the trace messages are mostly output at KERN_INFO. However the trace code also calls print_section() to hexdump the head of a free object. This is hard coded to use KERN_ERR, meaning the console is deluged with trace messages even if we've asked for quiet. Fix this the obvious way but adding a level parameter to print_section(), allowing calls from the trace code to use the same trace level as other trace messages. Link: http://lkml.kernel.org/r/20170113154850.518-1-daniel.thompson@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07slub/memcg: cure the brainless abuse of sysfs attributesThomas Gleixner
commit 478fe3037b2278d276d4cd9cd0ab06c4cb2e9b32 upstream. memcg_propagate_slab_attrs() abuses the sysfs attribute file functions to propagate settings from the root kmem_cache to a newly created kmem_cache. It does that with: attr->show(root, buf); attr->store(new, buf, strlen(bug); Aside of being a lazy and absurd hackery this is broken because it does not check the return value of the show() function. Some of the show() functions return 0 w/o touching the buffer. That means in such a case the store function is called with the stale content of the previous show(). That causes nonsense like invoking kmem_cache_shrink() on a newly created kmem_cache. In the worst case it would cause handing in an uninitialized buffer. This should be rewritten proper by adding a propagate() callback to those slub_attributes which must be propagated and avoid that insane conversion to and from ASCII, but that's too large for a hot fix. Check at least the return value of the show() function, so calling store() with stale content is prevented. Steven said: "It can cause a deadlock with get_online_cpus() that has been uncovered by recent cpu hotplug and lockdep changes that Thomas and Peter have been doing. Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(cpu_hotplug.lock); lock(slab_mutex); lock(cpu_hotplug.lock); lock(slab_mutex); *** DEADLOCK ***" Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1705201244540.2255@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reported-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07ksm: prevent crash after write_protect_page failsAndrea Arcangeli
commit a7306c3436e9c8e584a4b9fad5f3dc91be2a6076 upstream. "err" needs to be left set to -EFAULT if split_huge_page succeeds. Otherwise if "err" gets clobbered with zero and write_protect_page fails, try_to_merge_one_page() will succeed instead of returning -EFAULT and then try_to_merge_with_ksm_page() will continue thinking kpage is a PageKsm when in fact it's still an anonymous page. Eventually it'll crash in page_add_anon_rmap. This has been reproduced on Fedora25 kernel but I can reproduce with upstream too. The bug was introduced in commit f765f540598a ("ksm: prepare to new THP semantics") introduced in v4.5. page:fffff67546ce1cc0 count:4 mapcount:2 mapping:ffffa094551e36e1 index:0x7f0f46673 flags: 0x2ffffc0004007c(referenced|uptodate|dirty|lru|active|swapbacked) page dumped because: VM_BUG_ON_PAGE(!PageLocked(page)) page->mem_cgroup:ffffa09674bf0000 ------------[ cut here ]------------ kernel BUG at mm/rmap.c:1222! CPU: 1 PID: 76 Comm: ksmd Not tainted 4.9.3-200.fc25.x86_64 #1 RIP: do_page_add_anon_rmap+0x1c4/0x240 Call Trace: page_add_anon_rmap+0x18/0x20 try_to_merge_with_ksm_page+0x50b/0x780 ksm_scan_thread+0x1211/0x1410 ? prepare_to_wait_event+0x100/0x100 ? try_to_merge_with_ksm_page+0x780/0x780 kthread+0xd9/0xf0 ? kthread_park+0x60/0x60 ret_from_fork+0x25/0x30 Fixes: f765f54059 ("ksm: prepare to new THP semantics") Link: http://lkml.kernel.org/r/20170513131040.21732-1-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Federico Simoncelli <fsimonce@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07mm: consider memblock reservations for deferred memory initialization sizingMichal Hocko
commit 864b9a393dcb5aed09b8fd31b9bbda0fdda99374 upstream. We have seen an early OOM killer invocation on ppc64 systems with crashkernel=4096M: kthreadd invoked oom-killer: gfp_mask=0x16040c0(GFP_KERNEL|__GFP_COMP|__GFP_NOTRACK), nodemask=7, order=0, oom_score_adj=0 kthreadd cpuset=/ mems_allowed=7 CPU: 0 PID: 2 Comm: kthreadd Not tainted 4.4.68-1.gd7fe927-default #1 Call Trace: dump_stack+0xb0/0xf0 (unreliable) dump_header+0xb0/0x258 out_of_memory+0x5f0/0x640 __alloc_pages_nodemask+0xa8c/0xc80 kmem_getpages+0x84/0x1a0 fallback_alloc+0x2a4/0x320 kmem_cache_alloc_node+0xc0/0x2e0 copy_process.isra.25+0x260/0x1b30 _do_fork+0x94/0x470 kernel_thread+0x48/0x60 kthreadd+0x264/0x330 ret_from_kernel_thread+0x5c/0xa4 Mem-Info: active_anon:0 inactive_anon:0 isolated_anon:0 active_file:0 inactive_file:0 isolated_file:0 unevictable:0 dirty:0 writeback:0 unstable:0 slab_reclaimable:5 slab_unreclaimable:73 mapped:0 shmem:0 pagetables:0 bounce:0 free:0 free_pcp:0 free_cma:0 Node 7 DMA free:0kB min:0kB low:0kB high:0kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:52428800kB managed:110016kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:320kB slab_unreclaimable:4672kB kernel_stack:1152kB pagetables:0kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes lowmem_reserve[]: 0 0 0 0 Node 7 DMA: 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB = 0kB 0 total pagecache pages 0 pages in swap cache Swap cache stats: add 0, delete 0, find 0/0 Free swap = 0kB Total swap = 0kB 819200 pages RAM 0 pages HighMem/MovableOnly 817481 pages reserved 0 pages cma reserved 0 pages hwpoisoned the reason is that the managed memory is too low (only 110MB) while the rest of the the 50GB is still waiting for the deferred intialization to be done. update_defer_init estimates the initial memoty to initialize to 2GB at least but it doesn't consider any memory allocated in that range. In this particular case we've had Reserving 4096MB of memory at 128MB for crashkernel (System RAM: 51200MB) so the low 2GB is mostly depleted. Fix this by considering memblock allocations in the initial static initialization estimation. Move the max_initialise to reset_deferred_meminit and implement a simple memblock_reserved_memory helper which iterates all reserved blocks and sums the size of all that start below the given address. The cumulative size is than added on top of the initial estimation. This is still not ideal because reset_deferred_meminit doesn't consider holes and so reservation might be above the initial estimation whihch we ignore but let's make the logic simpler until we really need to handle more complicated cases. Fixes: 3a80a7fa7989 ("mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set") Link: http://lkml.kernel.org/r/20170531104010.GI27783@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@suse.de> Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07mlock: fix mlock count can not decrease in race conditionYisheng Xie
