[PATCH] garbage values in file /proc/net/sockstat

From: pravin shelar
Date: Mon Jan 23 2006 - 06:22:58 EST


In 2.6.16-rc1-mm1, (for x86_64 arch) cpu_possible_map is not same
as NR_CPUS (prefill_possible_map()). Therefore per cpu areas are allocated
for cpu_possible cpus only (setup_per_cpu_areas()). This causes sockstat
to return garbage value on x84_64 arch.

So these per_cpu accesses are geting relocated (RELOC_HIDE) using
boot_cpu_pda[]->data_offset which is not initialized.

There are other instances of same bug where per_cpu() macro is used
without cpu_possible() check. e.g. net/core/utils.c ::
net_random_reseed(), net/core/dev.c :: net_dev_init(), etc.

This patch fixes these bugs.

Regards,
Pravin.

---

Signed-off by: Pravin B. Shelar <pravins@xxxxxxxxxxxxxx>
Signed-off-by: Ravikiran Thirumalai <kiran@xxxxxxxxxxxx>
Signed-off-by: Shai Fultheim <shai@xxxxxxxxxxxx>

Index: linux-2.6.15.1/net/core/dev.c
===================================================================
--- linux-2.6.15.1.orig/net/core/dev.c 2006-01-23 02:31:13.000000000 -0800
+++ linux-2.6.15.1/net/core/dev.c 2006-01-23 02:32:12.000000000 -0800
@@ -3240,7 +3240,7 @@ static int __init net_dev_init(void)
* Initialise the packet receive queues.
*/

- for (i = 0; i < NR_CPUS; i++) {
+ for_each_cpu (i) {
struct softnet_data *queue;

queue = &per_cpu(softnet_data, i);
Index: linux-2.6.15.1/net/core/utils.c
===================================================================
--- linux-2.6.15.1.orig/net/core/utils.c 2006-01-23 02:31:13.000000000 -0800
+++ linux-2.6.15.1/net/core/utils.c 2006-01-23 02:32:12.000000000 -0800
@@ -133,7 +133,7 @@ static int net_random_reseed(void)
unsigned long seed[NR_CPUS];

get_random_bytes(seed, sizeof(seed));
- for (i = 0; i < NR_CPUS; i++) {
+ for_each_cpu(i) {
struct nrnd_state *state = &per_cpu(net_rand_state,i);
__net_srandom(state, seed[i]);
}
Index: linux-2.6.15.1/net/socket.c
===================================================================
--- linux-2.6.15.1.orig/net/socket.c 2006-01-23 02:31:13.000000000 -0800
+++ linux-2.6.15.1/net/socket.c 2006-01-23 02:32:12.000000000 -0800
@@ -2079,7 +2079,7 @@ void socket_seq_show(struct seq_file *se
int cpu;
int counter = 0;

- for (cpu = 0; cpu < NR_CPUS; cpu++)
+ for_each_cpu (cpu)
counter += per_cpu(sockets_in_use, cpu);

/* It can be negative, by the way. 8) */
-
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