[ 18/61] SCSI: mpt2sas: Fix unsafe using smp_processor_id() in preemptible

From: Greg KH
Date: Wed Jun 20 2012 - 14:39:45 EST


3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: "nagalakshmi.nandigama@xxxxxxx" <nagalakshmi.nandigama@xxxxxxx>

commit a2c658505bf5c75516ee0a79287223e86a2474af upstream.

When CONFIG_DEBUG_PREEMPT is enabled, bug is observed in the smp_processor_id().
This is because smp_processor_id() is not called in preempt safe condition.

To fix this issue, use raw_smp_processor_id instead of smp_processor_id.

Signed-off-by: Nagalakshmi Nandigama <nagalakshmi.nandigama@xxxxxxx>
Signed-off-by: James Bottomley <JBottomley@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/scsi/mpt2sas/mpt2sas_base.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -1785,7 +1785,7 @@ static inline void _base_writeq(__u64 b,
static inline u8
_base_get_msix_index(struct MPT2SAS_ADAPTER *ioc)
{
- return ioc->cpu_msix_table[smp_processor_id()];
+ return ioc->cpu_msix_table[raw_smp_processor_id()];
}

/**


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