This is a note to let you know that I've just added the patch titled
remoteproc: imx_dsp_rproc: Add mutex protection for workqueue
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
remoteproc-imx_dsp_rproc-add-mutex-protection-for-workqueue.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 47e6ab07018edebf94ce873cf50a05ec76ff2dde Mon Sep 17 00:00:00 2001
From: Shengjiu Wang <shengjiu.wang@xxxxxxx>
Date: Fri, 30 Sep 2022 15:50:16 +0800
Subject: remoteproc: imx_dsp_rproc: Add mutex protection for workqueue
From: Shengjiu Wang <shengjiu.wang@xxxxxxx>
commit 47e6ab07018edebf94ce873cf50a05ec76ff2dde upstream.
The workqueue may execute late even after remoteproc is stopped or
stopping, some resources (rpmsg device and endpoint) have been
released in rproc_stop_subdevices(), then rproc_vq_interrupt()
accessing these resources will cause kennel dump.
Call trace:
virtqueue_add_split+0x1ac/0x560
virtqueue_add_inbuf+0x4c/0x60
rpmsg_recv_done+0x15c/0x294
vring_interrupt+0x6c/0xa4
rproc_vq_interrupt+0x30/0x50
imx_dsp_rproc_vq_work+0x24/0x40 [imx_dsp_rproc]
process_one_work+0x1d0/0x354
worker_thread+0x13c/0x470
kthread+0x154/0x160
ret_from_fork+0x10/0x20
Add mutex protection in imx_dsp_rproc_vq_work(), if the state is
not running, then just skip calling rproc_vq_interrupt().
Also the flush workqueue operation can't be added in rproc stop
for the same reason. The call sequence is
rproc_shutdown
-> rproc_stop
->rproc_stop_subdevices
->rproc->ops->stop()
->imx_dsp_rproc_stop
->flush_work
-> rproc_vq_interrupt
The resource needed by rproc_vq_interrupt has been released in
rproc_stop_subdevices, so flush_work is not safe to be called in
imx_dsp_rproc_stop.
Fixes: ec0e5549f358 ("remoteproc: imx_dsp_rproc: Add remoteproc driver for DSP on i.MX")
Signed-off-by: Shengjiu Wang <shengjiu.wang@xxxxxxx>
Reviewed-by: Peng Fan <peng.fan@xxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1664524216-19949-1-git-send-email-shengjiu.wang@xxxxxxx
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/remoteproc/imx_dsp_rproc.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
--- a/drivers/remoteproc/imx_dsp_rproc.c
+++ b/drivers/remoteproc/imx_dsp_rproc.c
@@ -347,9 +347,6 @@ static int imx_dsp_rproc_stop(struct rpr
struct device *dev = rproc->dev.parent;
int ret = 0;
- /* Make sure work is finished */
- flush_work(&priv->rproc_work);
-
if (rproc->state == RPROC_CRASHED) {
priv->flags &= ~REMOTE_IS_READY;
return 0;
@@ -432,9 +429,18 @@ static void imx_dsp_rproc_vq_work(struct
{
struct imx_dsp_rproc *priv = container_of(work, struct imx_dsp_rproc,
rproc_work);
+ struct rproc *rproc = priv->rproc;
+
+ mutex_lock(&rproc->lock);
+
+ if (rproc->state != RPROC_RUNNING)
+ goto unlock_mutex;
rproc_vq_interrupt(priv->rproc, 0);
rproc_vq_interrupt(priv->rproc, 1);
+
+unlock_mutex:
+ mutex_unlock(&rproc->lock);
}
/**
Patches currently in stable-queue which might be from shengjiu.wang@xxxxxxx are
queue-6.1/remoteproc-imx_dsp_rproc-add-mutex-protection-for-workqueue.patch
