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 <li...@rasmusvillemoes.dk>
---
include/linux/bitmap.h | 2 +-
lib/bitmap.c | 7 +++++--
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 3399a9e..e1c8d08 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 ce2ec80..1e031f2 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);
--
1.9.2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
