[PATCH] drm/amd: Taint the kernel when enabling overdrive

[Alex Deucher]

On Wed, Sep 25, 2024 at 4:12 PM Mario Limonciello
<mario.limonciello at amd.com> wrote:
>
> On 9/25/2024 15:09, Alex Deucher wrote:
> > On Wed, Sep 25, 2024 at 4:05 PM Mario Limonciello
> > <mario.limonciello at amd.com> wrote:
> >>
> >> Some distributions have been patching amdgpu to enable overdrive by
> >> default which may compromise stability.  Furthermore when bug reports
> >> are brought upstream it's not obvious that the system has been tampered
> >> with.
> >>
> >> When overdrive is enabled taint the kernel and leave a critical message
> >> in the logs for users so that it's obvious in a bug report it's been
> >> tampered with.
> >>
> >> Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>
> >> ---
> >>   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 5 +++++
> >>   1 file changed, 5 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> >> index f57411ed2dc2..99717a1d7f61 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> >> @@ -3067,6 +3067,11 @@ static int __init amdgpu_init(void)
> >>          /* Ignore KFD init failures. Normal when CONFIG_HSA_AMD is not set. */
> >>          amdgpu_amdkfd_init();
> >>
> >> +       if (amdgpu_pp_feature_mask & PP_OVERDRIVE_MASK) {
> >> +               add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
> >> +               pr_crit("Overdrive is enabled, please disable it before reporting any bugs.\n");
> >
> > Might want to reword this to something like:
> > "Overdrive is enabled, please disable it before reporting any bugs
> > unrelated to overdrive.\n"
> >
> Thanks, good suggestion; I'll reword.  Are you in agreement with the
> selected taint code and location in the driver?

Yes, with that change, the patch is:
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

>
> > Alex
> >
> >> +       }
> >> +
> >>          /* let modprobe override vga console setting */
> >>          return pci_register_driver(&amdgpu_kms_pci_driver);
> >>
> >> --
> >> 2.43.0
> >>
>