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>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 75df61d9ecfb..3399a9ecd991 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -191,7 +191,7 @@ 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);
 }