diff options
| author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2014-08-06 16:10:22 -0700 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-04-11 10:59:32 +0200 |
| commit | 3056cb60d5b703ab78a66afe32fc571508952e23 (patch) | |
| tree | f5f1c923bf0a57a2eb6508091ee61d11babfbde0 | |
| parent | f28752989c4d7a076a2414cd6eaab8083fd1ea10 (diff) | |
lib: bitmap: add missing mask in bitmap_and
Apparently, bitmap_and is supposed to return whether the new bitmap is
empty. But it didn't take potential garbage bits in the last word into
account.
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>
| -rw-r--r-- | include/linux/bitmap.h | 2 | ||||
| -rw-r--r-- | lib/bitmap.c | 7 |
2 files changed, 6 insertions, 3 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 0d128516e..45dc7aa45 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -205,7 +205,7 @@ static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, const unsigned long *src2, unsigned int nbits) { if (small_const_nbits(nbits)) - return (*dst = *src1 & *src2) != 0; + return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0; return __bitmap_and(dst, src1, src2, nbits); } diff --git a/lib/bitmap.c b/lib/bitmap.c index 5516a9004..5b08bae39 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -189,11 +189,14 @@ int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits) { unsigned int k; - unsigned int nr = BITS_TO_LONGS(bits); + unsigned int lim = bits/BITS_PER_LONG; unsigned long result = 0; - for (k = 0; k < nr; k++) + for (k = 0; k < lim; k++) result |= (dst[k] = bitmap1[k] & bitmap2[k]); + if (bits % BITS_PER_LONG) + result |= (dst[k] = bitmap1[k] & bitmap2[k] & + BITMAP_LAST_WORD_MASK(bits)); return result != 0; } EXPORT_SYMBOL(__bitmap_and); |