linux-stable/mm
Mike Kravetz 5f4f5b1f44 mm: migration: fix migration of huge PMD shared pages
commit 017b1660df upstream.

The page migration code employs try_to_unmap() to try and unmap the source
page.  This is accomplished by using rmap_walk to find all vmas where the
page is mapped.  This search stops when page mapcount is zero.  For shared
PMD huge pages, the page map count is always 1 no matter the number of
mappings.  Shared mappings are tracked via the reference count of the PMD
page.  Therefore, try_to_unmap stops prematurely and does not completely
unmap all mappings of the source page.

This problem can result is data corruption as writes to the original
source page can happen after contents of the page are copied to the target
page.  Hence, data is lost.

This problem was originally seen as DB corruption of shared global areas
after a huge page was soft offlined due to ECC memory errors.  DB
developers noticed they could reproduce the issue by (hotplug) offlining
memory used to back huge pages.  A simple testcase can reproduce the
problem by creating a shared PMD mapping (note that this must be at least
PUD_SIZE in size and PUD_SIZE aligned (1GB on x86)), and using
migrate_pages() to migrate process pages between nodes while continually
writing to the huge pages being migrated.

To fix, have the try_to_unmap_one routine check for huge PMD sharing by
calling huge_pmd_unshare for hugetlbfs huge pages.  If it is a shared
mapping it will be 'unshared' which removes the page table entry and drops
the reference on the PMD page.  After this, flush caches and TLB.

mmu notifiers are called before locking page tables, but we can not be
sure of PMD sharing until page tables are locked.  Therefore, check for
the possibility of PMD sharing before locking so that notifiers can
prepare for the worst possible case.

