kernel/linux.git/mm/memory-failure.c, branch v6.18.21

mm/memory-failure: teach kill_accessing_process to accept hugetlb tail page pfn

2026-02-06T15:57:41+00:00

commit 057a6f2632c956483e2b2628477f0fcd1cd8a844 upstream. When a hugetlb folio is being poisoned again, try_memory_failure_hugetlb() passed head pfn to kill_accessing_process(), that is not right. The precise pfn of the poisoned page should be used in order to determine the precise vaddr as the SIGBUS payload. This issue has already been taken care of in the normal path, that is, hwpoison_user_mappings(), see [1][2]. Further more, for [3] to work correctly in the hugetlb repoisoning case, it's essential to inform VM the precise poisoned page, not the head page. [1] https://lkml.kernel.org/r/20231218135837.3310403-1-willy@infradead.org [2] https://lkml.kernel.org/r/20250224211445.2663312-1-jane.chu@oracle.com [3] https://lore.kernel.org/lkml/20251116013223.1557158-1-jiaqiyan@google.com/ Link: https://lkml.kernel.org/r/20260120232234.3462258-2-jane.chu@oracle.com Signed-off-by: Jane Chu Reviewed-by: Liam R. Howlett Acked-by: Miaohe Lin Cc: Chris Mason Cc: David Hildenbrand Cc: David Rientjes Cc: Jiaqi Yan Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Naoya Horiguchi Cc: Oscar Salvador Cc: Suren Baghdasaryan Cc: William Roche Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

mm/memory-failure: fix missing ->mf_stats count in hugetlb poison

2026-02-06T15:57:40+00:00

commit a148a2040191b12b45b82cb29c281cb3036baf90 upstream. When a newly poisoned subpage ends up in an already poisoned hugetlb folio, 'num_poisoned_pages' is incremented, but the per node ->mf_stats is not. Fix the inconsistency by designating action_result() to update them both. While at it, define __get_huge_page_for_hwpoison() return values in terms of symbol names for better readibility. Also rename folio_set_hugetlb_hwpoison() to hugetlb_update_hwpoison() since the function does more than the conventional bit setting and the fact three possible return values are expected. Link: https://lkml.kernel.org/r/20260120232234.3462258-1-jane.chu@oracle.com Fixes: 18f41fa616ee ("mm: memory-failure: bump memory failure stats to pglist_data") Signed-off-by: Jane Chu Acked-by: Miaohe Lin Cc: Chris Mason Cc: David Hildenbrand Cc: David Rientjes Cc: Jiaqi Yan Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Naoya Horiguchi Cc: Oscar Salvador Cc: Suren Baghdasaryan Cc: William Roche Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

mm, swap: cleanup swap cache API and add kerneldoc

2025-09-21T21:22:23+00:00

In preparation for replacing the swap cache backend with the swap table, clean up and add proper kernel doc for all swap cache APIs. Now all swap cache APIs are well-defined with consistent names. No feature change, only renaming and documenting. Link: https://lkml.kernel.org/r/20250916160100.31545-9-ryncsn@gmail.com Signed-off-by: Kairui Song Acked-by: Chris Li Reviewed-by: Barry Song Reviewed-by: Baolin Wang Acked-by: David Hildenbrand Suggested-by: Chris Li Cc: Baoquan He Cc: "Huang, Ying" Cc: Hugh Dickins Cc: Johannes Weiner Cc: Kemeng Shi Cc: kernel test robot Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Nhat Pham Cc: Yosry Ahmed Cc: Zi Yan Cc: SeongJae Park Signed-off-by: Andrew Morton

mm/memremap: remove unused get_dev_pagemap() parameter

2025-09-21T21:22:21+00:00

GUP no longer uses get_dev_pagemap(). As it was the only user of the get_dev_pagemap() pgmap caching feature it can be removed. Link: https://lkml.kernel.org/r/20250903225926.34702-2-apopple@nvidia.com Signed-off-by: Alistair Popple Acked-by: David Hildenbrand Reviewed-by: Jason Gunthorpe Reviewed-by: Dan Williams Cc: John Hubbard Cc: Oscar Salvador Cc: Peter Xu Signed-off-by: Andrew Morton

mm/hwpoison: decouple hwpoison_filter from mm/memory-failure.c

2025-09-21T21:22:21+00:00

mm/memory-failure.c defines and uses hwpoison_filter_* parameters but the values of those parameters can only be modified via mm/hwpoison-inject.c from userspace. They have a potentially different life time. Decouple those parameters from mm/memory-failure.c to fix this broken layering. Link: https://lkml.kernel.org/r/20250904062258.3336092-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Suggested-by: Michal Hocko Cc: David Hildenbrand Cc: Naoya Horiguchi Signed-off-by: Andrew Morton

Merge branch 'mm-hotfixes-stable' into mm-stable in order to pick up

2025-09-21T21:19:36+00:00

changes required by mm-stable material: hugetlb and damon.

