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ac311a14c6
linux/mm
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Shakeel Butt ac311a14c6 oom: decouple mems_allowed from oom_unkillable_task 
Commit ef08e3b498 ("[PATCH] cpusets: confine oom_killer to
mem_exclusive cpuset") introduces a heuristic where a potential
oom-killer victim is skipped if the intersection of the potential victim
and the current (the process triggered the oom) is empty based on the
reason that killing such victim most probably will not help the current
allocating process.

However the commit 7887a3da75 ("[PATCH] oom: cpuset hint") changed the
heuristic to just decrease the oom_badness scores of such potential
victim based on the reason that the cpuset of such processes might have
changed and previously they may have allocated memory on mems where the
current allocating process can allocate from.

Unintentionally 7887a3da75 ("[PATCH] oom: cpuset hint") introduced a
side effect as the oom_badness is also exposed to the user space through
/proc/[pid]/oom_score, so, readers with different cpusets can read
different oom_score of the same process.

Later, commit 6cf86ac6f3 ("oom: filter tasks not sharing the same
cpuset") fixed the side effect introduced by 7887a3da75 by moving the
cpuset intersection back to only oom-killer context and out of
oom_badness.  However the combination of ab290adbaf ("oom: make
oom_unkillable_task() helper function") and 26ebc98491 ("oom:
/proc/<pid>/oom_score treat kernel thread honestly") unintentionally
brought back the cpuset intersection check into the oom_badness
calculation function.

Other than doing cpuset/mempolicy intersection from oom_badness, the memcg
oom context is also doing cpuset/mempolicy intersection which is quite
wrong and is caught by syzcaller with the following report:

