kernel/git/stable/linux-stable.git/drivers/rpmsg, branch linux-5.10.y

rpmsg: glink: fix deadlock in endpoint destroy during driver detach

2026-09-14T11:18:59+00:00

[ Upstream commit 5a5a48e788e02fd8a8eb7188ce440572d6c12418 ] During driver detach, the device core holds the device mutex throughout the driver's remove callback chain. When the rpmsg endpoint is destroyed as part of that teardown, the GLINK endpoint destroy implementation attempts to unregister the underlying rpmsg device. That unregistration calls device_del(), which tries to re-acquire the same device mutex already held higher up the stack, causing rmmod to hang indefinitely. The deadlock manifests with the following call chain: [<0>] device_del+0x44/0x414 <- tries to acquire same mutex [<0>] device_unregister+0x18/0x34 [<0>] rpmsg_unregister_device+0x28/0x4c [<0>] qcom_glink_remove_rpmsg_device+0x70/0xc0 [<0>] qcom_glink_destroy_ept+0x58/0xbc [<0>] rpmsg_dev_remove+0x50/0x60 [<0>] device_remove+0x4c/0x80 [<0>] device_release_driver_internal+0x1cc/0x228 <- acquires device mutex [<0>] driver_detach+0x4c/0x98 [<0>] bus_remove_driver+0x6c/0xbc [<0>] driver_unregister+0x30/0x60 [<0>] unregister_rpmsg_driver+0x10/0x1c [<0>] fastrpc_exit+0x28/0x38 [fastrpc] [<0>] __arm64_sys_delete_module+0x1b8/0x294 [<0>] invoke_syscall+0x48/0x10c [<0>] el0_svc_common.constprop.0+0xc0/0xe0 [<0>] do_el0_svc+0x1c/0x28 [<0>] el0_svc+0x34/0x108 [<0>] el0t_64_sync_handler+0xa0/0xe4 [<0>] el0t_64_sync+0x198/0x19c The rpmsg device unregistration inside endpoint destroy is redundant. In both contexts where endpoint destruction is triggered: - Driver detach path: the driver core already tears down the rpmsg device. - Channel close path: the rpmsg device is already unregistered before endpoint destruction is reached. Remove the redundant unregistration to fix the deadlock. Co-developed-by: Deepak Kumar Singh Signed-off-by: Deepak Kumar Singh Signed-off-by: Vishnu Santhosh Tested-by: Bjorn Andersson Fixes: a53e356df548 ("rpmsg: glink: fix rpmsg device leak") Reviewed-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20260604-rpmsg-glink-fix-deadlock-destroy-ept-v1-1-b8a54ad1e4fd@oss.qualcomm.com Signed-off-by: Bjorn Andersson Signed-off-by: Sasha Levin

rpmsg: glink: remove duplicate code for rpmsg device remove

2026-09-14T11:18:59+00:00

[ Upstream commit 112766cdf2e5ea0a0f72b0304d57a6f74c066670 ] rpmsg device remove code is duplicated in at-least 2-3 places, add a helper function to remove this duplicated code. Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20250822100043.2604794-3-srinivas.kandagatla@oss.qualcomm.com Signed-off-by: Bjorn Andersson Stable-dep-of: 5a5a48e788e0 ("rpmsg: glink: fix deadlock in endpoint destroy during driver detach") Signed-off-by: Sasha Levin

rpmsg: glink: Remove the rpmsg dev in close_ack

2026-09-14T11:18:59+00:00

[ Upstream commit c7c182d4447e172f87e37d6c04879b94b8635b37 ] Un-register and register of rpmsg driver is sending invalid open_ack on closed channel. To avoid sending invalid open_ack case unregister the rpmsg device after receiving the local_close_ack from remote side. Signed-off-by: Deepak Kumar Singh Signed-off-by: Arun Kumar Neelakantam [bjorn: s/strlcpy/strscpy/] Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/1596086296-28529-5-git-send-email-deesin@codeaurora.org Stable-dep-of: 5a5a48e788e0 ("rpmsg: glink: fix deadlock in endpoint destroy during driver detach") Signed-off-by: Sasha Levin

rpmsg: glink: smem: order FIFO read after availability check

2026-09-14T11:18:39+00:00

commit 786439ad58763e04b91bc2ec5f590e463939f197 upstream. glink_smem_rx_peek() reads the RX FIFO payload after the caller has determined data is available via glink_smem_rx_avail(), which reads the remote-updated head index. A control dependency between the head read and the subsequent payload read does not order the two loads, so the CPU may speculatively read the FIFO before observing the head update and consume stale data the remote has not yet published. Add rmb() in glink_smem_rx_peek() before the memcpy_fromio() so the availability (head) read is ordered ahead of the FIFO payload read, matching the consumer pattern in Documentation/core-api/circular-buffers.rst. Fixes: caf989c350e8 ("rpmsg: glink: Introduce glink smem based transport") Cc: stable@vger.kernel.org Signed-off-by: Chunkai Deng Reviewed-by: Konrad Dybcio Link: https://lore.kernel.org/r/20260618-rpmsg-glink-smem-mb-v1-1-68a026453a69@oss.qualcomm.com Signed-off-by: Bjorn Andersson Signed-off-by: Greg Kroah-Hartman

