kernel-fxtec-pro1x/mm
Kirill A. Shutemov 2b294ac325 mm: avoid data corruption on CoW fault into PFN-mapped VMA
[ Upstream commit c3e5ea6ee574ae5e845a40ac8198de1fb63bb3ab ]

Jeff Moyer has reported that one of xfstests triggers a warning when run
on DAX-enabled filesystem:

	WARNING: CPU: 76 PID: 51024 at mm/memory.c:2317 wp_page_copy+0xc40/0xd50
	...
	wp_page_copy+0x98c/0xd50 (unreliable)
	do_wp_page+0xd8/0xad0
	__handle_mm_fault+0x748/0x1b90
	handle_mm_fault+0x120/0x1f0
	__do_page_fault+0x240/0xd70
	do_page_fault+0x38/0xd0
	handle_page_fault+0x10/0x30

The warning happens on failed __copy_from_user_inatomic() which tries to
copy data into a CoW page.

This happens because of race between MADV_DONTNEED and CoW page fault:

	CPU0					CPU1
 handle_mm_fault()
   do_wp_page()
     wp_page_copy()
       do_wp_page()
					madvise(MADV_DONTNEED)
					  zap_page_range()
					    zap_pte_range()
					      ptep_get_and_clear_full()
					      <TLB flush>
	 __copy_from_user_inatomic()
	 sees empty PTE and fails
	 WARN_ON_ONCE(1)
	 clear_page()

The solution is to re-try __copy_from_user_inatomic() under PTL after
checking that PTE is matches the orig_pte.

The second copy attempt can still fail, like due to non-readable PTE, but
there's nothing reasonable we can do about, except clearing the CoW page.

