From: Kees Cook <keescook@chromium.org>
To: Nathan Chancellor <nathan@kernel.org>
Cc: Hyun Kwon <hyun.kwon@xilinx.com>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
dri-devel@lists.freedesktop.org,
linux-arm-kernel@lists.infradead.org,
Nick Desaulniers <ndesaulniers@google.com>,
Tom Rix <trix@redhat.com>,
Sami Tolvanen <samitolvanen@google.com>,
llvm@lists.linux.dev, linux-kernel@vger.kernel.org,
patches@lists.linux.dev, Nathan Huckleberry <nhuck@google.com>,
Dan Carpenter <error27@gmail.com>
Subject: Re: [PATCH v2] drm: xlnx: Fix return type of zynqmp_dp_bridge_mode_valid
Date: Wed, 9 Nov 2022 11:07:12 -0800 [thread overview]
Message-ID: <202211091107.718BF1BE89@keescook> (raw)
In-Reply-To: <20221109001424.1422495-1-nathan@kernel.org>
On Tue, Nov 08, 2022 at 05:14:25PM -0700, Nathan Chancellor wrote:
> From: Nathan Huckleberry <nhuck@google.com>
>
> The mode_valid field in drm_bridge_helper_funcs is expected to be of
> type
> enum drm_mode_status (* mode_valid) (struct drm_bridge *bridge,
> struct drm_display_mode *mode);
>
> The mismatched return type breaks forward edge kCFI since the underlying
> function definition does not match the function hook definition. A new
> warning in clang will catch this at compile time:
>
> drivers/gpu/drm/xlnx/zynqmp_dp.c:1573:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' with an expression of type 'int (struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict]
> .mode_valid = zynqmp_dp_bridge_mode_valid,
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~
> 1 error generated.
>
> The return type of zynqmp_dp_bridge_mode_valid should be changed from
> int to enum drm_mode_status.
>
> Reported-by: Dan Carpenter <error27@gmail.com>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1703
> Link: https://github.com/ClangBuiltLinux/linux/issues/1750
> Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
WARNING: multiple messages have this Message-ID (diff)
From: Kees Cook <keescook@chromium.org>
To: Nathan Chancellor <nathan@kernel.org>
Cc: Dan Carpenter <error27@gmail.com>,
Hyun Kwon <hyun.kwon@xilinx.com>, Tom Rix <trix@redhat.com>,
llvm@lists.linux.dev, Nick Desaulniers <ndesaulniers@google.com>,
linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
patches@lists.linux.dev,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Sami Tolvanen <samitolvanen@google.com>,
Nathan Huckleberry <nhuck@google.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] drm: xlnx: Fix return type of zynqmp_dp_bridge_mode_valid
Date: Wed, 9 Nov 2022 11:07:12 -0800 [thread overview]
Message-ID: <202211091107.718BF1BE89@keescook> (raw)
In-Reply-To: <20221109001424.1422495-1-nathan@kernel.org>
On Tue, Nov 08, 2022 at 05:14:25PM -0700, Nathan Chancellor wrote:
> From: Nathan Huckleberry <nhuck@google.com>
>
> The mode_valid field in drm_bridge_helper_funcs is expected to be of
> type
> enum drm_mode_status (* mode_valid) (struct drm_bridge *bridge,
> struct drm_display_mode *mode);
>
> The mismatched return type breaks forward edge kCFI since the underlying
> function definition does not match the function hook definition. A new
> warning in clang will catch this at compile time:
>
> drivers/gpu/drm/xlnx/zynqmp_dp.c:1573:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' with an expression of type 'int (struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict]
> .mode_valid = zynqmp_dp_bridge_mode_valid,
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~
> 1 error generated.
>
> The return type of zynqmp_dp_bridge_mode_valid should be changed from
> int to enum drm_mode_status.
>
> Reported-by: Dan Carpenter <error27@gmail.com>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1703
> Link: https://github.com/ClangBuiltLinux/linux/issues/1750
> Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
WARNING: multiple messages have this Message-ID (diff)
From: Kees Cook <keescook@chromium.org>
To: Nathan Chancellor <nathan@kernel.org>
Cc: Hyun Kwon <hyun.kwon@xilinx.com>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
dri-devel@lists.freedesktop.org,
linux-arm-kernel@lists.infradead.org,
Nick Desaulniers <ndesaulniers@google.com>,
Tom Rix <trix@redhat.com>,
Sami Tolvanen <samitolvanen@google.com>,
llvm@lists.linux.dev, linux-kernel@vger.kernel.org,
patches@lists.linux.dev, Nathan Huckleberry <nhuck@google.com>,
Dan Carpenter <error27@gmail.com>
Subject: Re: [PATCH v2] drm: xlnx: Fix return type of zynqmp_dp_bridge_mode_valid
Date: Wed, 9 Nov 2022 11:07:12 -0800 [thread overview]
Message-ID: <202211091107.718BF1BE89@keescook> (raw)
In-Reply-To: <20221109001424.1422495-1-nathan@kernel.org>
On Tue, Nov 08, 2022 at 05:14:25PM -0700, Nathan Chancellor wrote:
> From: Nathan Huckleberry <nhuck@google.com>
>
> The mode_valid field in drm_bridge_helper_funcs is expected to be of
> type
> enum drm_mode_status (* mode_valid) (struct drm_bridge *bridge,
> struct drm_display_mode *mode);
>
> The mismatched return type breaks forward edge kCFI since the underlying
> function definition does not match the function hook definition. A new
> warning in clang will catch this at compile time:
>
> drivers/gpu/drm/xlnx/zynqmp_dp.c:1573:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' with an expression of type 'int (struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict]
> .mode_valid = zynqmp_dp_bridge_mode_valid,
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~
> 1 error generated.
>
> The return type of zynqmp_dp_bridge_mode_valid should be changed from
> int to enum drm_mode_status.
>
> Reported-by: Dan Carpenter <error27@gmail.com>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1703
> Link: https://github.com/ClangBuiltLinux/linux/issues/1750
> Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-11-09 19:07 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-09 0:14 [PATCH v2] drm: xlnx: Fix return type of zynqmp_dp_bridge_mode_valid Nathan Chancellor
2022-11-09 0:14 ` Nathan Chancellor
2022-11-09 0:14 ` Nathan Chancellor
2022-11-09 14:21 ` Laurent Pinchart
2022-11-09 14:21 ` Laurent Pinchart
2022-11-09 14:21 ` Laurent Pinchart
2022-11-09 19:07 ` Kees Cook [this message]
2022-11-09 19:07 ` Kees Cook
2022-11-09 19:07 ` Kees Cook
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