[PATCH v3 3/3] rpmsg: char: Rework exception handling of rpmsg_eptdev_add()

Dawei Li
2025-11-13T15:40:06Z

Rework error handling of rpmsg_eptdev_add() and its callers, following
rule of "release resource where it's allocated".

Fixes: 2410558f5f11 ("rpmsg: char: Implement eptdev based on anonymous inode")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/aPi6gPZE2_ztOjIW@stanley.mountain/

Signed-off-by: Dawei Li <dawei.li@linux.dev>
---
drivers/rpmsg/rpmsg_char.c | 60 +++++++++++++++++++++-----------------
1 file changed, 33 insertions(+), 27 deletions(-)

diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index 0919ad0a19df..92c176e9b0e4 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -460,44 +460,34 @@ static int rpmsg_eptdev_add(struct rpmsg_eptdev *eptdev,

eptdev->chinfo = chinfo;

- if (cdev) {
- ret = ida_alloc_max(&rpmsg_minor_ida, RPMSG_DEV_MAX - 1, GFP_KERNEL);
- if (ret < 0)
- goto free_eptdev;
-
- dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
- }
-
/* Anonymous inode device still need device name for dev_err() and friends */
ret = ida_alloc(&rpmsg_ept_ida, GFP_KERNEL);
if (ret < 0)
- goto free_minor_ida;
+ return ret;
dev->id = ret;
dev_set_name(dev, "rpmsg%d", ret);

- ret = 0;
-
if (cdev) {
+ ret = ida_alloc_max(&rpmsg_minor_ida, RPMSG_DEV_MAX - 1, GFP_KERNEL);
+ if (ret < 0) {
+ ida_free(&rpmsg_ept_ida, dev->id);
+ return ret;
+ }
+
+ dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
+
ret = cdev_device_add(&eptdev->cdev, &eptdev->dev);
- if (ret)
- goto free_ept_ida;
+ if (ret) {
+ ida_free(&rpmsg_ept_ida, dev->id);
+ ida_free(&rpmsg_minor_ida, MINOR(dev->devt));
+ return ret;
+ }
}

/* We can now rely on the release function for cleanup */
dev->release = rpmsg_eptdev_release_device;

- return ret;
-
-free_ept_ida:
- ida_free(&rpmsg_ept_ida, dev->id);
-free_minor_ida:
- if (cdev)
- ida_free(&rpmsg_minor_ida, MINOR(dev->devt));
-free_eptdev:
- dev_err(&eptdev->dev, "failed to add %s\n", eptdev->chinfo.name);
- kfree(eptdev);
-
- return ret;
+ return 0;
}

static int rpmsg_chrdev_eptdev_add(struct rpmsg_eptdev *eptdev, struct rpmsg_channel_info chinfo)
@@ -509,12 +499,17 @@ int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent
struct rpmsg_channel_info chinfo)
{
struct rpmsg_eptdev *eptdev;
+ int ret;

eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, parent);
if (IS_ERR(eptdev))
return PTR_ERR(eptdev);

- return rpmsg_chrdev_eptdev_add(eptdev, chinfo);
+ ret = rpmsg_chrdev_eptdev_add(eptdev, chinfo);
+ if (ret)
+ kfree(eptdev);
+
+ return ret;
}
EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create);

@@ -545,6 +540,12 @@ int rpmsg_anonymous_eptdev_create(struct rpmsg_device *rpdev, struct device *par

ret = rpmsg_eptdev_add(eptdev, chinfo, false);
if (ret) {
+ dev_err(&eptdev->dev, "failed to add %s\n", eptdev->chinfo.name);
+ /*
+ * Avoid put_device() or WARN() will be triggered due to absence of
+ * device::release(), refer to device_release().
+ */
+ kfree(eptdev);
return ret;
}

@@ -572,6 +573,7 @@ static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
struct rpmsg_channel_info chinfo;
struct rpmsg_eptdev *eptdev;
struct device *dev = &rpdev->dev;
+ int ret;

memcpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
chinfo.src = rpdev->src;
@@ -590,7 +592,11 @@ static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
*/
eptdev->default_ept->priv = eptdev;

- return rpmsg_chrdev_eptdev_add(eptdev, chinfo);
+ ret = rpmsg_chrdev_eptdev_add(eptdev, chinfo);
+ if (ret)
+ kfree(eptdev);
+
+ return ret;
}

static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
--
2.25.1