commit 70feee0e1ef331b22cc51f383d532a0d043fbdcc upstream. Kefeng reported that when running the follow test, the mlock count in meminfo will increase permanently: [1] testcase linux:~ # cat test_mlockal grep Mlocked /proc/meminfo for j in `seq 0 10` do for i in `seq 4 15` do ./p_mlockall >> log & done sleep 0.2 done # wait some time to let mlock counter decrease and 5s may not enough sleep 5 grep Mlocked /proc/meminfo linux:~ # cat p_mlockall.c #include <sys/mman.h> #include <stdlib.h> #include <stdio.h> #define SPACE_LEN 4096 int main(int argc, char ** argv) { int ret; void *adr = malloc(SPACE_LEN); if (!adr) return -1; ret = mlockall(MCL_CURRENT | MCL_FUTURE); printf("mlcokall ret = %d\n", ret); ret = munlockall(); printf("munlcokall ret = %d\n", ret); free(adr); return 0; } In __munlock_pagevec() we should decrement NR_MLOCK for each page where we clear the PageMlocked flag. Commit 1ebb7cc6a583 ("mm: munlock: batch NR_MLOCK zone state updates") has introduced a bug where we don't decrement NR_MLOCK for pages where we clear the flag, but fail to isolate them from the lru list (e.g. when the pages are on some other cpu's percpu pagevec). Since PageMlocked stays cleared, the NR_MLOCK accounting gets permanently disrupted by this. Fix it by counting the number of page whose PageMlock flag is cleared. Fixes: 1ebb7cc6a583 (" mm: munlock: batch NR_MLOCK zone state updates") Link: http://lkml.kernel.org/r/1495678405-54569-1-git-send-email-xieyisheng1@huawei.com Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com> Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com> Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Joern Engel <joern@logfs.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michel Lespinasse <walken@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: zhongjiang <zhongjiang@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07mm/migrate: fix refcount handling when !hugepage_migration_supported()Punit Agrawal
commit 30809f559a0d348c2dfd7ab05e9a451e2384962e upstream. On failing to migrate a page, soft_offline_huge_page() performs the necessary update to the hugepage ref-count. But when !hugepage_migration_supported() , unmap_and_move_hugepage() also decrements the page ref-count for the hugepage. The combined behaviour leaves the ref-count in an inconsistent state. This leads to soft lockups when running the overcommitted hugepage test from mce-tests suite. Soft offlining pfn 0x83ed600 at process virtual address 0x400000000000 soft offline: 0x83ed600: migration failed 1, type 1fffc00000008008 (uptodate|head) INFO: rcu_preempt detected stalls on CPUs/tasks: Tasks blocked on level-0 rcu_node (CPUs 0-7): P2715 (detected by 7, t=5254 jiffies, g=963, c=962, q=321) thugetlb_overco R running task 0 2715 2685 0x00000008 Call trace: dump_backtrace+0x0/0x268 show_stack+0x24/0x30 sched_show_task+0x134/0x180 rcu_print_detail_task_stall_rnp+0x54/0x7c rcu_check_callbacks+0xa74/0xb08 update_process_times+0x34/0x60 tick_sched_handle.isra.7+0x38/0x70 tick_sched_timer+0x4c/0x98 __hrtimer_run_queues+0xc0/0x300 hrtimer_interrupt+0xac/0x228 arch_timer_handler_phys+0x3c/0x50 handle_percpu_devid_irq+0x8c/0x290 generic_handle_irq+0x34/0x50 __handle_domain_irq+0x68/0xc0 gic_handle_irq+0x5c/0xb0 Address this by changing the putback_active_hugepage() in soft_offline_huge_page() to putback_movable_pages(). This only triggers on systems that enable memory failure handling (ARCH_SUPPORTS_MEMORY_FAILURE) but not hugepage migration (!ARCH_ENABLE_HUGEPAGE_MIGRATION). I imagine this wasn't triggered as there aren't many systems running this configuration. [akpm@linux-foundation.org: remove dead comment, per Naoya] Link: http://lkml.kernel.org/r/20170525135146.32011-1-punit.agrawal@arm.com Reported-by: Manoj Iyer <manoj.iyer@canonical.com> Tested-by: Manoj Iyer <manoj.iyer@canonical.com> Suggested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-20mm: prevent potential recursive reclaim due to clearing PF_MEMALLOCVlastimil Babka
commit 62be1511b1db8066220b18b7d4da2e6b9fdc69fb upstream. Patch series "more robust PF_MEMALLOC handling" This series aims to unify the setting and clearing of PF_MEMALLOC, which prevents recursive reclaim. There are some places that clear the flag unconditionally from current->flags, which may result in clearing a pre-existing flag. This already resulted in a bug report that Patch 1 fixes (without the new helpers, to make backporting easier). Patch 2 introduces the new helpers, modelled after existing memalloc_noio_* and memalloc_nofs_* helpers, and converts mm core to use them. Patches 3 and 4 convert non-mm code. This patch (of 4): __alloc_pages_direct_compact() sets PF_MEMALLOC to prevent deadlock during page migration by lock_page() (see the comment in __unmap_and_move()). Then it unconditionally clears the flag, which can clear a pre-existing PF_MEMALLOC flag and result in recursive reclaim. This was not a problem until commit a8161d1ed609 ("mm, page_alloc: restructure direct compaction handling in slowpath"), because direct compation was called only after direct reclaim, which was skipped when PF_MEMALLOC flag was set. Even now it's only a theoretical issue, as the new callsite of __alloc_pages_direct_compact() is reached only for costly orders and when gfp_pfmemalloc_allowed() is true, which means either __GFP_NOMEMALLOC is in gfp_flags or in_interrupt() is true. There is no such known context, but let's play it safe and make __alloc_pages_direct_compact() robust for cases where PF_MEMALLOC is already set. Fixes: a8161d1ed609 ("mm, page_alloc: restructure direct compaction handling in slowpath") Link: http://lkml.kernel.org/r/20170405074700.29871-2-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Boris Brezillon <boris.brezillon@free-electrons.com> Cc: Chris Leech <cleech@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Lee Duncan <lduncan@suse.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-27mm: prevent NR_ISOLATE_* stats from going negativeRabin Vincent
