Re: [PATCH v9 1/6] media: verisilicon: Do not set context src/dst formats in reset functions

[Marek Szyprowski]

Hi,

On 20.02.2023 11:48, Benjamin Gaignard wrote:
> Setting context source and destination formats should only be done
> in hantro_set_fmt_out() and hantro_set_fmt_cap() after check that
> the targeted queue is not busy.
> Remove these calls from hantro_reset_encoded_fmt() and
> hantro_reset_raw_fmt() to clean the driver.
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>

This patch landed recently in linux-next as commit db6f68b51e5c ("media: 
verisilicon: Do not set context src/dst formats in reset functions").

Unfortunately it causes the following regression during Debian boot on 
Odroid-M1 board:

--->8---

hantro-vpu fdea0000.video-codec: Adding to iommu group 0
hantro-vpu fdea0000.video-codec: registered rockchip,rk3568-vpu-dec as 
/dev/video0
hantro-vpu fdee0000.video-codec: Adding to iommu group 1
hantro-vpu fdee0000.video-codec: registered rockchip,rk3568-vepu-enc as 
/dev/video1
Unable to handle kernel NULL pointer dereference at virtual address 
0000000000000008
Mem abort info:
   ESR = 0x0000000096000004
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x04: level 0 translation fault
Data abort info:
   ISV = 0, ISS = 0x00000004
   CM = 0, WnR = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=00000001f446f000
[0000000000000008] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in: hantro_vpu v4l2_vp9 v4l2_h264 v4l2_mem2mem 
videobuf2_dma_contig snd_soc_simple_card display_connector 
snd_soc_simple_card_utils videobuf2_memops crct10dif_ce dwmac_rk 
rockchip_thermal videobuf2_v4l2 stmmac_platform rockchip_saradc 
industrialio_triggered_buffer kfifo_buf stmmac videodev pcs_xpcs 
rtc_rk808 videobuf2_common rockchipdrm panfrost mc drm_shmem_helper 
analogix_dp gpu_sched dw_mipi_dsi dw_hdmi drm_display_helper ip_tables 
x_tables ipv6
CPU: 3 PID: 171 Comm: v4l_id Not tainted 6.3.0-rc2+ #13478
Hardware name: Hardkernel ODROID-M1 (DT)
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : hantro_try_fmt+0xb4/0x280 [hantro_vpu]
lr : hantro_try_fmt+0xa8/0x280 [hantro_vpu]
...
Call trace:
  hantro_try_fmt+0xb4/0x280 [hantro_vpu]
  hantro_set_fmt_out+0x3c/0x278 [hantro_vpu]
  hantro_reset_raw_fmt+0x94/0xb4 [hantro_vpu]
  hantro_set_fmt_cap+0x23c/0x250 [hantro_vpu]
  hantro_reset_fmts+0x94/0xcc [hantro_vpu]
  hantro_open+0xd4/0x20c [hantro_vpu]
  v4l2_open+0x80/0x120 [videodev]
  chrdev_open+0xc0/0x22c
  do_dentry_open+0x13c/0x490
  vfs_open+0x2c/0x38
  path_openat+0x550/0x938
  do_filp_open+0x80/0x12c
  do_sys_openat2+0xb4/0x16c
  __arm64_sys_openat+0x64/0xac
  invoke_syscall+0x48/0x114
  el0_svc_common.constprop.0+0xfc/0x11c
  do_el0_svc+0x38/0xa4
  el0_svc+0x48/0xb8
  el0t_64_sync_handler+0xb8/0xbc
  el0t_64_sync+0x190/0x194
Code: 97fe726c f940aa80 52864a61 72a686c1 (b9400800)
---[ end trace 0000000000000000 ]---

I know that v4l_id tool, which is a part of systemd/udev, is known to 
crash badly on various vendor kernels (fixing this would be a really 
hard, especially assuming the brokenness of some vendor hacks), but I 
hoped that at least it should not be able to crash the mainline kernel.


> ---
>   drivers/media/platform/verisilicon/hantro_v4l2.c | 9 ++-------
>   1 file changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/media/platform/verisilicon/hantro_v4l2.c b/drivers/media/platform/verisilicon/hantro_v4l2.c
> index c0d427956210..d8aa42bd4cd4 100644
> --- a/drivers/media/platform/verisilicon/hantro_v4l2.c
> +++ b/drivers/media/platform/verisilicon/hantro_v4l2.c
> @@ -382,13 +382,10 @@ hantro_reset_encoded_fmt(struct hantro_ctx *ctx)
>   
>   	vpu_fmt = hantro_get_default_fmt(ctx, true);
>   
> -	if (ctx->is_encoder) {
> -		ctx->vpu_dst_fmt = vpu_fmt;
> +	if (ctx->is_encoder)
>   		fmt = &ctx->dst_fmt;
> -	} else {
> -		ctx->vpu_src_fmt = vpu_fmt;
> +	else
>   		fmt = &ctx->src_fmt;
> -	}
>   
>   	hantro_reset_fmt(fmt, vpu_fmt);
>   	fmt->width = vpu_fmt->frmsize.min_width;
> @@ -408,11 +405,9 @@ hantro_reset_raw_fmt(struct hantro_ctx *ctx)
>   	raw_vpu_fmt = hantro_get_default_fmt(ctx, false);
>   
>   	if (ctx->is_encoder) {
> -		ctx->vpu_src_fmt = raw_vpu_fmt;
>   		raw_fmt = &ctx->src_fmt;
>   		encoded_fmt = &ctx->dst_fmt;
>   	} else {
> -		ctx->vpu_dst_fmt = raw_vpu_fmt;
>   		raw_fmt = &ctx->dst_fmt;
>   		encoded_fmt = &ctx->src_fmt;
>   	}

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland