diff options
author | John Hubbard <jhubbard@nvidia.com> | 2020-06-03 15:56:40 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-03 20:09:42 -0700 |
commit | f81cd178ecfd0806c1d2859cfe0a162d80c81a69 (patch) | |
tree | 7abc36f482d48e1add0a8a9a573be4bebd167417 /mm/gup.c | |
parent | 2170ecfa768850bb29487baa3101c993ab7d7402 (diff) | |
download | linux-f81cd178ecfd0806c1d2859cfe0a162d80c81a69.tar.bz2 |
mm/gup: might_lock_read(mmap_sem) in get_user_pages_fast()
Instead of scattering these assertions across the drivers, do this
assertion inside the core of get_user_pages_fast*() functions. That also
includes pin_user_pages_fast*() routines.
Add a might_lock_read(mmap_sem) call to internal_get_user_pages_fast().
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Link: http://lkml.kernel.org/r/20200522010443.1290485-1-jhubbard@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/gup.c')
-rw-r--r-- | mm/gup.c | 3 |
1 files changed, 3 insertions, 0 deletions
@@ -2739,6 +2739,9 @@ static int internal_get_user_pages_fast(unsigned long start, int nr_pages, FOLL_FAST_ONLY))) return -EINVAL; + if (!(gup_flags & FOLL_FAST_ONLY)) + might_lock_read(¤t->mm->mmap_sem); + start = untagged_addr(start) & PAGE_MASK; addr = start; len = (unsigned long) nr_pages << PAGE_SHIFT; |