From: George Spelvin <linux@horizon.com>
Date: Wed, 26 Sep 2012 01:34:17 +0000 (+1000)
Subject: lib-vsprintf-optimize-put_dec_trunc8-fix
X-Git-Tag: next-20120927~1^2~152
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=613f59f0fd3128cd1e3ac0baa8c90198896815ca;p=karo-tx-linux.git

lib-vsprintf-optimize-put_dec_trunc8-fix

Rabin Vincent <rabin@rab.in> wrote:
> This patch breaks IP address printing with "%pI4" (and by extension,
> nfsroot).  Example:
>
>  - Before: 10.0.0.1
>  - After: 10...1

Mea culpa, and thank you for catching it!  As I said in my earlier
comment, I tested this most extensively wrapped by some sprintf code
that liked 0 converted to a 0-length string, as that works naturally
with the ANSI spec for %.0u.  And it turns out not to matter for the
usual printf code, as num_to_str special-cases that anyway.

The fix is straightforward:

Signed-off-by: George Spelvin <linux@horizon.com>
Cc: Rabin Vincent <rabin@rab.in>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index f58fc4b1eaf0..c2236f14640f 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -180,8 +180,6 @@ char *put_dec_trunc8(char *buf, unsigned r)
 		*buf++ = q - 10*r;
 	}
 
-	if (r == 0)
-		return buf;
 	q      = (r * 0x199a) >> 16;
 	*buf++ = (r - 10 * q)  + '0'; /* 6 */
 	if (q == 0)