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| author | Usama Arif <usama.arif@linux.dev> | 2026-07-06 04:42:05 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-07-30 19:40:24 -0700 |
| commit | eecd06034bf494f985cbcd1f062391d6a38f61c4 (patch) | |
| tree | 2e20a974a74dccbe79a1f99e12f434ce7926503c /fs/proc | |
| parent | b707057443702993350c7a7740ef6135fee9befe (diff) | |
| download | linux-next-eecd06034bf494f985cbcd1f062391d6a38f61c4.tar.gz linux-next-eecd06034bf494f985cbcd1f062391d6a38f61c4.zip | |
fs/proc: use softleaf_has_pfn() in pagemap PMD walker
pagemap_pmd_range_thp() assumes that every non-present PMD is a migration
entry and unconditionally calls softleaf_to_page(). This will crash on
any non-present PMD type that does not encode a PFN, such as the upcoming
PMD-level swap entries.
Guard the page lookup with softleaf_has_pfn(), matching how
pte_to_pagemap_entry() already handles non-present PTEs.
Link: https://lore.kernel.org/20260706114320.1643046-4-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs/proc')
| -rw-r--r-- | fs/proc/task_mmu.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 229d1fc3d7f1..95012243b9b3 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -2129,7 +2129,8 @@ static int pagemap_pmd_range_thp(pmd_t *pmdp, unsigned long addr, flags |= PM_SOFT_DIRTY; if (pmd_swp_uffd_wp(pmd)) flags |= PM_UFFD_WP; - page = softleaf_to_page(entry); + if (softleaf_has_pfn(entry)) + page = softleaf_to_page(entry); } if (page) { |