On Wed, Apr 22, 2020 at 9:13 AM limingyu <limingyu@xxxxxxxxxxxxx> wrote:
>
> For chip like CHIP_OLAND with si enabled(amdgpu.si_support=1),
> the amdgpu will expose pp_num_states to the /sys directory.
> In this moment, read the pp_num_states file will excute the
> amdgpu_get_pp_num_states func. In our case, the data hasn't
> been initialized, so the kernel will access some ilegal
> address, trigger the segmentfault and system will reboot soon:
>
> uos@uos-PC:~$ cat /sys/devices/pci0000\:00/0000\:00\:00.0/0000\:01\:00
> .0/pp_num_states
>
> Message from syslogd@uos-PC at Apr 22 09:26:20 ...
> kernel:[ 82.154129] Internal error: Oops: 96000004 [#1] SMP
>
> This patch aims to fix this problem, avoid that reading file
> triggers the kernel sementfault.
>
> Signed-off-by: limingyu <limingyu@xxxxxxxxxxxxx>
> Signed-off-by: zhoubinbin <zhoubinbin@xxxxxxxxxxxxx>
Applied. Thanks!
Alex
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
> index abe94a55ecad..17de9dc60ea1 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
> @@ -444,8 +444,10 @@ static ssize_t amdgpu_get_pp_num_states(struct device *dev,
> ret = smu_get_power_num_states(&adev->smu, &data);
> if (ret)
> return ret;
> - } else if (adev->powerplay.pp_funcs->get_pp_num_states)
> + } else if (adev->powerplay.pp_funcs->get_pp_num_states) {
> amdgpu_dpm_get_pp_num_states(adev, &data);
> + } else
> + memset(&data, 0, sizeof(data));
>
> pm_runtime_mark_last_busy(ddev->dev);
> pm_runtime_put_autosuspend(ddev->dev);
> --
> 2.20.1
>
>
>
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
_______________________________________________
amd-gfx mailing list
amd-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
