diff --git a/lib/bitmap.c b/lib/bitmap.c
index 75006c4036e9..162e2850c622 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -487,24 +487,24 @@ EXPORT_SYMBOL(bitmap_print_to_pagebuf);
 
 /*
  * Region 9-38:4/10 describes the following bitmap structure:
- * 0	   9  12    18			38
- * .........****......****......****......
- *	    ^  ^     ^			 ^
- *      start  off   group_len	       end
+ * 0	   9  12    18			38	     N
+ * .........****......****......****..................
+ *	    ^  ^     ^			 ^	     ^
+ *      start  off   group_len	       end	 nbits
  */
 struct region {
 	unsigned int start;
 	unsigned int off;
 	unsigned int group_len;
 	unsigned int end;
+	unsigned int nbits;
 };
 
-static int bitmap_set_region(const struct region *r,
-				unsigned long *bitmap, int nbits)
+static int bitmap_set_region(const struct region *r, unsigned long *bitmap)
 {
 	unsigned int start;
 
-	if (r->end >= nbits)
+	if (r->end >= r->nbits)
 		return -ERANGE;
 
 	for (start = r->start; start <= r->end; start += r->group_len)
@@ -640,7 +640,8 @@ int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
 	struct region r;
 	long ret;
 
-	bitmap_zero(maskp, nmaskbits);
+	r.nbits = nmaskbits;
+	bitmap_zero(maskp, r.nbits);
 
 	while (buf) {
 		buf = bitmap_find_region(buf);
@@ -655,7 +656,7 @@ int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
 		if (ret)
 			return ret;
 
-		ret = bitmap_set_region(&r, maskp, nmaskbits);
+		ret = bitmap_set_region(&r, maskp);
 		if (ret)
 			return ret;
 	}