[PATCH 4.19 08/43] mm/hugetlb: fix potential missing huge page size info

From: Greg Kroah-Hartman
Date: Mon Jan 18 2021 - 06:39:00 EST


From: Miaohe Lin <linmiaohe@xxxxxxxxxx>

commit 0eb98f1588c2cc7a79816d84ab18a55d254f481c upstream.

The huge page size is encoded for VM_FAULT_HWPOISON errors only. So if
we return VM_FAULT_HWPOISON, huge page size would just be ignored.

Link: https://lkml.kernel.org/r/20210107123449.38481-1-linmiaohe@xxxxxxxxxx
Fixes: aa50d3a7aa81 ("Encode huge page size for VM_FAULT_HWPOISON errors")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
mm/hugetlb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3852,7 +3852,7 @@ retry:
* So we need to block hugepage fault by PG_hwpoison bit check.
*/
if (unlikely(PageHWPoison(page))) {
- ret = VM_FAULT_HWPOISON |
+ ret = VM_FAULT_HWPOISON_LARGE |
VM_FAULT_SET_HINDEX(hstate_index(h));
goto backout_unlocked;
}