diff options
| author | Zi Yan <ziy@nvidia.com> | 2024-10-23 19:12:36 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-10-31 04:14:10 +0100 |
| commit | e0fc203748377835bbb4fb4c45174592214a3211 (patch) | |
| tree | 8210cec303f6bc8ca35ae21e70e1670aded7f1cf /mm/migrate.c | |
| parent | mm/codetag: fix null pointer check logic for ref and tag (diff) | |
| download | linux-e0fc203748377835bbb4fb4c45174592214a3211.tar.xz linux-e0fc203748377835bbb4fb4c45174592214a3211.zip | |
mm: avoid VM_BUG_ON when try to map an anon large folio to zero page.
An anonymous large folio can be split into non order-0 folios,
try_to_map_unused_to_zeropage() should not VM_BUG_ON compound pages but
just return false. This fixes the crash when splitting anonymous large
folios to non order-0 folios.
Link: https://lkml.kernel.org/r/20241023171236.1122535-1-ziy@nvidia.com
Fixes: b1f202060afe ("mm: remap unused subpages to shared zeropage when splitting isolated thp")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Usama Arif <usamaarif642@gmail.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to '')
| -rw-r--r-- | mm/migrate.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index df91248755e4..7e520562d421 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -206,7 +206,8 @@ static bool try_to_map_unused_to_zeropage(struct page_vma_mapped_walk *pvmw, pte_t newpte; void *addr; - VM_BUG_ON_PAGE(PageCompound(page), page); + if (PageCompound(page)) + return false; VM_BUG_ON_PAGE(!PageAnon(page), page); VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(pte_present(*pvmw->pte), page); |