Re: [PATCH] drm/amd/dc/dce120: Fix audio register mapping, stop triggering KASAN
From: Alex Deucher
Date: Thu Nov 17 2022 - 16:41:10 EST
On Mon, Nov 14, 2022 at 5:21 PM Lyude Paul <lyude@xxxxxxxxxx> wrote:
>
> There's been a very long running bug that seems to have been neglected for
> a while, where amdgpu consistently triggers a KASAN error at start:
>
> BUG: KASAN: global-out-of-bounds in read_indirect_azalia_reg+0x1d4/0x2a0 [amdgpu]
> Read of size 4 at addr ffffffffc2274b28 by task modprobe/1889
>
> After digging through amd's rather creative method for accessing registers,
> I eventually discovered the problem likely has to do with the fact that on
> my dce120 GPU there are supposedly 7 sets of audio registers. But we only
> define a register mapping for 6 sets.
>
> So, fix this and fix the KASAN warning finally.
>
> Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
This is the correct fix for asics having 7 audio instances. It looks
correct to me, assuming DCE12 actually has 7 audio instances.
@Wentland, Harry Do you know off hand? If you can confirm that, the
patch is:
Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>
> ---
> Sending this one separately from the rest of my fixes since:
>
> * It's definitely completely unrelated to the Gitlab 2171 issue
> * I'm not sure if this is the correct fix since it's in DC
>
> drivers/gpu/drm/amd/display/dc/dce120/dce120_resource.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/dce120/dce120_resource.c b/drivers/gpu/drm/amd/display/dc/dce120/dce120_resource.c
> index 1b70b78e2fa15..af631085e88c5 100644
> --- a/drivers/gpu/drm/amd/display/dc/dce120/dce120_resource.c
> +++ b/drivers/gpu/drm/amd/display/dc/dce120/dce120_resource.c
> @@ -359,7 +359,8 @@ static const struct dce_audio_registers audio_regs[] = {
> audio_regs(2),
> audio_regs(3),
> audio_regs(4),
> - audio_regs(5)
> + audio_regs(5),
> + audio_regs(6),
> };
>
> #define DCE120_AUD_COMMON_MASK_SH_LIST(mask_sh)\
> --
> 2.37.3
>