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authorRasmus Villemoes <linux@rasmusvillemoes.dk>2014-08-07 03:10:22 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-07 05:01:27 +0400
commit7e5f97d1927f41affa21aa5b321865ceab1994ce (patch)
tree671aaafdac301ef670434667f4b157cd127d8525 /lib
parentc5341ec8904ebff50f365a2626da6ab525d63b9e (diff)
downloadlinux-7e5f97d1927f41affa21aa5b321865ceab1994ce.tar.xz
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>
Diffstat (limited to 'lib')
-rw-r--r--lib/bitmap.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c
index faaf7206d4cf..ce2ec80bf431 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -185,11 +185,14 @@ 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);