diff options
| author | Andrea Arcangeli <aarcange@redhat.com> | 2019-02-01 14:20:16 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-06 17:30:14 +0100 |
| commit | 15033ca6bd1379883ebd7533ba8feff4563c7f03 (patch) | |
| tree | ea9ca52e2f22b66996bd54f93e308144341fc32a /mm/hugetlb.c | |
| parent | c7122344f9150289d053041081a07ce07de2a64f (diff) | |
mm/hugetlb.c: teach follow_hugetlb_page() to handle FOLL_NOWAIT
commit 1ac25013fb9e4ed595cd608a406191e93520881e upstream.
hugetlb needs the same fix as faultin_nopage (which was applied in
commit 96312e61282a ("mm/gup.c: teach get_user_pages_unlocked to handle
FOLL_NOWAIT")) or KVM hangs because it thinks the mmap_sem was already
released by hugetlb_fault() if it returned VM_FAULT_RETRY, but it wasn't
in the FOLL_NOWAIT case.
Link: http://lkml.kernel.org/r/20190109020203.26669-2-aarcange@redhat.com
Fixes: ce53053ce378 ("kvm: switch get_user_page_nowait() to get_user_pages_unlocked()")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Tested-by: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Reported-by: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 309fb8c969af..10e83672bfbe 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4269,7 +4269,8 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, break; } if (ret & VM_FAULT_RETRY) { - if (nonblocking) + if (nonblocking && + !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) *nonblocking = 0; *nr_pages = 0; /* |