linux-stable/mm
Hugh Dickins e8c716bc68 mm/khugepaged: fix regression in collapse_file()
There is no xas_pause(&xas) in collapse_file()'s main loop, at the points
where it does xas_unlock_irq(&xas) and then continues.

That would explain why, once two weeks ago and twice yesterday, I have
hit the VM_BUG_ON_PAGE(page != xas_load(&xas), page) since "mm/khugepaged:
fix iteration in collapse_file" removed the xas_set(&xas, index) just
before it: xas.xa_node could be left pointing to a stale node, if there
was concurrent activity on the file which transformed its xarray.

I tried inserting xas_pause()s, but then even bootup crashed on that
VM_BUG_ON_PAGE(): there appears to be a subtle "nextness" implicit in
xas_pause().

xas_next() and xas_pause() are good for use in simple loops, but not in
this one: xas_set() worked well until now, so use xas_set(&xas, index)
explicitly at the head of the loop; and change that VM_BUG_ON_PAGE() not
to need its own xas_set(), and not to interfere with the xa_state (which
would probably stop the crashes from xas_pause(), but I trust that less).

The user-visible effects of this bug (if VM_BUG_ONs are configured out)
would be data loss and data leak - potentially - though in practice I
expect it is more likely that a subsequent check (e.g. on mapping or on
nr_none) would notice an inconsistency, and just abandon the collapse.