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 28426 Comm: syz-executor.5 Not tainted 5.2.0-rc3-next-20190607
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:194 [inline]
RIP: 0010:has_intersects_mems_allowed mm/oom_kill.c:84 [inline]
RIP: 0010:oom_unkillable_task mm/oom_kill.c:168 [inline]
RIP: 0010:oom_unkillable_task+0x180/0x400 mm/oom_kill.c:155
Code: c1 ea 03 80 3c 02 00 0f 85 80 02 00 00 4c 8b a3 10 07 00 00 48 b8 00
00 00 00 00 fc ff df 4d 8d 74 24 10 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f
85 67 02 00 00 49 8b 44 24 10 4c 8d a0 68 fa ff ff
RSP: 0018:ffff888000127490 EFLAGS: 00010a03
RAX: dffffc0000000000 RBX: ffff8880a4cd5438 RCX: ffffffff818dae9c
RDX: 100000000c3cc602 RSI: ffffffff818dac8d RDI: 0000000000000001
RBP: ffff8880001274d0 R08: ffff888000086180 R09: ffffed1015d26be0
R10: ffffed1015d26bdf R11: ffff8880ae935efb R12: 8000000061e63007
R13: 0000000000000000 R14: 8000000061e63017 R15: 1ffff11000024ea6
FS:  00005555561f5940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000607304 CR3: 000000009237e000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
  oom_evaluate_task+0x49/0x520 mm/oom_kill.c:321
  mem_cgroup_scan_tasks+0xcc/0x180 mm/memcontrol.c:1169
  select_bad_process mm/oom_kill.c:374 [inline]
  out_of_memory mm/oom_kill.c:1088 [inline]
  out_of_memory+0x6b2/0x1280 mm/oom_kill.c:1035
  mem_cgroup_out_of_memory+0x1ca/0x230 mm/memcontrol.c:1573
  mem_cgroup_oom mm/memcontrol.c:1905 [inline]
  try_charge+0xfbe/0x1480 mm/memcontrol.c:2468
  mem_cgroup_try_charge+0x24d/0x5e0 mm/memcontrol.c:6073
  mem_cgroup_try_charge_delay+0x1f/0xa0 mm/memcontrol.c:6088
  do_huge_pmd_wp_page_fallback+0x24f/0x1680 mm/huge_memory.c:1201
  do_huge_pmd_wp_page+0x7fc/0x2160 mm/huge_memory.c:1359
  wp_huge_pmd mm/memory.c:3793 [inline]
  __handle_mm_fault+0x164c/0x3eb0 mm/memory.c:4006
  handle_mm_fault+0x3b7/0xa90 mm/memory.c:4053
  do_user_addr_fault arch/x86/mm/fault.c:1455 [inline]
  __do_page_fault+0x5ef/0xda0 arch/x86/mm/fault.c:1521
  do_page_fault+0x71/0x57d arch/x86/mm/fault.c:1552
  page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1156
RIP: 0033:0x400590
Code: 06 e9 49 01 00 00 48 8b 44 24 10 48 0b 44 24 28 75 1f 48 8b 14 24 48
8b 7c 24 20 be 04 00 00 00 e8 f5 56 00 00 48 8b 74 24 08 <89> 06 e9 1e 01
00 00 48 8b 44 24 08 48 8b 14 24 be 04 00 00 00 8b
RSP: 002b:00007fff7bc49780 EFLAGS: 00010206
RAX: 0000000000000001 RBX: 0000000000760000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 000000002000cffc RDI: 0000000000000001
RBP: fffffffffffffffe R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000760008
R13: 00000000004c55f2 R14: 0000000000000000 R15: 00007fff7bc499b0
Modules linked in:
---[ end trace a65689219582ffff ]---
RIP: 0010:__read_once_size include/linux/compiler.h:194 [inline]
RIP: 0010:has_intersects_mems_allowed mm/oom_kill.c:84 [inline]
RIP: 0010:oom_unkillable_task mm/oom_kill.c:168 [inline]
RIP: 0010:oom_unkillable_task+0x180/0x400 mm/oom_kill.c:155
Code: c1 ea 03 80 3c 02 00 0f 85 80 02 00 00 4c 8b a3 10 07 00 00 48 b8 00
00 00 00 00 fc ff df 4d 8d 74 24 10 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f
85 67 02 00 00 49 8b 44 24 10 4c 8d a0 68 fa ff ff
RSP: 0018:ffff888000127490 EFLAGS: 00010a03
RAX: dffffc0000000000 RBX: ffff8880a4cd5438 RCX: ffffffff818dae9c
RDX: 100000000c3cc602 RSI: ffffffff818dac8d RDI: 0000000000000001
RBP: ffff8880001274d0 R08: ffff888000086180 R09: ffffed1015d26be0
R10: ffffed1015d26bdf R11: ffff8880ae935efb R12: 8000000061e63007
R13: 0000000000000000 R14: 8000000061e63017 R15: 1ffff11000024ea6
FS:  00005555561f5940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f823000 CR3: 000000009237e000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600

The fix is to decouple the cpuset/mempolicy intersection check from
oom_unkillable_task() and make sure cpuset/mempolicy intersection check is
only done in the global oom context.

