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>
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 @@
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);