Re: [PATCH v4 3/4] misc: fastrpc: Allocate entire reserved memory for Audio PD in probe

[Dmitry Baryshkov]

On Thu, Apr 09, 2026 at 02:26:16PM +0800, Jianping Li wrote:
> Allocating and freeing Audio PD memory from userspace is unsafe because
> the kernel cannot reliably determine when the DSP has finished using the
> memory. Userspace may free buffers while they are still in use by the DSP,
> and remote free requests cannot be safely trusted.
> 
> Allocate the entire Audio PD reserved-memory region upfront during rpmsg
> probe and tie its lifetime to the rpmsg channel. This avoids userspace-
> controlled alloc/free and ensures memory is reclaimed only when the DSP
> shuts down.
> 
> Signed-off-by: Jianping Li <jianping.li@xxxxxxxxxxxxxxxx>
> ---
>  drivers/misc/fastrpc.c | 104 +++++++++++++++++++++--------------------
>  1 file changed, 53 insertions(+), 51 deletions(-)
> 

This patch applies neither to linux-next nor to the 7.0 branch. What was
the base for this series?

-- 
With best wishes
Dmitry