[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <202211020842.8F3ECD397@keescook>
Date: Wed, 2 Nov 2022 08:42:54 -0700
From: Kees Cook <keescook@...omium.org>
To: Nathan Chancellor <nathan@...nel.org>
Cc: Alex Deucher <alexander.deucher@....com>,
Christian König <christian.koenig@....com>,
"Pan, Xinhui" <Xinhui.Pan@....com>, amd-gfx@...ts.freedesktop.org,
dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
Nick Desaulniers <ndesaulniers@...gle.com>,
Tom Rix <trix@...hat.com>,
Sami Tolvanen <samitolvanen@...gle.com>, llvm@...ts.linux.dev,
patches@...ts.linux.dev
Subject: Re: [PATCH 1/2] drm/amdgpu: Fix type of second parameter in
trans_msg() callback
On Wed, Nov 02, 2022 at 08:25:39AM -0700, Nathan Chancellor wrote:
> With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
> indirect call targets are validated against the expected function
> pointer prototype to make sure the call target is valid to help mitigate
> ROP attacks. If they are not identical, there is a failure at run time,
> which manifests as either a kernel panic or thread getting killed. A
> proposed warning in clang aims to catch these at compile time, which
> reveals:
>
> drivers/gpu/drm/amd/amdgpu/mxgpu_ai.c:412:15: error: incompatible function pointer types initializing 'void (*)(struct amdgpu_device *, u32, u32, u32, u32)' (aka 'void (*)(struct amdgpu_device *, unsigned int, unsigned int, unsigned int, unsigned int)') with an expression of type 'void (struct amdgpu_device *, enum idh_request, u32, u32, u32)' (aka 'void (struct amdgpu_device *, enum idh_request, unsigned int, unsigned int, unsigned int)') [-Werror,-Wincompatible-function-pointer-types-strict]
> .trans_msg = xgpu_ai_mailbox_trans_msg,
> ^~~~~~~~~~~~~~~~~~~~~~~~~
> 1 error generated.
>
> drivers/gpu/drm/amd/amdgpu/mxgpu_nv.c:435:15: error: incompatible function pointer types initializing 'void (*)(struct amdgpu_device *, u32, u32, u32, u32)' (aka 'void (*)(struct amdgpu_device *, unsigned int, unsigned int, unsigned int, unsigned int)') with an expression of type 'void (struct amdgpu_device *, enum idh_request, u32, u32, u32)' (aka 'void (struct amdgpu_device *, enum idh_request, unsigned int, unsigned int, unsigned int)') [-Werror,-Wincompatible-function-pointer-types-strict]
> .trans_msg = xgpu_nv_mailbox_trans_msg,
> ^~~~~~~~~~~~~~~~~~~~~~~~~
> 1 error generated.
>
> The type of the second parameter in the prototype should be 'enum
> idh_request' instead of 'u32'. Update it to clear up the warnings.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1750
> Reported-by: Sami Tolvanen <samitolvanen@...gle.com>
> Signed-off-by: Nathan Chancellor <nathan@...nel.org>
Reviewed-by: Kees Cook <keescook@...omium.org>
--
Kees Cook
Powered by blists - more mailing lists