* [BUG] gpu: drm: amd: amdgpu: possible ABBA deadlock in amdgpu_set_power_dpm_force_performance_level() and amdgpu_debugfs_process_reg_op()
@ 2021-09-15 9:39 Jia-Ju Bai
2021-12-09 3:34 ` Jia-Ju Bai
0 siblings, 1 reply; 2+ messages in thread
From: Jia-Ju Bai @ 2021-09-15 9:39 UTC (permalink / raw)
To: alexander.deucher, christian.koenig, Xinhui.Pan, airlied, daniel,
Hawking.Zhang, Felix.Kuehling, ray.huang, lee.jones
Cc: amd-gfx, dri-devel, linux-kernel
Hello,
My static analysis tool reports a possible ABBA deadlock in the amdgpu
driver in Linux 5.10:
amdgpu_debugfs_process_reg_op()
mutex_lock(&adev->grbm_idx_mutex); --> Line 250 (Lock A)
mutex_lock(&adev->pm.mutex); --> Line 259 (Lock B)
amdgpu_set_power_dpm_force_performance_level()
mutex_lock(&adev->pm.mutex); --> Line 381 (Lock B)
pp_dpm_force_performance_level() --> function pointer via
"amdgpu_dpm_force_performance_level()"
pp_dpm_en_umd_pstate()
amdgpu_device_ip_set_clockgating_state()
gfx_v7_0_set_clockgating_state() --> function pointer via
"funcs->set_clockgating_state()"
gfx_v7_0_enable_mgcg()
mutex_lock(&adev->grbm_idx_mutex); --> Line 3646 (Lock A)
mutex_lock(&adev->grbm_idx_mutex); --> Line 3697 (Lock A)
When amdgpu_debugfs_process_reg_op() and
amdgpu_set_power_dpm_force_performance_level() are concurrently
executed, the deadlock can occur.
I am not quite sure whether this possible deadlock is real and how to
fix it if it is real.
Any feedback would be appreciated, thanks :)
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Best wishes,
Jia-Ju Bai
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [BUG] gpu: drm: amd: amdgpu: possible ABBA deadlock in amdgpu_set_power_dpm_force_performance_level() and amdgpu_debugfs_process_reg_op()
2021-09-15 9:39 [BUG] gpu: drm: amd: amdgpu: possible ABBA deadlock in amdgpu_set_power_dpm_force_performance_level() and amdgpu_debugfs_process_reg_op() Jia-Ju Bai
@ 2021-12-09 3:34 ` Jia-Ju Bai
0 siblings, 0 replies; 2+ messages in thread
From: Jia-Ju Bai @ 2021-12-09 3:34 UTC (permalink / raw)
To: alexander.deucher, christian.koenig, Xinhui.Pan, airlied, daniel,
Hawking.Zhang, Felix.Kuehling, ray.huang, lee.jones
Cc: dri-devel, amd-gfx, linux-kernel
Hello,
Could you please provide the feedback to my previous report?
Thanks a lot :)
Best wishes,
Jia-Ju Bai
On 2021/9/15 17:39, Jia-Ju Bai wrote:
> Hello,
>
> My static analysis tool reports a possible ABBA deadlock in the amdgpu
> driver in Linux 5.10:
>
> amdgpu_debugfs_process_reg_op()
> mutex_lock(&adev->grbm_idx_mutex); --> Line 250 (Lock A)
> mutex_lock(&adev->pm.mutex); --> Line 259 (Lock B)
>
> amdgpu_set_power_dpm_force_performance_level()
> mutex_lock(&adev->pm.mutex); --> Line 381 (Lock B)
> pp_dpm_force_performance_level() --> function pointer via
> "amdgpu_dpm_force_performance_level()"
> pp_dpm_en_umd_pstate()
> amdgpu_device_ip_set_clockgating_state()
> gfx_v7_0_set_clockgating_state() --> function pointer via
> "funcs->set_clockgating_state()"
> gfx_v7_0_enable_mgcg()
> mutex_lock(&adev->grbm_idx_mutex); --> Line 3646 (Lock A)
> mutex_lock(&adev->grbm_idx_mutex); --> Line 3697 (Lock A)
>
> When amdgpu_debugfs_process_reg_op() and
> amdgpu_set_power_dpm_force_performance_level() are concurrently
> executed, the deadlock can occur.
>
> I am not quite sure whether this possible deadlock is real and how to
> fix it if it is real.
> Any feedback would be appreciated, thanks :)
>
> Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
>
>
> Best wishes,
> Jia-Ju Bai
^ permalink raw reply [flat|nested] 2+ messages in thread
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2021-09-15 9:39 [BUG] gpu: drm: amd: amdgpu: possible ABBA deadlock in amdgpu_set_power_dpm_force_performance_level() and amdgpu_debugfs_process_reg_op() Jia-Ju Bai
2021-12-09 3:34 ` Jia-Ju Bai
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