From 66e5393a78b3fcca63e7748e38221dcca61c4aab Mon Sep 17 00:00:00 2001
From: Steven Rostedt <rostedt@goodmis.org>
Date: Tue, 27 Jun 2006 02:54:44 -0700
Subject: [PATCH] [PATCH] BUG() if setscheduler is called from interrupt
 context

Thomas Gleixner is adding the call to a rtmutex function in setscheduler.
This call grabs a spin_lock that is not always protected by interrupts
disabled.  So this means that setscheduler cant be called from interrupt
context.

To prevent this from happening in the future, this patch adds a
BUG_ON(in_interrupt()) in that function.  (Thanks to akpm <aka.  Andrew
Morton> for this suggestion).

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 kernel/sched.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/sched.c b/kernel/sched.c
index 19c0d5d16fef1..15abf08332454 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3862,6 +3862,8 @@ int sched_setscheduler(struct task_struct *p, int policy,
 	unsigned long flags;
 	runqueue_t *rq;
 
+	/* may grab non-irq protected spin_locks */
+	BUG_ON(in_interrupt());
 recheck:
 	/* double check policy once rq lock held */
 	if (policy < 0)
-- 
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