Re: [PATCH v7 3/5] misc: fastrpc: Fail Audio PD init when reserved memory is missing

[Jianping Li]

On 6/8/2026 2:11 PM, Dmitry Baryshkov wrote:
> On Tue, Jun 02, 2026 at 03:17:48PM +0800, Jianping Li wrote:
> > Audio PD static process creation assumes that a reserved-memory
> > region is defined in DT and exposed via cctx->remote_heap.
> >
> > If reserved-memory is missing or incomplete, the driver may pass
> > invalid address/size information to the DSP, leading to undefined
> > behavior or crashes.
> >
> > Add explicit validation for remote_heap presence and size before
> > sending the memory to DSP, and fail early if the configuration is
> > invalid.
> >
> > Fixes: 0871561055e66 ("misc: fastrpc: Add support for audiopd")
> > Cc: stable@xxxxxxxxxx
> > Signed-off-by: Jianping Li <jianping.li@xxxxxxxxxxxxxxxx>
> > ---
> >   drivers/misc/fastrpc.c | 7 +++++++
> >   1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
> > index a8a58f889d07..f46a8f53970d 100644
> > --- a/drivers/misc/fastrpc.c
> > +++ b/drivers/misc/fastrpc.c
> > @@ -1354,6 +1354,13 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
> >   	} inbuf;
> >   	u32 sc;
> >   
> > +	if (!fl->cctx->remote_heap ||
> > +	    !fl->cctx->remote_heap->dma_addr ||
> > +	    !fl->cctx->remote_heap->size) {
> > +		err = -ENOMEM;
> > +		dev_dbg(fl->sctx->dev, "remote heap memory region is not added\n");
> > +		return err;
> > +	}
> Won't this check without the next commit break the kernel? I don't see
> where else the remote heap is being allocated.

Yes, this check depends on remote_heap being populated during rpmsg
probe from the reserved-memory region, introduced in a subsequent
patch in this series.

If there is no dependency on the next series, the remote_heap allocation here after the if check.
The logic will be wrong.

> >   	args = kzalloc_objs(*args, FASTRPC_CREATE_STATIC_PROCESS_NARGS);
> >   	if (!args)
> >   		return -ENOMEM;
> > --
> > 2.43.0