linux/mm
Wang Nan 687cb0884a mm, oom_reaper: gather each vma to prevent leaking TLB entry
tlb_gather_mmu(&tlb, mm, 0, -1) means gathering the whole virtual memory
space.  In this case, tlb->fullmm is true.  Some archs like arm64
doesn't flush TLB when tlb->fullmm is true:

  commit 5a7862e830 ("arm64: tlbflush: avoid flushing when fullmm == 1").

Which causes leaking of tlb entries.

Will clarifies his patch:
 "Basically, we tag each address space with an ASID (PCID on x86) which
  is resident in the TLB. This means we can elide TLB invalidation when
  pulling down a full mm because we won't ever assign that ASID to
  another mm without doing TLB invalidation elsewhere (which actually
  just nukes the whole TLB).

  I think that means that we could potentially not fault on a kernel
  uaccess, because we could hit in the TLB"

There could be a window between complete_signal() sending IPI to other
cores and all threads sharing this mm are really kicked off from cores.
In this window, the oom reaper may calls tlb_flush_mmu_tlbonly() to
flush TLB then frees pages.  However, due to the above problem, the TLB
entries are not really flushed on arm64.  Other threads are possible to
access these pages through TLB entries.  Moreover, a copy_to_user() can
also write to these pages without generating page fault, causes
use-after-free bugs.

This patch gathers each vma instead of gathering full vm space.  In this
case tlb->fullmm is not true.  The behavior of oom reaper become similar
to munmapping before do_exit, which should be safe for all archs.

