LXR linux/scripts/gcc-plugins/Kconfig

   1preferred-plugin-hostcc := $(if-success,[ $(gcc-version) -ge 40800 ],$(HOSTCXX),$(HOSTCC))
   2
   3config PLUGIN_HOSTCC
   4        string
   5        default "$(shell,$(srctree)/scripts/gcc-plugin.sh "$(preferred-plugin-hostcc)" "$(HOSTCXX)" "$(CC)")" if CC_IS_GCC
   6        help
   7          Host compiler used to build GCC plugins.  This can be $(HOSTCXX),
   8          $(HOSTCC), or a null string if GCC plugin is unsupported.
   9
  10config HAVE_GCC_PLUGINS
  11        bool
  12        help
  13          An arch should select this symbol if it supports building with
  14          GCC plugins.
  15
  16menuconfig GCC_PLUGINS
  17        bool "GCC plugins"
  18        depends on HAVE_GCC_PLUGINS
  19        depends on PLUGIN_HOSTCC != ""
  20        help
  21          GCC plugins are loadable modules that provide extra features to the
  22          compiler. They are useful for runtime instrumentation and static analysis.
  23
  24          See Documentation/gcc-plugins.txt for details.
  25
  26if GCC_PLUGINS
  27
  28config GCC_PLUGIN_CYC_COMPLEXITY
  29        bool "Compute the cyclomatic complexity of a function" if EXPERT
  30        depends on !COMPILE_TEST        # too noisy
  31        help
  32          The complexity M of a function's control flow graph is defined as:
  33           M = E - N + 2P
  34          where
  35
  36          E = the number of edges
  37          N = the number of nodes
  38          P = the number of connected components (exit nodes).
  39
  40          Enabling this plugin reports the complexity to stderr during the
  41          build. It mainly serves as a simple example of how to create a
  42          gcc plugin for the kernel.
  43
  44config GCC_PLUGIN_SANCOV
  45        bool
  46        help
  47          This plugin inserts a __sanitizer_cov_trace_pc() call at the start of
  48          basic blocks. It supports all gcc versions with plugin support (from
  49          gcc-4.5 on). It is based on the commit "Add fuzzing coverage support"
  50          by Dmitry Vyukov <dvyukov@google.com>.
  51
  52config GCC_PLUGIN_LATENT_ENTROPY
  53        bool "Generate some entropy during boot and runtime"
  54        help
  55          By saying Y here the kernel will instrument some kernel code to
  56          extract some entropy from both original and artificially created
  57          program state.  This will help especially embedded systems where
  58          there is little 'natural' source of entropy normally.  The cost
  59          is some slowdown of the boot process (about 0.5%) and fork and
  60          irq processing.
  61
  62          Note that entropy extracted this way is not cryptographically
  63          secure!
  64
  65          This plugin was ported from grsecurity/PaX. More information at:
  66           * https://grsecurity.net/
  67           * https://pax.grsecurity.net/
  68
  69config GCC_PLUGIN_STRUCTLEAK
  70        bool "Force initialization of variables containing userspace addresses"
  71        # Currently STRUCTLEAK inserts initialization out of live scope of
  72        # variables from KASAN point of view. This leads to KASAN false
  73        # positive reports. Prohibit this combination for now.
  74        depends on !KASAN_EXTRA
  75        help
  76          This plugin zero-initializes any structures containing a
  77          __user attribute. This can prevent some classes of information
  78          exposures.
  79
  80          This plugin was ported from grsecurity/PaX. More information at:
  81           * https://grsecurity.net/
  82           * https://pax.grsecurity.net/
  83
  84config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
  85        bool "Force initialize all struct type variables passed by reference"
  86        depends on GCC_PLUGIN_STRUCTLEAK
  87        depends on !COMPILE_TEST
  88        help
  89          Zero initialize any struct type local variable that may be passed by
  90          reference without having been initialized.
  91
  92config GCC_PLUGIN_STRUCTLEAK_VERBOSE
  93        bool "Report forcefully initialized variables"
  94        depends on GCC_PLUGIN_STRUCTLEAK
  95        depends on !COMPILE_TEST        # too noisy
  96        help
  97          This option will cause a warning to be printed each time the
  98          structleak plugin finds a variable it thinks needs to be
  99          initialized. Since not all existing initializers are detected
 100          by the plugin, this can produce false positive warnings.
 101
 102config GCC_PLUGIN_RANDSTRUCT
 103        bool "Randomize layout of sensitive kernel structures"
 104        select MODVERSIONS if MODULES
 105        help
 106          If you say Y here, the layouts of structures that are entirely
 107          function pointers (and have not been manually annotated with
 108          __no_randomize_layout), or structures that have been explicitly
 109          marked with __randomize_layout, will be randomized at compile-time.
 110          This can introduce the requirement of an additional information
 111          exposure vulnerability for exploits targeting these structure
 112          types.
 113
 114          Enabling this feature will introduce some performance impact,
 115          slightly increase memory usage, and prevent the use of forensic
 116          tools like Volatility against the system (unless the kernel
 117          source tree isn't cleaned after kernel installation).
 118
 119          The seed used for compilation is located at
 120          scripts/gcc-plgins/randomize_layout_seed.h.  It remains after
 121          a make clean to allow for external modules to be compiled with
 122          the existing seed and will be removed by a make mrproper or
 123          make distclean.
 124
 125          Note that the implementation requires gcc 4.7 or newer.
 126
 127          This plugin was ported from grsecurity/PaX. More information at:
 128           * https://grsecurity.net/
 129           * https://pax.grsecurity.net/
 130
 131config GCC_PLUGIN_RANDSTRUCT_PERFORMANCE
 132        bool "Use cacheline-aware structure randomization"
 133        depends on GCC_PLUGIN_RANDSTRUCT
 134        depends on !COMPILE_TEST        # do not reduce test coverage
 135        help
 136          If you say Y here, the RANDSTRUCT randomization will make a
 137          best effort at restricting randomization to cacheline-sized
 138          groups of elements.  It will further not randomize bitfields
 139          in structures.  This reduces the performance hit of RANDSTRUCT
 140          at the cost of weakened randomization.
 141
 142endif
 143