linux/mm
Liu Shixin 56b274473d mm: hugetlb: independent PMD page table shared count
[ Upstream commit 59d9094df3 ]

The folio refcount may be increased unexpectly through try_get_folio() by
caller such as split_huge_pages.  In huge_pmd_unshare(), we use refcount
to check whether a pmd page table is shared.  The check is incorrect if
the refcount is increased by the above caller, and this can cause the page
table leaked:

 BUG: Bad page state in process sh  pfn:109324
 page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x66 pfn:0x109324
 flags: 0x17ffff800000000(node=0|zone=2|lastcpupid=0xfffff)
 page_type: f2(table)
 raw: 017ffff800000000 0000000000000000 0000000000000000 0000000000000000
 raw: 0000000000000066 0000000000000000 00000000f2000000 0000000000000000
 page dumped because: nonzero mapcount
 ...
 CPU: 31 UID: 0 PID: 7515 Comm: sh Kdump: loaded Tainted: G    B              6.13.0-rc2master+ #7
 Tainted: [B]=BAD_PAGE
 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
 Call trace:
  show_stack+0x20/0x38 (C)
  dump_stack_lvl+0x80/0xf8
  dump_stack+0x18/0x28
  bad_page+0x8c/0x130
  free_page_is_bad_report+0xa4/0xb0
  free_unref_page+0x3cc/0x620
  __folio_put+0xf4/0x158
  split_huge_pages_all+0x1e0/0x3e8
  split_huge_pages_write+0x25c/0x2d8
  full_proxy_write+0x64/0xd8
  vfs_write+0xcc/0x280
  ksys_write+0x70/0x110
  __arm64_sys_write+0x24/0x38
  invoke_syscall+0x50/0x120
  el0_svc_common.constprop.0+0xc8/0xf0
  do_el0_svc+0x24/0x38
  el0_svc+0x34/0x128
  el0t_64_sync_handler+0xc8/0xd0
  el0t_64_sync+0x190/0x198

The issue may be triggered by damon, offline_page, page_idle, etc, which
will increase the refcount of page table.

1. The page table itself will be discarded after reporting the
   "nonzero mapcount".

2. The HugeTLB page mapped by the page table miss freeing since we
   treat the page table as shared and a shared page table will not be
   unmapped.

Fix it by introducing independent PMD page table shared count.  As
described by comment, pt_index/pt_mm/pt_frag_refcount are used for s390
gmap, x86 pgds and powerpc, pt_share_count is used for x86/arm64/riscv
pmds, so we can reuse the field as pt_share_count.

