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authorRasmus Villemoes <linux@rasmusvillemoes.dk>2014-08-06 16:10:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-06 18:01:27 -0700
commit74e765319084bd2940a9612ada961f0f7385936c (patch)
tree3adcb5655903b6978283b96e3d062cd82f95b731
parent7e5f97d1927f41affa21aa5b321865ceab1994ce (diff)
lib: bitmap: add missing mask in bitmap_andnot
Apparently, bitmap_andnot 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.h2
-rw-r--r--lib/bitmap.c7
2 files changed, 6 insertions, 3 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 3399a9ecd99..e1c8d080c42 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -217,7 +217,7 @@ static inline int bitmap_andnot(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_andnot(dst, src1, src2, nbits);
}
diff --git a/lib/bitmap.c b/lib/bitmap.c
index ce2ec80bf43..1e031f2c9ab 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -223,11 +223,14 @@ int __bitmap_andnot(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_andnot);