Re: [PATCH] oom: fix the unsafe proc_oom_score()->badness() call

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, 30 Mar 2010, Oleg Nesterov wrote:

> proc_oom_score(task) have a reference to task_struct, but that is all.
> If this task was already released before we take tasklist_lock
> 
> 	- we can't use task->group_leader, it points to nowhere
> 
> 	- it is not safe to call badness() even if this task is
> 	  ->group_leader, has_intersects_mems_allowed() assumes
> 	  it is safe to iterate over ->thread_group list.
> 
> Add the pid_alive() check to ensure __unhash_process() was not called.
> 
> Note: I think we shouldn't use ->group_leader, badness() should return
> the same result for any sub-thread. However this is not true currently,
> and I think that ->mm check and list_for_each_entry(p->children) in
> badness are not right.
> 

I think it would be better to just use task and not task->group_leader.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>

[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux]     [Linux OMAP]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]