From bb17d110cbf270d5247a6e261c5ad50e362d1675 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Fri, 29 Apr 2022 21:59:45 +0200 Subject: [PATCH] rpmsg: Fix calling device_lock() on non-initialized device 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 Signed-off-by: Krzysztof Kozlowski Tested-by: Marek Szyprowski Link: https://lore.kernel.org/r/20220429195946.1061725-2-krzysztof.kozlowski@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/rpmsg/rpmsg_core.c | 33 ++++++++++++++++++++++++++++++--- drivers/rpmsg/rpmsg_internal.h | 14 +------------- drivers/rpmsg/rpmsg_ns.c | 14 +------------- include/linux/rpmsg.h | 8 ++++++++ 4 files changed, 40 insertions(+), 29 deletions(-) diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c index 95fc283f6af7..4938fc4eff00 100644 --- a/drivers/rpmsg/rpmsg_core.c +++ b/drivers/rpmsg/rpmsg_core.c @@ -593,24 +593,51 @@ 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 3e81642238d2..a22cd4abe7d1 100644 --- a/drivers/rpmsg/rpmsg_internal.h +++ b/drivers/rpmsg/rpmsg_internal.h @@ -94,19 +94,7 @@ int rpmsg_release_channel(struct rpmsg_device *rpdev, */ static inline int rpmsg_ctrldev_register_device(struct rpmsg_device *rpdev) { - int ret; - - strcpy(rpdev->id.name, "rpmsg_ctrl"); - 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/drivers/rpmsg/rpmsg_ns.c b/drivers/rpmsg/rpmsg_ns.c index 8eb8f328237e..c70ad03ff2e9 100644 --- a/drivers/rpmsg/rpmsg_ns.c +++ b/drivers/rpmsg/rpmsg_ns.c @@ -20,22 +20,10 @@ */ int rpmsg_ns_register_device(struct rpmsg_device *rpdev) { - int ret; - - strcpy(rpdev->id.name, "rpmsg_ns"); - ret = driver_set_override(&rpdev->dev, &rpdev->driver_override, - rpdev->id.name, strlen(rpdev->id.name)); - if (ret) - return ret; - rpdev->src = RPMSG_NS_ADDR; rpdev->dst = RPMSG_NS_ADDR; - ret = rpmsg_register_device(rpdev); - if (ret) - kfree(rpdev->driver_override); - - return ret; + return rpmsg_register_device_override(rpdev, "rpmsg_ns"); } EXPORT_SYMBOL(rpmsg_ns_register_device); diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h index 20c8cd1cde21..523c98b96cb4 100644 --- a/include/linux/rpmsg.h +++ b/include/linux/rpmsg.h @@ -165,6 +165,8 @@ static inline __rpmsg64 cpu_to_rpmsg64(struct rpmsg_device *rpdev, u64 val) #if IS_ENABLED(CONFIG_RPMSG) +int rpmsg_register_device_override(struct rpmsg_device *rpdev, + const char *driver_override); int rpmsg_register_device(struct rpmsg_device *rpdev); int rpmsg_unregister_device(struct device *parent, struct rpmsg_channel_info *chinfo); @@ -192,6 +194,12 @@ ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept); #else +static inline int rpmsg_register_device_override(struct rpmsg_device *rpdev, + const char *driver_override) +{ + return -ENXIO; +} + static inline int rpmsg_register_device(struct rpmsg_device *rpdev) { return -ENXIO;