From: Andi Kleen <ak@suse.de>
Date: Mon, 5 Nov 2007 22:50:56 +0000 (-0800)
Subject: Fix bitmap_scnlistprintf for empty masks
X-Git-Tag: v2.6.24-rc2~20
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0b030c2c2f0f1d98d5fe412e5b7cf7fd53f5221a;p=linux-2.6

Fix bitmap_scnlistprintf for empty masks

When a bitmap is empty bitmap_scnlistprintf() would leave the buffer
uninitialized.  Set it to an empty string in this case.

I didn't see any in normal kernel callers hitting this, but some custom
debug code of mine did.

Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 26ebafa8c4..2c9242e3fe 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -469,6 +469,10 @@ int bitmap_scnlistprintf(char *buf, unsigned int buflen,
 	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
 	int cur, rbot, rtop;
 
+	if (buflen == 0)
+		return 0;
+	buf[0] = 0;
+
 	rbot = cur = find_first_bit(maskp, nmaskbits);
 	while (cur < nmaskbits) {
 		rtop = cur;