commit fc280fe871449ead4bdbd1665fa52c7c01c64765 upstream. Commit 6afcf8ef0ca0 ("mm, compaction: fix NR_ISOLATED_* stats for pfn based migration") moved the dec_node_page_state() call (along with the page_is_file_cache() call) to after putback_lru_page(). But page_is_file_cache() can change after putback_lru_page() is called, so it should be called before putback_lru_page(), as it was before that patch, to prevent NR_ISOLATE_* stats from going negative. Without this fix, non-CONFIG_SMP kernels end up hanging in the while(too_many_isolated()) { congestion_wait() } loop in shrink_active_list() due to the negative stats. Mem-Info: active_anon:32567 inactive_anon:121 isolated_anon:1 active_file:6066 inactive_file:6639 isolated_file:4294967295 ^^^^^^^^^^ unevictable:0 dirty:115 writeback:0 unstable:0 slab_reclaimable:2086 slab_unreclaimable:3167 mapped:3398 shmem:18366 pagetables:1145 bounce:0 free:1798 free_pcp:13 free_cma:0 Fixes: 6afcf8ef0ca0 ("mm, compaction: fix NR_ISOLATED_* stats for pfn based migration") Link: http://lkml.kernel.org/r/1492683865-27549-1-git-send-email-rabin.vincent@axis.com Signed-off-by: Rabin Vincent <rabinv@axis.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Ming Ling <ming.ling@spreadtrum.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-21mm: memcontrol: use special workqueue for creating per-memcg cachesVladimir Davydov
commit 13583c3d3224508582ec03d881d0b68dd3ee8e10 upstream. Creating a lot of cgroups at the same time might stall all worker threads with kmem cache creation works, because kmem cache creation is done with the slab_mutex held. The problem was amplified by commits 801faf0db894 ("mm/slab: lockless decision to grow cache") in case of SLAB and 81ae6d03952c ("mm/slub.c: replace kick_all_cpus_sync() with synchronize_sched() in kmem_cache_shrink()") in case of SLUB, which increased the maximal time the slab_mutex can be held. To prevent that from happening, let's use a special ordered single threaded workqueue for kmem cache creation. This shouldn't introduce any functional changes regarding how kmem caches are created, as the work function holds the global slab_mutex during its whole runtime anyway, making it impossible to run more than one work at a time. By using a single threaded workqueue, we just avoid creating a thread per each work. Ordering is required to avoid a situation when a cgroup's work is put off indefinitely because there are other cgroups to serve, in other words to guarantee fairness. Link: https://bugzilla.kernel.org/show_bug.cgi?id=172981 Link: http://lkml.kernel.org/r/20161004131417.GC1862@esperanza Signed-off-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reported-by: Doug Smythies <dsmythies@telus.net> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-21zsmalloc: expand class bitMinchan Kim
commit 85d492f28d056c40629fc25d79f54da618a29dc4 upstream. Now 64K page system, zsamlloc has 257 classes so 8 class bit is not enough. With that, it corrupts the system when zsmalloc stores 65536byte data(ie, index number 256) so that this patch increases class bit for simple fix for stable backport. We should clean up this mess soon. index size 0 32 1 288 .. .. 204 52256 256 65536 Fixes: 3783689a1 ("zsmalloc: introduce zspage structure") Link: http://lkml.kernel.org/r/1492042622-12074-3-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-21thp: fix MADV_DONTNEED vs. MADV_FREE raceKirill A. Shutemov
commit 58ceeb6bec86d9140f9d91d71a710e963523d063 upstream. Both MADV_DONTNEED and MADV_FREE handled with down_read(mmap_sem). It's critical to not clear pmd intermittently while handling MADV_FREE to avoid race with MADV_DONTNEED: CPU0: CPU1: madvise_free_huge_pmd() pmdp_huge_get_and_clear_full() madvise_dontneed() zap_pmd_range() pmd_trans_huge(*pmd) == 0 (without ptl) // skip the pmd set_pmd_at(); // pmd is re-established It results in MADV_DONTNEED skipping the pmd, leaving it not cleared. It violates MADV_DONTNEED interface and can result is userspace misbehaviour. Basically it's the same race as with numa balancing in change_huge_pmd(), but a bit simpler to mitigate: we don't need to preserve dirty/young flags here due to MADV_FREE functionality. [kirill.shutemov@linux.intel.com: Urgh... Power is special again] Link: http://lkml.kernel.org/r/20170303102636.bhd2zhtpds4mt62a@black.fi.intel.com Link: http://lkml.kernel.org/r/20170302151034.27829-4-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-12mm/mempolicy.c: fix error handling in set_mempolicy and mbind.Chris Salls
commit cf01fb9985e8deb25ccf0ea54d916b8871ae0e62 upstream. In the case that compat_get_bitmap fails we do not want to copy the bitmap to the user as it will contain uninitialized stack data and leak sensitive data. Signed-off-by: Chris Salls <salls@cs.ucsb.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-12mm/page_alloc.c: fix print order in show_free_areas()Alexander Polakov
commit 1f06b81aea5ecba2c1f8afd87e0ba1b9f8f90160 upstream. Fixes: 11fb998986a72a ("mm: move most file-based accounting to the node") Link: http://lkml.kernel.org/r/1490377730.30219.2.camel@beget.ru Signed-off-by: Alexander Polyakov <apolyakov@beget.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08mm: workingset: fix premature shadow node shrinking with cgroupsJohannes Weiner
commit 0cefabdaf757a6455d75f00cb76874e62703ed18 upstream. Commit 0a6b76dd23fa ("mm: workingset: make shadow node shrinker memcg aware") enabled cgroup-awareness in the shadow node shrinker, but forgot to also enable cgroup-awareness in the list_lru the shadow nodes sit on. Consequently, all shadow nodes are sitting on a global (per-NUMA node) list, while the shrinker applies the limits according to the amount of cache in the cgroup its shrinking. The result is excessive pressure on the shadow nodes from cgroups that have very little cache. Enable memcg-mode on the shadow node LRUs, such that per-cgroup limits are applied to per-cgroup lists. Fixes: 0a6b76dd23fa ("mm: workingset: make shadow node shrinker memcg aware") Link: http://lkml.kernel.org/r/20170322005320.8165-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov@tarantool.org> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08mm, hugetlb: use pte_present() instead of pmd_present() in follow_huge_pmd()Naoya Horiguchi
