bitmap: Fix bitmap_allocate1() bug when n_bits is a multiple of 32.

In function bitmap_allocate1(), the last "unsigned long" in bitmap was
set to all 0-bits when (n_bits % BITMAP_ULONG_BITS == 0).  This commit
correctly sets it to all 1-bits.

Signed-off-by: ZhengLingyun <konghuarukhr@163.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

diff --git a/AUTHORS b/AUTHORS
index 26e1f7f..eb9df6c 100644 (file)
--- a/AUTHORS
+++ b/AUTHORS
@@ -95,6 +95,7 @@ Vivien Bernet-Rollande  vbr@soprive.net
 Wei Yongjun             yjwei@cn.fujitsu.com
 Yasuhito Takamiya       yasuhito@gmail.com
 Yu Zhiguo               yuzg@cn.fujitsu.com
+ZhengLingyun            konghuarukhr@163.com
 Zoltan Kiss             zoltan.kiss@citrix.com
 Zhi Yong Wu             zwu.kernel@gmail.com
 Zang MingJie            zealot0630@gmail.com

diff --git a/lib/bitmap.c b/lib/bitmap.c
index d607526..ac568e9 100644 (file)
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -24,6 +24,7 @@ bitmap_allocate1(size_t n_bits)
 {
     size_t n_bytes = bitmap_n_bytes(n_bits);
     size_t n_longs = bitmap_n_longs(n_bits);
+    size_t r_bits = n_bits % BITMAP_ULONG_BITS;
     unsigned long *bitmap;
 
     /* Allocate and initialize most of the bitmap. */
@@ -32,7 +33,9 @@ bitmap_allocate1(size_t n_bits)
 
     /* Ensure that the last "unsigned long" in the bitmap only has as many
      * 1-bits as there actually should be. */
-    bitmap[n_longs - 1] = (1UL << (n_bits % BITMAP_ULONG_BITS)) - 1;
+    if (r_bits) {
+        bitmap[n_longs - 1] = (1UL << r_bits) - 1;
+    }
 
     return bitmap;
 }