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)")" if CC_IS_GCC 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. config GCC_PLUGINS bool depends on HAVE_GCC_PLUGINS depends on PLUGIN_HOSTCC != "" default y 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. menu "GCC plugins" depends on 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 . 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_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. config GCC_PLUGIN_ARM_SSP_PER_TASK bool depends on GCC_PLUGINS && ARM endmenu