From e0a5a6c38190a5016bcb0f1267324a19b846a35a Mon Sep 17 00:00:00 2001 From: Mingkai Hu Date: Mon, 16 Apr 2012 10:05:06 +0800 Subject: [PATCH] powerpc/mpic_msgr: add lock for MPIC message global variable Also fix issue of accessing invalid msgr pointer issue. The local msgr pointer in fucntion mpic_msgr_get will be accessed before getting a valid address which will cause kernel crash. Signed-off-by: Mingkai Hu Signed-off-by: Kumar Gala --- arch/powerpc/sysdev/mpic_msgr.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/sysdev/mpic_msgr.c b/arch/powerpc/sysdev/mpic_msgr.c index 6e7fa386e76a..dc1cfe380070 100644 --- a/arch/powerpc/sysdev/mpic_msgr.c +++ b/arch/powerpc/sysdev/mpic_msgr.c @@ -27,6 +27,7 @@ static struct mpic_msgr **mpic_msgrs; static unsigned int mpic_msgr_count; +static DEFINE_RAW_SPINLOCK(msgrs_lock); static inline void _mpic_msgr_mer_write(struct mpic_msgr *msgr, u32 value) { @@ -56,12 +57,11 @@ struct mpic_msgr *mpic_msgr_get(unsigned int reg_num) if (reg_num >= mpic_msgr_count) return ERR_PTR(-ENODEV); - raw_spin_lock_irqsave(&msgr->lock, flags); - if (mpic_msgrs[reg_num]->in_use == MSGR_FREE) { - msgr = mpic_msgrs[reg_num]; + raw_spin_lock_irqsave(&msgrs_lock, flags); + msgr = mpic_msgrs[reg_num]; + if (msgr->in_use == MSGR_FREE) msgr->in_use = MSGR_INUSE; - } - raw_spin_unlock_irqrestore(&msgr->lock, flags); + raw_spin_unlock_irqrestore(&msgrs_lock, flags); return msgr; } -- 2.34.1