On 2012-04-12 18:16:56 (+0800), harryxiyou <harryxiyou@xxxxxxxxx> wrote:
> Hi greg,
>
> I write a module for inserting a PCB or delete a PCB to kernel's
> PCB tree, but when i run it something wrong happens to me like following.
> My environment is "Linux 10 2.6.35-22-generic #33-Ubuntu SMP Sun Sep
> 19 20:34:50 UTC 2010 i686 GNU/Linux"
>
>
> printk("Search for insert task-------->\n");
> task = &init_task;
> list_for_each(pos, &task->tasks) {
> p = list_entry(pos, struct task_struct, tasks);
> count++;
> if (0 == p->pid) {
> rm_task(p);
> }
> printk("pid: %d, state: %ld, comm: %s\n", p->pid, p->state, p->comm);
> }
>
You're iterating over the tasks list without locking it.
What do you think happens if someone else comes along and modifies it
while you're reading it?
Try to take the tasklist_lock.
Regards,
Kristof
_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@xxxxxxxxxxxxxxxxx
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
