linux/mm
Kirill A. Shutemov 2bcd64e5aa mm, thp: close race between mremap() and split_huge_page()
commit dd18dbc2d4 upstream.

It's critical for split_huge_page() (and migration) to catch and freeze
all PMDs on rmap walk.  It gets tricky if there's concurrent fork() or
mremap() since usually we copy/move page table entries on dup_mm() or
move_page_tables() without rmap lock taken.  To get it work we rely on
rmap walk order to not miss any entry.  We expect to see destination VMA
after source one to work correctly.

But after switching rmap implementation to interval tree it's not always
possible to preserve expected walk order.

It works fine for dup_mm() since new VMA has the same vma_start_pgoff()
/ vma_last_pgoff() and explicitly insert dst VMA after src one with
vma_interval_tree_insert_after().

But on move_vma() destination VMA can be merged into adjacent one and as
result shifted left in interval tree.  Fortunately, we can detect the
situation and prevent race with rmap walk by moving page table entries
under rmap lock.  See commit 38a76013ad.

Problem is that we miss the lock when we move transhuge PMD.  Most
likely this bug caused the crash[1].

[1] http://thread.gmane.org/gmane.linux.kernel.mm/96473

Fixes: 108d6642ad ("mm anon rmap: remove anon_vma_moveto_tail")