Link: https://lore.kernel.org/linux-mm/f18e4b64-3f88-a8ab-56cc-d1f5f9c58d4@google.com/
Fixes: c8a8f3b4a9 ("mm/khugepaged: fix iteration in collapse_file")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: stable@kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Stevens <stevensd@chromium.org>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-06-29 09:41:45 -07:00
..
damon Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
kasan kasan,kmsan: remove __GFP_KSWAPD_RECLAIM usage from kasan/kmsan 2023-06-23 16:59:26 -07:00
kfence mm: kfence: fix false positives on big endian 2023-05-17 15:24:33 -07:00
kmsan kasan,kmsan: remove __GFP_KSWAPD_RECLAIM usage from kasan/kmsan 2023-06-23 16:59:26 -07:00
backing-dev.c mm: backing-dev: make bdi_class a static const structure 2023-06-23 16:59:27 -07:00
balloon_compaction.c mm: Convert all PageMovable users to movable_operations 2022-08-02 12:34:03 -04:00
bootmem_info.c bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem 2022-08-28 14:02:45 -07:00
cma.c mm/page_owner/cma: show pfn in cma/page_owner with hex format 2023-06-19 16:19:32 -07:00
cma.h
cma_debug.c mm/cma_debug: show complete cma name in debugfs directories 2022-09-11 20:25:50 -07:00
cma_sysfs.c mm: cma: make kobj_type structure constant 2023-03-28 16:20:06 -07:00
compaction.c mm: compaction: convert to use a folio in isolate_migratepages_block() 2023-06-23 16:59:31 -07:00
debug.c mm: update validate_mm() to use vma iterator 2023-06-09 16:25:31 -07:00
debug_page_alloc.c mm: page_alloc: split out DEBUG_PAGEALLOC 2023-06-09 16:25:23 -07:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug_vm_pgtable,page_table_check: warn pte map fails 2023-06-19 16:19:15 -07:00
dmapool.c dmapool: create/destroy cleanup 2023-06-09 16:25:17 -07:00
dmapool_test.c dmapool: add alloc/free performance test 2023-04-05 19:42:38 -07:00
early_ioremap.c mm/early_ioremap.c: improve the execution efficiency of early_ioremap_setup() 2023-06-09 16:25:56 -07:00
fadvise.c mm: remove unnecessary pagevec includes 2023-06-23 16:59:31 -07:00
fail_page_alloc.c mm: page_alloc: split out FAIL_PAGE_ALLOC 2023-06-09 16:25:23 -07:00
failslab.c mm: fix unexpected changes to {failslab|fail_page_alloc}.attr 2022-11-22 18:50:44 -08:00
filemap.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
folio-compat.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
frontswap.c mm: zswap: support exclusive loads 2023-06-19 16:19:05 -07:00
gup.c Merge branch 'expand-stack' 2023-06-28 20:35:21 -07:00
gup_test.c Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
gup_test.h mm/gup_test: start/stop/read functionality for PIN LONGTERM test 2022-11-08 17:37:15 -08:00
highmem.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
hmm.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
huge_memory.c mm: remove references to pagevec 2023-06-23 16:59:30 -07:00
hugetlb.c hugetlb: revert use of page_cache_next_miss() 2023-06-23 16:59:32 -07:00
hugetlb_cgroup.c mm/hugetlb: increase use of folios in alloc_huge_page() 2023-02-13 15:54:27 -08:00
hugetlb_vmemmap.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
hugetlb_vmemmap.h mm: hugetlb_vmemmap: improve hugetlb_vmemmap code readability 2022-08-08 18:06:43 -07:00
hwpoison-inject.c mm/hwpoison: add __init/__exit annotations to module init/exit funcs 2022-10-03 14:03:05 -07:00
init-mm.c IOMMU Updates for Linux 6.4 2023-04-30 13:00:38 -07:00
internal.h - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
interval_tree.c
io-mapping.c
ioremap.c mm: ioremap: Add ioremap/iounmap_allowed() 2022-06-27 12:22:31 +01:00
Kconfig Merge branch 'expand-stack' 2023-06-28 20:35:21 -07:00
Kconfig.debug mm: page_table_check: Make it dependent on EXCLUSIVE_SYSTEM_RAM 2023-05-29 16:14:28 +01:00
khugepaged.c mm/khugepaged: fix regression in collapse_file() 2023-06-29 09:41:45 -07:00
kmemleak.c lib/stackdepot, mm: rename stack_depot_want_early_init 2023-02-16 20:43:49 -08:00
ksm.c mm: remove references to pagevec 2023-06-23 16:59:30 -07:00
list_lru.c mm: kmem: make mem_cgroup_from_obj() vmalloc()-safe 2022-06-16 19:48:31 -07:00
maccess.c mm: Fix copy_from_user_nofault(). 2023-04-12 17:36:23 -07:00
madvise.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
Makefile mm: page_alloc: split out DEBUG_PAGEALLOC 2023-06-09 16:25:23 -07:00
mapping_dirty_helpers.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
memblock.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
memcontrol.c mm/memcontrol: do not tweak node in mem_cgroup_init() 2023-06-23 16:59:26 -07:00
memfd.c memfd: check for non-NULL file_seals in memfd_create() syscall 2023-06-19 13:19:31 -07:00
memory-failure.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
memory-tiers.c memory tier: remove unneeded !IS_ENABLED(CONFIG_MIGRATION) check 2023-06-19 16:19:29 -07:00
memory.c Merge branch 'expand-stack' 2023-06-28 20:35:21 -07:00
memory_hotplug.c mm: remove unnecessary pagevec includes 2023-06-23 16:59:31 -07:00
mempolicy.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
mempool.c mempool: do not use ksize() for poisoning 2022-11-30 15:58:41 -08:00
memremap.c mm/memremap.c: fix outdated comment in devm_memremap_pages 2023-02-09 16:51:46 -08:00
memtest.c mm/memtest: add results of early memtest to /proc/meminfo 2023-04-05 19:42:55 -07:00
migrate.c mm: remove unnecessary pagevec includes 2023-06-23 16:59:31 -07:00
