Re: [PATCH v5] misc: fastrpc: check qcom_scm_assign_mem() return in rpmsg_probe

[Greg KH <gregkh@linuxfoundation.org>]

On Sat, Jan 17, 2026 at 10:03:51PM +0800, Xingjing Deng wrote:
> In the SDSP probe path, qcom_scm_assign_mem() is used to assign the
> reserved memory to the configured VMIDs, but its return value was not
> checked.
> 
> Fail the probe if the SCM call fails to avoid continuing with an
> unexpected/incorrect memory permission configuration.
> 
> The file has passed the check of checkpatch.
> 
> Fixes: c3c0363bc72d4 ("misc: fastrpc: support complete DMA pool access to the DSP")
> Cc: stable@vger.kernel.org # 6.11-rc1
> Signed-off-by: Xingjing Deng <xjdeng@buaa.edu.cn>
> ---
> v5:
> - Squash the functional change and indentation fix into a single patch.
> - Link to v4: https://lore.kernel.org/linux-arm-msm/2026011637-statute-showy-2c3f@gregkh/T/#t
> 
> v4:
> - Format the indentation
> - Link to v3: https://lore.kernel.org/linux-arm-msm/20260113084352.72itrloj5w7qb5o3@hu-mojha-hyd.qualcomm.com/T/#t
> 
> v3:
> - Add missing linux-kernel@vger.kernel.org to cc list.
> - Standarlize changelog placement/format.
> - Link to v2: https://lore.kernel.org/linux-arm-msm/20260113063618.e2ke47gy3hnfi67e@hu-mojha-hyd.qualcomm.com/T/#t
> 
> v2:
> - Add Fixes: and Cc: stable tags.
> - Link to v1: https://lore.kernel.org/linux-arm-msm/20260113022550.4029635-1-xjdeng@buaa.edu.cn/T/#u
> ---
>  drivers/misc/fastrpc.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
> index fb3b54e05928..d9650efa443f 100644
> --- a/drivers/misc/fastrpc.c
> +++ b/drivers/misc/fastrpc.c
> @@ -2338,8 +2338,13 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
>  		if (!err) {
>  			src_perms = BIT(QCOM_SCM_VMID_HLOS);
>  
> -			qcom_scm_assign_mem(res.start, resource_size(&res), &src_perms,
> -				    data->vmperms, data->vmcount);
> +			err = qcom_scm_assign_mem(res.start, resource_size(&res), &src_perms,
> +					data->vmperms, data->vmcount);
> +			if (err) {
> +				dev_err(rdev, "Failed to assign memory phys 0x%llx size 0x%llx err %d",
> +				    res.start, resource_size(&res), err);

Shouldn't the caller function report the error?

How as this found and tested?

thanks,

greg k-h