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authorMingkai Hu <Mingkai.hu@freescale.com>2012-04-16 10:05:06 +0800
committerKumar Gala <galak@kernel.crashing.org>2012-04-19 14:55:56 -0500
commite0a5a6c38190a5016bcb0f1267324a19b846a35a (patch)
tree7b8c6f20b23303f6d6cca4d32010fab70bc73b7b
parentbdce27c7f7bc7cf5c3a264bab9de056bd9cb0c9d (diff)
downloadlinux-e0a5a6c38190a5016bcb0f1267324a19b846a35a.tar.bz2
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 <Mingkai.hu@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
-rw-r--r--arch/powerpc/sysdev/mpic_msgr.c10
1 files 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;
}