[PATCH v2] ARM: MM: bugfix: initialize spinlock for init_mm.context

[Catalin Marinas]

On Tue, 2010-09-28 at 02:06 +0100, MyungJoo Ham wrote:
> init_mm used at kernel/sched.c:idle_task_exit() has spin_lock
> (init_mm.context.id_lock) that is not initialized when spin_lock/unlock
> is called at an ARM machine. Note that mm_struct.context.id_lock is usually
> initialized except for the instance of init_mm at linux/arch/arm/mm/context.c
> 
> Not initializing this spinlock incurs "BUG: pinlock bad magic" warning when
> spinlock debug is enabled. We have observed such instances when testing PM in
> S5PC210 machines.
> 
> 
> Signed-off-by: MyungJoo Ham <myungjoo.ham at samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>

Acked-by: Catalin Marinas <catalin.marinas at arm.com>