Re:Re: [PATCH] amdgpu: fixes memleak issue when init failed

[赵军奎]

发件人："Christian König" <christian.koenig at amd.com>
发送日期：2020-04-21 21:02:27
收件人："赵军奎" <bernard at vivo.com>
抄送人：Alex Deucher <alexander.deucher at amd.com>,"David (ChunMing) Zhou" <David1.Zhou at amd.com>,David Airlie <airlied at linux.ie>,Daniel Vetter <daniel at ffwll.ch>,Tom St Denis <tom.stdenis at amd.com>,Ori Messinger <Ori.Messinger at amd.com>,Sam Ravnborg <sam at ravnborg.org>,amd-gfx at lists.freedesktop.org,dri-devel at lists.freedesktop.org,linux-kernel at vger.kernel.org,opensource.kernel at vivo.com
主题：Re: [PATCH] amdgpu: fixes memleak issue when init failed>Am 21.04.20 um 14:09 schrieb 赵军奎:
>> From: "Christian König" <christian.koenig at amd.com>
>> Date: 2020-04-21 19:22:49
>> To:  Bernard Zhao <bernard at vivo.com>,Alex Deucher <alexander.deucher at amd.com>,"David (ChunMing) Zhou" <David1.Zhou at amd.com>,David Airlie <airlied at linux.ie>,Daniel Vetter <daniel at ffwll.ch>,Tom St Denis <tom.stdenis at amd.com>,Ori Messinger <Ori.Messinger at amd.com>,Sam Ravnborg <sam at ravnborg.org>,amd-gfx at lists.freedesktop.org,dri-devel at lists.freedesktop.org,linux-kernel at vger.kernel.org
>> Cc:  opensource.kernel at vivo.com
>> Subject: Re: [PATCH] amdgpu: fixes memleak issue when init failed>Am 21.04.20 um 13:17 schrieb Bernard Zhao:
>>>> VRAM manager and DRM MM when init failed, there is no operaction
>>>> to free kzalloc memory & remove device file.
>>>> This will lead to memleak & cause stability issue.
>>> NAK, failure to create sysfs nodes are not critical.
>>>
>>> Christian.
>>>
>> OK, get it.
>> By the way, should i modify this patch to just handle <kfree(mgr)> in error branch, or that it is also unnecessary?
>
>What you can do is to drop the "return ret" if anything with the sysfs 
>nodes goes wrong and instead print the error code.

Emmm, for this part, i am not sure, my modify first print the error, secone release not free memory, 
and last return error, make everything clear to the system.
I think it`s the same with what you mentioned, is there something that I misunderstood?

>
>It's really annoying that loading, unloading and loading the driver 
>again sometimes fails because we have a bug in the sysfs files cleanup.
>
>We certainly should fix those bugs as well, but they are just not 
>critical for correct driver functionality.
>
>Regards,
>Christian.


>>
>> Regards,
>> Bernard
>>
>>>> Signed-off-by: Bernard Zhao <bernard at vivo.com>
>>>> ---
>>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 24 ++++++++++++++++----
>>>>    1 file changed, 19 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>>> index 82a3299e53c0..4c5fb153e6b4 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>>> @@ -175,30 +175,44 @@ static int amdgpu_vram_mgr_init(struct ttm_mem_type_manager *man,
>>>>    	ret = device_create_file(adev->dev, &dev_attr_mem_info_vram_total);
>>>>    	if (ret) {
>>>>    		DRM_ERROR("Failed to create device file mem_info_vram_total\n");
>>>> -		return ret;
>>>> +		goto VRAM_TOTAL_FAIL;
>>>>    	}
>>>>    	ret = device_create_file(adev->dev, &dev_attr_mem_info_vis_vram_total);
>>>>    	if (ret) {
>>>>    		DRM_ERROR("Failed to create device file mem_info_vis_vram_total\n");
>>>> -		return ret;
>>>> +		goto VIS_VRAM_TOTA_FAIL;
>>>>    	}
>>>>    	ret = device_create_file(adev->dev, &dev_attr_mem_info_vram_used);
>>>>    	if (ret) {
>>>>    		DRM_ERROR("Failed to create device file mem_info_vram_used\n");
>>>> -		return ret;
>>>> +		goto VRAM_USED_FAIL;
>>>>    	}
>>>>    	ret = device_create_file(adev->dev, &dev_attr_mem_info_vis_vram_used);
>>>>    	if (ret) {
>>>>    		DRM_ERROR("Failed to create device file mem_info_vis_vram_used\n");
>>>> -		return ret;
>>>> +		goto VIS_VRAM_USED_FAIL;
>>>>    	}
>>>>    	ret = device_create_file(adev->dev, &dev_attr_mem_info_vram_vendor);
>>>>    	if (ret) {
>>>>    		DRM_ERROR("Failed to create device file mem_info_vram_vendor\n");
>>>> -		return ret;
>>>> +		goto VRAM_VERDOR_FAIL;
>>>>    	}
>>>>    
>>>>    	return 0;
>>>> +
>>>> +VRAM_VERDOR_FAIL:
>>>> +	device_remove_file(adev->dev, &dev_attr_mem_info_vis_vram_used);
>>>> +VIS_VRAM_USED_FAIL:
>>>> +	device_remove_file(adev->dev, &dev_attr_mem_info_vram_used);
>>>> +RVAM_USED_FAIL:
>>>> +	device_remove_file(adev->dev, &dev_attr_mem_info_vis_vram_total);
>>>> +VIS_VRAM_TOTA_FAIL:
>>>> +	device_remove_file(adev->dev, &dev_attr_mem_info_vram_total);
>>>> +VRAM_TOTAL_FAIL:
>>>> +	kfree(mgr);
>>>> +	man->priv = NULL;
>>>> +
>>>> +	return ret;
>>>>    }
>>>>    
>>>>    /**
>>
>