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author | 2020-04-01 21:08:02 -0700 | |
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committer | 2020-04-02 09:35:29 -0700 | |
commit | ad415db817964e96df824e8bb1a861527f8012b6 (patch) | |
tree | 5abd261ea2673311680dccb73bfd6da3d17746b5 | |
parent | mm/gup: rename "nonblocking" to "locked" where proper (diff) | |
download | linux-ad415db817964e96df824e8bb1a861527f8012b6.tar.gz linux-ad415db817964e96df824e8bb1a861527f8012b6.tar.bz2 linux-ad415db817964e96df824e8bb1a861527f8012b6.zip |
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 <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Brian Geffon <bgeffon@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Link: http://lkml.kernel.org/r/20200220155353.8676-3-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | mm/gup.c | 10 |
1 files changed, 10 insertions, 0 deletions
@@ -1065,6 +1065,16 @@ 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); + BUG_ON(ret != 0); + goto out; + } continue; } } |