From: Eric Dumazet <dada1@cosmosbay.com>
Date: Thu, 29 Nov 2007 12:07:57 +0000 (+1100)
Subject: NET: Corrects a bug in ip_rt_acct_read()
X-Git-Tag: v2.6.23.10~22
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c2f1eef5597779c7111747f51aa9d76945a8cee0;p=thirdparty%2Fkernel%2Fstable.git

NET: Corrects a bug in ip_rt_acct_read()

[NET]: Corrects a bug in ip_rt_acct_read()

[ Upstream commit: 483b23ffa3a5f44767038b0a676d757e0668437e ]

It seems that stats of cpu 0 are counted twice, since
for_each_possible_cpu() is looping on all possible cpus, including 0

Before percpu conversion of ip_rt_acct, we should also remove the
assumption that CPU 0 is online (or even possible)

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index c7ca94bd152cc..198b7322d16a0 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2913,18 +2913,14 @@ static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
 	offset /= sizeof(u32);
 
 	if (length > 0) {
-		u32 *src = ((u32 *) IP_RT_ACCT_CPU(0)) + offset;
 		u32 *dst = (u32 *) buffer;
 
-		/* Copy first cpu. */
 		*start = buffer;
-		memcpy(dst, src, length);
+		memset(dst, 0, length);
 
-		/* Add the other cpus in, one int at a time */
 		for_each_possible_cpu(i) {
 			unsigned int j;
-
-			src = ((u32 *) IP_RT_ACCT_CPU(i)) + offset;
+			u32 *src = ((u32 *) IP_RT_ACCT_CPU(i)) + offset;
 
 			for (j = 0; j < length/4; j++)
 				dst[j] += src[j];