Link: https://lkml.kernel.org/r/20241216071147.3984217-1-liushixin2@huawei.com
Fixes: 39dde65c99 ("[PATCH] shared page table for hugetlb page")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Ken Chen <kenneth.w.chen@intel.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2025-01-17 13:36:26 +01:00
..
damon mm/damon/vaddr: fix issue in damon_va_evenly_split_region() 2024-12-14 20:00:21 +01:00
kasan kasan: make report_lock a raw spinlock 2024-12-14 19:59:57 +01:00
kfence LoongArch changes for v6.6 2023-09-08 12:16:52 -07:00
kmsan kmsan: do not wipe out origin when doing partial unpoisoning 2024-06-16 13:47:41 +02:00
backing-dev.c blk-wbt: Fix detection of dirty-throttled tasks 2024-02-23 09:25:16 +01:00
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/cma: drop incorrect alignment check in cma_init_reserved_mem 2024-06-16 13:47:42 +02:00
cma.h mm/cma: provide option to opt out from exposing pages on activation failure 2022-03-22 15:57:09 -07:00
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, treewide: introduce NR_PAGE_ORDERS 2024-05-02 16:32:41 +02:00
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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
debug_vm_pgtable.c mm/debug_vm_pgtable: drop RANDOM_ORVALUE trick 2024-08-19 06:04:31 +02:00
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 mm: support order-1 folios in the page cache 2024-11-17 15:08:59 +01:00
folio-compat.c filemap: Add fgf_t typedef 2023-07-24 18:04:30 -04:00
gup.c mm: gup: stop abusing try_grab_folio 2024-08-19 06:04:24 +02:00
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: enable page walking API to lock vmas during the walk 2023-08-21 13:07:20 -07:00
huge_memory.c mm/thp: fix deferred split unqueue naming and locking 2024-11-17 15:08:59 +01:00
hugetlb.c mm: hugetlb: independent PMD page table shared count 2025-01-17 13:36:26 +01:00
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: hugetlb_vmemmap: fix a race between vmemmap pmd split 2023-08-18 10:12:14 -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 mm: move dummy_vm_ops out of a header 2023-08-21 13:37:46 -07:00
internal.h Rename .data.once to .data..once to fix resetting WARN*_ONCE 2024-12-09 10:32:59 +01:00
interval_tree.c mm/interval_tree: add comments to improve code readability 2021-04-30 11:20:38 -07:00
io-mapping.c mm: add a io_mapping_map_user helper 2021-04-30 11:20:39 -07:00
ioremap.c mm: ioremap: remove unneeded ioremap_allowed and iounmap_allowed 2023-08-18 10:12:36 -07:00
Kconfig mm: z3fold: deprecate CONFIG_Z3FOLD 2024-10-10 11:58:02 +02:00
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 the arguments order in khugepaged_collapse_file trace point 2024-11-01 01:58:26 +01:00
kmemleak.c mm/kmemleak: fix sleeping function called from invalid context at print message 2025-01-09 13:32:09 +01:00
ksm.c mm/ksm: fix ksm_zero_pages accounting 2024-06-16 13:47:41 +02:00
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/madvise: make MADV_POPULATE_(READ|WRITE) handle VM_FAULT_RETRY properly 2024-05-02 16:32:40 +02:00
Makefile - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list") 2023-08-29 14:25:26 -07:00
mapping_dirty_helpers.c mm: fix clean_record_shared_mapping_range kernel-doc 2023-08-24 16:20:30 -07:00
memblock.c memblock: use numa_valid_node() helper to check for invalid node ID 2025-01-17 13:36:09 +01:00
memcontrol.c mm/thp: fix deferred split unqueue naming and locking 2024-11-17 15:08:59 +01:00
memfd.c revert "memfd: improve userspace warnings for missing exec-related flags". 2023-09-05 11:11:52 -07:00
memory-failure.c mm/memory-failure: use raw_spinlock_t in struct memory_failure_cpu 2024-08-29 17:33:15 +02:00
memory-tiers.c memory tier: use helper macro __ATTR_RW() 2023-08-18 10:12:38 -07:00
memory.c mm: don't install PMD mappings when THPs are disabled by the hw/process/vma 2024-11-08 16:28:27 +01:00
memory_hotplug.c x86/kaslr: Expose and use the end of the physical memory address space 2024-09-12 11:11:25 +02:00
mempolicy.c mm/mempolicy: fix migrate_to_node() assuming there is at least one VMA in a MM 2024-12-14 20:00:18 +01:00
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 memtest: use {READ,WRITE}_ONCE in memory scanning 2024-04-03 15:28:33 +02:00
migrate.c vmscan,migrate: fix page count imbalance on node stats when demoting pages 2024-11-08 16:28:26 +01:00
migrate_device.c Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
mincore.c mm: enable page walking API to lock vmas during the walk 2023-08-21 13:07:20 -07:00
mlock.c merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes 2023-08-21 14:26:20 -07:00
mm_init.c efi: disable mirror feature during crashkernel 2024-01-31 16:18:56 -08:00
mm_slot.h mm: introduce common struct mm_slot 2022-10-03 14:02:43 -07:00
mmap.c mm: resolve faulty mmap_region() error path behaviour 2024-11-22 15:38:37 +01:00
mmap_lock.c mm: mmap_lock: replace get_memcg_path_buf() with on-stack buffer 2024-08-03 08:54:12 +02:00
mmu_gather.c mm: fix kernel-doc warning from tlb_flush_rmaps() 2023-08-24 16:20:30 -07:00
mmu_notifier.c mmu_notifiers: rename invalidate_range notifier 2023-08-18 10:12:41 -07:00
