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| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2024-03-29 01:58:27 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-04-26 06:56:31 +0300 |
| commit | 7e8347413e5bc4d54712942dad43bfcf2501ab3b (patch) | |
| tree | 019894cbfec801994672d9c1ed00df78cc036fd0 /mm/page_vma_mapped.c | |
| parent | 835c3a25aa373d486514e4e0f5a7450ea82ae489 (diff) | |
| download | linux-7e8347413e5bc4d54712942dad43bfcf2501ab3b.tar.xz | |
mm: correct page_mapped_in_vma() for large folios
Patch series "Unify vma_address and vma_pgoff_address".
The current vma_address() pretends that the ambiguity between head & tail
page is an advantage. If you pass a head page to vma_address(), it will
operate on all pages in the folio, while if you pass a tail page, it will
operate on a single page. That's not what any of the callers actually
want, so first convert all callers to use vma_pgoff_address() and then
rename vma_pgoff_address() to vma_address().
This patch (of 3):
If 'page' is the first page of a large folio then vma_address() will scan
for any page in the entire folio. This can lead to page_mapped_in_vma()
returning true if some of the tail pages are mapped and the head page is
not. This could lead to memory failure choosing to kill a task
unnecessarily.
Link: https://lkml.kernel.org/r/20240328225831.1765286-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240328225831.1765286-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/page_vma_mapped.c')
| -rw-r--r-- | mm/page_vma_mapped.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 74d2de15fb5e..ac48d6284bad 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -325,6 +325,8 @@ next_pte: */ int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma) { + struct folio *folio = page_folio(page); + pgoff_t pgoff = folio->index + folio_page_idx(folio, page); struct page_vma_mapped_walk pvmw = { .pfn = page_to_pfn(page), .nr_pages = 1, @@ -332,7 +334,7 @@ int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma) .flags = PVMW_SYNC, }; - pvmw.address = vma_address(page, vma); + pvmw.address = vma_pgoff_address(pgoff, 1, vma); if (pvmw.address == -EFAULT) return 0; if (!page_vma_mapped_walk(&pvmw)) |