[PATCH stable-5.4] mm/memory-failure: fix an incorrect use of tail pages

[Liu Shixin]

When backport commit c79c5a0a00a9 to 5.4-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: 85015a96bc24 ("mm/memory-failure: check the mapcount of the precise page")
Signed-off-by: Liu Shixin <liushixin2@xxxxxxxxxx>
---
 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 c6453f9ffd4d..0e7566c25939 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1030,7 +1030,7 @@ 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