4.4-stable review patch. If anyone has any objections, please let me know.
------------------
[ Upstream commit 389b6699a2aa0b457aa69986e9ddf39f3b4030fd ]
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....@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shish...@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.f...@intel.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
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 0c7f0bae001a..b6cc841de79d 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -664,18 +664,11 @@ 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;
@@ -683,6 +676,14 @@ 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:
--
2.19.1
