[PATCH v2] ARM: MM: bugfix: initialize spinlock for init_mm.context
MyungJoo Ham
myungjoo.ham at samsung.com
Mon Sep 27 21:06:30 EDT 2010
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>
--
changes
v2: fixed incorrect initializer parameter (list_lock -> id_lock)
---
arch/arm/include/asm/mmu.h | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/arch/arm/include/asm/mmu.h b/arch/arm/include/asm/mmu.h
index 68870c7..c18540b 100644
--- a/arch/arm/include/asm/mmu.h
+++ b/arch/arm/include/asm/mmu.h
@@ -13,6 +13,10 @@ typedef struct {
#ifdef CONFIG_CPU_HAS_ASID
#define ASID(mm) ((mm)->context.id & 255)
+
+/* init_mm.context.id_lock should be initialized. */
+#define INIT_MM_CONTEXT(name) \
+ .context.id_lock = __SPIN_LOCK_UNLOCKED(name.context.id_lock),
#else
#define ASID(mm) (0)
#endif
--
1.6.3.3
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