Konstantin Khlebnikov b800c91a05 mm: fix corner case in anon_vma endless growing prevention ... Fix for BUG_ON(anon_vma->degree) splashes in unlink_anon_vmas() ("kernel BUG at mm/rmap.c:399!") caused by commit 7a3ef208e6 ("mm: prevent endless growth of anon_vma hierarchy") Anon_vma_clone() is usually called for a copy of source vma in destination argument. If source vma has anon_vma it should be already in dst->anon_vma. NULL in dst->anon_vma is used as a sign that it's called from anon_vma_fork(). In this case anon_vma_clone() finds anon_vma for reusing. Vma_adjust() calls it differently and this breaks anon_vma reusing logic: anon_vma_clone() links vma to old anon_vma and updates degree counters but vma_adjust() overrides vma->anon_vma right after that. As a result final unlink_anon_vmas() decrements degree for wrong anon_vma. This patch assigns ->anon_vma before calling anon_vma_clone(). Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Reported-and-tested-by: Chris Clayton <chris2553@googlemail.com> Reported-and-tested-by: Oded Gabbay <oded.gabbay@amd.com> Reported-and-tested-by: Chih-Wei Huang <cwhuang@android-x86.org> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Daniel Forrest <dan.forrest@ssec.wisc.edu> Cc: Michal Hocko <mhocko@suse.cz> Cc: stable@vger.kernel.org # to match back-porting of 7a3ef208e6 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2015-01-11 11:45:10 -08:00
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backing-dev.c
balloon_compaction.c
bootmem.c
cleancache.c
cma.c
compaction.c
debug-pagealloc.c
debug.c
dmapool.c
early_ioremap.c
fadvise.c
failslab.c
filemap.c
filemap_xip.c
fremap.c
frontswap.c
gup.c
highmem.c
huge_memory.c
hugetlb.c
hugetlb_cgroup.c
hwpoison-inject.c
init-mm.c
internal.h
interval_tree.c
iov_iter.c
Kconfig
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c
ksm.c
list_lru.c
maccess.c
madvise.c
Makefile
memblock.c
memcontrol.c
memory-failure.c
memory.c
memory_hotplug.c
mempolicy.c
mempool.c
migrate.c
mincore.c
mlock.c
mm_init.c
mmap.c	mm: fix corner case in anon_vma endless growing prevention	2015-01-11 11:45:10 -08:00
mmu_context.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c
msync.c
nobootmem.c
nommu.c
oom_kill.c
page-writeback.c
page_alloc.c
page_counter.c
page_ext.c
page_io.c
page_isolation.c
page_owner.c
pagewalk.c
percpu-km.c
percpu-vm.c
percpu.c
pgtable-generic.c
process_vm_access.c
quicklist.c
readahead.c
rmap.c
shmem.c
slab.c
slab.h
slab_common.c
slob.c
slub.c
sparse-vmemmap.c
sparse.c
swap.c
swap_cgroup.c
swap_state.c
swapfile.c
truncate.c
util.c
vmacache.c
vmalloc.c
vmpressure.c
vmscan.c
vmstat.c
workingset.c
zbud.c
zpool.c
zsmalloc.c
zswap.c