RE: [PATCH v6 12/12] rpmsg: Fix kfree() of static memory on setting driver_override

Hi Krzysztof Kozlowski,

Thanks for the patch.

Subject: [PATCH v6 12/12] rpmsg: Fix kfree() of static memory on setting driver_override

The driver_override field from platform driver should not be initialized from static memory (string literal) because the core later kfree() it, for example when driver_override is set via sysfs.

Use dedicated helper to set driver_override properly.

Fixes: 950a7388f02b ("rpmsg: Turn name service into a stand alone driver") Fixes: c0cdc19f84a4 ("rpmsg: Driver for user space endpoint interface") Signed-off-by: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org

---

drivers/rpmsg/rpmsg_internal.h | 13 +++++++++++-- drivers/rpmsg/rpmsg_ns.c | 14 ++++++++++++-- include/linux/rpmsg.h | 6 ++++-- 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h index d4b23fd019a8..1a2fb8edf5d3 100644 --- a/drivers/rpmsg/rpmsg_internal.h +++ b/drivers/rpmsg/rpmsg_internal.h @@ -94,10 +94,19 @@ 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");

• rpdev->driver_override = "rpmsg_ctrl";

• ret = driver_set_override(&rpdev->dev, &rpdev->driver_override,

• 		  "rpmsg_ctrl", strlen("rpmsg_ctrl"));
  

Is it not possible to use rpdev->id.name instead of "rpmsg_ctrl" ? rpdev->id.name has "rpmsg_ctrl" from strcpy(rpdev->id.name, "rpmsg_ctrl");

Same for "rpmsg_ns" as well

Cheers, Biju

• if (ret)

• return ret;
  

• ret = rpmsg_register_device(rpdev);
• if (ret)

• kfree(rpdev->driver_override);
  
  

• return rpmsg_register_device(rpdev);

• return ret;

}

#endif diff --git a/drivers/rpmsg/rpmsg_ns.c b/drivers/rpmsg/rpmsg_ns.c index 762ff1ae279f..95a51543f5ad 100644 --- a/drivers/rpmsg/rpmsg_ns.c +++ b/drivers/rpmsg/rpmsg_ns.c @@ -20,12 +20,22 @@ */ int rpmsg_ns_register_device(struct rpmsg_device *rpdev) {

• int ret;
• strcpy(rpdev->id.name, "rpmsg_ns");

• rpdev->driver_override = "rpmsg_ns";

• ret = driver_set_override(&rpdev->dev, &rpdev->driver_override,

• 		  "rpmsg_ns", strlen("rpmsg_ns"));
  

• if (ret)

• return ret;
  

• rpdev->src = RPMSG_NS_ADDR; rpdev->dst = RPMSG_NS_ADDR;

• return rpmsg_register_device(rpdev);

• ret = rpmsg_register_device(rpdev);
• if (ret)

• kfree(rpdev->driver_override);
  

• return ret;

} EXPORT_SYMBOL(rpmsg_ns_register_device);

diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h index 02fa9116cd60..20c8cd1cde21 100644 --- a/include/linux/rpmsg.h +++ b/include/linux/rpmsg.h @@ -41,7 +41,9 @@ struct rpmsg_channel_info {

• rpmsg_device - device that belong to the rpmsg bus
• @dev: the device struct
• @id: device id (used to match between rpmsg drivers and devices)

• • @driver_override: driver name to force a match

• • @driver_override: driver name to force a match; do not set directly,

• •               because core frees it; use driver_set_override() to
    

• •               set or clear it.
    

  • @src: local address
  • @dst: destination address
  • @ept: the rpmsg endpoint of this channel @@ -51,7 +53,7 @@ struct

rpmsg_channel_info { struct rpmsg_device { struct device dev; struct rpmsg_device_id id;

• char *driver_override;

• const char *driver_override; u32 src; u32 dst; struct rpmsg_endpoint *ept;

-- 2.32.0

---