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author | Andrea Arcangeli <aarcange@redhat.com> | 2017-03-10 01:16:28 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-03-10 02:01:09 +0100 |
commit | 6bbc4a4144b1a69743022ac68dfaf6e7d993abb9 (patch) | |
tree | 6a9eaa82d3bb88a8de32ee18320559491fea8780 /firmware/ttusb-budget | |
parent | Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/ke... (diff) | |
download | linux-6bbc4a4144b1a69743022ac68dfaf6e7d993abb9.tar.xz linux-6bbc4a4144b1a69743022ac68dfaf6e7d993abb9.zip |
userfaultfd: shmem: __do_fault requires VM_FAULT_NOPAGE
__do_fault assumes vmf->page has been initialized and is valid if
VM_FAULT_NOPAGE is not returned by vma->vm_ops->fault(vma, vmf).
handle_userfault() in turn should return VM_FAULT_NOPAGE if it doesn't
return VM_FAULT_SIGBUS or VM_FAULT_RETRY (the other two possibilities).
This VM_FAULT_NOPAGE case is only invoked when signal are pending and it
didn't matter for anonymous memory before. It only started to matter
since shmem was introduced. hugetlbfs also takes a different path and
doesn't exercise __do_fault.
Link: http://lkml.kernel.org/r/20170228154201.GH5816@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'firmware/ttusb-budget')
0 files changed, 0 insertions, 0 deletions