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

[Nicolas Dufresne <nicolas.dufresne@collabora.com>]

Le vendredi 21 juillet 2023 à 01:58 +0000, Yunfei Dong (董云飞) a écrit :
> 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@mediatek.com>
> > > ---
> > >  .../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.

Ack.

Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>

> 
> 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;
> > 
> >