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Michel Lespinasse <walken@google.com>
Cc: Dave Jones <davej@redhat.com>
Cc: David Miller <davem@davemloft.net>
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>
History 2014-06-07 10:28:10 -07:00
..
backing-dev.c bdi: avoid oops on device removal 2014-04-26 17:19:05 -07:00
balloon_compaction.c mm: print more details for bad_page() 2014-01-23 16:36:50 -08:00
bootmem.c mm/bootmem.c: remove unused local `map' 2013-11-13 12:09:09 +09:00
bounce.c block: Convert bio_for_each_segment() to bvec_iter 2013-11-23 22:33:49 -08:00
cleancache.c mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE 2014-01-23 16:36:50 -08:00
compaction.c mm/compaction: break out of loop on !PageBuddy in isolate_freepages_block 2014-03-10 17:26:20 -07:00
debug-pagealloc.c mm, x86: Remove debug_pagealloc_enabled 2011-12-06 09:24:07 +01:00
dmapool.c dmapool: make DMAPOOL_DEBUG detect corruption of free marker 2012-12-11 17:22:24 -08:00
fadvise.c teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long 2013-03-03 22:46:22 -05:00
failslab.c switch debugfs to umode_t 2012-01-03 22:54:56 -05:00
filemap.c fix O_SYNC|O_APPEND syncing the wrong range on write() 2014-02-09 15:18:09 -05:00
filemap_xip.c seqcount: Add lockdep functionality to seqcount/seqlock structures 2013-11-06 12:40:26 +01:00
fremap.c mm: fix bad rss-counter if remap_file_pages raced migration 2014-03-19 16:21:49 -07:00
frontswap.c frontswap: fix incorrect zeroing and allocation size for frontswap_map 2013-06-12 16:29:46 -07:00
highmem.c Some nice cleanups, and even a patch my wife did as a "live" demo for 2012-12-20 08:37:05 -08:00
huge_memory.c thp: close race between split and zap huge pages 2014-05-31 13:20:30 -07:00
hugetlb.c mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages() 2014-05-31 13:20:30 -07:00
hugetlb_cgroup.c mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE 2014-01-23 16:36:50 -08:00
hwpoison-inject.c mm/hwpoison: add '#' to hwpoison_inject 2014-01-21 16:19:48 -08:00
init-mm.c atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
internal.h mm: page_alloc: spill to remote nodes before waking kswapd 2014-05-06 07:59:35 -07:00
interval_tree.c mm: add CONFIG_DEBUG_VM_RB build option 2012-10-09 16:22:42 +09:00
Kconfig mm/Kconfig: fix URL for zsmalloc benchmark 2014-03-10 17:26:20 -07:00
Kconfig.debug mm: more intensive memory corruption debugging 2012-01-10 16:30:42 -08:00
kmemcheck.c kmemcheck: Fix build errors due to missing slab.h 2010-03-30 22:02:32 +09:00
kmemleak-test.c kmemleak: remove memset by using kzalloc 2011-01-27 18:31:51 +00:00
kmemleak.c mm: kmemleak: avoid false negatives on vmalloc'ed objects 2013-11-13 12:09:07 +09:00
ksm.c mm: close PageTail race 2014-03-04 07:55:47 -08:00
list_lru.c mm: list_lru: fix almost infinite loop causing effective livelock 2013-10-30 12:57:46 -07:00
maccess.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
madvise.c mm/hwpoison: fix traversal of hugetlbfs pages to avoid printk flood 2013-09-30 14:31:02 -07:00
Makefile zsmalloc: move it under mm 2014-01-30 16:56:55 -08:00
memblock.c memblock: add limit checking to memblock_virt_alloc 2014-01-29 16:22:40 -08:00
memcontrol.c memcg: reparent charges of children before processing parent 2014-03-04 07:55:48 -08:00
memory-failure.c mm: close PageTail race 2014-03-04 07:55:47 -08:00
memory.c mm: make fixup_user_fault() check the vma access rights too 2014-06-07 10:28:08 -07:00
memory_hotplug.c mm/memory_hotplug.c: move register_memory_resource out of the lock_memory_hotplug 2014-01-23 16:36:52 -08:00
mempolicy.c mm/mempolicy.c: fix mempolicy printing in numa_maps 2014-01-30 16:56:56 -08:00
mempool.c mm/mempool.c: convert kmalloc_node(...GFP_ZERO...) to kzalloc_node(...) 2013-09-11 15:58:14 -07:00
migrate.c mm: fix swapops.h:131 bug if remap_file_pages raced migration 2014-03-20 22:09:09 -07:00
mincore.c mm: do_mincore() cleanup 2014-01-23 16:36:52 -08:00
mlock.c mm: try_to_unmap_cluster() should lock_page() before mlocking 2014-05-06 07:59:35 -07:00
mm_init.c mm: bring back /sys/kernel/mm 2014-01-27 21:02:39 -08:00
mmap.c mm: ignore VM_SOFTDIRTY on VMA merging 2014-01-23 16:36:53 -08:00
mmu_context.c mm: remove old aio use_mm() comment 2013-05-07 18:38:27 -07:00
mmu_notifier.c mm: audit/fix non-modular users of module_init in core code 2014-01-23 16:36:52 -08:00
mmzone.c mm: numa: Change page last {nid,pid} into {cpu,pid} 2013-10-09 14:47:45 +02:00
mprotect.c mm: Use ptep/pmdp_set_numa() for updating _PAGE_NUMA bit 2014-02-17 11:19:36 +11:00
mremap.c mm, thp: close race between mremap() and split_huge_page() 2014-06-07 10:28:10 -07:00
msync.c sanitize vfs_fsync calling conventions 2010-05-21 18:31:21 -04:00
nobootmem.c mm/nobootmem: free_all_bootmem again 2014-01-23 16:36:52 -08:00
nommu.c mm: add overcommit_kbytes sysctl variable 2014-01-21 16:19:44 -08:00
oom_kill.c mm, oom: base root bonus on current usage 2014-01-30 16:56:56 -08:00
page-writeback.c mm: __set_page_dirty_nobuffers() uses spin_lock_irqsave() instead of spin_lock_irq() 2014-02-06 13:48:51 -08:00
page_alloc.c mm: page_alloc: spill to remote nodes before waking kswapd 2014-05-06 07:59:35 -07:00
page_cgroup.c Merge branch 'akpm' (incoming from Andrew) 2014-01-21 19:05:45 -08:00
page_io.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
page_isolation.c mm: memory-hotplug: enable memory hotplug to handle hugepage 2013-09-11 15:57:48 -07:00
pagewalk.c mm/pagewalk.c: fix walk_page_range() access of wrong PTEs 2013-10-30 14:27:03 -07:00
percpu-km.c percpu: clear memory allocated with the km allocator 2010-10-02 10:28:42 +03:00
percpu-vm.c mm: fix kernel-doc warnings 2012-06-20 14:39:36 -07:00
percpu.c Merge branch 'akpm' (incoming from Andrew) 2014-01-21 19:05:45 -08:00
pgtable-generic.c mm: fix TLB flush race between migration, and change_protection_range 2013-12-18 19:04:51 -08:00
process_vm_access.c Fix: compat_rw_copy_check_uvector() misuse in aio, readv, writev, and security keys 2013-03-12 11:05:45 -07:00
quicklist.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
readahead.c mm/readahead.c: fix do_readahead() for no readpage(s) 2014-01-29 16:22:40 -08:00
rmap.c mm: try_to_unmap_cluster() should lock_page() before mlocking 2014-05-06 07:59:35 -07:00
shmem.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-01-28 08:38:04 -08:00
slab.c mm: Fix warning on make htmldocs caused by slab.c 2014-01-31 13:52:25 +02:00
slab.h memcg, slab: RCU protect memcg_params for root caches 2014-01-23 16:36:51 -08:00
slab_common.c slab: fix wrong retval on kmem_cache_create_memcg error path 2014-01-29 16:22:40 -08:00
slob.c mm/sl[aou]b: Move kmallocXXX functions to common code 2013-09-04 20:51:33 +03:00
slub.c slub: do not assert not having lock in removing freed partial 2014-02-10 16:01:42 -08:00
sparse-vmemmap.c mm/sparse: use memblock apis for early memory allocations 2014-01-21 16:19:47 -08:00
sparse.c mm/sparse: use memblock apis for early memory allocations 2014-01-21 16:19:47 -08:00
swap.c mm: close PageTail race 2014-03-04 07:55:47 -08:00
swap_state.c swap: add a simple detector for inappropriate swapin readahead 2014-02-06 13:48:51 -08:00
swapfile.c mm/swap: fix race on swap_info reuse between swapoff and swapon 2014-02-06 13:48:51 -08:00
truncate.c truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
util.c mm: add overcommit_kbytes sysctl variable 2014-01-21 16:19:44 -08:00
vmalloc.c Revert "mm/vmalloc: interchage the implementation of vmalloc_to_{pfn,page}" 2014-01-27 21:02:39 -08:00
vmpressure.c arm, pm, vmpressure: add missing slab.h includes 2014-02-03 13:24:01 -05:00
vmscan.c mm/page-writeback.c: do not count anon pages as dirtyable memory 2014-01-29 16:22:39 -08:00
vmstat.c mm, x86: Account for TLB flushes only when debugging 2014-01-25 09:10:41 +01:00
zbud.c mm/zbud: fix some trivial typos in comments 2013-09-11 15:57:35 -07:00
zsmalloc.c zsmalloc: add copyright 2014-01-30 16:56:55 -08:00
zswap.c mm/zswap.c: change params from hidden to ro 2014-01-23 16:36:50 -08:00