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| author | Michael S. Tsirkin | 2018-04-14 00:35:23 +0200 |
|---|---|---|
| committer | Linus Torvalds | 2018-04-14 02:10:27 +0200 |
| commit | d081107867b85cc7454b9d4f5aea47f65bcf06d1 (patch) | |
| tree | 4cd38640b68f5b53262a2a1e354e3c6efc131103 /mm/gup.c | |
| parent | get_user_pages_fast(): return -EFAULT on access_ok failure (diff) | |
| download | kernel-qcow2-linux-d081107867b85cc7454b9d4f5aea47f65bcf06d1.tar.gz kernel-qcow2-linux-d081107867b85cc7454b9d4f5aea47f65bcf06d1.tar.xz kernel-qcow2-linux-d081107867b85cc7454b9d4f5aea47f65bcf06d1.zip | |
mm/gup.c: document return value
__get_user_pages_fast handles errors differently from
get_user_pages_fast: the former always returns the number of pages
pinned, the later might return a negative error code.
Link: http://lkml.kernel.org/r/1522962072-182137-6-git-send-email-mst@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/gup.c')
| -rw-r--r-- | mm/gup.c | 4 |
1 files changed, 3 insertions, 1 deletions
@@ -1740,7 +1740,9 @@ bool gup_fast_permitted(unsigned long start, int nr_pages, int write) /* * Like get_user_pages_fast() except it's IRQ-safe in that it won't fall back to - * the regular GUP. It will only return non-negative values. + * the regular GUP. + * Note a difference with get_user_pages_fast: this always returns the + * number of pages pinned, 0 if no pages were pinned. */ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages) |