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

Greg KH
2007-12-13T07:12:29Z

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

------------------
From: Eric Dumazet <dada1@cosmosbay.com>

[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>

---
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];

--