On 28.03.24 23:58, Matthew Wilcox (Oracle) wrote:
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.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
mm/page_vma_mapped.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
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 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
*/
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))
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
--
Cheers,
David / dhildenb
