linux/scripts/gcc-plugins/Kconfig
<<
>>
Prefs
   1# SPDX-License-Identifier: GPL-2.0-only
   2config HAVE_GCC_PLUGINS
   3        bool
   4        help
   5          An arch should select this symbol if it supports building with
   6          GCC plugins.
   7
   8menuconfig GCC_PLUGINS
   9        bool "GCC plugins"
  10        depends on HAVE_GCC_PLUGINS
  11        depends on CC_IS_GCC
  12        depends on $(success,test -e $(shell,$(CC) -print-file-name=plugin)/include/plugin-version.h)
  13        default y
  14        help
  15          GCC plugins are loadable modules that provide extra features to the
  16          compiler. They are useful for runtime instrumentation and static analysis.
  17
  18          See Documentation/kbuild/gcc-plugins.rst for details.
  19
  20if GCC_PLUGINS
  21
  22config GCC_PLUGIN_CYC_COMPLEXITY
  23        bool "Compute the cyclomatic complexity of a function" if EXPERT
  24        depends on !COMPILE_TEST        # too noisy
  25        help
  26          The complexity M of a function's control flow graph is defined as:
  27           M = E - N + 2P
  28          where
  29
  30          E = the number of edges
  31          N = the number of nodes
  32          P = the number of connected components (exit nodes).
  33
  34          Enabling this plugin reports the complexity to stderr during the
  35          build. It mainly serves as a simple example of how to create a
  36          gcc plugin for the kernel.
  37
  38config GCC_PLUGIN_SANCOV
  39        bool
  40        help
  41          This plugin inserts a __sanitizer_cov_trace_pc() call at the start of
  42          basic blocks. It supports all gcc versions with plugin support (from
  43          gcc-4.5 on). It is based on the commit "Add fuzzing coverage support"
  44          by Dmitry Vyukov <dvyukov@google.com>.
  45
  46config GCC_PLUGIN_LATENT_ENTROPY
  47        bool "Generate some entropy during boot and runtime"
  48        help
  49          By saying Y here the kernel will instrument some kernel code to
  50          extract some entropy from both original and artificially created
  51          program state.  This will help especially embedded systems where
  52          there is little 'natural' source of entropy normally.  The cost
  53          is some slowdown of the boot process (about 0.5%) and fork and
  54          irq processing.
  55
  56          Note that entropy extracted this way is not cryptographically
  57          secure!
  58
  59          This plugin was ported from grsecurity/PaX. More information at:
  60           * https://grsecurity.net/
  61           * https://pax.grsecurity.net/
  62
  63config GCC_PLUGIN_RANDSTRUCT
  64        bool "Randomize layout of sensitive kernel structures"
  65        select MODVERSIONS if MODULES
  66        help
  67          If you say Y here, the layouts of structures that are entirely
  68          function pointers (and have not been manually annotated with
  69          __no_randomize_layout), or structures that have been explicitly
  70          marked with __randomize_layout, will be randomized at compile-time.
  71          This can introduce the requirement of an additional information
  72          exposure vulnerability for exploits targeting these structure
  73          types.
  74
  75          Enabling this feature will introduce some performance impact,
  76          slightly increase memory usage, and prevent the use of forensic
  77          tools like Volatility against the system (unless the kernel
  78          source tree isn't cleaned after kernel installation).
  79
  80          The seed used for compilation is located at
  81          scripts/gcc-plugins/randomize_layout_seed.h.  It remains after
  82          a make clean to allow for external modules to be compiled with
  83          the existing seed and will be removed by a make mrproper or
  84          make distclean.
  85
  86          Note that the implementation requires gcc 4.7 or newer.
  87
  88          This plugin was ported from grsecurity/PaX. More information at:
  89           * https://grsecurity.net/
  90           * https://pax.grsecurity.net/
  91
  92config GCC_PLUGIN_RANDSTRUCT_PERFORMANCE
  93        bool "Use cacheline-aware structure randomization"
  94        depends on GCC_PLUGIN_RANDSTRUCT
  95        depends on !COMPILE_TEST        # do not reduce test coverage
  96        help
  97          If you say Y here, the RANDSTRUCT randomization will make a
  98          best effort at restricting randomization to cacheline-sized
  99          groups of elements.  It will further not randomize bitfields
 100          in structures.  This reduces the performance hit of RANDSTRUCT
 101          at the cost of weakened randomization.
 102
 103config GCC_PLUGIN_ARM_SSP_PER_TASK
 104        bool
 105        depends on GCC_PLUGINS && ARM
 106
 107endif
 108