Re: [PATCH v4 08/11] misc: fastrpc: Fix ownership reassignment of remote heap

[Dmitry Baryshkov]

On Thu, Jun 06, 2024 at 10:29:28PM +0530, Ekansh Gupta wrote:
> Audio PD daemon will allocate memory for audio PD dynamic loading
> usage when it is attaching for the first time to audio PD. As
> part of this, the memory ownership is moved to the VM where
> audio PD can use it. In case daemon process is killed without any
> impact to DSP audio PD, the daemon process will retry to attach to
> audio PD and in this case memory won't be reallocated. If the invoke
> fails due to any reason, as part of err_invoke, the memory ownership
> is getting reassigned to HLOS even when the memory was not allocated.
> At this time the audio PD might still be using the memory and an
> attemp of ownership reassignment would result in memory issue.
> 
> Fixes: 0871561055e6 ("misc: fastrpc: Add support for audiopd")

Fixes before functional changes.

> Cc: stable <stable@xxxxxxxxxx>
> Signed-off-by: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx>
> ---
>  drivers/misc/fastrpc.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
> index 3686b2d34741..68c1595446d5 100644
> --- a/drivers/misc/fastrpc.c
> +++ b/drivers/misc/fastrpc.c
> @@ -1334,6 +1334,7 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
>  	u64 phys = 0, size = 0;
>  	char *name;
>  	int err;
> +	bool scm_done = false;
>  	struct {
>  		int pgid;
>  		u32 namelen;
> @@ -1398,6 +1399,7 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
>  					phys, size, err);
>  				goto err_map;
>  			}
> +			scm_done = true;
>  		}
>  	}
>  
> @@ -1439,7 +1441,7 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
>  
>  	return 0;
>  err_invoke:
> -	if (fl->cctx->vmcount) {
> +	if (fl->cctx->vmcount && scm_done) {
>  		u64 src_perms = 0;
>  		struct qcom_scm_vmperm dst_perms;
>  		u32 i;
> -- 
> 2.43.0
> 

-- 
With best wishes
Dmitry