On Mon, Oct 15, 2012 at 11:58 PM, David Rientjes <rientjes@xxxxxxxxxx> wrote: > On Mon, 15 Oct 2012, KOSAKI Motohiro wrote: > >> I don't think 80de7c3138ee9fd86a98696fd2cf7ad89b995d0a is right fix. > > It's certainly not a complete fix, but I think it's a much better result > of the race, i.e. we don't panic anymore, we simply fail the read() > instead. Even though 80de7c3138ee9fd86a98696fd2cf7ad89b995d0a itself is simple. It bring to caller complex. That's not good and have no worth. >> we should >> close a race (or kill remain ref count leak) if we still have. > > As I mentioned earlier in the thread, the read() is done here on a task > while only a reference to the task_struct is taken and we do not hold > task_lock() which is required for task->mempolicy. Once that is fixed, > mpol_to_str() should never be called for !task->mempolicy so it will never > need to return -EINVAL in such a condition. I agree that's obviously a bug and we should fix it. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>