Looks good to me! Den mån 16 maj 2022 kl 20:15 skrev Alex Deucher <alexdeuc...@gmail.com>:
> On Mon, May 16, 2022 at 2:10 PM Christian König > <ckoenig.leichtzumer...@gmail.com> wrote: > > > > Am 16.05.22 um 19:49 schrieb Ernst Sjöstrand: > > > > Den mån 16 maj 2022 kl 17:13 skrev Alex Deucher <alexdeuc...@gmail.com>: > >> > >> On Sun, May 15, 2022 at 11:46 AM Ernst Sjöstrand <ern...@gmail.com> > wrote: > >> > > >> > smatch found this problem on amd-staging-drm-next: > >> > > >> > drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1443 > amdgpu_discovery_get_vcn_info() error: buffer overflow > 'adev->vcn.vcn_codec_disable_mask' 2 <= 3 > >> > > >> > This is caused by: > >> > #define AMDGPU_MAX_VCN_INSTANCES 2 > >> > #define VCN_INFO_TABLE_MAX_NUM_INSTANCES 4 > >> > > >> > Can we just drop VCN_INFO_TABLE_MAX_NUM_INSTANCES completely and use > AMDGPU_MAX_VCN_INSTANCES everywhere instead (and bump it to 4)? > >> > >> We should be able to bump AMDGPU_MAX_VCN_INSTANCES to 4 (although it > >> would waste some memory in the places it is used at this point). > >> VCN_INFO_TABLE_MAX_NUM_INSTANCES is part of a firmware structure so we > >> can't change that without breaking the firmware structure. > >> > >> Alex > > > > > > It would be nice to get rid of this pattern and make sure it doesn't > happen again when the VCN info table is raised to 5. > > It's very similar to the HWIP_MAX_INSTANCE issue. > > > > > > No, as Alex explained that distinction is intentional. > > > > The firmware definition is 4 for future extensions, that doesn't mean > that this is currently used. > > > > There is currently simply no need to set AMDGPU_MAX_VCN_INSTANCES to > more than 2. > > Right. The attached patch should protect against the scenario you are > envisioning. > > Alex > > > > > Regards, > > Christian. > > > > > > //E > > > > >