[PATCH 1/4] drivers/scsi/qla2xxx/qla_init.c: convert nested spin_lock_irqsave to spin_lock

Julia Lawall julia at diku.dk
Tue Oct 19 20:43:53 EST 2010


From: Julia Lawall <julia at diku.dk>

If spin_lock_irqsave is called twice in a row with the same second
argument, the interrupt state at the point of the second call overwrites
the value saved by the first call.  Indeed, the second call does not need
to save the interrupt state, so it is changed to a simple spin_lock.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression lock1,lock2;
expression flags;
@@

*spin_lock_irqsave(lock1,flags)
... when != flags
*spin_lock_irqsave(lock2,flags)
// </smpl>

Signed-off-by: Julia Lawall <julia at diku.dk>

---
 drivers/scsi/qla2xxx/qla_init.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index 3cafbef..c8d0b12 100644
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -1818,14 +1818,14 @@ qla2x00_init_rings(scsi_qla_host_t *vha)
 		qla2x00_init_response_q_entries(rsp);
 	}
 
-	spin_lock_irqsave(&ha->vport_slock, flags);
+	spin_lock(&ha->vport_slock);
 	/* Clear RSCN queue. */
 	list_for_each_entry(vp, &ha->vp_list, list) {
 		vp->rscn_in_ptr = 0;
 		vp->rscn_out_ptr = 0;
 	}
 
-	spin_unlock_irqrestore(&ha->vport_slock, flags);
+	spin_unlock(&ha->vport_slock);
 
 	ha->isp_ops->config_rings(vha);
 



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