Vlastimil Babka c6f34a8de6 mm, compaction: make capture control handling safe wrt interrupts ... commit b9e20f0da1f5c9c68689450a8cb436c9486434c8 upstream. Hugh reports: "While stressing compaction, one run oopsed on NULL capc->cc in __free_one_page()'s task_capc(zone): compact_zone_order() had been interrupted, and a page was being freed in the return from interrupt. Though you would not expect it from the source, both gccs I was using (4.8.1 and 7.5.0) had chosen to compile compact_zone_order() with the ".cc = &cc" implemented by mov %rbx,-0xb0(%rbp) immediately before callq compact_zone - long after the "current->capture_control = &capc". An interrupt in between those finds capc->cc NULL (zeroed by an earlier rep stos). This could presumably be fixed by a barrier() before setting current->capture_control in compact_zone_order(); but would also need more care on return from compact_zone(), in order not to risk leaking a page captured by interrupt just before capture_control is reset. Maybe that is the preferable fix, but I felt safer for task_capc() to exclude the rather surprising possibility of capture at interrupt time" I have checked that gcc10 also behaves the same. The advantage of fix in compact_zone_order() is that we don't add another test in the page freeing hot path, and that it might prevent future problems if we stop exposing pointers to uninitialized structures in current task. So this patch implements the suggestion for compact_zone_order() with barrier() (and WRITE_ONCE() to prevent store tearing) for setting current->capture_control, and prevents page leaking with WRITE_ONCE/READ_ONCE in the proper order. Link: http://lkml.kernel.org/r/20200616082649.27173-1-vbabka@suse.cz Fixes: 5e1f0f098b46 ("mm, compaction: capture a page under direct compaction") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Hugh Dickins <hughd@google.com> Suggested-by: Hugh Dickins <hughd@google.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: Li Wang <liwang@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: <stable@vger.kernel.org> [5.1+] 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>		2021-03-16 16:31:23 +08:00
..
kasan	kasan: disable branch tracing for core runtime	2021-03-16 16:28:20 +08:00
Kconfig	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
Kconfig.debug	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
Makefile	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
backing-dev.c	bdi: add a ->dev_name field to struct backing_dev_info	2021-03-16 16:27:44 +08:00
balloon_compaction.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
cleancache.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
cma.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
cma.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
cma_debug.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
compaction.c	mm, compaction: make capture control handling safe wrt interrupts	2021-03-16 16:31:23 +08:00
debug.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
debug_page_ref.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
dmapool.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
early_ioremap.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
fadvise.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
failslab.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
filemap.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
frame_vector.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
frontswap.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
gup.c	gup: document and work around "COW can break either way" issue	2021-03-16 16:29:05 +08:00
gup_benchmark.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
highmem.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
hmm.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
huge_memory.c	mm: thp: make the THP mapcount atomic against __split_huge_pmd_locked()	2021-03-16 16:29:40 +08:00
hugetlb.c	mm/hugetlb: fix a addressing exception caused by huge_pte_offset	2021-03-16 16:26:56 +08:00
hugetlb_cgroup.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
hwpoison-inject.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
init-mm.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
internal.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
interval_tree.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
khugepaged.c	mm,thp: stop leaking unreleased file pages	2021-03-16 16:28:36 +08:00
kmemleak-test.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
kmemleak.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
ksm.c	mm/ksm: fix NULL pointer dereference when KSM zero page is enabled	2021-03-16 16:26:56 +08:00
list_lru.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
maccess.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
madvise.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
memblock.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
memcontrol.c	mm/memcontrol.c: add missed css_put()	2021-03-16 16:31:10 +08:00
memfd.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
memory-failure.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
memory.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
memory_hotplug.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mempolicy.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mempool.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
memremap.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
memtest.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
migrate.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mincore.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mlock.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mm_init.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mmap.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mmu_context.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mmu_gather.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mmu_notifier.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mmzone.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mprotect.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mremap.c	mm: Fix mremap not considering huge pmd devmap	2021-03-16 16:28:43 +08:00
msync.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
nommu.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
oom_kill.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
page-writeback.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
page_alloc.c	mm: call cond_resched() from deferred_init_memmap()	2021-03-16 16:29:40 +08:00
page_counter.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
page_ext.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
page_idle.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
page_io.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
page_isolation.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
page_owner.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
page_poison.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
page_vma_mapped.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
pagewalk.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
percpu-internal.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
percpu-km.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
percpu-stats.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
percpu-vm.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
percpu.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
pgtable-generic.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
process_vm_access.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
readahead.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
rmap.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
rodata_test.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
shmem.c	shmem: fix possible deadlocks on shmlock_user_lock	2021-03-16 16:27:44 +08:00
shuffle.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
shuffle.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
slab.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
slab.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
slab_common.c	mm/slab: use memzero_explicit() in kzfree()	2021-03-16 16:31:09 +08:00
slob.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
slub.c	mm/slub: fix stack overruns with SLUB_STATS	2021-03-16 16:31:14 +08:00
sparse-vmemmap.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
sparse.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
swap.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
swap_cgroup.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
swap_slots.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
swap_state.c	mm: fix swap cache node allocation mask	2021-03-16 16:31:13 +08:00
swapfile.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
truncate.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
usercopy.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
userfaultfd.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
util.c	mm: add kvfree_sensitive() for freeing sensitive data objects	2021-03-16 16:28:58 +08:00
vmacache.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
vmalloc.c	vmalloc: fix remap_vmalloc_range() bounds checks	2021-03-16 16:26:56 +08:00
vmpressure.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
vmscan.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
vmstat.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
workingset.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
z3fold.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
zbud.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
zpool.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
zsmalloc.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
zswap.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00