commit c9d398fa237882ea07167e23bcfc5e6847066518 upstream. I found the race condition which triggers the following bug when move_pages() and soft offline are called on a single hugetlb page concurrently. Soft offlining page 0x119400 at 0x700000000000 BUG: unable to handle kernel paging request at ffffea0011943820 IP: follow_huge_pmd+0x143/0x190 PGD 7ffd2067 PUD 7ffd1067 PMD 0 [61163.582052] Oops: 0000 [#1] SMP Modules linked in: binfmt_misc ppdev virtio_balloon parport_pc pcspkr i2c_piix4 parport i2c_core acpi_cpufreq ip_tables xfs libcrc32c ata_generic pata_acpi virtio_blk 8139too crc32c_intel ata_piix serio_raw libata virtio_pci 8139cp virtio_ring virtio mii floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: cap_check] CPU: 0 PID: 22573 Comm: iterate_numa_mo Tainted: P OE 4.11.0-rc2-mm1+ #2 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:follow_huge_pmd+0x143/0x190 RSP: 0018:ffffc90004bdbcd0 EFLAGS: 00010202 RAX: 0000000465003e80 RBX: ffffea0004e34d30 RCX: 00003ffffffff000 RDX: 0000000011943800 RSI: 0000000000080001 RDI: 0000000465003e80 RBP: ffffc90004bdbd18 R08: 0000000000000000 R09: ffff880138d34000 R10: ffffea0004650000 R11: 0000000000c363b0 R12: ffffea0011943800 R13: ffff8801b8d34000 R14: ffffea0000000000 R15: 000077ff80000000 FS: 00007fc977710740(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffea0011943820 CR3: 000000007a746000 CR4: 00000000001406f0 Call Trace: follow_page_mask+0x270/0x550 SYSC_move_pages+0x4ea/0x8f0 SyS_move_pages+0xe/0x10 do_syscall_64+0x67/0x180 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7fc976e03949 RSP: 002b:00007ffe72221d88 EFLAGS: 00000246 ORIG_RAX: 0000000000000117 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc976e03949 RDX: 0000000000c22390 RSI: 0000000000001400 RDI: 0000000000005827 RBP: 00007ffe72221e00 R08: 0000000000c2c3a0 R09: 0000000000000004 R10: 0000000000c363b0 R11: 0000000000000246 R12: 0000000000400650 R13: 00007ffe72221ee0 R14: 0000000000000000 R15: 0000000000000000 Code: 81 e4 ff ff 1f 00 48 21 c2 49 c1 ec 0c 48 c1 ea 0c 4c 01 e2 49 bc 00 00 00 00 00 ea ff ff 48 c1 e2 06 49 01 d4 f6 45 bc 04 74 90 <49> 8b 7c 24 20 40 f6 c7 01 75 2b 4c 89 e7 8b 47 1c 85 c0 7e 2a RIP: follow_huge_pmd+0x143/0x190 RSP: ffffc90004bdbcd0 CR2: ffffea0011943820 ---[ end trace e4f81353a2d23232 ]--- Kernel panic - not syncing: Fatal exception Kernel Offset: disabled This bug is triggered when pmd_present() returns true for non-present hugetlb, so fixing the present check in follow_huge_pmd() prevents it. Using pmd_present() to determine present/non-present for hugetlb is not correct, because pmd_present() checks multiple bits (not only _PAGE_PRESENT) for historical reason and it can misjudge hugetlb state. Fixes: e66f17ff7177 ("mm/hugetlb: take page table lock in follow_huge_pmd()") Link: http://lkml.kernel.org/r/1490149898-20231-1-git-send-email-n-horiguchi@ah.jp.nec.com Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08mm: rmap: fix huge file mmap accounting in the memcg statsJohannes Weiner
commit 553af430e7c981e6e8fa5007c5b7b5773acc63dd upstream. Huge pages are accounted as single units in the memcg's "file_mapped" counter. Account the correct number of base pages, like we do in the corresponding node counter. Link: http://lkml.kernel.org/r/20170322005111.3156-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-26percpu: acquire pcpu_lock when updating pcpu_nr_empty_pop_pagesTahsin Erdogan
commit 320661b08dd6f1746d5c7ab4eb435ec64b97cd45 upstream. Update to pcpu_nr_empty_pop_pages in pcpu_alloc() is currently done without holding pcpu_lock. This can lead to bad updates to the variable. Add missing lock calls. Fixes: b539b87fed37 ("percpu: implmeent pcpu_nr_empty_pop_pages and chunk->nr_populated") Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-22slub: move synchronize_sched out of slab_mutex on shrinkVladimir Davydov
[ Upstream commit 89e364db71fb5e7fc8d93228152abfa67daf35fa ] synchronize_sched() is a heavy operation and calling it per each cache owned by a memory cgroup being destroyed may take quite some time. What is worse, it's currently called under the slab_mutex, stalling all works doing cache creation/destruction. Actually, there isn't much point in calling synchronize_sched() for each cache - it's enough to call it just once - after setting cpu_partial for all caches and before shrinking them. This way, we can also move it out of the slab_mutex, which we have to hold for iterating over the slab cache list. Link: https://bugzilla.kernel.org/show_bug.cgi?id=172991 Link: http://lkml.kernel.org/r/0a10d71ecae3db00fb4421bcd3f82bcc911f4be4.1475329751.git.vdavydov.dev@gmail.com Signed-off-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reported-by: Doug Smythies <dsmythies@telus.net> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-15mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()Tahsin Erdogan
commit 40e952f9d687928b32db20226f085ae660a7237c upstream. mem_cgroup_free() indirectly calls wb_domain_exit() which is not prepared to deal with a struct wb_domain object that hasn't executed wb_domain_init(). For instance, the following warning message is printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc(): INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x67/0x99 register_lock_class+0x36d/0x540 __lock_acquire+0x7f/0x1a30 lock_acquire+0xcc/0x200 del_timer_sync+0x3c/0xc0 wb_domain_exit+0x14/0x20 mem_cgroup_free+0x14/0x40 mem_cgroup_css_alloc+0x3f9/0x620 cgroup_apply_control_enable+0x190/0x390 cgroup_mkdir+0x290/0x3d0 kernfs_iop_mkdir+0x58/0x80 vfs_mkdir+0x10e/0x1a0 SyS_mkdirat+0xa8/0xd0 SyS_mkdir+0x14/0x20 entry_SYSCALL_64_fastpath+0x18/0xad Add __mem_cgroup_free() which skips wb_domain_exit(). This is used by both mem_cgroup_free() and mem_cgroup_alloc() clean up. Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions") Link: http://lkml.kernel.org/r/20170306192122.24262-1-tahsin@google.com Signed-off-by: Tahsin Erdogan <tahsin@google.com> Acked-by: Michal Hocko <mhocko@suse.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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-15thp: fix another corner case of munlock() vs. THPsKirill A. Shutemov
