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authorAlexander Usyskin <alexander.usyskin@intel.com>2016-11-16 22:51:28 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-11-17 16:37:49 +0100
commitc110cdb171488c60295d49fda16634cfec58ae28 (patch)
treef3edd6897111ed220fcd73358b3aa293d721f788
parentbd47b5269dbb316211fee18c706d015adbf1d696 (diff)
downloadop-kernel-dev-c110cdb171488c60295d49fda16634cfec58ae28.zip
op-kernel-dev-c110cdb171488c60295d49fda16634cfec58ae28.tar.gz
mei: bus: make a client pointer always available
Change life time of the client pointer, allocate it upon client device creation and free it upon device destruction, instead of upon connection and disconnection. This helps to eliminate racy NULL checks in the bus code. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/misc/mei/bus.c31
1 files changed, 15 insertions, 16 deletions
diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 7c075e9..483587f 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -187,9 +187,6 @@ ssize_t mei_cldev_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
{
struct mei_cl *cl = cldev->cl;
- if (cl == NULL)
- return -ENODEV;
-
return __mei_cl_send(cl, buf, length, MEI_CL_IO_TX_BLOCKING);
}
EXPORT_SYMBOL_GPL(mei_cldev_send);
@@ -207,9 +204,6 @@ ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
{
struct mei_cl *cl = cldev->cl;
- if (cl == NULL)
- return -ENODEV;
-
return __mei_cl_recv(cl, buf, length);
}
EXPORT_SYMBOL_GPL(mei_cldev_recv);
@@ -403,7 +397,7 @@ EXPORT_SYMBOL_GPL(mei_cldev_ver);
*/
bool mei_cldev_enabled(struct mei_cl_device *cldev)
{
- return cldev->cl && mei_cl_is_connected(cldev->cl);
+ return mei_cl_is_connected(cldev->cl);
}
EXPORT_SYMBOL_GPL(mei_cldev_enabled);
@@ -423,14 +417,13 @@ int mei_cldev_enable(struct mei_cl_device *cldev)
cl = cldev->cl;
- if (!cl) {
+ if (cl->state == MEI_FILE_UNINITIALIZED) {
mutex_lock(&bus->device_lock);
- cl = mei_cl_alloc_linked(bus);
+ ret = mei_cl_link(cl);
mutex_unlock(&bus->device_lock);
- if (IS_ERR(cl))
- return PTR_ERR(cl);
+ if (ret)
+ return ret;
/* update pointers */
- cldev->cl = cl;
cl->cldev = cldev;
}
@@ -471,7 +464,7 @@ int mei_cldev_disable(struct mei_cl_device *cldev)
struct mei_cl *cl;
int err;
- if (!cldev || !cldev->cl)
+ if (!cldev)
return -ENODEV;
cl = cldev->cl;
@@ -497,9 +490,6 @@ out:
mei_cl_flush_queues(cl, NULL);
mei_cl_unlink(cl);
- kfree(cl);
- cldev->cl = NULL;
-
mutex_unlock(&bus->device_lock);
return err;
}
@@ -754,6 +744,7 @@ static void mei_cl_bus_dev_release(struct device *dev)
mei_me_cl_put(cldev->me_cl);
mei_dev_bus_put(cldev->bus);
+ kfree(cldev->cl);
kfree(cldev);
}
@@ -786,17 +777,25 @@ static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
struct mei_me_client *me_cl)
{
struct mei_cl_device *cldev;
+ struct mei_cl *cl;
cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
if (!cldev)
return NULL;
+ cl = mei_cl_allocate(bus);
+ if (!cl) {
+ kfree(cldev);
+ return NULL;
+ }
+
device_initialize(&cldev->dev);
cldev->dev.parent = bus->dev;
cldev->dev.bus = &mei_cl_bus_type;
cldev->dev.type = &mei_cl_device_type;
cldev->bus = mei_dev_bus_get(bus);
cldev->me_cl = mei_me_cl_get(me_cl);
+ cldev->cl = cl;
mei_cl_bus_set_name(cldev);
cldev->is_added = 0;
INIT_LIST_HEAD(&cldev->bus_list);
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