Re: [PATCH] remoteproc: imx_rproc: Add mutex protection for workqueue

[Peng Fan <peng.fan@oss.nxp.com>]

On Mon, Mar 31, 2025 at 07:22:45PM +0800, Peng Fan (OSS) wrote:
>From: Peng Fan <peng.fan@nxp.com>
>
>Same as
>commit 47e6ab07018e ("remoteproc: imx_dsp_rproc: Add mutex
>protection for workqueue") and commit 35bdafda40cc ("remoteproc:
>stm32_rproc: Add mutex protection for workqueue"), imx_rproc driver
>also has similar issue, although no issue reported until now.
>
>Reuse the commit log from the fix to imx_dsp_rproc:
>
>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
> virtqueue_add_inbuf
> rpmsg_recv_done
> vring_interrupt
> rproc_vq_interrupt
> imx_rproc_vq_work
> process_one_work
> worker_thread
> kthread
> ret_from_fork
>
>Signed-off-by: Peng Fan <peng.fan@nxp.com>
>---
> drivers/remoteproc/imx_rproc.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
>diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
>index 74299af1d7f1..f933c8f4fc8b 100644
>--- a/drivers/remoteproc/imx_rproc.c
>+++ b/drivers/remoteproc/imx_rproc.c
>@@ -5,6 +5,7 @@
> 
> #include <dt-bindings/firmware/imx/rsrc.h>
> #include <linux/arm-smccc.h>
>+#include <linux/cleanup.h>
> #include <linux/clk.h>
> #include <linux/err.h>
> #include <linux/firmware/imx/sci.h>
>@@ -785,6 +786,11 @@ static void imx_rproc_vq_work(struct work_struct *work)
> 					      rproc_work);
> 	struct rproc *rproc = priv->rproc;
> 
>+	guard(mutex)(&rproc->lock);
>+
>+	if (rproc->state != RPROC_RUNNING)

Rethink this, I may need update this to
"if (rproc->state != RPROC_RUNNING && rproc->state != RPROC_ATTACHED)"
same as stm32_rproc.c.

Thanks,
Peng

>+		return;
>+
> 	idr_for_each(&rproc->notifyids, imx_rproc_notified_idr_cb, rproc);
> }
> 
>-- 
>2.37.1
>