On Wed, Oct 20, 2021 at 10:48:59AM -0700, Nathan Chancellor wrote:

On Wed, Oct 20, 2021 at 10:35:54AM -0700, Kees Cook wrote:

quoted

This plugin has no impact on the resulting binary, is disabled
under COMPILE_TEST, and is not enabled on any builds I'm aware of.
Additionally, given the clarified purpose of GCC plugins in the kernel,
remove cyc_complexity.

Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <redacted>
Cc: Nick Desaulniers <redacted>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-hardening@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Signed-off-by: Kees Cook <redacted>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

One comment below.

quoted

---
 Documentation/kbuild/gcc-plugins.rst        |  2 -
 scripts/Makefile.gcc-plugins                |  2 -
 scripts/gcc-plugins/Kconfig                 | 16 -----
 scripts/gcc-plugins/cyc_complexity_plugin.c | 69 ---------------------
 4 files changed, 89 deletions(-)
 delete mode 100644 scripts/gcc-plugins/cyc_complexity_plugin.c

diff --git a/Documentation/kbuild/gcc-plugins.rst b/Documentation/kbuild/gcc-plugins.rst
index 4b28c7a4032f..0ba76719f1b9 100644
--- a/Documentation/kbuild/gcc-plugins.rst
+++ b/Documentation/kbuild/gcc-plugins.rst

@@ -96,7 +96,6 @@ Enable the GCC plugin infrastructure and some plugin(s) you want to use
 in the kernel config::
 
 	CONFIG_GCC_PLUGINS=y
-	CONFIG_GCC_PLUGIN_CYC_COMPLEXITY=y
 	CONFIG_GCC_PLUGIN_LATENT_ENTROPY=y
 	...
 

There is a comment about the cyc_complexity plugin at the very end of
this file that should also be removed it seems:

"See the cyc_complexity_plugin.c (CONFIG_GCC_PLUGIN_CYC_COMPLEXITY) GCC plugin."

Yup; I think it was hiding from you, see here:

quoted

@@ -115,4 +114,3 @@ The GCC plugins are in scripts/gcc-plugins/. You need to put plugin source files
 right under scripts/gcc-plugins/. Creating subdirectories is not supported.
 It must be added to scripts/gcc-plugins/Makefile, scripts/Makefile.gcc-plugins
 and a relevant Kconfig file.
-See the cyc_complexity_plugin.c (CONFIG_GCC_PLUGIN_CYC_COMPLEXITY) GCC plugin.

    ^^^^

:)

Thanks!

-Kees

-- 
Kees Cook