[PATCH v1 3/5] misc: fastrpc: Fix initial memory allocation for Audio PD memory pool

[Dmitry Baryshkov]

On Thu, 22 May 2025 at 07:58, Ekansh Gupta
<ekansh.gupta at oss.qualcomm.com> wrote:
>
>
>
> On 5/19/2025 7:01 PM, Dmitry Baryshkov wrote:
> > On Mon, May 19, 2025 at 04:23:28PM +0530, Ekansh Gupta wrote:
> >>
> >> On 5/19/2025 3:47 PM, Dmitry Baryshkov wrote:
> >>> On Tue, May 13, 2025 at 09:58:23AM +0530, Ekansh Gupta wrote:
> >>>> The initially allocated memory is not properly included in the pool,
> >>>> leading to potential issues with memory management. Set the number
> >>> What is 'properly'? Which issues?
> >> inbuf.pageslen is getting updated to 1 in case buffer is allocated,
> > Is it a flag or some page count?
>
> This is page count,

If it is page count, then why is it '1' instead of being calculated
based on the init.memlen?

> based on this count, DSP with add memory to audioPD
> pool. If it is 0, the memory is not added.
>
> >
> >> which only
> >> happens if (!fl->cctx->audio_init_mem).
> > You are describing patch behaviour.
> >
> >> Till now pageslen is always 0 irrespective of whether the memory is allocated
> >> or not due to which audio PD is never able to use this memory.
> > and the is current behaviour. So this answers the first question.
> > 'properly'. Now, the second quesiton. 'Which issues?'
>
> The issues is actually memory leak as the initial memory is never
> used by audio PD and it will immediately make a remote heap request
> as no memory is added to the pool initially.
>
> I'll capture this also in the commit text.
>
> >
> >> I'll update this to the commit in the next spin.
> >>
> >>>> of pages to one to ensure that the initially allocated memory is
> >>>> correctly added to the Audio PD memory pool.
> >>>>
> >>>> Fixes: 0871561055e66 ("misc: fastrpc: Add support for audiopd")
> >>>> Cc: stable at kernel.org
> >>>> Signed-off-by: Ekansh Gupta <ekansh.gupta at oss.qualcomm.com>
> >>>> ---
> >>>>  drivers/misc/fastrpc.c | 7 ++++---
> >>>>  1 file changed, 4 insertions(+), 3 deletions(-)
> >>>>
> >>>> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
> >>>> index d4e38b5e5e6c..b629e24f00bc 100644
> >>>> --- a/drivers/misc/fastrpc.c
> >>>> +++ b/drivers/misc/fastrpc.c
> >>>> @@ -1311,6 +1311,9 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
> >>>>            goto err;
> >>>>    }
> >>>>
> >>>> +  inbuf.client_id = fl->client_id;
> >>>> +  inbuf.namelen = init.namelen;
> >>>> +  inbuf.pageslen = 0;
> >>>>    if (!fl->cctx->audio_init_mem) {
> >>>>            err = fastrpc_remote_heap_alloc(fl, fl->sctx->dev, init.memlen,
> >>>>                                            &buf);
> >>>> @@ -1335,12 +1338,10 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
> >>>>                    list_add_tail(&buf->node, &fl->cctx->rhmaps);
> >>>>                    spin_unlock_irqrestore(&fl->cctx->lock, flags);
> >>>>                    fl->cctx->audio_init_mem = true;
> >>>> +                  inbuf.pageslen = 1;
> >>>>            }
> >>>>    }
> >>>>
> >>>> -  inbuf.client_id = fl->client_id;
> >>>> -  inbuf.namelen = init.namelen;
> >>>> -  inbuf.pageslen = 0;
> >>>>    fl->pd = USER_PD;
> >>>>
> >>>>    args[0].ptr = (u64)(uintptr_t)&inbuf;
> >>>> --
> >>>> 2.34.1
> >>>>
>


-- 
With best wishes
Dmitry