Commit 7e5f97d1 authored by Rasmus Villemoes's avatar Rasmus Villemoes Committed by Linus Torvalds
Browse files

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: default avatarRasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c5341ec8
......@@ -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);
}
......
......@@ -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);
......
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