Link: http://lkml.kernel.org/r/20171107095453.179940-1-wangnan0@huawei.com
Fixes: aac4536355 ("mm, oom: introduce oom reaper")
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Bob Liu <liubo95@huawei.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-29 18:40:42 -08:00
..
kasan slab, slub, slob: add slab_flags_t 2017-11-15 18:21:01 -08:00
backing-dev.c backing-dev: kill unused pdflush_proc_obsolete() 2017-10-06 08:15:15 -06:00
balloon_compaction.c virtio_balloon: fix deadlock on OOM 2017-11-14 23:57:38 +02:00
bootmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cleancache.c fs: switch ->s_uuid to uuid_t 2017-06-05 16:59:12 +02:00
cma_debug.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cma.c mm/cma.c: change pr_info to pr_err for cma_alloc fail log 2017-11-15 18:21:03 -08:00
cma.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compaction.c mm, compaction: remove unneeded pageblock_skip_persistent() checks 2017-11-17 16:10:00 -08:00
debug_page_ref.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
debug.c mm: consolidate page table accounting 2017-11-15 18:21:04 -08:00
dmapool.c lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
early_ioremap.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fadvise.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
failslab.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
filemap.c AFS development 2017-11-16 11:41:22 -08:00
frame_vector.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
frontswap.c mm, frontswap: convert frontswap_enabled to static key 2016-07-26 16:19:19 -07:00
gup_benchmark.c mm: add infrastructure for get_user_pages_fast() benchmarking 2017-11-17 16:10:04 -08:00
gup.c Merge branch 'x86/urgent' into x86/mm, to pick up fixes 2017-10-20 13:06:52 +02:00
highmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hmm.c mm/hmm: remove redundant variable align_end 2017-11-15 18:21:07 -08:00
huge_memory.c mm, thp: Do not make pmd/pud dirty without a reason 2017-11-27 12:26:29 -08:00
hugetlb_cgroup.c mm, hugetlb_cgroup: round limit_in_bytes down to hugepage size 2016-05-20 17:58:30 -07:00
hugetlb.c mm/mmu_notifier: avoid double notification when it is useless 2017-11-15 18:21:03 -08:00
hwpoison-inject.c mm: hwpoison: call shake_page() unconditionally 2017-05-03 15:52:12 -07:00
init-mm.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
internal.h mm, thp: Do not make pmd/pud dirty without a reason 2017-11-27 12:26:29 -08:00
interval_tree.c lib/interval_tree: fast overlap detection 2017-09-08 18:26:49 -07:00
Kconfig mm: add infrastructure for get_user_pages_fast() benchmarking 2017-11-17 16:10:04 -08:00
Kconfig.debug kmemcheck: rip it out 2017-11-15 18:21:05 -08:00
khugepaged.c mm, thp: Do not make pmd/pud dirty without a reason 2017-11-27 12:26:29 -08:00
kmemcheck.c kmemcheck: rip it out 2017-11-15 18:21:05 -08:00
kmemleak-test.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
kmemleak.c kmemcheck: remove annotations 2017-11-15 18:21:04 -08:00
ksm.c mm/mmu_notifier: avoid double notification when it is useless 2017-11-15 18:21:03 -08:00
list_lru.c mm/list_lru.c: mark expected switch fall-through 2017-11-15 18:21:07 -08:00
maccess.c x86: remove more uaccess_32.h complexity 2016-05-22 17:21:27 -07:00
madvise.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Makefile mm: add infrastructure for get_user_pages_fast() benchmarking 2017-11-17 16:10:04 -08:00
memblock.c mm: define memblock_virt_alloc_try_nid_raw 2017-11-15 18:21:05 -08:00
memcontrol.c mm: slabinfo: remove CONFIG_SLABINFO 2017-11-15 18:21:01 -08:00
memory_hotplug.c memory hotplug: fix comments when adding section 2017-11-15 18:21:07 -08:00
memory-failure.c mm, soft_offline: improve hugepage soft offlining error log 2017-11-15 18:21:05 -08:00
memory.c mm, thp: Do not make pmd/pud dirty without a reason 2017-11-27 12:26:29 -08:00
mempolicy.c mm, sysctl: make NUMA stats configurable 2017-11-15 18:21:07 -08:00
mempool.c mm/mempool.c: use kmalloc_array_node() 2017-11-15 18:21:02 -08:00
memtest.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
migrate.c mm, thp: Do not make pmd/pud dirty without a reason 2017-11-27 12:26:29 -08:00
mincore.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mlock.c mm: mlock: remove lru_add_drain_all() 2017-11-15 18:21:07 -08:00
mm_init.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
mmap.c mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags 2017-11-03 06:26:22 -07:00
mmu_context.c sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
mmu_notifier.c mm/mmu_notifier: avoid call to invalidate_range() in range_end() 2017-11-15 18:21:03 -08:00
mmzone.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mprotect.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mremap.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
msync.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
nobootmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
nommu.c Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 18:13:32 -07:00
oom_kill.c mm, oom_reaper: gather each vma to prevent leaking TLB entry 2017-11-29 18:40:42 -08:00
page_alloc.c mm, memory_hotplug: do not back off draining pcp free pages from kworker context 2017-11-29 18:40:42 -08:00
page_counter.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page_ext.c mm/page_ext.c: check if page_ext is not prepared 2017-11-15 18:21:07 -08:00
page_idle.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page_io.c mm, swap: skip swapcache for swapin of synchronous device 2017-11-15 18:21:02 -08:00
page_isolation.c mm: distinguish CMA and MOVABLE isolation in has_unmovable_pages() 2017-11-15 18:21:02 -08:00
page_owner.c mm/page_owner.c: reduce page_owner structure size 2017-11-15 18:21:03 -08:00
page_poison.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page_vma_mapped.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page-writeback.c block/laptop_mode: Convert timers to use timer_setup() 2017-11-21 15:46:44 -08:00
pagewalk.c mm/pagewalk.c: report holes in hugetlb ranges 2017-11-15 13:12:08 -08:00
percpu-internal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
percpu-km.c percpu: replace area map allocator with bitmap 2017-07-26 17:41:05 -04:00
percpu-stats.c percpu: fix starting offset for chunk statistics traversal 2017-09-27 14:45:57 -07:00
percpu-vm.c mm: remove __GFP_COLD 2017-11-15 18:21:06 -08:00
percpu.c Merge branch 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2017-11-15 14:17:11 -08:00
pgtable-generic.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
process_vm_access.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h> 2017-03-02 08:42:28 +01:00
quicklist.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
readahead.c mm: don't cap request size based on read-ahead setting 2016-12-12 18:55:08 -08:00
rmap.c mm: remove cold parameter from free_hot_cold_page* 2017-11-15 18:21:06 -08:00
rodata_test.c mm: fix RODATA_TEST failure "rodata_test: test data was not read only" 2017-10-03 17:54:24 -07:00
shmem.c Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
slab_common.c kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK 2017-11-15 18:21:04 -08:00
slab.c kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK 2017-11-15 18:21:04 -08:00
slab.h kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK 2017-11-15 18:21:04 -08:00
slob.c slab, slub, slob: add slab_flags_t 2017-11-15 18:21:01 -08:00
slub.c kmemcheck: rip it out 2017-11-15 18:21:05 -08:00
sparse-vmemmap.c mm, sparse: do not swamp log with huge vmemmap allocation failures 2017-11-15 18:21:07 -08:00
sparse.c mm: stop zeroing memory during allocation in vmemmap 2017-11-15 18:21:05 -08:00
swap_cgroup.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swap_slots.c mm/swap_slots.c: fix race conditions in swap_slots cache init 2017-11-15 18:21:03 -08:00
swap_state.c mm: remove cold parameter for release_pages 2017-11-15 18:21:06 -08:00
swap.c mm, pagevec: rename pagevec drained field 2017-11-15 18:21:06 -08:00
swapfile.c mm: swap: SWP_SYNCHRONOUS_IO: skip swapcache only if swapped page has no other reference 2017-11-15 18:21:02 -08:00
truncate.c mm, pagevec: remove cold parameter for pagevecs 2017-11-15 18:21:06 -08:00
usercopy.c mm/usercopy: Drop extra is_vmalloc_or_module() check 2017-04-05 12:30:18 -07:00
userfaultfd.c userfaultfd: shmem: wire up shmem_mfill_zeropage_pte 2017-09-06 17:27:28 -07:00
util.c mm: rename global_page_state to global_zone_page_state 2017-09-06 17:27:29 -07:00
vmacache.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vmalloc.c Revert "vmalloc: back off when the current task is killed" 2017-10-13 16:18:32 -07:00
vmpressure.c mm, vmpressure: pass-through notification support 2017-07-10 16:32:31 -07:00
vmscan.c mm: remove cold parameter from free_hot_cold_page* 2017-11-15 18:21:06 -08:00
vmstat.c mm, sysctl: make NUMA stats configurable 2017-11-15 18:21:07 -08:00
workingset.c mm, truncate: do not check mapping for every page being truncated 2017-11-15 18:21:06 -08:00
z3fold.c mm/z3fold.c: use kref to prevent page free/compact race 2017-11-17 16:10:00 -08:00
zbud.c mm/zbud.c: use list_last_entry() instead of list_tail_entry() 2016-01-15 11:40:52 -08:00
zpool.c
zsmalloc.c zsmalloc: calling zs_map_object() from irq is a bug 2017-11-15 18:21:03 -08:00
zswap.c mm/zswap.c: delete an error message for a failed memory allocation in zswap_dstmem_prepare() 2017-07-06 16:24:35 -07:00