Mar 29 2010

powerpc/vio: Add missing unlock in error path 

Author: Julia Lawall <julia@diku.dk>

Add an unlock before exiting the function.

A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// 
@r exists@
expression E1;
identifier f;
@@

f (...) { <+...
* spin_lock_irq (E1,...);
... when != E1
* return ...;
...+> }
// 

Signed-off-by: Julia Lawall 
Acked-by: Stephen Rothwell 
Signed-off-by: Benjamin Herrenschmidt 

---
 arch/powerpc/kernel/vio.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
 
diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c
index 2f57956..2a3428b 100644
--- a/arch/powerpc/kernel/vio.c
+++ b/arch/powerpc/kernel/vio.c
@@ -645,8 +645,10 @@ void vio_cmo_set_dev_desired(struct vio_dev *viodev, size_t desired)
 			found = 1;
 			break;
 		}
-	if (!found)
+	if (!found) {
+		spin_unlock_irqrestore(&vio_cmo.lock, flags);
 		return;
+	}
 
 	/* Increase/decrease in desired device entitlement */
 	if (desired >= viodev->cmo.desired) {

qlambert