tools: allocate bitmaps in units of unsigned long

Allocate enough memory so that the returned pointer can be safely
accessed as an array of unsigned long.

The actual bitmap size in units of bytes, as returned by bitmap_size,
remains unchanged.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Wei Liu <wl@xen.org>

diff --git a/tools/libs/ctrl/xc_bitops.h b/tools/libs/ctrl/xc_bitops.h
index 3d3a09772a863a8d5e4ba05ea46ec417e546010a..d6c5ea513852a6402fb0ea6d28a6ef27c904d010 100644 (file)
--- a/tools/libs/ctrl/xc_bitops.h
+++ b/tools/libs/ctrl/xc_bitops.h
@@ -21,7 +21,10 @@ static inline unsigned long bitmap_size(unsigned long nr_bits)
 
 static inline void *bitmap_alloc(unsigned long nr_bits)
 {
-    return calloc(1, bitmap_size(nr_bits));
+    unsigned long longs;
+
+    longs = (nr_bits + BITS_PER_LONG - 1) / BITS_PER_LONG;
+    return calloc(longs, sizeof(unsigned long));
 }
 
 static inline void bitmap_set(void *addr, unsigned long nr_bits)