[shakeelb@google.com: change function name and update comment]
  Link: http://lkml.kernel.org/r/20190628152421.198994-3-shakeelb@google.com
Link: http://lkml.kernel.org/r/20190624212631.87212-3-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reported-by: syzbot+d0fc9d3c166bc5e4a94b@syzkaller.appspotmail.com
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Jackson <pj@sgi.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
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>
2019-07-12 11:05:47 -07:00
..
kasan mm/kasan: change kasan_check_{read,write} to return boolean 2019-07-12 11:05:42 -07:00
backing-dev.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
balloon_compaction.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
cleancache.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
cma_debug.c mm/cma_debug.c: fix the break condition in cma_maxchunk_get() 2019-05-14 09:47:45 -07:00
cma.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 98 2019-05-24 17:37:54 +02:00
cma.h
compaction.c mm, compaction: make sure we isolate a valid PFN 2019-06-01 15:51:32 -07:00
debug_page_ref.c
debug.c mm: update references to page _refcount 2019-05-14 19:52:47 -07:00
dmapool.c mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options 2019-07-12 11:05:46 -07:00
early_ioremap.c
fadvise.c vfs: implement readahead(2) using POSIX_FADV_WILLNEED 2018-08-30 20:01:32 +02:00
failslab.c mm/failslab.c: by default, do not fail allocations with direct reclaim only 2019-07-12 11:05:43 -07:00
filemap.c mm/filemap.c: correct the comment about VM_FAULT_RETRY 2019-07-12 11:05:43 -07:00
frame_vector.c
frontswap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
gup_benchmark.c mm/gup: replace get_user_pages_longterm() with FOLL_LONGTERM 2019-05-14 09:47:45 -07:00
gup.c mm/gup.c: mark undo_dev_pagemap as __maybe_unused 2019-07-12 11:05:45 -07:00
highmem.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
hmm.c mm/devm_memremap_pages: fix final page put race 2019-06-13 17:34:56 -10:00
huge_memory.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
hugetlb_cgroup.c mm: rename page_counter's count/limit into usage/max 2018-06-07 17:34:35 -07:00
hugetlb.c mm: hugetlb: soft-offline: dissolve_free_huge_page() return zero on !PageHuge 2019-06-29 16:43:45 +08:00
hwpoison-inject.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
init-mm.c mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids 2018-07-17 09:35:30 +02:00
internal.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
interval_tree.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248 2019-06-19 17:09:08 +02:00
Kconfig mm: move the powerpc hugepd code to mm/gup.c 2019-07-12 11:05:45 -07:00
Kconfig.debug mm, debug_pagealloc: use a page type instead of page_ext flag 2019-07-12 11:05:43 -07:00
khugepaged.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
kmemleak-test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
kmemleak.c mm/kmemleak.c: change error at _write when kmemleak is disabled 2019-07-12 11:05:42 -07:00
ksm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
list_lru.c mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages 2019-07-12 11:05:44 -07:00
maccess.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
madvise.c mm/mmu_notifier: use correct mmu_notifier events for each invalidation 2019-05-14 09:47:49 -07:00
Makefile mm: consolidate the get_user_pages* implementations 2019-07-12 11:05:45 -07:00
memblock.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
memcontrol.c mm, oom: remove redundant task_in_mem_cgroup() check 2019-07-12 11:05:47 -07:00
memfd.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
memory_hotplug.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
memory-failure.c mm/memory-failure.c: clarify error message 2019-07-12 11:05:47 -07:00
memory.c mm: use down_read_killable for locking mmap_sem in access_remote_vm 2019-07-12 11:05:47 -07:00
mempolicy.c mm/mempolicy.c: fix an incorrect rebind node in mpol_rebind_nodemask 2019-06-29 16:43:44 +08:00
mempool.c docs/core-api/mm: fix return value descriptions in mm/ 2019-03-05 21:07:20 -08:00
memtest.c
migrate.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
mincore.c mm/mincore.c: fix race between swapoff and mincore 2019-07-12 11:05:43 -07:00
mlock.c mm/mlock.c: change count_mm_mlocked_page_nr return type 2019-06-13 17:34:56 -10:00
mm_init.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
mmap.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
mmu_context.c
mmu_gather.c mm: mmu_gather: remove __tlb_reset_range() for force flush 2019-06-13 17:34:56 -10:00
