The commit is pushed to "branch-rh8-4.18.0-80.1.2.vz8.3.x-ovz" and will appear
at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-80.1.2.vz8.3.6
------>
commit 2a2c0236eabd1c7483e50b1c04828b94fc15b645
Author: Peter Xu <pet...@redhat.com>
Date: Mon Apr 20 10:34:07 2020 +0300
mm/gup: fix __get_user_pages() on fault retry of hugetlb
When follow_hugetlb_page() returns with *locked==0, it means we've got a
VM_FAULT_RETRY within the fauling process and we've released the mmap_sem.
When that happens, we should stop and bail out.
Signed-off-by: Peter Xu <pet...@redhat.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Tested-by: Brian Geffon <bgef...@google.com>
Cc: Andrea Arcangeli <aarca...@redhat.com>
Cc: Bobby Powers <bobbypow...@gmail.com>
Cc: David Hildenbrand <da...@redhat.com>
Cc: Denis Plotnikov <dplotni...@virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilb...@redhat.com>
Cc: Hugh Dickins <hu...@google.com>
Cc: Jerome Glisse <jgli...@redhat.com>
Cc: Johannes Weiner <han...@cmpxchg.org>
Cc: "Kirill A . Shutemov" <kir...@shutemov.name>
Cc: Martin Cracauer <craca...@cons.org>
Cc: Marty McFadden <mcfadd...@llnl.gov>
Cc: Matthew Wilcox <wi...@infradead.org>
Cc: Maya Gokhale <gokha...@llnl.gov>
Cc: Mel Gorman <mgor...@suse.de>
Cc: Mike Kravetz <mike.krav...@oracle.com>
Cc: Mike Rapoport <r...@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xe...@openvz.org>
Link: http://lkml.kernel.org/r/20200220155353.8676-3-pet...@redhat.com
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
https://jira.sw.ru/browse/PSBM-102938
(cherry picked from commit ad415db817964e96df824e8bb1a861527f8012b6)
Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com>
---
mm/gup.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/mm/gup.c b/mm/gup.c
index f609ac36aa9a..e06aa55b65b2 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -699,6 +699,15 @@ static long __get_user_pages(struct task_struct *tsk,
struct mm_struct *mm,
i = follow_hugetlb_page(mm, vma, pages, vmas,
&start, &nr_pages, i,
gup_flags, locked);
+ if (locked && *locked == 0) {
+ /*
+ * We've got a VM_FAULT_RETRY
+ * and we've lost mmap_sem.
+ * We must stop here.
+ */
+ BUG_ON(gup_flags & FOLL_NOWAIT);
+ goto out;
+ }
continue;
}
}
@@ -755,6 +764,7 @@ static long __get_user_pages(struct task_struct *tsk,
struct mm_struct *mm,
start += page_increm * PAGE_SIZE;
nr_pages -= page_increm;
} while (nr_pages);
+out:
return i;
}
_______________________________________________
Devel mailing list
Devel@openvz.org
https://lists.openvz.org/mailman/listinfo/devel
