Yang Shi eac96c3efd mm: filemap: check if THP has hwpoisoned subpage for PMD page fault ... When handling shmem page fault the THP with corrupted subpage could be PMD mapped if certain conditions are satisfied. But kernel is supposed to send SIGBUS when trying to map hwpoisoned page. There are two paths which may do PMD map: fault around and regular fault. Before commit f9ce0be71d ("mm: Cleanup faultaround and finish_fault() codepaths") the thing was even worse in fault around path. The THP could be PMD mapped as long as the VMA fits regardless what subpage is accessed and corrupted. After this commit as long as head page is not corrupted the THP could be PMD mapped. In the regular fault path the THP could be PMD mapped as long as the corrupted page is not accessed and the VMA fits. This loophole could be fixed by iterating every subpage to check if any of them is hwpoisoned or not, but it is somewhat costly in page fault path. So introduce a new page flag called HasHWPoisoned on the first tail page. It indicates the THP has hwpoisoned subpage(s). It is set if any subpage of THP is found hwpoisoned by memory failure and after the refcount is bumped successfully, then cleared when the THP is freed or split. The soft offline path doesn't need this since soft offline handler just marks a subpage hwpoisoned when the subpage is migrated successfully. But shmem THP didn't get split then migrated at all. Link: https://lkml.kernel.org/r/20211020210755.23964-3-shy828301@gmail.com Fixes: 800d8c63b2 ("shmem: add huge pages support") Signed-off-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2021-10-28 17:18:55 -07:00
..
acpi	ACPI: tools: fix compilation error	2021-10-07 19:18:19 +02:00
asm-generic	asm-generic: build fixes for v5.15	2021-10-08 11:57:54 -07:00
clocksource
crypto
drm
dt-bindings	linux-watchdog 5.15-rc1 tag	2021-09-07 13:52:46 -07:00
keys
kunit	kunit: fix kernel-doc warnings due to mismatched arg names	2021-10-06 17:54:07 -06:00
kvm	KVM: arm64: Fix PMU probe ordering	2021-09-20 12:43:34 +01:00
linux	mm: filemap: check if THP has hwpoisoned subpage for PMD page fault	2021-10-28 17:18:55 -07:00
math-emu
media
memory
misc
net	mptcp: fix corrupt receiver key in MPC + data + checksum	2021-10-28 08:19:06 -07:00
pcmcia
ras
rdma
scsi	scsi: core: Remove 'current_tag'	2021-09-22 00:13:38 -04:00
soc	net: dsa: tag_ocelot_8021q: break circular dependency with ocelot switch lib	2021-10-12 17:35:18 -07:00
sound	ALSA: hda: intel: Allow repeatedly probing on codec configuration errors	2021-10-07 09:15:22 +02:00
target
trace	block-5.15-2021-10-17	2021-10-17 19:25:20 -10:00
uapi	Networking fixes for 5.15-rc7, including fixes from netfilter, and can.	2021-10-21 15:36:50 -10:00
vdso
video
xen	xen/privcmd: drop "pages" parameter from xen_remap_pfn()	2021-10-05 08:20:27 +02:00