Messages in this thread | | | Subject | Re: [PATCH] amdgpu: fixes memleak issue when init failed | From | Christian König <> | Date | Wed, 22 Apr 2020 09:27:23 +0200 |
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Am 22.04.20 um 02:56 schrieb 赵军奎: > 发件人:"Christian König" <christian.koenig@amd.com> > 发送日期:2020-04-21 22:53:47 > 收件人:"赵军奎" <bernard@vivo.com> > 抄送人:Alex Deucher <alexander.deucher@amd.com>,"David (ChunMing) Zhou" <David1.Zhou@amd.com>,David Airlie <airlied@linux.ie>,Daniel Vetter <daniel@ffwll.ch>,Tom St Denis <tom.stdenis@amd.com>,Ori Messinger <Ori.Messinger@amd.com>,Sam Ravnborg <sam@ravnborg.org>,amd-gfx@lists.freedesktop.org,dri-devel@lists.freedesktop.org,linux-kernel@vger.kernel.org,opensource.kernel@vivo.com > 主题:Re: [PATCH] amdgpu: fixes memleak issue when init failed>Am 21.04.20 um 15:39 schrieb 赵军奎: >>> 发件人:"Christian König" <christian.koenig@amd.com> >>> 发送日期:2020-04-21 21:02:27 >>> 收件人:"赵军奎" <bernard@vivo.com> >>> 抄送人:Alex Deucher <alexander.deucher@amd.com>,"David (ChunMing) Zhou" <David1.Zhou@amd.com>,David Airlie <airlied@linux.ie>,Daniel Vetter <daniel@ffwll.ch>,Tom St Denis <tom.stdenis@amd.com>,Ori Messinger <Ori.Messinger@amd.com>,Sam Ravnborg <sam@ravnborg.org>,amd-gfx@lists.freedesktop.org,dri-devel@lists.freedesktop.org,linux-kernel@vger.kernel.org,opensource.kernel@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@amd.com> >>>>> Date: 2020-04-21 19:22:49 >>>>> To: Bernard Zhao <bernard@vivo.com>,Alex Deucher <alexander.deucher@amd.com>,"David (ChunMing) Zhou" <David1.Zhou@amd.com>,David Airlie <airlied@linux.ie>,Daniel Vetter <daniel@ffwll.ch>,Tom St Denis <tom.stdenis@amd.com>,Ori Messinger <Ori.Messinger@amd.com>,Sam Ravnborg <sam@ravnborg.org>,amd-gfx@lists.freedesktop.org,dri-devel@lists.freedesktop.org,linux-kernel@vger.kernel.org >>>>> Cc: opensource.kernel@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? >> Yes, maybe an example makes it more clear what to do here. Currently we >> print and error and return when something with the sysfs files goes wrong: >> >> if (ret) { >> DRM_ERROR("Failed to create device file mem_info_vram_total\n"); >> return ret; >> } >> >> But what we should do instead is just to print an error and continue and >> in the end return success status: >> >> if (ret) >> DRM_ERROR("Failed to create device file mem_info_vram_total >> (%d)\n", r); >> >> ... >> return 0; >> >> Regards, >> Christian. >> > Emmm, i am still confused about two points: > 1 Does that mean there is no failed case in this function?
Well the kzalloc can still fail.
> 2 There is no need to free the kzmalloc space(no possibility of memory leak )?
Correct, yes.
Regards, Christian.
> > Regards, > Bernard > >>>> 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@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; >>>>>>> } >>>>>>> >>>>>>> /** >
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