When "nbits = 0", which means no bits to mask, this macro is expected to
return 0, instead of 0xffffffff. This patch changes the macro to return
0 when there is no bit needs to be masked.
Signed-off-by: Wei Wang <wei.w.w...@intel.com>
CC: Juan Quintela <quint...@redhat.com>
CC: Dr. David Alan Gilbert <dgilb...@redhat.com>
CC: Peter Xu <pet...@redhat.com>
---
include/qemu/bitmap.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
v1->v2 ChangeLog:
- fix the macro directly, instead of fixing the callers one by one.
diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h
index 509eedd..9372423 100644
--- a/include/qemu/bitmap.h
+++ b/include/qemu/bitmap.h
@@ -60,7 +60,10 @@
*/
#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
-#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
+#define BITMAP_LAST_WORD_MASK(nbits) \
+( \
+ nbits ? (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) : 0 \
+)
#define DECLARE_BITMAP(name,bits) \
unsigned long name[BITS_TO_LONGS(bits)]
--
2.7.4
