tree 14da37d4c3debe116e378f3de20099babf0de1c3
parent e9ef073a0796e46c24f037237291efe56fc28ad9
author Matthias Kaehlcke <mka@chromium.org> 1504912473 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1504920408 -0700

bitops: avoid integer overflow in GENMASK(_ULL)

GENMASK(_ULL) performs a left-shift of ~0UL(L), which technically
results in an integer overflow.  clang raises a warning if the overflow
occurs in a preprocessor expression.  Clear the low-order bits through a
substraction instead of the left-shift to avoid the overflow.

(akpm: no change in .text size in my testing)

Link: http://lkml.kernel.org/r/20170803212020.24939-1-mka@chromium.org
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>