commit 6ebb4a1b848fe75323135f93e72c78f8780fd268 upstream. The following test case triggers BUG() in munlock_vma_pages_range(): int main(int argc, char *argv[]) { int fd; system("mount -t tmpfs -o huge=always none /mnt"); fd = open("/mnt/test", O_CREAT | O_RDWR); ftruncate(fd, 4UL << 20); mmap(NULL, 4UL << 20, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED | MAP_LOCKED, fd, 0); mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_LOCKED, fd, 0); munlockall(); return 0; } The second mmap() create PTE-mapping of the first huge page in file. It makes kernel munlock the page as we never keep PTE-mapped page mlocked. On munlockall() when we handle vma created by the first mmap(), munlock_vma_page() returns page_mask == 0, as the page is not mlocked anymore. On next iteration follow_page_mask() return tail page, but page_mask is HPAGE_NR_PAGES - 1. It makes us skip to the first tail page of the next huge page and step on VM_BUG_ON_PAGE(PageMlocked(page)). The fix is not use the page_mask from follow_page_mask() at all. It has no use for us. Link: http://lkml.kernel.org/r/20170302150252.34120-1-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12mm, vmscan: consider eligible zones in get_scan_countMichal Hocko
commit 71ab6cfe88dcf9f6e6a65eb85cf2bda20a257682 upstream. get_scan_count() considers the whole node LRU size when - doing SCAN_FILE due to many page cache inactive pages - calculating the number of pages to scan In both cases this might lead to unexpected behavior especially on 32b systems where we can expect lowmem memory pressure very often. A large highmem zone can easily distort SCAN_FILE heuristic because there might be only few file pages from the eligible zones on the node lru and we would still enforce file lru scanning which can lead to trashing while we could still scan anonymous pages. The later use of lruvec_lru_size can be problematic as well. Especially when there are not many pages from the eligible zones. We would have to skip over many pages to find anything to reclaim but shrink_node_memcg would only reduce the remaining number to scan by SWAP_CLUSTER_MAX at maximum. Therefore we can end up going over a large LRU many times without actually having chance to reclaim much if anything at all. The closer we are out of memory on lowmem zone the worse the problem will be. Fix this by filtering out all the ineligible zones when calculating the lru size for both paths and consider only sc->reclaim_idx zones. The patch would need to be tweaked a bit to apply to 4.10 and older but I will do that as soon as it hits the Linus tree in the next merge window. Link: http://lkml.kernel.org/r/20170117103702.28542-3-mhocko@kernel.org Fixes: b2e18757f2c9 ("mm, vmscan: begin reclaiming pages on a per-node basis") Signed-off-by: Michal Hocko <mhocko@suse.com> Tested-by: Trevor Cordes <trevor@tecnopolis.ca> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12mm, vmscan: cleanup lru size claculationsMichal Hocko
commit fd538803731e50367b7c59ce4ad3454426a3d671 upstream. lruvec_lru_size returns the full size of the LRU list while we sometimes need a value reduced only to eligible zones (e.g. for lowmem requests). inactive_list_is_low is one such user. Later patches will add more of them. Add a new parameter to lruvec_lru_size and allow it filter out zones which are not eligible for the given context. Link: http://lkml.kernel.org/r/20170117103702.28542-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12mm: do not access page->mapping directly on page_endioMinchan Kim
commit dd8416c47715cf324c9a16f13273f9fda87acfed upstream. With rw_page, page_endio is used for completing IO on a page and it propagates write error to the address space if the IO fails. The problem is it accesses page->mapping directly which might be okay for file-backed pages but it shouldn't for anonymous page. Otherwise, it can corrupt one of field from anon_vma under us and system goes panic randomly. swap_writepage bdev_writepage ops->rw_page I encountered the BUG during developing new zram feature and it was really hard to figure it out because it made random crash, somtime mmap_sem lockdep, sometime other places where places never related to zram/zsmalloc, and not reproducible with some configuration. When I consider how that bug is subtle and people do fast-swap test with brd, it's worth to add stable mark, I think. Fixes: dd6bd0d9c7db ("swap: use bdev_read_page() / bdev_write_page()") Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Michal Hocko <mhocko@suse.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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12mm: vmpressure: fix sending wrong events on underflowVinayak Menon
commit e1587a4945408faa58d0485002c110eb2454740c upstream. At the end of a window period, if the reclaimed pages is greater than scanned, an unsigned underflow can result in a huge pressure value and thus a critical event. Reclaimed pages is found to go higher than scanned because of the addition of reclaimed slab pages to reclaimed in shrink_node without a corresponding increment to scanned pages. Minchan Kim mentioned that this can also happen in the case of a THP page where the scanned is 1 and reclaimed could be 512. Link: http://lkml.kernel.org/r/1486641577-11685-1-git-send-email-vinmenon@codeaurora.org Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Shiraz Hashim <shashim@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12mm/page_alloc: fix nodes for reclaim in fast pathGavin Shan