mm: introduce memdesc_flags_t

2025-09-13T23:55:07+00:00

Patch series "Add and use memdesc_flags_t". At some point struct page will be separated from struct slab and struct folio. This is a step towards that by introducing a type for the 'flags' word of all three structures. This gives us a certain amount of type safety by establishing that some of these unsigned longs are different from other unsigned longs in that they contain things like node ID, section number and zone number in the upper bits. That lets us have functions that can be easily called by anyone who has a slab, folio or page (but not easily by anyone else) to get the node or zone. There's going to be some unusual merge problems with this as some odd bits of the kernel decide they want to print out the flags value or something similar by writing page->flags and now they'll need to write page->flags.f instead. That's most of the churn here. Maybe we should be removing these things from the debug output? This patch (of 11): Wrap the unsigned long flags in a typedef. In upcoming patches, this will provide a strong hint that you can't just pass a random unsigned long to functions which take this as an argument. [willy@infradead.org: s/flags/flags.f/ in several architectures] Link: https://lkml.kernel.org/r/aKMgPRLD-WnkPxYm@casper.infradead.org [nicola.vetrini@gmail.com: mips: fix compilation error] Link: https://lore.kernel.org/lkml/CA+G9fYvkpmqGr6wjBNHY=dRp71PLCoi2341JxOudi60yqaeUdg@mail.gmail.com/ Link: https://lkml.kernel.org/r/20250825214245.1838158-1-nicola.vetrini@gmail.com Link: https://lkml.kernel.org/r/20250805172307.1302730-1-willy@infradead.org Link: https://lkml.kernel.org/r/20250805172307.1302730-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Zi Yan Cc: Shakeel Butt Signed-off-by: Andrew Morton

mm/memory-failure: fix VM_BUG_ON_PAGE(PagePoisoned(page)) when unpoison memory

2025-09-09T06:45:11+00:00

When I did memory failure tests, below panic occurs: page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page)) kernel BUG at include/linux/page-flags.h:616! Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40 RIP: 0010:unpoison_memory+0x2f3/0x590 RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 Call Trace: unpoison_memory+0x2f3/0x590 simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 debugfs_attr_write+0x42/0x60 full_proxy_write+0x5b/0x80 vfs_write+0xd5/0x540 ksys_write+0x64/0xe0 do_syscall_64+0xb9/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f08f0314887 RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887 RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001 RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00 Modules linked in: hwpoison_inject ---[ end trace 0000000000000000 ]--- RIP: 0010:unpoison_memory+0x2f3/0x590 RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 Kernel panic - not syncing: Fatal exception Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) ---[ end Kernel panic - not syncing: Fatal exception ]--- The root cause is that unpoison_memory() tries to check the PG_HWPoison flags of an uninitialized page. So VM_BUG_ON_PAGE(PagePoisoned(page)) is triggered. This can be reproduced by below steps: 1.Offline memory block: echo offline > /sys/devices/system/memory/memory12/state 2.Get offlined memory pfn: page-types -b n -rlN 3.Write pfn to unpoison-pfn echo > /sys/kernel/debug/hwpoison/unpoison-pfn This scenario can be identified by pfn_to_online_page() returning NULL. And ZONE_DEVICE pages are never expected, so we can simply fail if pfn_to_online_page() == NULL to fix the bug. Link: https://lkml.kernel.org/r/20250828024618.1744895-1-linmiaohe@huawei.com Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") Signed-off-by: Miaohe Lin Suggested-by: David Hildenbrand Acked-by: David Hildenbrand Cc: Naoya Horiguchi Cc: Signed-off-by: Andrew Morton

mm/memory-failure: fix redundant updates for already poisoned pages

2025-09-04T00:10:38+00:00

Duplicate memory errors can be reported by multiple sources. Passing an already poisoned page to action_result() causes issues: * The amount of hardware corrupted memory is incorrectly updated. * Per NUMA node MF stats are incorrectly updated. * Redundant "already poisoned" messages are printed. Avoid those issues by: * Skipping hardware corrupted memory updates for already poisoned pages. * Skipping per NUMA node MF stats updates for already poisoned pages. * Dropping redundant "already poisoned" messages. Make MF_MSG_ALREADY_POISONED consistent with other action_page_types and make calls to action_result() consistent for already poisoned normal pages and huge pages. Link: https://lkml.kernel.org/r/aLCiHMy12Ck3ouwC@hpe.com Fixes: b8b9488d50b7 ("mm/memory-failure: improve memory failure action_result messages") Signed-off-by: Kyle Meyer Reviewed-by: Jiaqi Yan Acked-by: David Hildenbrand Reviewed-by: Jane Chu Acked-by: Miaohe Lin Cc: Borislav Betkov Cc: Kyle Meyer Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: "Luck, Tony" Cc: Michal Hocko Cc: Mike Rapoport Cc: Naoya Horiguchi Cc: Oscar Salvador Cc: Russ Anderson Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton

mm/memory-failure: fix infinite UCE for VM_PFNMAP pfn

2025-08-19T23:35:56+00:00

When memory_failure() is called for a already hwpoisoned pfn, kill_accessing_process() will be called to kill current task. However, if the vma of the accessing vaddr is VM_PFNMAP, walk_page_range() will skip the vma in walk_page_test() and return 0. Before commit aaf99ac2ceb7 ("mm/hwpoison: do not send SIGBUS to processes with recovered clean pages"), kill_accessing_process() will return EFAULT. For x86, the current task will be killed in kill_me_maybe(). However, after this commit, kill_accessing_process() simplies return 0, that means UCE is handled properly, but it doesn't actually. In such case, the user task will trigger UCE infinitely. To fix it, add .test_walk callback for hwpoison_walk_ops to scan all vmas. Link: https://lkml.kernel.org/r/20250815073209.1984582-1-tujinjiang@huawei.com Fixes: aaf99ac2ceb7 ("mm/hwpoison: do not send SIGBUS to processes with recovered clean pages") Signed-off-by: Jinjiang Tu Acked-by: David Hildenbrand Acked-by: Miaohe Lin Reviewed-by: Jane Chu Cc: Kefeng Wang Cc: Naoya Horiguchi Cc: Oscar Salvador Cc: Shuai Xue Cc: Zi Yan Cc: Signed-off-by: Andrew Morton