lib: bitmap: add missing mask in bitmap_shift_right

There is no guarantee that *src does not contain garbage bits outside
the lower nbits, so we need to mask it before the shift-and-assign.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Rasmus Villemoes 2014-08-06 16:10:20 -07:00 committed by Linus Torvalds
parent 2ac521d332
commit c5341ec890

View File

@ -284,7 +284,7 @@ static inline void bitmap_shift_right(unsigned long *dst,
const unsigned long *src, int n, int nbits)
{
if (small_const_nbits(nbits))
*dst = *src >> n;
*dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> n;
else
__bitmap_shift_right(dst, src, n, nbits);
}