Re: [PATCH 1/2] media: mediatek: vcodec: checking decoder ack message parameter

[Yunfei Dong (董云飞)]

Hi Nicolas,

Thanks for your review.

On Thu, 2023-07-20 at 16:22 -0400, Nicolas Dufresne wrote:
> Hi,
> 
> Le lundi 17 juillet 2023 à 16:13 +0800, Yunfei Dong a écrit :
> > Need to checking all parameters of msg data are valid or not,
> > in case of access null pointer or unreasonable value leading
> > to kernel reboot.
> > 
> > Signed-off-by: Yunfei Dong <yunfei.dong@xxxxxxxxxxxx>
> > ---
> >  .../vcodec/decoder/mtk_vcodec_dec_drv.h       |  2 +
> >  .../mediatek/vcodec/decoder/vdec_vpu_if.c     | 77 ++++++++++++---
> > ----
> >  2 files changed, 52 insertions(+), 27 deletions(-)
> > 
> > diff --git
> > a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv
> > .h
> > b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv
> > .h
> > index c8b4374c5e6c..1ea5dbb475dd 100644
> > ---
> > a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv
> > .h
> > +++
> > b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv
> > .h
> > @@ -160,6 +160,7 @@ struct mtk_vcodec_dec_pdata {
> >   * @hw_id: hardware index used to identify different hardware.
> >   *
> >   * @msg_queue: msg queue used to store lat buffer information.
> > + * @vpu_inst: vpu instance pointer.
> >   */
> >  struct mtk_vcodec_dec_ctx {
> >  	enum mtk_instance_type type;
> > @@ -202,6 +203,7 @@ struct mtk_vcodec_dec_ctx {
> >  	int hw_id;
> >  
> >  	struct vdec_msg_queue msg_queue;
> > +	void *vpu_inst;
> >  };
> >  
> >  /**
> > diff --git
> > a/drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c
> > b/drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c
> > index 82c3dc8c4127..23cfe5c6c90b 100644
> > --- a/drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c
> > +++ b/drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c
> > @@ -72,6 +72,21 @@ static void handle_get_param_msg_ack(const
> > struct vdec_vpu_ipi_get_param_ack *ms
> >  	}
> >  }
> >  
> > +static bool vpu_dec_check_ap_inst(struct mtk_vcodec_dec_dev
> > *dec_dev, struct vdec_vpu_inst *vpu)
> > +{
> > +	struct mtk_vcodec_dec_ctx *ctx;
> > +	int ret = false;
> > +
> > +	list_for_each_entry(ctx, &dec_dev->ctx_list, list) {
> 
> I'm not quite fully aware of the threading model in place, but this
> ctx_list is
> normally protected by dev->dev_mutex, and is not being protected
> here. I also
> don't know which type of interrupt handler we are in here.
> 
If the device is opened, one ctx will be inserted to ctx_list, then the
handler interface will be called. 

1: This function just used to check whether the context is reasonable,
no need to add mutex to protect because the context already in ctx_list
in oped period. This function won't be called after deinit ctx from
ctx_list.

2: This handler will be called when ap send message to scp.

