From: Peter Zijlstra <peterz@infradead.org>
To: Tommi Rantala <tt.rantala@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>, Dave Jones <davej@redhat.com>,
trinity@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: sched_rr_get_interval NULL pointer OOPS
Date: Mon, 27 Jan 2014 11:54:13 +0100 [thread overview]
Message-ID: <20140127105413.GC11314@laptop.programming.kicks-ass.net> (raw)
In-Reply-To: <CA+ydwtpvqv7pHFiQsPX+DeRyjKVvxvS2SKxXEttdT=PQr6qqFQ@mail.gmail.com>
On Fri, Jan 24, 2014 at 10:55:56PM +0200, Tommi Rantala wrote:
> Hello,
>
> Trinity triggered the following bug in two separate qemu virtual
> machines after fuzzing v3.13-3995-g0dc3fd0 for a day or two. I have
> not been running Trinity in a while, so no idea if this is a
> regression or not.
>
> If I'm reading this right, it's oopsing in kernel/sched/core.c:
>
> SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
> struct timespec __user *, interval)
> {
> ...
> rq = task_rq_lock(p, &flags);
> time_slice = p->sched_class->get_rr_interval(rq, p); <==
> task_rq_unlock(rq, p, &flags);
> ...
---
Subject: sched: make sched_class::get_rr_interval optional
Not all classes implement (or can implement) a useful get_rr_interval()
function, default to a 0 time-slice for them.
Reported-by: Tommi Rantala <tt.rantala@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
---
Index: linux-2.6/kernel/sched/core.c
===================================================================
--- linux-2.6.orig/kernel/sched/core.c
+++ linux-2.6/kernel/sched/core.c
@@ -4324,7 +4324,9 @@ SYSCALL_DEFINE2(sched_rr_get_interval, p
goto out_unlock;
rq = task_rq_lock(p, &flags);
- time_slice = p->sched_class->get_rr_interval(rq, p);
+ time_slice = 0;
+ if (p->sched_class->get_rr_interval)
+ time_slice = p->sched_class->get_rr_interval(rq, p);
task_rq_unlock(rq, p, &flags);
rcu_read_unlock();
prev parent reply other threads:[~2014-01-27 10:54 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-24 20:55 sched_rr_get_interval NULL pointer OOPS Tommi Rantala
2014-01-24 21:00 ` Dave Jones
2014-01-27 10:54 ` Peter Zijlstra [this message]
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