linux.git/scripts/gcc-plugins/Kconfig, branch v6.18.21

Merge tag 'gcc-minimum-version-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2025-05-31T15:16:52+00:00

Pull compiler version requirement update from Arnd Bergmann:
 "Require gcc-8 and binutils-2.30

  x86 already uses gcc-8 as the minimum version, this changes all other
  architectures to the same version. gcc-8 is used is Debian 10 and Red
  Hat Enterprise Linux 8, both of which are still supported, and
  binutils 2.30 is the oldest corresponding version on those.

  Ubuntu Pro 18.04 and SUSE Linux Enterprise Server 15 both use gcc-7 as
  the system compiler but additionally include toolchains that remain
  supported.

  With the new minimum toolchain versions, a number of workarounds for
  older versions can be dropped, in particular on x86_64 and arm64.
  Importantly, the updated compiler version allows removing two of the
  five remaining gcc plugins, as support for sancov and structeak
  features is already included in modern compiler versions.

  I tried collecting the known changes that are possible based on the
  new toolchain version, but expect that more cleanups will be possible.

  Since this touches multiple architectures, I merged the patches
  through the asm-generic tree."

* tag 'gcc-minimum-version-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  Makefile.kcov: apply needed compiler option unconditionally in CFLAGS_KCOV
  Documentation: update binutils-2.30 version reference
  gcc-plugins: remove SANCOV gcc plugin
  Kbuild: remove structleak gcc plugin
  arm64: drop binutils version checks
  raid6: skip avx512 checks
  kbuild: require gcc-8 and binutils-2.30

gcc-plugins: remove SANCOV gcc plugin

2025-04-30T19:57:09+00:00

With the minimum gcc version raised to 8.1, all supported compilers
now understand the -fsanitize-coverage=trace-pc option, and there
is no longer a need for the separate compiler plugin.

Since only gcc-5 was able to use the plugin for several year now,
it was already likely unused.

Signed-off-by: Arnd Bergmann

gcc-plugins: Remove ARM_SSP_PER_TASK plugin

2025-04-28T17:32:43+00:00

As part of trying to remove GCC plugins from Linux, drop the
ARM_SSP_PER_TASK plugin. The feature is available upstream since GCC
12, so anyone needing newer kernels with per-task ssp can update their
compiler[1].

Suggested-by: Arnd Bergmann 
Link: https://lore.kernel.org/all/08393aa3-05a3-4e3f-8004-f374a3ec4b7e@app.fastmail.com/ [1]
Acked-by: Arnd Bergmann 
Acked-by: Ard Biesheuvel 
Link: https://lore.kernel.org/r/20250409160409.work.168-kees@kernel.org
Signed-off-by: Kees Cook

randstruct: Reorganize Kconfigs and attribute macros

2022-05-08T08:33:06+00:00

In preparation for Clang supporting randstruct, reorganize the Kconfigs,
move the attribute macros, and generalize the feature to be named
CONFIG_RANDSTRUCT for on/off, CONFIG_RANDSTRUCT_FULL for the full
randomization mode, and CONFIG_RANDSTRUCT_PERFORMANCE for the cache-line
sized mode.

Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20220503205503.3054173-4-keescook@chromium.org

gcc-plugins: Remove cyc_complexity

2021-10-21T15:41:47+00:00

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 
Cc: Michal Marek 
Cc: Nick Desaulniers 
Cc: Jonathan Corbet 
Cc: linux-hardening@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Signed-off-by: Kees Cook 
Reviewed-by: Miguel Ojeda 
Reviewed-by: Nathan Chancellor 
Acked-by: Nick Desaulniers 
Acked-by: Ard Biesheuvel 
Link: https://lore.kernel.org/r/20211020173554.38122-3-keescook@chromium.org

gcc-plugins: Explicitly document purpose and deprecation schedule

2021-10-21T15:41:38+00:00

GCC plugins should only exist when some compiler feature needs to be
proven but does not exist in either GCC nor Clang. For example, if a
desired feature is already in Clang, it should be added to GCC upstream.
Document this explicitly.