rpmsg: core: fix race in driver_override_show() and use core helper

2026-03-04T12:20:13+00:00

[ Upstream commit 42023d4b6d2661a40ee2dcf7e1a3528a35c638ca ] The driver_override_show function reads the driver_override string without holding the device_lock. However, the store function modifies and frees the string while holding the device_lock. This creates a race condition where the string can be freed by the store function while being read by the show function, leading to a use-after-free. To fix this, replace the rpmsg_string_attr macro with explicit show and store functions. The new driver_override_store uses the standard driver_set_override helper. Since the introduction of driver_set_override, the comments in include/linux/rpmsg.h have stated that this helper must be used to set or clear driver_override, but the implementation was not updated until now. Because driver_set_override modifies and frees the string while holding the device_lock, the new driver_override_show now correctly holds the device_lock during the read operation to prevent the race. Additionally, since rpmsg_string_attr has only ever been used for driver_override, removing the macro simplifies the code. Fixes: 39e47767ec9b ("rpmsg: Add driver_override device attribute for rpmsg_device") Cc: stable@vger.kernel.org Signed-off-by: Gui-Dong Han Link: https://lore.kernel.org/r/20251202174948.12693-1-hanguidong02@gmail.com Signed-off-by: Mathieu Poirier Signed-off-by: Sasha Levin

rpmsg: glink: fix rpmsg device leak

2026-01-19T12:11:52+00:00

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 Reviewed-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20250822100043.2604794-2-srinivas.kandagatla@oss.qualcomm.com Signed-off-by: Bjorn Andersson Signed-off-by: Greg Kroah-Hartman

rpmsg: qcom_smd: Fix uninitialized return variable in __qcom_smd_send()

2025-06-27T10:04:05+00:00

[ Upstream commit 5de775df3362090a6e90046d1f2d83fe62489aa0 ] The "ret" variable isn't initialized if we don't enter the loop. For example, if "channel->state" is not SMD_CHANNEL_OPENED. Fixes: 33e3820dda88 ("rpmsg: smd: Use spinlock in tx path") Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/aAkhvV0nSbrsef1P@stanley.mountain Signed-off-by: Bjorn Andersson Signed-off-by: Sasha Levin

rpmsg: glink: Propagate TX failures in intentless mode as well

2024-12-14T18:48:13+00:00

commit 7a68f9fa97357a0f2073c9c31ed4101da4fce93e upstream. As support for splitting transmission over several messages using TX_DATA_CONT was introduced it does not immediately return the return value of qcom_glink_tx(). The result is that in the intentless case (i.e. intent == NULL), the code will continue to send all additional chunks. This is wasteful, and it's possible that the send operation could incorrectly indicate success, if the last chunk fits in the TX fifo. Fix the condition. Fixes: 8956927faed3 ("rpmsg: glink: Add TX_DATA_CONT command while sending") Reviewed-by: Chris Lew Signed-off-by: Bjorn Andersson Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20230418163018.785524-2-quic_bjorande@quicinc.com Signed-off-by: Greg Kroah-Hartman

rpmsg: glink: use only lower 16-bits of param2 for CMD_OPEN name length

2024-12-14T18:48:03+00:00

[ Upstream commit 06c59d97f63c1b8af521fa5aef8a716fb988b285 ] The name len field of the CMD_OPEN packet is only 16-bits and the upper 16-bits of "param2" are a different "prio" field, which can be nonzero in certain situations, and CMD_OPEN packets can be unexpectedly dropped because of this. Fix this by masking out the upper 16 bits of param2. Fixes: b4f8e52b89f6 ("rpmsg: Introduce Qualcomm RPM glink driver") Signed-off-by: Jonathan Marek Reviewed-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20241007235935.6216-1-jonathan@marek.ca Signed-off-by: Bjorn Andersson Signed-off-by: Sasha Levin

rpmsg: glink: Fix GLINK command prefix

2024-12-14T18:48:03+00:00

[ Upstream commit 4e816d0318fdfe8932da80dbf04ba318b13e4b3a ] The upstream GLINK driver was first introduced to communicate with the RPM on MSM8996, presumably as an artifact from that era the command defines was prefixed RPM_CMD, while they actually are GLINK_CMDs. Let's rename these, to keep things tidy. No functional change. Signed-off-by: Bjorn Andersson Reviewed-by: Chris Lew Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20230214225933.2025595-1-quic_bjorande@quicinc.com Stable-dep-of: 06c59d97f63c ("rpmsg: glink: use only lower 16-bits of param2 for CMD_OPEN name length") Signed-off-by: Sasha Levin