migrate_device.c mm: remove references to pagevec 2023-06-23 16:59:30 -07:00
mincore.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
mlock.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
mm_init.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
mm_slot.h mm: introduce common struct mm_slot 2022-10-03 14:02:43 -07:00
mmap.c Merge branch 'expand-stack' 2023-06-28 20:35:21 -07:00
mmap_lock.c
mmu_gather.c mm: prefer xxx_page() alloc/free functions for order-0 pages 2023-03-28 16:20:16 -07:00
mmu_notifier.c mm/mmu_notifier: remove unused mmu_notifier_range_update_to_read_only export 2023-02-02 22:32:54 -08:00
mmzone.c mm: multi-gen LRU: groundwork 2022-09-26 19:46:09 -07:00
mprotect.c Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
mremap.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
msync.c mm/msync: use vma_find() instead of vma linked list 2022-09-26 19:46:25 -07:00
nommu.c mm: always expand the stack with the mmap write lock held 2023-06-27 09:41:30 -07:00
oom_kill.c mm, oom: do not check 0 mask in out_of_memory() 2023-06-09 16:25:20 -07:00
page-writeback.c mm: kill lock|unlock_page_memcg() 2023-06-19 16:19:33 -07:00
page_alloc.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
page_counter.c mm: page_counter: remove unneeded atomic ops for low/min 2022-09-11 20:26:01 -07:00
page_ext.c mm/page_ext: init page_ext early if there are no deferred struct pages 2023-02-02 22:33:22 -08:00
page_idle.c mm: page_idle: convert page idle to use a folio 2023-01-18 17:12:52 -08:00
page_io.c swap: use __bio_add_page to add page to bio 2023-05-31 09:50:02 -06:00
page_isolation.c mm: page_isolation: write proper kerneldoc 2023-06-19 16:18:59 -07:00
page_owner.c mm/page_owner/cma: show pfn in cma/page_owner with hex format 2023-06-19 16:19:32 -07:00
page_poison.c
page_reporting.c mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
page_reporting.h
page_table_check.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
page_vma_mapped.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
pagewalk.c mm/pagewalk: walk_pte_range() allow for pte_offset_map() 2023-06-19 16:19:14 -07:00
percpu-internal.h percpu-internal/pcpu_chunk: re-layout pcpu_chunk structure to reduce false sharing 2023-06-19 16:19:29 -07:00
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c mm: memcontrol: rename memcg_kmem_enabled() 2023-02-16 20:43:56 -08:00
pgalloc-track.h
pgtable-generic.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
process_vm_access.c mm/gup: remove unused vmas parameter from pin_user_pages_remote() 2023-06-09 16:25:25 -07:00
ptdump.c mm: ptdump should use ptep_get_lockless() 2023-06-19 16:19:24 -07:00
readahead.c mm: remove unnecessary pagevec includes 2023-06-23 16:59:31 -07:00
rmap.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
rodata_test.c mm/rodata_test: use PAGE_ALIGNED() helper 2022-10-03 14:03:05 -07:00
secretmem.c mm/mlock: rename mlock_future_check() to mlock_future_ok() 2023-06-09 16:25:38 -07:00
shmem.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
show_mem.c mm: page_alloc: collect mem statistic into show_mem.c 2023-06-09 16:25:22 -07:00
shrinker_debug.c Revert "mm: shrinkers: make count and scan in shrinker debugfs lockless" 2023-06-19 13:19:34 -07:00
shuffle.c mm/shuffle: convert module_param_call to module_param_cb 2022-10-03 14:03:07 -07:00
shuffle.h mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
slab.c mm/slab: simplify create_kmalloc_cache() args and make it static 2023-06-19 16:19:20 -07:00
slab.h - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
slab_common.c mm: slab: reduce the kmalloc() minimum alignment if DMA bouncing possible 2023-06-19 16:19:23 -07:00
slub.c slub: Replace cmpxchg_double() 2023-06-05 09:36:39 +02:00
sparse-vmemmap.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
sparse.c - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in 2023-06-28 10:59:38 -07:00
swap.c mm: remove references to pagevec 2023-06-23 16:59:30 -07:00
swap.h mm: remove the __swap_writepage return value 2023-02-02 22:33:33 -08:00
swap_cgroup.c mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled 2022-10-03 14:03:36 -07:00
swap_slots.c mm/swap: convert put_swap_page() to put_swap_folio() 2022-10-03 14:02:46 -07:00
swap_state.c mm: remove unnecessary pagevec includes 2023-06-23 16:59:31 -07:00
swapfile.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
truncate.c mm: remove references to pagevec 2023-06-23 16:59:30 -07:00
usercopy.c mm: Fix copy_from_user_nofault(). 2023-04-12 17:36:23 -07:00
userfaultfd.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
util.c mm: uninline kstrdup() 2023-04-08 13:45:37 -07:00
vmalloc.c Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
vmpressure.c
vmscan.c mm/vmscan: fix root proactive reclaim unthrottling unbalanced node 2023-06-23 16:59:32 -07:00
vmstat.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
workingset.c Multi-gen LRU: fix workingset accounting 2023-06-09 16:25:46 -07:00
z3fold.c mm: zswap: remove shrink from zpool interface 2023-06-19 16:19:27 -07:00
zbud.c mm: zswap: remove shrink from zpool interface 2023-06-19 16:19:27 -07:00
zpool.c mm: zswap: remove shrink from zpool interface 2023-06-19 16:19:27 -07:00
zsmalloc.c mm: zswap: remove shrink from zpool interface 2023-06-19 16:19:27 -07:00
zswap.c mm: zswap: fix double invalidate with exclusive loads 2023-06-23 16:59:31 -07:00