sched: fix crash in sys_sched_rr_get_interval() (77034937) · Commits · 戴 / test

Luiz Fernando N. Capitulino reported that sched_rr_get_interval() crashes for SCHED_OTHER tasks that are on an idle runqueue. The fix is to return a 0 timeslice for tasks that are on an idle runqueue. (and which are not running, obviously) this also shrinks the code a bit: text data bss dec hex filename 47903 3934 336 52173 cbcd sched.o.before 47885 3934 336 52155 cbbb sched.o.after Reported-by:

Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br> Signed-off-by:

Ingo Molnar <mingo@elte.hu>

kernel/sched.c

+9 −5

Original line number	Diff line number	Diff line
		@@ -4850,17 +4850,21 @@ long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval)
		if (retval)
		goto out_unlock;

		if (p->policy == SCHED_FIFO)
		/*
		* Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER
		* tasks that are on an otherwise idle runqueue:
		*/
		time_slice = 0;
		else if (p->policy == SCHED_RR)
		if (p->policy == SCHED_RR) {
		time_slice = DEF_TIMESLICE;
		else {
		} else {
		struct sched_entity *se = &p->se;
		unsigned long flags;
		struct rq *rq;

		rq = task_rq_lock(p, &flags);
		time_slice = NS_TO_JIFFIES(sched_slice(cfs_rq_of(se), se));
		if (rq->cfs.load.weight)
		time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
		task_rq_unlock(rq, &flags);
		}
		read_unlock(&tasklist_lock);

Admin message