userfaultfd: hugetlbfs: fix userfaultfd_huge_must_wait() pte access
authorJanosch Frank <frankja@linux.ibm.com>
Wed, 4 Jul 2018 00:02:39 +0000 (17:02 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 4 Jul 2018 00:32:18 +0000 (17:32 -0700)
commit1e2c043628c7736dd56536d16c0ce009bc834ae7
treee511865feee12b1d6ba326588fb7aa36ada14951
parent410da1e12ffed61129d61df5b7adce4d08c7f17c
userfaultfd: hugetlbfs: fix userfaultfd_huge_must_wait() pte access

Use huge_ptep_get() to translate huge ptes to normal ptes so we can
check them with the huge_pte_* functions.  Otherwise some architectures
will check the wrong values and will not wait for userspace to bring in
the memory.

Link: http://lkml.kernel.org/r/20180626132421.78084-1-frankja@linux.ibm.com
Fixes: 369cd2121be4 ("userfaultfd: hugetlbfs: userfaultfd_huge_must_wait for hugepmd ranges")
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/userfaultfd.c