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Commit 85015a96 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Greg Kroah-Hartman
Browse files

mm/memory-failure: check the mapcount of the precise page 

[ Upstream commit c79c5a0a00a9457718056b588f312baadf44e471 ]

A process may map only some of the pages in a folio, and might be missed
if it maps the poisoned page but not the head page.  Or it might be
unnecessarily hit if it maps the head page, but not the poisoned page.

Link: https://lkml.kernel.org/r/20231218135837.3310403-3-willy@infradead.org


Fixes: 7af446a8 ("HWPOISON, hugetlb: enable error handling path for hugepage")
Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 3d8fab93

mm/memory-failure.c

+3 −3
Original line number Diff line number Diff line
@@ -986,7 +986,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, 
	 * This check implies we don't kill processes if their pages

	 * are in the swap cache early. Those are always late kills.

	 */

	if (!page_mapped(hpage))

	if (!page_mapped(p))

		return true;



	if (PageKsm(p)) {
@@ -1030,10 +1030,10 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, 
	if (kill)

		collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);



	unmap_success = try_to_unmap(hpage, ttu);

	unmap_success = try_to_unmap(p, ttu);

	if (!unmap_success)

		pr_err("Memory failure: %#lx: failed to unmap page (mapcount=%d)\n",

		       pfn, page_mapcount(hpage));

		       pfn, page_mapcount(p));



	/*

	 * try_to_unmap() might put mlocked page in lru cache, so call