[PATCH v2 0/3] mm/get_user_pages_fast fixes, cleanups

From: Michael S. Tsirkin
Date: Thu Apr 05 2018 - 17:03:54 EST


Turns out get_user_pages_fast and __get_user_pages_fast return different
values on error when given a single page: __get_user_pages_fast returns
0. get_user_pages_fast returns either 0 or an error.

Callers of get_user_pages_fast expect an error so fix it up to return an
error consistently.

Stress the difference between get_user_pages_fast and __get_user_pages_fast
to make sure callers aren't confused.

Changes from v1:
limit code changes to get_user_pages_fast.
document __get_user_pages_fast
fix a bug in caller

Michael S. Tsirkin (3):
mm/gup_benchmark: handle gup failures
gup: return -EFAULT on access_ok failure
mm/gup: document return value

arch/mips/mm/gup.c | 2 ++
arch/s390/mm/gup.c | 2 ++
arch/sh/mm/gup.c | 2 ++
arch/sparc/mm/gup.c | 4 ++++
mm/gup.c | 9 +++++++--
mm/gup_benchmark.c | 5 +++--
mm/util.c | 6 ++++--
7 files changed, 24 insertions(+), 6 deletions(-)

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MST