Reported-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Jeff Moyer <jmoyer@redhat.com>
Cc: <stable@vger.kernel.org>
Cc: Justin He <Justin.He@arm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Link: http://lkml.kernel.org/r/20200218154151.13349-1-kirill.shutemov@linux.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:14:36 +02:00
..
kasan kernel/memremap, kasan: make ZONE_DEVICE with work with KASAN 2018-08-17 16:20:30 -07:00
backing-dev.c writeback: synchronize sync(2) against cgroup writeback membership switches 2019-03-05 17:58:50 +01:00
balloon_compaction.c virtio_balloon: fix deadlock on OOM 2017-11-14 23:57:38 +02:00
bootmem.c docs/mm: bootmem: add overview documentation 2018-08-02 12:17:27 -06:00
cleancache.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
cma.c mm/cma.c: fail if fixed declaration can't be honored 2019-08-06 19:06:51 +02:00
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 mm/cma_debug.c: fix the break condition in cma_maxchunk_get() 2019-06-15 11:54:01 +02:00
compaction.c mm/compaction.c: clear total_{migrate,free}_scanned before scanning a new zone 2019-10-05 13:10:13 +02:00
debug.c mm: get rid of vmacache_flush_all() entirely 2018-09-13 15:18:04 -10:00
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 mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
early_ioremap.c mm/early_ioremap: Fix boot hang with earlyprintk=efi,keep 2017-12-11 14:54:44 +01:00
fadvise.c vfs: implement readahead(2) using POSIX_FADV_WILLNEED 2018-08-30 20:01:32 +02:00
failslab.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
filemap.c mm/filemap.c: don't initiate writeback if mapping has no dirty pages 2019-11-12 19:21:20 +01:00
frame_vector.c mm/frame_vector.c: release a semaphore in 'get_vaddr_frames()' 2017-12-14 16:00:48 -08:00
frontswap.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
gup.c mm/gup.c: remove some BUG_ONs from get_gate_page() 2019-07-31 07:27:08 +02:00
gup_benchmark.c mm/gup_benchmark.c: prevent integer overflow in ioctl 2019-12-01 09:17:07 +01:00
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/memory_hotplug: shrink zones when offlining memory 2020-01-29 16:43:27 +01:00
huge_memory.c mm/thp: fix __split_huge_pmd_locked() for migration PMD 2020-09-26 18:01:28 +02:00
hugetlb.c mm/hugetlb: fix a race between hugetlb sysctl handlers 2020-09-09 19:04:32 +02:00
hugetlb_cgroup.c mm: hugetlb: switch to css_tryget() in hugetlb_cgroup_charge_cgroup() 2019-11-20 18:45:20 +01:00
hwpoison-inject.c mm/memory_failure: Remove unused trapno from memory_failure 2018-01-23 12:17:42 -06:00
init-mm.c mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids 2018-07-17 09:35:30 +02:00
internal.h vmscan: return NODE_RECLAIM_NOSCAN in node_reclaim() when CONFIG_NUMA is n 2019-12-05 09:20:57 +01:00
interval_tree.c mm/interval_tree.c: use vma_pages() helper 2018-01-31 17:18:37 -08:00
Kconfig mm/hmm: select mmu notifier when selecting HMM 2019-06-15 11:54:00 +02:00
Kconfig.debug mm: clarify CONFIG_PAGE_POISONING and usage 2018-08-22 10:52:44 -07:00
khugepaged.c khugepaged: adjust VM_BUG_ON_MM() in __khugepaged_enter() 2020-08-26 10:30:58 +02:00
kmemleak-test.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
kmemleak.c Revert "kmemleak: allow to coexist with fault injection" 2019-08-25 10:47:58 +02:00
ksm.c mm/ksm: fix NULL pointer dereference when KSM zero page is enabled 2020-04-29 16:31:28 +02:00
list_lru.c mm/list_lru.c: fix memory leak in __memcg_init_list_lru_node 2019-06-19 08:17:59 +02:00
maccess.c uaccess: Add non-pagefault user-space write function 2020-09-09 19:04:29 +02:00
madvise.c mm: madvise(MADV_DODUMP): allow hugetlbfs pages 2018-10-05 16:32:05 -07:00
Makefile vfs: implement readahead(2) using POSIX_FADV_WILLNEED 2018-08-30 20:01:32 +02:00
memblock.c mm/page_alloc.c: deduplicate __memblock_free_early() and memblock_free() 2019-12-05 09:20:58 +01:00
memcontrol.c mm/memcg: fix refcount error while moving and swapping 2020-07-29 10:16:57 +02:00
memfd.c memfd: Use radix_tree_deref_slot_protected to avoid the warning. 2019-11-20 18:47:53 +01:00
memory-failure.c mm/memory-failure: poison read receives SIGKILL instead of SIGBUS if mmaped more than once 2019-10-29 09:19:59 +01:00
memory.c mm: avoid data corruption on CoW fault into PFN-mapped VMA 2020-10-01 13:14:36 +02:00
memory_hotplug.c mm/memory_hotplug: fix remove_memory() lockdep splat 2020-02-11 04:33:56 -08:00
mempolicy.c mm: mempolicy: require at least one nodeid for MPOL_PREFERRED 2020-04-13 10:45:06 +02:00
mempool.c mm/mempool.c: add missing parameter description 2018-08-22 10:52:44 -07:00
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: move_pages: report the number of non-attempted pages 2020-02-11 04:33:56 -08:00
mincore.c mm/mincore.c: make mincore() more conservative 2019-05-22 07:37:40 +02:00
mlock.c mm/mlock.c: change count_mm_mlocked_page_nr return type 2019-07-10 09:53:40 +02:00
mm_init.c mm: access zone->node via zone_to_nid() and zone_set_nid() 2018-08-22 10:52:45 -07:00
mmap.c mm/mmap.c: Add cond_resched() for exit_mmap() CPU stalls 2020-08-19 08:14:52 +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: use hlist_add_head_rcu() 2019-07-31 07:27:08 +02:00
