Re: [PATCH V2] remoteproc: imx_rproc: Add mutex protection for workqueue

[Mathieu Poirier <mathieu.poirier@linaro.org>]

On Tue, Apr 01, 2025 at 10:04:02PM +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.
> 
> 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
> 
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
> 
> V2:
>  Add RPROC_ATTACHED check, because i.MX supports remote cores started by
>  bootloader.
>  Update commit and add R-b from Frank
> 
>  drivers/remoteproc/imx_rproc.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 

NACK - for the reasons I have explained in "[PATCH V2] remoteproc: core: Clear table_sz when rproc_shutdown"


> diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
> index 74299af1d7f1..4819a9e57543 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 && rproc->state != RPROC_ATTACHED)
> +		return;
> +
>  	idr_for_each(&rproc->notifyids, imx_rproc_notified_idr_cb, rproc);
>  }
>  
> -- 
> 2.37.1
>