[QUEUED v20160420 07/19] stm class: Fix stm device initialization order

From: Alexander Shishkin
Date: Wed Apr 20 2016 - 06:46:26 EST


Currently, stm_register_device() makes the device visible and then
proceeds to initializing spinlocks and other properties, which leaves
a window when the device can already be opened but is not yet fully
operational.

Fix this by reversing the initialization order.

Reported-by: Alan Cox <alan.cox@xxxxxxxxx>
Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Reviewed-by: Laurent Fert <laurent.fert@xxxxxxxxx>
---
drivers/hwtracing/stm/core.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index e55ed67142..2591442e2c 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -666,18 +666,11 @@ int stm_register_device(struct device *parent, struct stm_data *stm_data,
stm->dev.parent = parent;
stm->dev.release = stm_device_release;

- err = kobject_set_name(&stm->dev.kobj, "%s", stm_data->name);
- if (err)
- goto err_device;
-
- err = device_add(&stm->dev);
- if (err)
- goto err_device;
-
mutex_init(&stm->link_mutex);
spin_lock_init(&stm->link_lock);
INIT_LIST_HEAD(&stm->link_list);

+ /* initialize the object before it is accessible via sysfs */
spin_lock_init(&stm->mc_lock);
mutex_init(&stm->policy_mutex);
stm->sw_nmasters = nmasters;
@@ -685,6 +678,14 @@ int stm_register_device(struct device *parent, struct stm_data *stm_data,
stm->data = stm_data;
stm_data->stm = stm;

+ err = kobject_set_name(&stm->dev.kobj, "%s", stm_data->name);
+ if (err)
+ goto err_device;
+
+ err = device_add(&stm->dev);
+ if (err)
+ goto err_device;
+
return 0;

err_device:
--
2.8.0.rc3