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authorDenis V. Lunev <den@openvz.org>2008-05-20 15:12:44 -0700
committerDavid S. Miller <davem@davemloft.net>2008-05-20 15:12:44 -0700
commitd3ede327e83f202c3a0962e207318f65717c5eb7 (patch)
tree2875979c06b127edc325bf77518837c28477ebd5
parent5fb13570543f4ae022996c9d7c0c099c8abf22dd (diff)
pktgen: make sure that pktgen_thread_worker has been executed
The following courruption can happen during pktgen stop: list_del corruption. prev->next should be ffff81007e8a5e70, but was 6b6b6b6b6b6b6b6b kernel BUG at lib/list_debug.c:67! :pktgen:pktgen_thread_worker+0x374/0x10b0 ? autoremove_wake_function+0x0/0x40 ? _spin_unlock_irqrestore+0x42/0x80 ? :pktgen:pktgen_thread_worker+0x0/0x10b0 kthread+0x4d/0x80 child_rip+0xa/0x12 ? restore_args+0x0/0x30 ? kthread+0x0/0x80 ? child_rip+0x0/0x12 RIP list_del+0x48/0x70 The problem is that pktgen_thread_worker can not be executed if kthread_stop has been called too early. Insert a completion on the normal initialization path to make sure that pktgen_thread_worker will gain the control for sure. Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: Alexey Dobriyan <adobriyan@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/core/pktgen.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 8dca2111049..fdf537707e5 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -390,6 +390,7 @@ struct pktgen_thread {
int cpu;
wait_queue_head_t queue;
+ struct completion start_done;
};
#define REMOVE 1
@@ -3414,6 +3415,7 @@ static int pktgen_thread_worker(void *arg)
BUG_ON(smp_processor_id() != cpu);
init_waitqueue_head(&t->queue);
+ complete(&t->start_done);
pr_debug("pktgen: starting pktgen/%d: pid=%d\n", cpu, task_pid_nr(current));
@@ -3615,6 +3617,7 @@ static int __init pktgen_create_thread(int cpu)
INIT_LIST_HEAD(&t->if_list);
list_add_tail(&t->th_list, &pktgen_threads);
+ init_completion(&t->start_done);
p = kthread_create(pktgen_thread_worker, t, "kpktgend_%d", cpu);
if (IS_ERR(p)) {
@@ -3639,6 +3642,7 @@ static int __init pktgen_create_thread(int cpu)
}
wake_up_process(p);
+ wait_for_completion(&t->start_done);
return 0;
}