From 4a5e85f4eb8fd18b1266342d100e4f0849544ca0 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Tue, 17 Jun 2025 16:35:32 +0200 Subject: [PATCH] fs/proc/task_mmu: fix PAGE_IS_PFNZERO detection for the huge zero folio is_zero_pfn() does not work for the huge zero folio. Fix it by using is_huge_zero_pmd(). This can cause the PAGEMAP_SCAN ioctl against /proc/pid/pagemap to present pages as PAGE_IS_PRESENT rather than as PAGE_IS_PFNZERO. Found by code inspection. Link: https://lkml.kernel.org/r/20250617143532.2375383-1-david@redhat.com Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs") Signed-off-by: David Hildenbrand Cc: Muhammad Usama Anjum Cc: Signed-off-by: Andrew Morton --- fs/proc/task_mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 27972c0749e7..4be91eb6ea5c 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -2182,7 +2182,7 @@ static unsigned long pagemap_thp_category(struct pagemap_scan_private *p, categories |= PAGE_IS_FILE; } - if (is_zero_pfn(pmd_pfn(pmd))) + if (is_huge_zero_pmd(pmd)) categories |= PAGE_IS_PFNZERO; if (pmd_soft_dirty(pmd)) categories |= PAGE_IS_SOFT_DIRTY; -- 2.50.1