mmzone.c mm: multi-gen LRU: groundwork 2022-09-26 19:46:09 -07:00
mprotect.c mm: refactor map_deny_write_exec() 2024-11-22 15:38:37 +01:00
mremap.c mm/mremap: fix move_normal_pmd/retract_page_tables race 2024-10-22 15:46:21 +02:00
msync.c mm/msync: use vma_find() instead of vma linked list 2022-09-26 19:46:25 -07:00
nommu.c mm: refactor arch_calc_vm_flag_bits() and arm64 MTE handling 2024-11-22 15:38:37 +01:00
oom_kill.c mm: remove redundant K() macro definition 2023-08-21 13:37:44 -07:00
page-writeback.c Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again" 2024-07-11 12:49:16 +02:00
page_alloc.c mm: page_alloc: move mlocked flag clearance into free_pages_prepare() 2024-12-14 19:59:51 +01:00
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: move functions around for minor cleanups to page_ext 2023-08-18 10:12:31 -07:00
page_idle.c mm: page_idle: convert page idle to use a folio 2023-01-18 17:12:52 -08:00
page_io.c zswap: make zswap_load() take a folio 2023-08-21 13:37:27 -07:00
page_isolation.c mm/hugetlb: get rid of page_hstate() 2023-08-18 10:12:39 -07:00
page_owner.c mm/page_ext: use page_ext_data helper in page_owner 2023-08-21 13:37:27 -07:00
page_poison.c mm/page_poison: remove unused page_ext.h from page_poison 2023-08-21 13:37:30 -07:00
page_reporting.c mm, treewide: introduce NR_PAGE_ORDERS 2024-05-02 16:32:41 +02:00
page_reporting.h mm/page_reporting: export reporting order as module parameter 2021-06-29 10:53:47 -07:00
page_table_check.c mm/page_table_check: support userfault wr-protect entries 2024-08-19 06:04:29 +02:00
page_vma_mapped.c mm: correct stale comment of function check_pte 2023-08-18 10:12:13 -07:00
pagewalk.c mm/pagewalk: fix bootstopping regression from extra pte_unmap() 2023-09-02 08:39:21 -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: flush tlb in pcpu_reclaim_populated() 2021-07-04 18:30:17 +00:00
percpu-stats.c mm: use vmalloc_array and vcalloc for array allocations 2022-03-08 09:30:46 -05:00
percpu-vm.c percpu: flush tlb in pcpu_reclaim_populated() 2021-07-04 18:30:17 +00:00
percpu.c mm: Introduce flush_cache_vmap_early() 2024-02-16 19:10:52 +01:00
pgalloc-track.h mm: fix typos in comments 2021-05-07 00:26:35 -07:00
pgtable-generic.c mm: fix race between __split_huge_pmd_locked() and GUP-fast 2024-06-16 13:47:40 +02:00
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/readahead: fix large folio support in async readahead 2025-01-09 13:32:08 +01:00
rmap.c mm: hugetlb: add huge page size param to set_huge_pte_at() 2023-09-29 17:20:47 -07:00
rodata_test.c mm/rodata_test: use PAGE_ALIGNED() helper 2022-10-03 14:03:05 -07:00
secretmem.c secretmem: disable memfd_secret() if arch cannot set direct map 2024-10-17 15:24:37 +02:00
shmem.c mm: refactor arch_calc_vm_flag_bits() and arm64 MTE handling 2024-11-22 15:38:37 +01:00
shmem_quota.c tmpfs: fix race on handling dquot rbtree 2024-04-03 15:28:54 +02:00
show_mem.c mm, treewide: introduce NR_PAGE_ORDERS 2024-05-02 16:32:41 +02:00
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 Randomized slab caches for kmalloc() 2023-07-18 10:07:47 +02:00
slab.h mm/slub: Avoid list corruption when removing a slab from the full list 2024-12-09 10:33:06 +01:00
slab_common.c mm: krealloc: Fix MTE false alarm in __do_krealloc 2024-11-17 15:08:58 +01:00
slub.c mm/slub: Avoid list corruption when removing a slab from the full list 2024-12-09 10:33:06 +01:00
sparse-vmemmap.c mm/vmemmap: allow architectures to override how vmemmap optimization works 2023-08-18 10:12:53 -07:00
sparse.c x86/kaslr: Expose and use the end of the physical memory address space 2024-09-12 11:11:25 +02:00
swap.c mm: page_alloc: move mlocked flag clearance into free_pages_prepare() 2024-12-14 19:59:51 +01:00
swap.h mm/swap: fix race when skipping swapcache 2024-03-01 13:35:00 +01:00
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/swap: inline folio_set_swap_entry() and folio_swap_entry() 2023-08-24 16:20:28 -07:00
swapfile.c mm/swapfile: skip HugeTLB pages for unuse_vma 2024-10-22 15:46:21 +02:00
truncate.c mm: Fix missing folio invalidation calls during truncation 2024-09-04 13:28:23 +02:00
usercopy.c mm: Fix copy_from_user_nofault(). 2023-04-12 17:36:23 -07:00
userfaultfd.c userfaultfd: fix checks for huge PMDs 2024-09-12 11:11:27 +02:00
util.c mm: only enforce minimum stack gap size if it's sensible 2024-10-04 16:30:02 +02:00
vmalloc.c vmalloc: fix accounting with i915 2024-12-27 13:58:53 +01:00
vmpressure.c net-memcg: Fix scope of sockmem pressure indicators 2023-08-16 12:21:32 +01:00
vmscan.c mm: vmscan: account for free pages to prevent infinite Loop in throttle_direct_reclaim() 2025-01-09 13:32:09 +01:00
vmstat.c vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event 2024-12-09 10:33:05 +01:00
workingset.c mm: ratelimit stat flush from workingset shrinker 2024-06-16 13:47:31 +02:00
z3fold.c mm/z3fold: remove obsolete comment for struct z3fold_pool 2023-08-21 13:37:51 -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 merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes 2023-08-21 14:26:20 -07:00
zswap.c mm: zswap: fix missing folio cleanup in writeback race path 2024-03-01 13:35:10 +01:00