rpmsg: glink: fix rpmsg device leak

commit a53e356df548f6b0e82529ef3cc6070f42622189 upstream.

While testing rpmsg-char interface it was noticed that duplicate sysfs
entries are getting created and below warning is noticed.

Reason for this is that we are leaking rpmsg device pointer, setting it
null without actually unregistering device.
Any further attempts to unregister fail because rpdev is NULL,
resulting in a leak.

Fix this by unregistering rpmsg device before removing its reference
from rpmsg channel.

sysfs: cannot create duplicate filename '/devices/platform/soc@0/3700000.remot
eproc/remoteproc/remoteproc1/3700000.remoteproc:glink-edge/3700000.remoteproc:
glink-edge.adsp_apps.-1.-1'
[  114.115347] CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not
 tainted 6.16.0-rc4 #7 PREEMPT
[  114.115355] Hardware name: Qualcomm Technologies, Inc. Robotics RB3gen2 (DT)
[  114.115358] Workqueue: events qcom_glink_work
[  114.115371] Call trace:8
[  114.115374]  show_stack+0x18/0x24 (C)
[  114.115382]  dump_stack_lvl+0x60/0x80
[  114.115388]  dump_stack+0x18/0x24
[  114.115393]  sysfs_warn_dup+0x64/0x80
[  114.115402]  sysfs_create_dir_ns+0xf4/0x120
[  114.115409]  kobject_add_internal+0x98/0x260
[  114.115416]  kobject_add+0x9c/0x108
[  114.115421]  device_add+0xc4/0x7a0
[  114.115429]  rpmsg_register_device+0x5c/0xb0
[  114.115434]  qcom_glink_work+0x4bc/0x820
[  114.115438]  process_one_work+0x148/0x284
[  114.115446]  worker_thread+0x2c4/0x3e0
[  114.115452]  kthread+0x12c/0x204
[  114.115457]  ret_from_fork+0x10/0x20
[  114.115464] kobject: kobject_add_internal failed for 3700000.remoteproc:
glink-edge.adsp_apps.-1.-1 with -EEXIST, don't try to register things with
the same name in the same directory.
[  114.250045] rpmsg 3700000.remoteproc:glink-edge.adsp_apps.-1.-1:
device_add failed: -17

Fixes: 835764ddd9af ("rpmsg: glink: Move the common glink protocol implementation to glink_native.c")
Cc: Stable@vger.kernel.org
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250822100043.2604794-2-srinivas.kandagatla@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
index fec59c6b6fdb1c08a704abeee125b762bc70d6ed..e5e0924935b9b53f6ef10448e59396c8651c9548 100644 (file)
--- a/drivers/rpmsg/qcom_glink_native.c
+++ b/drivers/rpmsg/qcom_glink_native.c
@@ -1244,6 +1244,7 @@ static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
 {
        struct glink_channel *channel = to_glink_channel(ept);
        struct qcom_glink *glink = channel->glink;
+       struct rpmsg_channel_info chinfo;
        unsigned long flags;
 
        spin_lock_irqsave(&channel->recv_lock, flags);
@@ -1251,6 +1252,13 @@ static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
        spin_unlock_irqrestore(&channel->recv_lock, flags);
 
        /* Decouple the potential rpdev from the channel */
+       if (channel->rpdev) {
+               strscpy_pad(chinfo.name, channel->name, sizeof(chinfo.name));
+               chinfo.src = RPMSG_ADDR_ANY;
+               chinfo.dst = RPMSG_ADDR_ANY;
+
+               rpmsg_unregister_device(glink->dev, &chinfo);
+       }
        channel->rpdev = NULL;
 
        qcom_glink_send_close_req(glink, channel);