[PATCH 2/4] powerpc/mpic_msgr: add lock for MPIC message global variable
From: Mingkai Hu <hidden>
Date: 2012-04-16 02:20:04
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
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 <redacted> --- arch/powerpc/sysdev/mpic_msgr.c | 10 +++++----- 1 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/sysdev/mpic_msgr.c b/arch/powerpc/sysdev/mpic_msgr.c
index 6e7fa38..dc1cfe3 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; }
--
1.7.5.1