gcc-plugins: split out Kconfig entries to scripts/gcc-plugins/Kconfig

Collect relevant code into the scripts/gcc-plugins directory.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

1 files changed, 142 insertions, 0 deletions

diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig
new file mode 100644
index 000000000000..7430a7c77a4a
--- /dev/null
+++ b/scripts/gcc-plugins/Kconfig
@@ -0,0 +1,142 @@
+preferred-plugin-hostcc := $(if-success,[ $(gcc-version) -ge 40800 ],$(HOSTCXX),$(HOSTCC))
+
+config PLUGIN_HOSTCC
+	string
+	default "$(shell,$(srctree)/scripts/gcc-plugin.sh "$(preferred-plugin-hostcc)" "$(HOSTCXX)" "$(CC)")"
+	help
+	  Host compiler used to build GCC plugins.  This can be $(HOSTCXX),
+	  $(HOSTCC), or a null string if GCC plugin is unsupported.
+
+config HAVE_GCC_PLUGINS
+	bool
+	help
+	  An arch should select this symbol if it supports building with
+	  GCC plugins.
+
+menuconfig GCC_PLUGINS
+	bool "GCC plugins"
+	depends on HAVE_GCC_PLUGINS
+	depends on PLUGIN_HOSTCC != ""
+	help
+	  GCC plugins are loadable modules that provide extra features to the
+	  compiler. They are useful for runtime instrumentation and static analysis.
+
+	  See Documentation/gcc-plugins.txt for details.
+
+if GCC_PLUGINS
+
+config GCC_PLUGIN_CYC_COMPLEXITY
+	bool "Compute the cyclomatic complexity of a function" if EXPERT
+	depends on !COMPILE_TEST	# too noisy
+	help
+	  The complexity M of a function's control flow graph is defined as:
+	   M = E - N + 2P
+	  where
+
+	  E = the number of edges
+	  N = the number of nodes
+	  P = the number of connected components (exit nodes).
+
+	  Enabling this plugin reports the complexity to stderr during the
+	  build. It mainly serves as a simple example of how to create a
+	  gcc plugin for the kernel.
+
+config GCC_PLUGIN_SANCOV
+	bool
+	help
+	  This plugin inserts a __sanitizer_cov_trace_pc() call at the start of
+	  basic blocks. It supports all gcc versions with plugin support (from
+	  gcc-4.5 on). It is based on the commit "Add fuzzing coverage support"
+	  by Dmitry Vyukov <dvyukov@google.com>.
+
+config GCC_PLUGIN_LATENT_ENTROPY
+	bool "Generate some entropy during boot and runtime"
+	help
+	  By saying Y here the kernel will instrument some kernel code to
+	  extract some entropy from both original and artificially created
+	  program state.  This will help especially embedded systems where
+	  there is little 'natural' source of entropy normally.  The cost
+	  is some slowdown of the boot process (about 0.5%) and fork and
+	  irq processing.
+
+	  Note that entropy extracted this way is not cryptographically
+	  secure!
+
+	  This plugin was ported from grsecurity/PaX. More information at:
+	   * https://grsecurity.net/
+	   * https://pax.grsecurity.net/
+
+config GCC_PLUGIN_STRUCTLEAK
+	bool "Force initialization of variables containing userspace addresses"
+	# Currently STRUCTLEAK inserts initialization out of live scope of
+	# variables from KASAN point of view. This leads to KASAN false
+	# positive reports. Prohibit this combination for now.
+	depends on !KASAN_EXTRA
+	help
+	  This plugin zero-initializes any structures containing a
+	  __user attribute. This can prevent some classes of information
+	  exposures.
+
+	  This plugin was ported from grsecurity/PaX. More information at:
+	   * https://grsecurity.net/
+	   * https://pax.grsecurity.net/
+
+config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
+	bool "Force initialize all struct type variables passed by reference"
+	depends on GCC_PLUGIN_STRUCTLEAK
+	depends on !COMPILE_TEST
+	help
+	  Zero initialize any struct type local variable that may be passed by
+	  reference without having been initialized.
+
+config GCC_PLUGIN_STRUCTLEAK_VERBOSE
+	bool "Report forcefully initialized variables"
+	depends on GCC_PLUGIN_STRUCTLEAK
+	depends on !COMPILE_TEST	# too noisy
+	help
+	  This option will cause a warning to be printed each time the
+	  structleak plugin finds a variable it thinks needs to be
+	  initialized. Since not all existing initializers are detected
+	  by the plugin, this can produce false positive warnings.
+
+config GCC_PLUGIN_RANDSTRUCT
+	bool "Randomize layout of sensitive kernel structures"
+	select MODVERSIONS if MODULES
+	help
+	  If you say Y here, the layouts of structures that are entirely
+	  function pointers (and have not been manually annotated with
+	  __no_randomize_layout), or structures that have been explicitly
+	  marked with __randomize_layout, will be randomized at compile-time.
+	  This can introduce the requirement of an additional information
+	  exposure vulnerability for exploits targeting these structure
+	  types.
+
+	  Enabling this feature will introduce some performance impact,
+	  slightly increase memory usage, and prevent the use of forensic
+	  tools like Volatility against the system (unless the kernel
+	  source tree isn't cleaned after kernel installation).
+
+	  The seed used for compilation is located at
+	  scripts/gcc-plgins/randomize_layout_seed.h.  It remains after
+	  a make clean to allow for external modules to be compiled with
+	  the existing seed and will be removed by a make mrproper or
+	  make distclean.
+
+	  Note that the implementation requires gcc 4.7 or newer.
+
+	  This plugin was ported from grsecurity/PaX. More information at:
+	   * https://grsecurity.net/
+	   * https://pax.grsecurity.net/
+
+config GCC_PLUGIN_RANDSTRUCT_PERFORMANCE
+	bool "Use cacheline-aware structure randomization"
+	depends on GCC_PLUGIN_RANDSTRUCT
+	depends on !COMPILE_TEST	# do not reduce test coverage
+	help
+	  If you say Y here, the RANDSTRUCT randomization will make a
+	  best effort at restricting randomization to cacheline-sized
+	  groups of elements.  It will further not randomize bitfields
+	  in structures.  This reduces the performance hit of RANDSTRUCT
+	  at the cost of weakened randomization.
+
+endif