commit e02dc017c3032dcdce1b993af0db135462e1b4b7 upstream. When @node_reclaim_node isn't 0, the page allocator tries to reclaim pages if the amount of free memory in the zones are below the low watermark. On Power platform, none of NUMA nodes are scanned for page reclaim because no nodes match the condition in zone_allows_reclaim(). On Power platform, RECLAIM_DISTANCE is set to 10 which is the distance of Node-A to Node-A. So the preferred node even won't be scanned for page reclaim. __alloc_pages_nodemask() get_page_from_freelist() zone_allows_reclaim() Anton proposed the test code as below: # cat alloc.c : int main(int argc, char *argv[]) { void *p; unsigned long size; unsigned long start, end; start = time(NULL); size = strtoul(argv[1], NULL, 0); printf("To allocate %ldGB memory\n", size); size <<= 30; p = malloc(size); assert(p); memset(p, 0, size); end = time(NULL); printf("Used time: %ld seconds\n", end - start); sleep(3600); return 0; } The system I use for testing has two NUMA nodes. Both have 128GB memory. In below scnario, the page caches on node#0 should be reclaimed when it encounters pressure to accommodate request of allocation. # echo 2 > /proc/sys/vm/zone_reclaim_mode; \ sync; \ echo 3 > /proc/sys/vm/drop_caches; \ # taskset -c 0 cat file.32G > /dev/null; \ grep FilePages /sys/devices/system/node/node0/meminfo Node 0 FilePages: 33619712 kB # taskset -c 0 ./alloc 128 # grep FilePages /sys/devices/system/node/node0/meminfo Node 0 FilePages: 33619840 kB # grep MemFree /sys/devices/system/node/node0/meminfo Node 0 MemFree: 186816 kB With the patch applied, the pagecache on node-0 is reclaimed when its free memory is running out. It's the expected behaviour. # echo 2 > /proc/sys/vm/zone_reclaim_mode; \ sync; \ echo 3 > /proc/sys/vm/drop_caches # taskset -c 0 cat file.32G > /dev/null; \ grep FilePages /sys/devices/system/node/node0/meminfo Node 0 FilePages: 33605568 kB # taskset -c 0 ./alloc 128 # grep FilePages /sys/devices/system/node/node0/meminfo Node 0 FilePages: 1379520 kB # grep MemFree /sys/devices/system/node/node0/meminfo Node 0 MemFree: 317120 kB Fixes: 5f7a75acdb24 ("mm: page_alloc: do not cache reclaim distances") Link: http://lkml.kernel.org/r/1486532455-29613-1-git-send-email-gwshan@linux.vnet.ibm.com Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Anton Blanchard <anton@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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-26block: fix double-free in the failure path of cgwb_bdi_init()Tejun Heo
commit 5f478e4ea5c5560b4e40eb136991a09f9389f331 upstream. When !CONFIG_CGROUP_WRITEBACK, bdi has single bdi_writeback_congested at bdi->wb_congested. cgwb_bdi_init() allocates it with kzalloc() and doesn't do further initialization. This usually works fine as the reference count gets bumped to 1 by wb_init() and the put from wb_exit() releases it. However, when wb_init() fails, it puts the wb base ref automatically freeing the wb and the explicit kfree() in cgwb_bdi_init() error path ends up trying to free the same pointer the second time causing a double-free. Fix it by explicitly initilizing the refcnt to 1 and putting the base ref from cgwb_bdi_destroy(). Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Dmitry Vyukov <dvyukov@google.com> Fixes: a13f35e87140 ("writeback: don't embed root bdi_writeback_congested in bdi_writeback") Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-14mm/slub.c: fix random_seq offset destructionSean Rees
commit a810007afe239d59c1115fcaa06eb5b480f876e9 upstream. Commit 210e7a43fa90 ("mm: SLUB freelist randomization") broke USB hub initialisation as described in https://bugzilla.kernel.org/show_bug.cgi?id=177551. Bail out early from init_cache_random_seq if s->random_seq is already initialised. This prevents destroying the previously computed random_seq offsets later in the function. If the offsets are destroyed, then shuffle_freelist will truncate page->freelist to just the first object (orphaning the rest). Fixes: 210e7a43fa90 ("mm: SLUB freelist randomization") Link: http://lkml.kernel.org/r/20170207140707.20824-1-sean@erifax.org Signed-off-by: Sean Rees <sean@erifax.org> Reported-by: <userwithuid@gmail.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: Thomas Garnier <thgarnie@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-09mm, fs: check for fatal signals in do_generic_file_read()Michal Hocko
commit 5abf186a30a89d5b9c18a6bf93a2c192c9fd52f6 upstream. do_generic_file_read() can be told to perform a large request from userspace. If the system is under OOM and the reading task is the OOM victim then it has an access to memory reserves and finishing the full request can lead to the full memory depletion which is dangerous. Make sure we rather go with a short read and allow the killed task to terminate. Link: http://lkml.kernel.org/r/20170201092706.9966-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-09base/memory, hotplug: fix a kernel oops in show_valid_zones()Toshi Kani
commit a96dfddbcc04336bbed50dc2b24823e45e09e80c upstream. Reading a sysfs "memoryN/valid_zones" file leads to the following oops when the first page of a range is not backed by struct page. show_valid_zones() assumes that 'start_pfn' is always valid for page_zone(). BUG: unable to handle kernel paging request at ffffea017a000000 IP: show_valid_zones+0x6f/0x160 This issue may happen on x86-64 systems with 64GiB or more memory since their memory block size is bumped up to 2GiB. [1] An example of such systems is desribed below. 0x3240000000 is only aligned by 1GiB and this memory block starts from 0x3200000000, which is not backed by struct page. BIOS-e820: [mem 0x0000003240000000-0x000000603fffffff] usable Since test_pages_in_a_zone() already checks holes, fix this issue by extending this function to return 'valid_start' and 'valid_end' for a given range. show_valid_zones() then proceeds with the valid range. [1] 'Commit bdee237c0343 ("x86: mm: Use 2GB memory block size on large-memory x86-64 systems")' Link: http://lkml.kernel.org/r/20170127222149.30893-3-toshi.kani@hpe.com Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-09mm/memory_hotplug.c: check start_pfn in test_pages_in_a_zone()Toshi Kani
