[PATCH stable-4.19] mm/memory-failure: fix an incorrect use of tail pages

[PATCH stable-4.19] mm/memory-failure: fix an incorrect use of tail pages

[Liu Shixin]

When backport commit c79c5a0a00a9 to 4.19-stable, there is a mistake change.
The head page instead of tail page should be passed to try_to_unmap(),
otherwise unmap will failed as follows.

 Memory failure: 0x121c10: failed to unmap page (mapcount=1)
 Memory failure: 0x121c10: recovery action for unmapping failed page: Ignored

Fixes: c6f50413f2aa ("mm/memory-failure: check the mapcount of the precise page")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
---
 mm/memory-failure.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index c971d5e11f93..5fce5df0fe35 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1033,7 +1033,7 @@ 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(p, ttu);
+	unmap_success = try_to_unmap(hpage, ttu);
 	if (!unmap_success)
 		pr_err("Memory failure: %#lx: failed to unmap page (mapcount=%d)\n",
 		       pfn, page_mapcount(p));
-- 
2.25.1

Patch "mm/memory-failure: fix an incorrect use of tail pages" has been added to the 4.19-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mm/memory-failure: fix an incorrect use of tail pages

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mm-memory-failure-fix-an-incorrect-use-of-tail-pages.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From liushixin2@huawei.com  Sat Mar 30 10:11:48 2024
From: Liu Shixin <liushixin2@huawei.com>
Date: Thu, 7 Mar 2024 20:51:50 +0800
Subject: mm/memory-failure: fix an incorrect use of tail pages
To: Matthew Wilcox <willy@infradead.org>, Andrew Morton <akpm@linux-foundation.org>, Sasha Levin <sashal@kernel.org>, Dan Williams <dan.j.williams@intel.com>, Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>, <stable@vger.kernel.org>, Liu Shixin <liushixin2@huawei.com>
Message-ID: <20240307125150.2849068-1-liushixin2@huawei.com>

From: Liu Shixin <liushixin2@huawei.com>

When backport commit c79c5a0a00a9 to 4.19-stable, there is a mistake change.
The head page instead of tail page should be passed to try_to_unmap(),
otherwise unmap will failed as follows.

 Memory failure: 0x121c10: failed to unmap page (mapcount=1)
 Memory failure: 0x121c10: recovery action for unmapping failed page: Ignored

Fixes: c6f50413f2aa ("mm/memory-failure: check the mapcount of the precise page")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 mm/memory-failure.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1033,7 +1033,7 @@ static bool hwpoison_user_mappings(struc
 	if (kill)
 		collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
 
-	unmap_success = try_to_unmap(p, ttu);
+	unmap_success = try_to_unmap(hpage, ttu);
 	if (!unmap_success)
 		pr_err("Memory failure: %#lx: failed to unmap page (mapcount=%d)\n",
 		       pfn, page_mapcount(p));


Patches currently in stable-queue which might be from liushixin2@huawei.com are

queue-4.19/mm-memory-failure-fix-an-incorrect-use-of-tail-pages.patch