Additionally, mark the plugins with matching upstream GCC features as
removable past their respective GCC versions.

Cc: Masahiro Yamada 
Cc: Michal Marek 
Cc: Nick Desaulniers 
Cc: Jonathan Corbet 
Cc: James Morris 
Cc: "Serge E. Hallyn" 
Cc: Nathan Chancellor 
Cc: linux-hardening@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: llvm@lists.linux.dev
Signed-off-by: Kees Cook 
Reviewed-by: Nathan Chancellor 
Reviewed-by: Miguel Ojeda 
Acked-by: Nick Desaulniers 
Acked-by: Ard Biesheuvel 
Link: https://lore.kernel.org/r/20211020173554.38122-2-keescook@chromium.org

gcc-plugins: simplify GCC plugin-dev capability test

2020-12-04T22:09:55+00:00

Linus pointed out a third of the time in the Kconfig parse stage comes
from the single invocation of cc1plus in scripts/gcc-plugin.sh [1],
and directly testing plugin-version.h for existence cuts down the
overhead a lot. [2]

This commit takes one step further to kill the build test entirely.

The small piece of code was probably intended to test the C++ designated
initializer, which was not supported until C++20.

In fact, with -pedantic option given, both GCC and Clang emit a warning.

$ echo 'class test { public: int test; } test = { .test = 1 };' | g++ -x c++ -pedantic - -fsyntax-only
:1:43: warning: C++ designated initializers only available with '-std=c++2a' or '-std=gnu++2a' [-Wpedantic]
$ echo 'class test { public: int test; } test = { .test = 1 };' | clang++ -x c++ -pedantic - -fsyntax-only
:1:43: warning: designated initializers are a C++20 extension [-Wc++20-designator]
class test { public: int test; } test = { .test = 1 };
                                          ^
1 warning generated.

Otherwise, modern C++ compilers should be able to build the code, and
hopefully skipping this test should not make any practical problem.

Checking the existence of plugin-version.h is still needed to ensure
the plugin-dev package is installed. The test code is now small enough
to be embedded in scripts/gcc-plugins/Kconfig.

[1] https://lore.kernel.org/lkml/CAHk-=wjU4DCuwQ4pXshRbwDCUQB31ScaeuDo1tjoZ0_PjhLHzQ@mail.gmail.com/
[2] https://lore.kernel.org/lkml/CAHk-=whK0aQxs6Q5ijJmYF1n2ch8cVFSUzU5yUM_HOjig=+vnw@mail.gmail.com/

Reported-by: Linus Torvalds 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20201203125700.161354-1-masahiroy@kernel.org

gcc-plugins: fix gcc-plugins directory path in documentation

2020-06-28T03:16:55+00:00

Fix typos "plgins" -> "plugins".

Signed-off-by: Masahiro Yamada 
Acked-by: Kees Cook

compiler/gcc: Raise minimum GCC version for kernel builds to 4.8

2020-04-15T20:36:20+00:00

It is very rare to see versions of GCC prior to 4.8 being used to build
the mainline kernel. These old compilers are also know to have codegen
issues which can lead to silent miscompilation:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145

Raise the minimum GCC version for kernel build to 4.8 and remove some
tautological Kconfig dependencies as a consequence.

Cc: Masahiro Yamada 
Acked-by: Arnd Bergmann 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Will Deacon

gcc-plugins: drop support for GCC <= 4.7

2020-04-08T15:13:45+00:00

Nobody was opposed to raising minimum GCC version to 4.8 [1]
So, we will drop GCC <= 4.7 support sooner or later.

We always use C++ compiler for building plugins for GCC >= 4.8.

This commit drops the plugin support for GCC <= 4.7 a bit earlier,
which allows us to dump lots of code.

[1] https://lkml.org/lkml/2020/1/23/545

Signed-off-by: Masahiro Yamada 
Acked-by: Kees Cook