commit deb88a2a19e85842d79ba96b05031739ec327ff4 upstream. Patch series "fix a kernel oops when reading sysfs valid_zones", v2. A sysfs memory file is created for each 2GiB memory block on x86-64 when the system has 64GiB or more memory. [1] When the start address of a memory block is not backed by struct page, i.e. a memory range is not aligned by 2GiB, reading its 'valid_zones' attribute file leads to a kernel oops. This issue was observed on multiple x86-64 systems with more than 64GiB of memory. This patch-set fixes this issue. Patch 1 first fixes an issue in test_pages_in_a_zone(), which does not test the start section. Patch 2 then fixes the kernel oops by extending test_pages_in_a_zone() to return valid [start, end). Note for stable kernels: The memory block size change was made by commit bdee237c0343 ("x86: mm: Use 2GB memory block size on large-memory x86-64 systems"), which was accepted to 3.9. However, this patch-set depends on (and fixes) the change to test_pages_in_a_zone() made by commit 5f0f2887f4de ("mm/memory_hotplug.c: check for missing sections in test_pages_in_a_zone()"), which was accepted to 4.4. So, I recommend that we backport it up to 4.4. [1] 'Commit bdee237c0343 ("x86: mm: Use 2GB memory block size on large-memory x86-64 systems")' This patch (of 2): test_pages_in_a_zone() does not check 'start_pfn' when it is aligned by section since 'sec_end_pfn' is set equal to 'pfn'. Since this function is called for testing the range of a sysfs memory file, 'start_pfn' is always aligned by section. Fix it by properly setting 'sec_end_pfn' to the next section pfn. Also make sure that this function returns 1 only when the range belongs to a zone. Link: http://lkml.kernel.org/r/20170127222149.30893-2-toshi.kani@hpe.com Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Banman <abanman@sgi.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-09zswap: disable changing params if init failsDan Streetman
commit d7b028f56a971a2e4d8d7887540a144eeefcd4ab upstream. Add zswap_init_failed bool that prevents changing any of the module params, if init_zswap() fails, and set zswap_enabled to false. Change 'enabled' param to a callback, and check zswap_init_failed before allowing any change to 'enabled', 'zpool', or 'compressor' params. Any driver that is built-in to the kernel will not be unloaded if its init function returns error, and its module params remain accessible for users to change via sysfs. Since zswap uses param callbacks, which assume that zswap has been initialized, changing the zswap params after a failed initialization will result in WARNING due to the param callbacks expecting a pool to already exist. This prevents that by immediately exiting any of the param callbacks if initialization failed. This was reported here: https://marc.info/?l=linux-mm&m=147004228125528&w=4 And fixes this WARNING: [ 429.723476] WARNING: CPU: 0 PID: 5140 at mm/zswap.c:503 __zswap_pool_current+0x56/0x60 The warning is just noise, and not serious. However, when init fails, zswap frees all its percpu dstmem pages and its kmem cache. The kmem cache might be serious, if kmem_cache_alloc(NULL, gfp) has problems; but the percpu dstmem pages are definitely a problem, as they're used as temporary buffer for compressed pages before copying into place in the zpool. If the user does get zswap enabled after an init failure, then zswap will likely Oops on the first page it tries to compress (or worse, start corrupting memory). Fixes: 90b0fc26d5db ("zswap: change zpool/compressor at runtime") Link: http://lkml.kernel.org/r/20170124200259.16191-2-ddstreet@ieee.org Signed-off-by: Dan Streetman <dan.streetman@canonical.com> Reported-by: Marcin Miroslaw <marcin@mejor.pl> Cc: Seth Jennings <sjenning@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-01mm, memcg: do not retry precharge chargesDavid Rientjes
commit 3674534b775354516e5c148ea48f51d4d1909a78 upstream. When memory.move_charge_at_immigrate is enabled and precharges are depleted during move, mem_cgroup_move_charge_pte_range() will attempt to increase the size of the precharge. Prevent precharges from ever looping by setting __GFP_NORETRY. This was probably the intention of the GFP_KERNEL & ~__GFP_NORETRY, which is pointless as written. Fixes: 0029e19ebf84 ("mm: memcontrol: remove explicit OOM parameter in charge path") Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1701130208510.69402@chino.kir.corp.google.com Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.com> 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-01memory_hotplug: make zone_can_shift() return a boolean valueYasuaki Ishimatsu
commit 8a1f780e7f28c7c1d640118242cf68d528c456cd upstream. online_{kernel|movable} is used to change the memory zone to ZONE_{NORMAL|MOVABLE} and online the memory. To check that memory zone can be changed, zone_can_shift() is used. Currently the function returns minus integer value, plus integer value and 0. When the function returns minus or plus integer value, it means that the memory zone can be changed to ZONE_{NORNAL|MOVABLE}. But when the function returns 0, there are two meanings. One of the meanings is that the memory zone does not need to be changed. For example, when memory is in ZONE_NORMAL and onlined by online_kernel the memory zone does not need to be changed. Another meaning is that the memory zone cannot be changed. When memory is in ZONE_NORMAL and onlined by online_movable, the memory zone may not be changed to ZONE_MOVALBE due to memory online limitation(see Documentation/memory-hotplug.txt). In this case, memory must not be onlined. The patch changes the return type of zone_can_shift() so that memory online operation fails when memory zone cannot be changed as follows: Before applying patch: # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 7864320 managed 7864320 # echo online_movable > memory4097/state # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 8388608 managed 8388608 online_movable operation succeeded. But memory is onlined as ZONE_NORMAL, not ZONE_MOVABLE. After applying patch: # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 7864320 managed 7864320 # echo online_movable > memory4097/state bash: echo: write error: Invalid argument # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 7864320 managed 7864320 online_movable operation failed because of failure of changing the memory zone from ZONE_NORMAL to ZONE_MOVABLE Fixes: df429ac03936 ("memory-hotplug: more general validation of zone during online") Link: http://lkml.kernel.org/r/2f9c3837-33d7-b6e5-59c0-6ca4372b2d84@gmail.com Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by: Reza Arbab <arbab@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-01mm, page_alloc: fix premature OOM when racing with cpuset mems updateVlastimil Babka