Link: http://lkml.kernel.org/r/20180823205917.16297-2-mike.kravetz@oracle.com
[mike.kravetz@oracle.com: make _range_in_vma() a static inline]
  Link: http://lkml.kernel.org/r/6063f215-a5c8-2f0c-465a-2c515ddc952d@oracle.com
Fixes: 39dde65c99 ("shared page table for hugetlb page")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-13 09:27:22 +02:00
..
kasan kasan: fix shadow_size calculation error in kasan_module_alloc 2018-08-24 13:09:12 +02:00
backing-dev.c bdi: Fix another oops in wb_workfn() 2018-07-22 14:28:49 +02:00
balloon_compaction.c mm/migrate: new migrate mode MIGRATE_SYNC_NO_COPY 2017-09-08 18:26:46 -07:00
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.c mm/cma.c: take __GFP_NOWARN into account in cma_alloc() 2017-10-13 16:18:32 -07:00
cma.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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
compaction.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: get rid of vmacache_flush_all() entirely 2018-09-19 22:43:48 +02:00
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
dmapool.c lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
early_ioremap.c mm/early_ioremap: Fix boot hang with earlyprintk=efi,keep 2018-02-25 11:08:03 +01:00
fadvise.c mm/fadvise.c: fix signed overflow UBSAN complaint 2018-09-15 09:45:28 +02:00
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 mm/filemap.c: fix NULL pointer in page_cache_tree_insert() 2018-04-24 09:36:39 +02:00
frame_vector.c mm/frame_vector.c: release a semaphore in 'get_vaddr_frames()' 2018-03-03 10:24:21 +01:00
frontswap.c mm, frontswap: convert frontswap_enabled to static key 2016-07-26 16:19:19 -07:00
gup.c mm: do not bug_on on incorrect length in __mm_populate() 2018-07-17 11:39:29 +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: hmm_pfns_bad() was accessing wrong struct 2018-04-24 09:36:22 +02:00
huge_memory.c mm/huge_memory.c: fix data loss when splitting a file pmd 2018-07-25 11:25:08 +02:00
hugetlb.c mm: migration: fix migration of huge PMD shared pages 2018-10-13 09:27:22 +02:00
hugetlb_cgroup.c mm, hugetlb_cgroup: round limit_in_bytes down to hugepage size 2016-05-20 17:58:30 -07:00
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, oom: do not rely on TIF_MEMDIE for memory reserves access 2017-09-06 17:27:30 -07:00
interval_tree.c lib/interval_tree: fast overlap detection 2017-09-08 18:26:49 -07:00
Kconfig mm: don't allow deferred pages with NEED_PER_CPU_KM 2018-05-22 18:53:58 +02:00
Kconfig.debug kmemcheck: rip it out 2018-02-22 15:42:24 +01:00
khugepaged.c mm, thp: do not cause memcg oom for thp 2018-05-30 07:52:19 +02:00
kmemleak-test.c
kmemleak.c mm/kmemleak.c: wait for scan completion before disabling free 2018-05-30 07:52:21 +02:00
ksm.c mm/ksm.c: ignore STABLE_FLAG of rmap_item->address in rmap_walk_ksm() 2018-07-03 11:25:03 +02:00
list_lru.c mm: memcontrol: use vmalloc fallback for large kmem memcg arrays 2017-10-03 17:54:25 -07:00
maccess.c x86: remove more uaccess_32.h complexity 2016-05-22 17:21:27 -07:00
madvise.c mm: madvise(MADV_DODUMP): allow hugetlbfs pages 2018-10-10 08:54:22 +02:00
Makefile kmemcheck: rip it out 2018-02-22 15:42:24 +01:00
memblock.c Revert "mm: page_alloc: skip over regions of invalid pfns where possible" 2018-03-28 18:24:39 +02:00
memcontrol.c memcg: remove memcg_cgroup::id from IDR on mem_cgroup_css_alloc() failure 2018-09-05 09:26:32 +02:00
memory-failure.c mm: hwpoison: disable memory error handling on 1GB hugepage 2018-07-11 16:29:20 +02:00
memory.c mm/tlb: Remove tlb_remove_table() non-concurrent condition 2018-09-09 19:55:59 +02:00
memory_hotplug.c mm/memory_hotplug: define find_{smallest|biggest}_section_pfn as unsigned long 2017-10-03 17:54:26 -07:00
mempolicy.c mm/mempolicy.c: avoid use uninitialized preferred_node 2018-05-30 07:52:19 +02:00
mempool.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mm_init.c
mmap.c mm: do not bug_on on incorrect length in __mm_populate() 2018-07-17 11:39:29 +02:00
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: kill invalidate_page 2017-08-31 16:13:00 -07:00
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 x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings 2018-08-15 18:12:51 +02:00
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: fix concurrent munlock and oom reaper unmap, v3 2018-05-16 10:10:27 +02:00
page-writeback.c writeback: safer lock nesting 2018-04-24 09:36:39 +02:00
page_alloc.c mm, page_alloc: do not break __GFP_THISNODE by zonelist reset 2018-06-26 08:06:33 +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 2017-11-24 08:37:05 +01:00
page_idle.c mm: thp: fix potential clearing to referenced flag in page_idle_clear_pte_refs_one() 2018-05-30 07:52:24 +02:00
page_io.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page_isolation.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page_owner.c mm/page_owner: fix recursion bug after changing skip entries 2018-05-30 07:52:21 +02:00
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 mm, page_vma_mapped: Drop faulty pointer arithmetics in check_pte() 2018-01-23 19:58:21 +01:00
pagewalk.c mm/pagewalk.c: report holes in hugetlb ranges 2017-11-24 08:37:04 +01:00
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: add __GFP_NORETRY semantics to the percpu balancing path 2018-04-08 14:26:29 +02:00
percpu-stats.c percpu: fix starting offset for chunk statistics traversal 2017-09-27 14:45:57 -07:00
percpu-vm.c percpu: add __GFP_NORETRY semantics to the percpu balancing path 2018-04-08 14:26:29 +02:00
percpu.c percpu: include linux/sched.h for cond_resched() 2018-05-09 09:51:48 +02:00
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 readahead: stricter check for bdi io_pages 2018-09-09 19:55:53 +02:00
rmap.c mm: migration: fix migration of huge PMD shared pages 2018-10-13 09:27:22 +02:00
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 mm: shmem.c: Correctly annotate new inodes for lockdep 2018-09-29 03:06:04 -07:00
slab.c mm, slab: memcg_link the SLAB's kmem_cache 2018-05-30 07:52:21 +02:00
slab.h kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK 2018-02-22 15:42:23 +01:00
slab_common.c slub: fix failure when we delete and create a slab cache 2018-07-03 11:25:04 +02:00
slob.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
slub.c slub: make ->cpu_partial unsigned int 2018-10-03 17:00:55 -07:00
sparse-vmemmap.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sparse.c mm: sections are not offlined during memory hotremove 2018-05-16 10:10:27 +02:00
swap.c mm: avoid marking swap cached page as lazyfree 2017-10-03 17:54:24 -07:00
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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swap_state.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swapfile.c x86/speculation/l1tf: Limit swap file size to MAX_PA/2 2018-08-15 18:12:51 +02:00
truncate.c mm/truncate.c: fix THP handling in invalidate_mapping_pages() 2017-07-10 16:32:32 -07:00
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 mm: get rid of vmacache_flush_all() entirely 2018-09-19 22:43:48 +02:00
vmalloc.c mm: vmalloc: avoid racy handling of debugobjects in vunmap 2018-08-03 07:50:23 +02:00
vmpressure.c mm, vmpressure: pass-through notification support 2017-07-10 16:32:31 -07:00
vmscan.c mm: fix the NULL mapping case in __isolate_lru_page() 2018-06-05 11:41:54 +02:00
vmstat.c Revert mm/vmstat.c: fix vmstat_update() preemption BUG 2018-07-11 16:29:24 +02:00
workingset.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
z3fold.c z3fold: fix memory leak 2018-05-30 07:52:23 +02:00
zbud.c
zpool.c
zsmalloc.c zsmalloc: calling zs_map_object() from irq is a bug 2017-12-14 09:53:10 +01:00
zswap.c zswap: re-check zswap_is_full() after do zswap_shrink() 2018-09-05 09:26:30 +02:00