linux-kernel - Re: [PATCH] amdgpu/uvd: use kmemdup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <573DA0F2.2020503@amd.com>
Date:	Thu, 19 May 2016 13:18:10 +0200
From:	Christian König <christian.koenig@....com>
To:	Muhammad Falak R Wani <falakreyaz@...il.com>,
	David Airlie <airlied@...ux.ie>
CC:	Alex Deucher <alexander.deucher@....com>,
	Chunming Zhou <David1.Zhou@....com>,
	Jammy Zhou <Jammy.Zhou@....com>, Leo Liu <leo.liu@....com>,
	Sonny Jiang <sonny.jiang@....com>,
	<dri-devel@...ts.freedesktop.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] amdgpu/uvd: use kmemdup

Am 19.05.2016 um 13:11 schrieb Muhammad Falak R Wani:
> Use kmemdup when some other buffer is immediately copied into allocated
> region. It replaces call to allocation followed by memcpy, by a single
> call to kmemdup.
>
> Signed-off-by: Muhammad Falak R Wani <falakreyaz@...il.com>

NAK, actually using memcpy() is wrong in the first place.

The UVD BO is in VRAM so the pointer is pointing to IO memory here, so 
this should be memcpy_fromio() instead of memcpy().

Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c
> index 01abfc2..c977ab6 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c
> @@ -295,12 +295,10 @@ int amdgpu_uvd_suspend(struct amdgpu_device *adev)
>   	size = amdgpu_bo_size(adev->uvd.vcpu_bo);
>   	ptr = adev->uvd.cpu_addr;
>   
> -	adev->uvd.saved_bo = kmalloc(size, GFP_KERNEL);
> +	adev->uvd.saved_bo = kmemdup(ptr, size, GFP_KERNEL);
>   	if (!adev->uvd.saved_bo)
>   		return -ENOMEM;
>   
> -	memcpy(adev->uvd.saved_bo, ptr, size);
> -
>   	return 0;
>   }
>