iommu/omap: Fix error return paths in omap_iommu_attach()

There are couple of issues with the error return paths in
omap_iommu_attach():
1. omap_iommu_attach() returns NULL or ERR_PTR in case of error,
   but omap_iommu_attach_dev() only checks for IS_ERR. Thus a NULL
   return value (in case driver_find_device fails) will cause the
   kernel to panic when omap_iommu_attach_dev() dereferences the
   pointer.
2. A try_module_get() failure returns a valid success value as
   returned from iommu_enable().

Both the above issues have been fixed up to return the proper
ERR_PTR.

Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index fff2ffdc26f47a1ec9b31194a43437b1d869485f..647e4ba0df95698f671a355dd1d69e453b43be7f 100644 (file)
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -863,7 +863,7 @@ static int device_match_by_alias(struct device *dev, void *data)
  **/
 static struct omap_iommu *omap_iommu_attach(const char *name, u32 *iopgd)
 {
-       int err = -ENOMEM;
+       int err;
        struct device *dev;
        struct omap_iommu *obj;
 
@@ -871,7 +871,7 @@ static struct omap_iommu *omap_iommu_attach(const char *name, u32 *iopgd)
                                (void *)name,
                                device_match_by_alias);
        if (!dev)
-               return NULL;
+               return ERR_PTR(-ENODEV);
 
        obj = to_iommu(dev);
 
@@ -890,8 +890,10 @@ static struct omap_iommu *omap_iommu_attach(const char *name, u32 *iopgd)
                goto err_enable;
        flush_iotlb_all(obj);
 
-       if (!try_module_get(obj->owner))
+       if (!try_module_get(obj->owner)) {
+               err = -ENODEV;
                goto err_module;
+       }
 
        spin_unlock(&obj->iommu_lock);