linux/Documentation/vm
zhenwei pi 67f22ba775 mm/memory-failure: disable unpoison once hw error happens
Currently unpoison_memory(unsigned long pfn) is designed for soft
poison(hwpoison-inject) only.  Since 17fae1294a, the KPTE gets cleared
on a x86 platform once hardware memory corrupts.

Unpoisoning a hardware corrupted page puts page back buddy only, the
kernel has a chance to access the page with *NOT PRESENT* KPTE.  This
leads BUG during accessing on the corrupted KPTE.

Suggested by David&Naoya, disable unpoison mechanism when a real HW error
happens to avoid BUG like this:

 Unpoison: Software-unpoisoned page 0x61234
 BUG: unable to handle page fault for address: ffff888061234000
 #PF: supervisor write access in kernel mode
 #PF: error_code(0x0002) - not-present page
 PGD 2c01067 P4D 2c01067 PUD 107267063 PMD 10382b063 PTE 800fffff9edcb062
 Oops: 0002 [#1] PREEMPT SMP NOPTI
 CPU: 4 PID: 26551 Comm: stress Kdump: loaded Tainted: G   M       OE     5.18.0.bm.1-amd64 #7
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
 RIP: 0010:clear_page_erms+0x7/0x10
 Code: ...
 RSP: 0000:ffffc90001107bc8 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: 0000000000000901 RCX: 0000000000001000
 RDX: ffffea0001848d00 RSI: ffffea0001848d40 RDI: ffff888061234000
 RBP: ffffea0001848d00 R08: 0000000000000901 R09: 0000000000001276
 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000001
 R13: 0000000000000000 R14: 0000000000140dca R15: 0000000000000001
 FS:  00007fd8b2333740(0000) GS:ffff88813fd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffff888061234000 CR3: 00000001023d2005 CR4: 0000000000770ee0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  <TASK>
  prep_new_page+0x151/0x170
  get_page_from_freelist+0xca0/0xe20
  ? sysvec_apic_timer_interrupt+0xab/0xc0
  ? asm_sysvec_apic_timer_interrupt+0x1b/0x20
  __alloc_pages+0x17e/0x340
  __folio_alloc+0x17/0x40
  vma_alloc_folio+0x84/0x280
  __handle_mm_fault+0x8d4/0xeb0
  handle_mm_fault+0xd5/0x2a0
  do_user_addr_fault+0x1d0/0x680
  ? kvm_read_and_reset_apf_flags+0x3b/0x50
  exc_page_fault+0x78/0x170
  asm_exc_page_fault+0x27/0x30

Link: https://lkml.kernel.org/r/20220615093209.259374-2-pizhenwei@bytedance.com
Fixes: 847ce401df ("HWPOISON: Add unpoisoning support")
Fixes: 17fae1294a ("x86/{mce,mm}: Unmap the entire page if the whole page is affected and poisoned")
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>	[5.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-16 19:11:32 -07:00
..
damon Docs/damon: update outdated term 'regions update interval' 2022-03-22 15:57:12 -07:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
active_mm.rst docs/vm: fix 'mm_count' vs 'mm_users' counter confusion 2020-10-13 18:38:32 -07:00
arch_pgtable_helpers.rst Documentation: arch_pgtable_helpers: demote pgtable list headings 2022-04-16 02:44:49 -06:00
balance.rst
bootmem.rst mm,doc: Add new documentation structure 2022-05-09 16:41:24 -06:00
free_page_reporting.rst mm/page_reporting: add free page reporting documentation 2020-04-07 10:43:39 -07:00
frontswap.rst frontswap: remove frontswap_shrink 2022-01-22 08:33:38 +02:00
highmem.rst Documentation/vm: rework "Temporary Virtual Mappings" section 2022-05-13 16:48:55 -07:00
hmm.rst mm/migrate.c: remove MIGRATE_PFN_LOCKED 2021-11-11 09:34:35 -08:00
hugetlbfs_reserv.rst docs/vm: Minor editorial changes in the THP and hugetlbfs 2019-04-30 06:34:40 -06:00
hwpoison.rst mm/memory-failure: disable unpoison once hw error happens 2022-06-16 19:11:32 -07:00
index.rst Yang Shi has improved the behaviour of khugepaged collapsing of readonly 2022-05-26 12:32:41 -07:00
ksm.rst docs: get rid of :c:type explicit declarations for structs 2020-10-15 07:49:40 +02:00
memory-model.rst docs: remove description of DISCONTIGMEM 2021-06-29 10:53:55 -07:00
mmu_notifier.rst docs/vm: trivial fixes to several spelling mistakes 2020-10-22 16:11:04 -06:00
numa.rst docs: cgroup-v1: add it to the admin-guide book 2019-07-15 11:03:02 -03:00
oom.rst mm,doc: Add new documentation structure 2022-05-09 16:41:24 -06:00
overcommit-accounting.rst docs/vm: clarify overcommit amount sysctl behavior 2021-12-16 15:53:22 -07:00
page_allocation.rst mm,doc: Add new documentation structure 2022-05-09 16:41:24 -06:00
page_cache.rst mm,doc: Add new documentation structure 2022-05-09 16:41:24 -06:00
page_frags.rst docs: vm: page_frags.rst: Fix the reference of stale function 2020-05-15 11:34:55 -06:00
page_migration.rst mm: migrate: correct the hugetlb migration stats 2022-01-15 16:30:30 +02:00
page_owner.rst docs: vm/page_owner: tweak literal block in STANDARD FORMAT SPECIFIERS 2022-05-13 07:20:18 -07:00
page_reclaim.rst mm,doc: Add new documentation structure 2022-05-09 16:41:24 -06:00
page_table_check.rst docs/vm: Fix typo in *harden* 2022-01-27 11:22:34 -07:00
page_tables.rst mm,doc: Add new documentation structure 2022-05-09 16:41:24 -06:00
physical_memory.rst mm,doc: Add new documentation structure 2022-05-09 16:41:24 -06:00
process_addrs.rst mm,doc: Add new documentation structure 2022-05-09 16:41:24 -06:00
remap_file_pages.rst
shmfs.rst mm,doc: Add new documentation structure 2022-05-09 16:41:24 -06:00
slab.rst mm,doc: Add new documentation structure 2022-05-09 16:41:24 -06:00
slub.rst slab, documentation: add description of debugfs files for SLUB caches 2022-04-06 11:09:48 +02:00
split_page_table_lock.rst Documentation: fix typos in split page table lock description 2021-01-18 13:27:18 -07:00
swap.rst mm,doc: Add new documentation structure 2022-05-09 16:41:24 -06:00
transhuge.rst mm: gup: remove FOLL_SPLIT 2021-04-30 11:20:37 -07:00
unevictable-lru.rst mm/munlock: update Documentation/vm/unevictable-lru.rst 2022-04-01 11:46:09 -07:00
vmalloc.rst mm,doc: Add new documentation structure 2022-05-09 16:41:24 -06:00
vmalloced-kernel-stacks.rst docs/vm: add vmalloced-kernel-stacks document 2022-01-15 16:30:28 +02:00
vmemmap_dedup.rst mm/sparse-vmemmap: improve memory savings for compound devmaps 2022-04-28 23:16:16 -07:00
z3fold.rst
zsmalloc.rst