Re: [PATCH 1/1] drm/amdgpu: fix NULL pointer dereference for Renoir

From: Dirk Gouders
Date: Thu Oct 01 2020 - 16:37:33 EST


Dirk Gouders <dirk@xxxxxxxxxxx> writes:

> Commit c1cf79ca5ced46 (drm/amdgpu: use IP discovery table for renoir)
> introduced a NULL pointer dereference when booting with
> amdgpu.discovery=0, because it removed the call of vega10_reg_base_init()
> for that case.
>
> Fix this by calling that funcion if amdgpu_discovery == 0 in addition to
> the case that amdgpu_discovery_reg_base_init() failed.
>
> Fixes: c1cf79ca5ced46 (drm/amdgpu: use IP discovery table for renoir)
> Signed-off-by: Dirk Gouders <dirk@xxxxxxxxxxx>
> Cc: Hawking Zhang <Hawking.Zhang@xxxxxxx>
> Cc: Evan Quan <evan.quan@xxxxxxx>
> ---
> drivers/gpu/drm/amd/amdgpu/soc15.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/soc15.c b/drivers/gpu/drm/amd/amdgpu/soc15.c
> index 84d811b6e48b..f8cb62b326d6 100644
> --- a/drivers/gpu/drm/amd/amdgpu/soc15.c
> +++ b/drivers/gpu/drm/amd/amdgpu/soc15.c
> @@ -694,12 +694,12 @@ static void soc15_reg_base_init(struct amdgpu_device *adev)
> * it doesn't support SRIOV. */
> if (amdgpu_discovery) {
> r = amdgpu_discovery_reg_base_init(adev);
> - if (r) {
> - DRM_WARN("failed to init reg base from ip discovery table, "
> - "fallback to legacy init method\n");
> - vega10_reg_base_init(adev);
> - }
> + if (r == 0)
> + break;

Grrr, wrong indentation here.
But I will wait for your review before v1.

Dirk


> + DRM_WARN("failed to init reg base from ip discovery table, "
> + "fallback to legacy init method\n");
> }
> + vega10_reg_base_init(adev);
> break;
> case CHIP_VEGA20:
> vega20_reg_base_init(adev);