[patch 39/60] NET: Corrects a bug in ip_rt_acct_read()

[Greg KH]

2.6.23-stable review patch.  If anyone has any objections, please let us
know.

------------------
From: Eric Dumazet <dada1@xxxxxxxxxxxxx>

[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@xxxxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 net/ipv4/route.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2913,18 +2913,14 @@ static int ip_rt_acct_read(char *buffer,
 	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];

-- 
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