commit e47483bca2cc59a4593b37a270b16ee42b1d9f08 upstream. Ganapatrao Kulkarni reported that the LTP test cpuset01 in stress mode triggers OOM killer in few seconds, despite lots of free memory. The test attempts to repeatedly fault in memory in one process in a cpuset, while changing allowed nodes of the cpuset between 0 and 1 in another process. The problem comes from insufficient protection against cpuset changes, which can cause get_page_from_freelist() to consider all zones as non-eligible due to nodemask and/or current->mems_allowed. This was masked in the past by sufficient retries, but since commit 682a3385e773 ("mm, page_alloc: inline the fast path of the zonelist iterator") we fix the preferred_zoneref once, and don't iterate over the whole zonelist in further attempts, thus the only eligible zones might be placed in the zonelist before our starting point and we always miss them. A previous patch fixed this problem for current->mems_allowed. However, cpuset changes also update the task's mempolicy nodemask. The fix has two parts. We have to repeat the preferred_zoneref search when we detect cpuset update by way of seqcount, and we have to check the seqcount before considering OOM. [akpm@linux-foundation.org: fix typo in comment] Link: http://lkml.kernel.org/r/20170120103843.24587-5-vbabka@suse.cz Fixes: c33d6c06f60f ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Ganapatrao Kulkarni <gpkulkarni@gmail.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-01mm, page_alloc: move cpuset seqcount checking to slowpathVlastimil Babka
commit 5ce9bfef1d27944c119a397a9d827bef795487ce upstream. This is a preparation for the following patch to make review simpler. While the primary motivation is a bug fix, this also simplifies the fast path, although the moved code is only enabled when cpusets are in use. Link: http://lkml.kernel.org/r/20170120103843.24587-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Ganapatrao Kulkarni <gpkulkarni@gmail.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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-01mm, page_alloc: fix fast-path race with cpuset update or removalVlastimil Babka
commit 16096c25bf0ca5d87e4fa6ec6108ba53feead212 upstream. Ganapatrao Kulkarni reported that the LTP test cpuset01 in stress mode triggers OOM killer in few seconds, despite lots of free memory. The test attempts to repeatedly fault in memory in one process in a cpuset, while changing allowed nodes of the cpuset between 0 and 1 in another process. One possible cause is that in the fast path we find the preferred zoneref according to current mems_allowed, so that it points to the middle of the zonelist, skipping e.g. zones of node 1 completely. If the mems_allowed is updated to contain only node 1, we never reach it in the zonelist, and trigger OOM before checking the cpuset_mems_cookie. This patch fixes the particular case by redoing the preferred zoneref search if we switch back to the original nodemask. The condition is also slightly changed so that when the last non-root cpuset is removed, we don't miss it. Note that this is not a full fix, and more patches will follow. Link: http://lkml.kernel.org/r/20170120103843.24587-3-vbabka@suse.cz Fixes: 682a3385e773 ("mm, page_alloc: inline the fast path of the zonelist iterator") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Ganapatrao Kulkarni <gpkulkarni@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-01mm, page_alloc: fix check for NULL preferred_zoneVlastimil Babka
commit ea57485af8f4221312a5a95d63c382b45e7840dc upstream. Patch series "fix premature OOM regression in 4.7+ due to cpuset races". This is v2 of my attempt to fix the recent report based on LTP cpuset stress test [1]. The intention is to go to stable 4.9 LTSS with this, as triggering repeated OOMs is not nice. That's why the patches try to be not too intrusive. Unfortunately why investigating I found that modifying the testcase to use per-VMA policies instead of per-task policies will bring the OOM's back, but that seems to be much older and harder to fix problem. I have posted a RFC [2] but I believe that fixing the recent regressions has a higher priority. Longer-term we might try to think how to fix the cpuset mess in a better and less error prone way. I was for example very surprised to learn, that cpuset updates change not only task->mems_allowed, but also nodemask of mempolicies. Until now I expected the parameter to alloc_pages_nodemask() to be stable. I wonder why do we then treat cpusets specially in get_page_from_freelist() and distinguish HARDWALL etc, when there's unconditional intersection between mempolicy and cpuset. I would expect the nodemask adjustment for saving overhead in g_p_f(), but that clearly doesn't happen in the current form. So we have both crazy complexity and overhead, AFAICS. [1] https://lkml.kernel.org/r/CAFpQJXUq-JuEP=QPidy4p_=FN0rkH5Z-kfB4qBvsf6jMS87Edg@mail.gmail.com [2] https://lkml.kernel.org/r/7c459f26-13a6-a817-e508-b65b903a8378@suse.cz This patch (of 4): Since commit c33d6c06f60f ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") we have a wrong check for NULL preferred_zone, which can theoretically happen due to concurrent cpuset modification. We check the zoneref pointer which is never NULL and we should check the zone pointer. Also document this in first_zones_zonelist() comment per Michal Hocko. Fixes: c33d6c06f60f ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") Link: http://lkml.kernel.org/r/20170120103843.24587-2-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Ganapatrao Kulkarni <gpkulkarni@gmail.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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-01mm/mempolicy.c: do not put mempolicy before using its nodemaskVlastimil Babka
commit d51e9894d27492783fc6d1b489070b4ba66ce969 upstream. Since commit be97a41b291e ("mm/mempolicy.c: merge alloc_hugepage_vma to alloc_pages_vma") alloc_pages_vma() can potentially free a mempolicy by mpol_cond_put() before accessing the embedded nodemask by __alloc_pages_nodemask(). The commit log says it's so "we can use a single exit path within the function" but that's clearly wrong. We can still do that when doing mpol_cond_put() after the allocation attempt. Make sure the mempolicy is not freed prematurely, otherwise __alloc_pages_nodemask() can end up using a bogus nodemask, which could lead e.g. to premature OOM. Fixes: be97a41b291e ("mm/mempolicy.c: merge alloc_hugepage_vma to alloc_pages_vma") Link: http://lkml.kernel.org/r/20170118141124.8345-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>