Messages in this thread | | | Date | Fri, 2 Sep 2005 09:29:25 +0800 | From | Zhou Yingchao <> | Subject | Re: A couple of OOM killer races |
| |
On 9/2/05, Richard Hayden <rahaydenuk@yahoo.co.uk> wrote: > Hi all, > > It appears there is no protection in badness() (called by > out_of_memory() for each process) when it reads p->mm->total_vm. Another > processor (or a kernel preemption) could presumably run do_exit and then > exit_mm, freeing the process in question's reference to its mm just > after the (!p->mm) check but before it reads p->mm->total_vm, making the > latter reference a null pointer reference.
In badness, the tasklist_lock has been hold. And when an exit signal delived to it because other thread call do_group_exit, it need to hold the tasklist_lock first, so we are protected.
-- Yingchao Zhou - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |