[patch] pi-futex: missing pi_waiters plist initialization

From: Heiko Carstens
Date: Mon Jul 24 2006 - 07:26:24 EST

From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>

Initialize init task's pi_waiters plist. Otherwise cpu hotplug of cpu 0
might crash, since rt_mutex_getprio() accesses an uninitialized list head.

call chain which led to crash:


Using PLIST_HEAD_INIT in the INIT_TASK macro doesn't work unfortunately, since
the pi_waiters member is only conditionally present.

Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>

kernel/sched.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/kernel/sched.c b/kernel/sched.c
index b44b9a4..db1014d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6761,6 +6761,11 @@ #endif

+ plist_head_init(&init_task.pi_waiters, &init_task.pi_lock);
* The boot idle thread does lazy MMU switching as well:
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