mmu_notifier.c mm/mmu_notifier: use hlist_add_head_rcu() 2019-07-12 11:05:46 -07:00
mmzone.c
mprotect.c mm/mprotect.c: fix compilation warning because of unused 'mm' variable 2019-05-14 09:47:51 -07:00
mremap.c mm/mmu_notifier: contextual information for event triggering invalidation 2019-05-14 09:47:49 -07:00
msync.c
nommu.c mm: use down_read_killable for locking mmap_sem in access_remote_vm 2019-07-12 11:05:47 -07:00
oom_kill.c oom: decouple mems_allowed from oom_unkillable_task 2019-07-12 11:05:47 -07:00
page_alloc.c mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options 2019-07-12 11:05:46 -07:00
page_counter.c memcg: introduce memory.min 2018-06-07 17:34:36 -07:00
page_ext.c mm, debug_pagealloc: use a page type instead of page_ext flag 2019-07-12 11:05:43 -07:00
page_idle.c mm/page_idle.c: fix oops because end_pfn is larger than max_pfn 2019-06-29 16:43:45 +08:00
page_io.c mm, swap: use rbtree for swap_extent 2019-07-12 11:05:43 -07:00
page_isolation.c mm/page_isolation.c: change the prototype of undo_isolate_page_range() 2019-07-12 11:05:43 -07:00
page_owner.c mm/page_owner: Simplify stack trace handling 2019-04-29 12:37:50 +02:00
page_poison.c page_poison: play nicely with KASAN 2019-03-05 21:07:13 -08:00
page_vma_mapped.c mm/rmap: map_pte() was not handling private ZONE_DEVICE page properly 2018-10-31 08:54:11 -07:00
page-writeback.c mm: remove the account_page_dirtied export 2019-07-12 11:05:42 -07:00
pagewalk.c mm: kernel-doc: add missing parameter descriptions 2018-04-05 21:36:27 -07:00
percpu-internal.h percpu: convert chunk hints to be based on pcpu_block_md 2019-03-13 12:25:31 -07:00
percpu-km.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu-stats.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu-vm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
pgtable-generic.c x86/mm: Page size aware flush_tlb_mm_range() 2018-10-09 16:51:11 +02:00
process_vm_access.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
quicklist.c
readahead.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
rmap.c mm/rmap.c: use the pra.mapcount to do the check 2019-05-14 09:47:49 -07:00
rodata_test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
shmem.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
shuffle.c mm: maintain randomization of page free lists 2019-05-14 19:52:48 -07:00
shuffle.h mm: maintain randomization of page free lists 2019-05-14 19:52:48 -07:00
slab_common.c mm, memcg: add a memcg_slabinfo debugfs file 2019-07-12 11:05:44 -07:00
slab.c mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options 2019-07-12 11:05:46 -07:00
slab.h mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options 2019-07-12 11:05:46 -07:00
slob.c mm/slab: refactor common ksize KASAN logic into slab_common.c 2019-07-12 11:05:42 -07:00
slub.c mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options 2019-07-12 11:05:46 -07:00
sparse-vmemmap.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
sparse.c mm/sparse.c: clean up obsolete code comment 2019-05-14 09:47:48 -07:00
swap_cgroup.c
swap_slots.c mm, swap, get_swap_pages: use entry_size instead of cluster in parameter 2018-08-22 10:52:44 -07:00
swap_state.c mm/swap_state.c: simplify total_swapcache_pages() with get_swap_device() 2019-07-12 11:05:43 -07:00
swap.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
swapfile.c mm, swap: use rbtree for swap_extent 2019-07-12 11:05:43 -07:00
truncate.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
usercopy.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
userfaultfd.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
util.c mm: consolidate the get_user_pages* implementations 2019-07-12 11:05:45 -07:00
vmacache.c mm: get rid of vmacache_flush_all() entirely 2018-09-13 15:18:04 -10:00
vmalloc.c mm: vmalloc: show number of vmalloc pages in /proc/meminfo 2019-07-12 11:05:47 -07:00
vmpressure.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
vmscan.c mm: vmscan: correct some vmscan counters for THP swapout 2019-07-12 11:05:46 -07:00
vmstat.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
workingset.c mm: memcontrol: make cgroup stats and events query API explicitly local 2019-05-14 19:52:53 -07:00
z3fold.c mm/z3fold.c: lock z3fold page before __SetPageMovable() 2019-07-12 11:05:40 -07:00
zbud.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
zpool.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
zsmalloc.c mm/zsmalloc.c: fix fall-through annotation 2018-10-26 16:26:35 -07:00
zswap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00