arch/x86/kernel: Add missing spin_unlock

commit 84fe6c19e4a598e8071e3bd1b2c923454eae1268 upstream.

Add a spin_unlock missing on the error path.  The locks and unlocks are
balanced in other functions, so it seems that the same should be the case
here.

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

// <smpl>
@@
expression E1;
@@

* spin_lock(E1,...);
  <+... when != E1
  if (...) {
    ... when != E1
*   return ...;
  }
  ...+>
* spin_unlock(E1,...);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index b9ce0fdf2cb54e51fa876f456bf7b7270443e7f5..29e5e6ea0bfb70b5a886c44771ee58ff68ace0ba 100644 (file)
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -1420,6 +1420,7 @@ static int __attach_device(struct device *dev,
                           struct protection_domain *domain)
 {
        struct iommu_dev_data *dev_data, *alias_data;
+       int ret;
 
        dev_data   = get_dev_data(dev);
        alias_data = get_dev_data(dev_data->alias);
@@ -1431,13 +1432,14 @@ static int __attach_device(struct device *dev,
        spin_lock(&domain->lock);
 
        /* Some sanity checks */
+       ret = -EBUSY;
        if (alias_data->domain != NULL &&
            alias_data->domain != domain)
-               return -EBUSY;
+               goto out_unlock;
 
        if (dev_data->domain != NULL &&
            dev_data->domain != domain)
-               return -EBUSY;
+               goto out_unlock;
 
        /* Do real assignment */
        if (dev_data->alias != dev) {
@@ -1453,10 +1455,14 @@ static int __attach_device(struct device *dev,
 
        atomic_inc(&dev_data->bind);
 
+       ret = 0;
+
+out_unlock:
+
        /* ready */
        spin_unlock(&domain->lock);
 
-       return 0;
+       return ret;
 }
 
 /*