Best Regards,
Yunfei Dong
> > +		if (!IS_ERR_OR_NULL(ctx) && ctx->vpu_inst == vpu) {
> > +			ret = true;
> > +			break;
> > +		}
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> >  /*
> >   * vpu_dec_ipi_handler - Handler for VPU ipi message.
> >   *
> > @@ -84,44 +99,51 @@ static void handle_get_param_msg_ack(const
> > struct vdec_vpu_ipi_get_param_ack *ms
> >   */
> >  static void vpu_dec_ipi_handler(void *data, unsigned int len, void
> > *priv)
> >  {
> > +	struct mtk_vcodec_dec_dev *dec_dev;
> >  	const struct vdec_vpu_ipi_ack *msg = data;
> > -	struct vdec_vpu_inst *vpu = (struct vdec_vpu_inst *)
> > -					(unsigned long)msg-
> > >ap_inst_addr;
> > +	struct vdec_vpu_inst *vpu;
> >  
> > -	if (!vpu) {
> > +	dec_dev = (struct mtk_vcodec_dec_dev *)priv;
> > +	vpu = (struct vdec_vpu_inst *)(unsigned long)msg->ap_inst_addr;
> > +	if (!priv || !vpu) {
> >  		mtk_v4l2_vdec_err(vpu->ctx, "ap_inst_addr is NULL, did
> > the SCP hang or crash?");
> >  		return;
> >  	}
> >  
> > -	mtk_vdec_debug(vpu->ctx, "+ id=%X", msg->msg_id);
> > +	if (!vpu_dec_check_ap_inst(dec_dev, vpu) || msg->msg_id <
> > VPU_IPIMSG_DEC_INIT_ACK ||
> > +	    msg->msg_id > VPU_IPIMSG_DEC_GET_PARAM_ACK) {
> > +		mtk_v4l2_vdec_err(vpu->ctx, "vdec msg id not correctly
> > => 0x%x", msg->msg_id);
> > +		vpu->failure = -EINVAL;
> > +		goto error;
> > +	}
> >  
> >  	vpu->failure = msg->status;
> > -	vpu->signaled = 1;
> > +	if (msg->status != 0)
> > +		goto error;
> >  
> > -	if (msg->status == 0) {
> > -		switch (msg->msg_id) {
> > -		case VPU_IPIMSG_DEC_INIT_ACK:
> > -			handle_init_ack_msg(data);
> > -			break;
> > +	switch (msg->msg_id) {
> > +	case VPU_IPIMSG_DEC_INIT_ACK:
> > +		handle_init_ack_msg(data);
> > +		break;
> >  
> > -		case VPU_IPIMSG_DEC_START_ACK:
> > -		case VPU_IPIMSG_DEC_END_ACK:
> > -		case VPU_IPIMSG_DEC_DEINIT_ACK:
> > -		case VPU_IPIMSG_DEC_RESET_ACK:
> > -		case VPU_IPIMSG_DEC_CORE_ACK:
> > -		case VPU_IPIMSG_DEC_CORE_END_ACK:
> > -			break;
> > +	case VPU_IPIMSG_DEC_START_ACK:
> > +	case VPU_IPIMSG_DEC_END_ACK:
> > +	case VPU_IPIMSG_DEC_DEINIT_ACK:
> > +	case VPU_IPIMSG_DEC_RESET_ACK:
> > +	case VPU_IPIMSG_DEC_CORE_ACK:
> > +	case VPU_IPIMSG_DEC_CORE_END_ACK:
> > +		break;
> >  
> > -		case VPU_IPIMSG_DEC_GET_PARAM_ACK:
> > -			handle_get_param_msg_ack(data);
> > -			break;
> > -		default:
> > -			mtk_vdec_err(vpu->ctx, "invalid msg=%X", msg-
> > >msg_id);
> > -			break;
> > -		}
> > +	case VPU_IPIMSG_DEC_GET_PARAM_ACK:
> > +		handle_get_param_msg_ack(data);
> > +		break;
> > +	default:
> > +		mtk_vdec_err(vpu->ctx, "invalid msg=%X", msg->msg_id);
> > +		break;
> >  	}
> >  
> > -	mtk_vdec_debug(vpu->ctx, "- id=%X", msg->msg_id);
> > +error:
> > +	vpu->signaled = 1;
> >  }
> >  
> >  static int vcodec_vpu_send_msg(struct vdec_vpu_inst *vpu, void
> > *msg, int len)
> > @@ -182,9 +204,10 @@ int vpu_dec_init(struct vdec_vpu_inst *vpu)
> >  
> >  	init_waitqueue_head(&vpu->wq);
> >  	vpu->handler = vpu_dec_ipi_handler;
> > +	vpu->ctx->vpu_inst = vpu;
> >  
> >  	err = mtk_vcodec_fw_ipi_register(vpu->ctx->dev->fw_handler,
> > vpu->id,
> > -					 vpu->handler, "vdec", NULL);
> > +					 vpu->handler, "vdec", vpu-
> > >ctx->dev);
> >  	if (err) {
> >  		mtk_vdec_err(vpu->ctx, "vpu_ipi_register fail
> > status=%d", err);
> >  		return err;
> > @@ -193,7 +216,7 @@ int vpu_dec_init(struct vdec_vpu_inst *vpu)
> >  	if (vpu->ctx->dev->vdec_pdata->hw_arch ==
> > MTK_VDEC_LAT_SINGLE_CORE) {
> >  		err = mtk_vcodec_fw_ipi_register(vpu->ctx->dev-
> > >fw_handler,
> >  						 vpu->core_id, vpu-
> > >handler,
> > -						 "vdec", NULL);
> > +						 "vdec", vpu->ctx-
> > >dev);
> >  		if (err) {
> >  			mtk_vdec_err(vpu->ctx, "vpu_ipi_register core
> > fail status=%d", err);
> >  			return err;
> 
>