author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> 2017-03-09 17:24:07 +0300
committer: Linus Torvalds <torvalds@linux-foundation.org> 2017-03-09 11:48:47 -0800
commit: c2febafc67734a62196c1b9dfba926412d4077ba
parent: 048456dcf2c56ad6f6248e2899dda92fb6a613f6
Commit Summary:
Diffstat:
1 file changed, 5 insertions, 1 deletion
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 973607df579d..02ce3944d0f5 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -267,6 +267,7 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
{
struct mm_struct *mm = ctx->mm;
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd, _pmd;
pte_t *pte;
@@ -277,7 +278,10 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
pgd = pgd_offset(mm, address);
if (!pgd_present(*pgd))
goto out;
- pud = pud_offset(pgd, address);
+ p4d = p4d_offset(pgd, address);
+ if (!p4d_present(*p4d))
+ goto out;
+ pud = pud_offset(p4d, address);
if (!pud_present(*pud))
goto out;
pmd = pmd_offset(pud, address);