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 mm, numa: fix bad pmd by atomically check for pmd_trans_huge when marking page tables prot_numa 2020-03-11 14:15:00 +01:00
mremap.c mm: Fix mremap not considering huge pmd devmap 2020-06-07 13:17:53 +02:00
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 mm/memblock: add a name for memblock flags enumeration 2018-08-02 12:17:27 -06:00
nommu.c x86/mm: split vmalloc_sync_all() 2020-03-25 08:06:13 +01:00
oom_kill.c memcg, oom: don't require __GFP_FS when invoking memcg OOM killer 2019-10-05 13:10:07 +02:00
page-writeback.c mm/page-writeback.c: avoid potential division by zero in wb_min_max_ratio() 2020-01-23 08:21:31 +01:00
page_alloc.c mm, page_alloc: fix core hung in free_pcppages_bulk() 2020-08-26 10:30:59 +02:00
page_counter.c mm/page_counter.c: fix protection usage propagation 2020-08-21 11:05:33 +02:00
page_ext.c mm/page_ext.c: fix an imbalance with kmemleak 2019-04-05 22:32:58 +02:00
page_idle.c mm/page_idle.c: fix oops because end_pfn is larger than max_pfn 2019-07-03 13:14:45 +02:00
page_io.c mm/page_io.c: do not free shared swap slots 2019-12-01 09:17:35 +01:00
page_isolation.c mm, migrate: remove reason argument from new_page_t 2018-04-11 10:28:32 -07:00
page_owner.c mm/page_owner: don't access uninitialized memmaps when reading /proc/pagetypeinfo 2019-10-29 09:19:58 +01:00
page_poison.c page_poison: play nicely with KASAN 2019-04-05 22:32:59 +02:00
page_vma_mapped.c mm/rmap: map_pte() was not handling private ZONE_DEVICE page properly 2018-11-13 11:08:46 -08:00
pagewalk.c mm: pagewalk: fix termination condition in walk_pte_range() 2020-10-01 13:14:32 +02:00
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: convert spin_lock_irq to spin_lock_irqsave. 2019-02-12 19:47:12 +01:00
percpu-stats.c treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
percpu-vm.c percpu: allow select gfp to be passed to underlying allocators 2018-02-18 05:33:01 -08:00
percpu.c percpu: fix first chunk size calculation for populated bitmap 2020-09-23 12:11:01 +02:00
pgtable-generic.c mm: do not lose dirty and accessed bits in pmdp_invalidate() 2018-01-31 17:18:38 -08:00
process_vm_access.c mm: docs: add blank lines to silence sphinx "Unexpected indentation" errors 2018-02-06 18:32:48 -08:00
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 vfs: implement readahead(2) using POSIX_FADV_WILLNEED 2018-08-30 20:01:32 +02:00
rmap.c mm/hmm: fix bad subpage pointer in try_to_unmap_one 2019-08-25 10:47:43 +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 shmem: fix possible deadlocks on shmlock_user_lock 2020-05-20 08:18:32 +02:00
slab.c mm/slab.c: fix an infinite loop in leaks_show() 2019-06-15 11:54:01 +02:00
slab.h mm: add support for kmem caches in DMA32 zone 2019-04-03 06:26:28 +02:00
slab_common.c mm: memcg/slab: fix memory leak at non-root kmem_cache destroy 2020-07-29 10:16:57 +02:00
slob.c slab: __GFP_ZERO is incompatible with a constructor 2018-06-07 17:34:34 -07:00
slub.c mm: slub: fix conversion of freelist_corrupted() 2020-09-09 19:04:31 +02:00
sparse-vmemmap.c mm/sparse: delete old sparse_init and enable new one 2018-08-17 16:20:32 -07:00
sparse.c mm/memory_hotplug: remove "zone" parameter from sparse_remove_one_section 2020-01-29 16:43:26 +01:00
swap.c mm/swap: fix release_pages() when releasing devmap pages 2019-07-31 07:27:03 +02:00
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, get_swap_pages: use entry_size instead of cluster in parameter 2018-08-22 10:52:44 -07:00
swap_state.c mm: fix swap cache node allocation mask 2020-07-09 09:37:09 +02:00
swapfile.c mm/swapfile.c: swap_next should increase position index 2020-10-01 13:14:32 +02:00
truncate.c mm: cleancache: fix corruption on missed inode invalidation 2018-12-05 19:32:13 +01:00
usercopy.c usercopy: Avoid HIGHMEM pfn warning 2019-10-11 18:20:58 +02:00
userfaultfd.c hugetlb: use same fault hash key for shared and private mappings 2019-05-22 07:37:40 +02:00
util.c mm: add kvfree_sensitive() for freeing sensitive data objects 2020-06-22 09:05:01 +02:00
vmacache.c mm: get rid of vmacache_flush_all() entirely 2018-09-13 15:18:04 -10:00
vmalloc.c mm/vmalloc.c: don't dereference possible NULL pointer in __vunmap() 2020-06-03 08:19:49 +02:00
vmpressure.c mm/vmpressure.c: fix a signedness bug in vmpressure_register_event() 2019-10-17 13:45:19 -07:00
vmscan.c mm: memcg: fix memcg reclaim soft lockup 2020-09-26 18:01:32 +02:00
vmstat.c mm/vmstat.c: fix NUMA statistics updates 2019-12-13 08:51:27 +01:00
workingset.c mm/list_lru: introduce list_lru_shrink_walk_irq() 2018-08-17 16:20:32 -07:00
z3fold.c z3fold: fix possible reclaim races 2018-12-01 09:37:33 +01:00
zbud.c mm: docs: fix parameter names mismatch 2018-02-06 18:32:48 -08:00
zpool.c mm/zpool.c: zpool_evictable: fix mismatch in parameter name and kernel-doc 2018-02-21 15:35:43 -08:00
zsmalloc.c mm/zsmalloc.c: fix the migrated zspage statistics. 2020-01-09 10:19:00 +01:00
zswap.c zswap: re-check zswap_is_full() after do zswap_shrink() 2018-07-26 19:38:03 -07:00