From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
commit bb17d110cbf270d5247a6e261c5ad50e362d1675 upstream.
driver_set_override() helper uses device_lock() so it should not be
called before rpmsg_register_device() (which calls device_register()).
Effect can be seen with CONFIG_DEBUG_MUTEXES:
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: CPU: 3 PID: 57 at kernel/locking/mutex.c:582 __mutex_lock+0x1ec/0x430
...
Call trace:
__mutex_lock+0x1ec/0x430
mutex_lock_nested+0x44/0x50
driver_set_override+0x124/0x150
qcom_glink_native_probe+0x30c/0x3b0
glink_rpm_probe+0x274/0x350
platform_probe+0x6c/0xe0
really_probe+0x17c/0x3d0
__driver_probe_device+0x114/0x190
driver_probe_device+0x3c/0xf0
...
Refactor the rpmsg_register_device() function to use two-step device
registering (initialization + add) and call driver_set_override() in
proper moment.
This moves the code around, so while at it also NULL-ify the
rpdev->driver_override in error path to be sure it won't be kfree()
second time.
Fixes: 42cd402b8fd4 ("rpmsg: Fix kfree() of static memory on setting driver_override")
Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220429195946.1061725-2-krzysztof.kozlowski@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Lee Jones <lee@xxxxxxxxxx>
---
drivers/rpmsg/rpmsg_core.c | 33 ++++++++++++++++++++++++++++++---
drivers/rpmsg/rpmsg_internal.h | 14 +-------------
include/linux/rpmsg.h | 8 ++++++++
3 files changed, 39 insertions(+), 16 deletions(-)
diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 458ddfc09120b..9041d65bc8af6 100644
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -526,24 +526,51 @@ static struct bus_type rpmsg_bus = {
.remove = rpmsg_dev_remove,
};
-int rpmsg_register_device(struct rpmsg_device *rpdev)
+/*
+ * A helper for registering rpmsg device with driver override and name.
+ * Drivers should not be using it, but instead rpmsg_register_device().
+ */
+int rpmsg_register_device_override(struct rpmsg_device *rpdev,
+ const char *driver_override)
{
struct device *dev = &rpdev->dev;
int ret;
+ if (driver_override)
+ strcpy(rpdev->id.name, driver_override);
+
dev_set_name(&rpdev->dev, "%s.%s.%d.%d", dev_name(dev->parent),
rpdev->id.name, rpdev->src, rpdev->dst);
rpdev->dev.bus = &rpmsg_bus;
- ret = device_register(&rpdev->dev);
+ device_initialize(dev);
+ if (driver_override) {
+ ret = driver_set_override(dev, &rpdev->driver_override,
+ driver_override,
+ strlen(driver_override));
+ if (ret) {
+ dev_err(dev, "device_set_override failed: %d\n", ret);
+ return ret;
+ }
+ }
+
+ ret = device_add(dev);
if (ret) {
- dev_err(dev, "device_register failed: %d\n", ret);
+ dev_err(dev, "device_add failed: %d\n", ret);
+ kfree(rpdev->driver_override);
+ rpdev->driver_override = NULL;
put_device(&rpdev->dev);
}
return ret;
}
+EXPORT_SYMBOL(rpmsg_register_device_override);
+
+int rpmsg_register_device(struct rpmsg_device *rpdev)
+{
+ return rpmsg_register_device_override(rpdev, NULL);
+}
EXPORT_SYMBOL(rpmsg_register_device);
/*
diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
index 9165e3c811be4..f305279e2e24c 100644
--- a/drivers/rpmsg/rpmsg_internal.h
+++ b/drivers/rpmsg/rpmsg_internal.h
@@ -84,19 +84,7 @@ struct device *rpmsg_find_device(struct device *parent,
*/
static inline int rpmsg_chrdev_register_device(struct rpmsg_device *rpdev)
{
- int ret;
-
- strcpy(rpdev->id.name, "rpmsg_chrdev");
- ret = driver_set_override(&rpdev->dev, &rpdev->driver_override,
- rpdev->id.name, strlen(rpdev->id.name));
- if (ret)
- return ret;
-
- ret = rpmsg_register_device(rpdev);
- if (ret)
- kfree(rpdev->driver_override);
-
- return ret;
+ return rpmsg_register_device_override(rpdev, "rpmsg_ctrl");
}
#endif
diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
index 6e7690e20dc51..267533fecbdd9 100644
--- a/include/linux/rpmsg.h
+++ b/include/linux/rpmsg.h
@@ -115,6 +115,8 @@ struct rpmsg_driver {
#if IS_ENABLED(CONFIG_RPMSG)
+int rpmsg_register_device_override(struct rpmsg_device *rpdev,
+ const char *driver_override);
int register_rpmsg_device(struct rpmsg_device *dev);
void unregister_rpmsg_device(struct rpmsg_device *dev);
int __register_rpmsg_driver(struct rpmsg_driver *drv, struct module *owner);
@@ -139,6 +141,12 @@ __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
#else
+static inline int rpmsg_register_device_override(struct rpmsg_device *rpdev,
+ const char *driver_override)
+{
+ return -ENXIO;
+}
+
static inline int register_rpmsg_device(struct rpmsg_device *dev)
{
return -ENXIO;
--
2.42.0.820.g83a721a137-goog
