On Tue, 2010-06-29 at 07:58 +0300, Artem Bityutskiy wrote: > On Wed, 2010-06-23 at 21:41 +0200, Oleg Nesterov wrote: > > On 06/23, Kees Cook wrote: > > > > > > @@ -956,7 +957,15 @@ void set_task_comm(struct task_struct *tsk, char *buf) > > > */ > > > memset(tsk->comm, 0, TASK_COMM_LEN); > > > wmb(); > > > > Off-topic. I'd wish I could understand this barrier. Since the lockless > > reader doesn't do rmb() I don't see how this can help. > > This wmb() looks wrong to me as well. To achieve what the comment in > this function says, it should be smp_wmb() and we should have smp_rmb() > in the reading side, AFAIU. > > > OTOH, I don't > > understand why it is needed, we never change ->comm[TASK_COMM_LEN-1] == '0'. > > I think the idea was that readers can see incomplete names, but not > messed up names, consisting of old and new ones. Yes, that was the intent, but I do see how it is unnecessary. So I'm fine with it and the memset being removed. Thanks for catching this! -john -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
