On Sat, 2011-05-28 at 16:35 +0000, tip-bot for KOSAKI Motohiro wrote: > +++ b/kernel/kthread.c > @@ -202,8 +202,8 @@ void kthread_bind(struct task_struct *p, unsigned int cpu) > return; > } > > - p->cpus_allowed = cpumask_of_cpu(cpu); > - p->rt.nr_cpus_allowed = 1; > + /* It's safe because the task is inactive. */ > + do_set_cpus_allowed(p, cpumask_of(cpu)); > p->flags |= PF_THREAD_BOUND; > } I just happened to be staring at this stuff again, and I'm wondering how and why this is correct. After kthread_create() the thread exists and is exposed in the pid-hash, therefore userspace can come and do sys_sched_setaffinity() on it, and since we're not holding any locks and set PF_THREAD_BOUND _after_ setting cpus_allowed, things can end up funny. Hmm? -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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