1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
>> 2 preferred-plugin-hostcc := $(if-success,[ $(gcc-version) -ge 40800 ],$(HOSTCXX),$(HOSTCC))
>> 3
>> 4 config PLUGIN_HOSTCC
>> 5 string
>> 6 default "$(shell,$(srctree)/scripts/gcc-plugin.sh "$(preferred-plugin-hostcc)" "$(HOSTCXX)" "$(CC)")" if CC_IS_GCC
>> 7 help
>> 8 Host compiler used to build GCC plugins. This can be $(HOSTCXX),
>> 9 $(HOSTCC), or a null string if GCC plugin is unsupported.
>> 10
2 config HAVE_GCC_PLUGINS 11 config HAVE_GCC_PLUGINS
3 bool 12 bool
4 help 13 help
5 An arch should select this symbol if 14 An arch should select this symbol if it supports building with
6 GCC plugins. 15 GCC plugins.
7 16
8 menuconfig GCC_PLUGINS !! 17 config GCC_PLUGINS
9 bool "GCC plugins" !! 18 bool
10 depends on HAVE_GCC_PLUGINS 19 depends on HAVE_GCC_PLUGINS
11 depends on CC_IS_GCC !! 20 depends on PLUGIN_HOSTCC != ""
12 depends on $(success,test -e $(shell,$ <<
13 default y 21 default y
14 help 22 help
15 GCC plugins are loadable modules tha 23 GCC plugins are loadable modules that provide extra features to the
16 compiler. They are useful for runtim 24 compiler. They are useful for runtime instrumentation and static analysis.
17 25
18 See Documentation/kbuild/gcc-plugins !! 26 See Documentation/core-api/gcc-plugins.rst for details.
19 27
20 if GCC_PLUGINS !! 28 menu "GCC plugins"
>> 29 depends on GCC_PLUGINS
>> 30
>> 31 config GCC_PLUGIN_CYC_COMPLEXITY
>> 32 bool "Compute the cyclomatic complexity of a function" if EXPERT
>> 33 depends on !COMPILE_TEST # too noisy
>> 34 help
>> 35 The complexity M of a function's control flow graph is defined as:
>> 36 M = E - N + 2P
>> 37 where
>> 38
>> 39 E = the number of edges
>> 40 N = the number of nodes
>> 41 P = the number of connected components (exit nodes).
>> 42
>> 43 Enabling this plugin reports the complexity to stderr during the
>> 44 build. It mainly serves as a simple example of how to create a
>> 45 gcc plugin for the kernel.
21 46
22 config GCC_PLUGIN_SANCOV 47 config GCC_PLUGIN_SANCOV
23 bool 48 bool
24 # Plugin can be removed once the kerne <<
25 depends on !CC_HAS_SANCOV_TRACE_PC <<
26 help 49 help
27 This plugin inserts a __sanitizer_co 50 This plugin inserts a __sanitizer_cov_trace_pc() call at the start of
28 basic blocks. It supports all gcc ve 51 basic blocks. It supports all gcc versions with plugin support (from
29 gcc-4.5 on). It is based on the comm 52 gcc-4.5 on). It is based on the commit "Add fuzzing coverage support"
30 by Dmitry Vyukov <dvyukov@google.com> 53 by Dmitry Vyukov <dvyukov@google.com>.
31 54
32 config GCC_PLUGIN_LATENT_ENTROPY 55 config GCC_PLUGIN_LATENT_ENTROPY
33 bool "Generate some entropy during boo 56 bool "Generate some entropy during boot and runtime"
34 help 57 help
35 By saying Y here the kernel will ins 58 By saying Y here the kernel will instrument some kernel code to
36 extract some entropy from both origi 59 extract some entropy from both original and artificially created
37 program state. This will help espec 60 program state. This will help especially embedded systems where
38 there is little 'natural' source of 61 there is little 'natural' source of entropy normally. The cost
39 is some slowdown of the boot process 62 is some slowdown of the boot process (about 0.5%) and fork and
40 irq processing. 63 irq processing.
41 64
42 Note that entropy extracted this way 65 Note that entropy extracted this way is not cryptographically
43 secure! 66 secure!
44 67
45 This plugin was ported from grsecuri 68 This plugin was ported from grsecurity/PaX. More information at:
46 * https://grsecurity.net/ 69 * https://grsecurity.net/
47 * https://pax.grsecurity.net/ 70 * https://pax.grsecurity.net/
48 71
>> 72 config GCC_PLUGIN_RANDSTRUCT
>> 73 bool "Randomize layout of sensitive kernel structures"
>> 74 select MODVERSIONS if MODULES
>> 75 help
>> 76 If you say Y here, the layouts of structures that are entirely
>> 77 function pointers (and have not been manually annotated with
>> 78 __no_randomize_layout), or structures that have been explicitly
>> 79 marked with __randomize_layout, will be randomized at compile-time.
>> 80 This can introduce the requirement of an additional information
>> 81 exposure vulnerability for exploits targeting these structure
>> 82 types.
>> 83
>> 84 Enabling this feature will introduce some performance impact,
>> 85 slightly increase memory usage, and prevent the use of forensic
>> 86 tools like Volatility against the system (unless the kernel
>> 87 source tree isn't cleaned after kernel installation).
>> 88
>> 89 The seed used for compilation is located at
>> 90 scripts/gcc-plgins/randomize_layout_seed.h. It remains after
>> 91 a make clean to allow for external modules to be compiled with
>> 92 the existing seed and will be removed by a make mrproper or
>> 93 make distclean.
>> 94
>> 95 Note that the implementation requires gcc 4.7 or newer.
>> 96
>> 97 This plugin was ported from grsecurity/PaX. More information at:
>> 98 * https://grsecurity.net/
>> 99 * https://pax.grsecurity.net/
>> 100
>> 101 config GCC_PLUGIN_RANDSTRUCT_PERFORMANCE
>> 102 bool "Use cacheline-aware structure randomization"
>> 103 depends on GCC_PLUGIN_RANDSTRUCT
>> 104 depends on !COMPILE_TEST # do not reduce test coverage
>> 105 help
>> 106 If you say Y here, the RANDSTRUCT randomization will make a
>> 107 best effort at restricting randomization to cacheline-sized
>> 108 groups of elements. It will further not randomize bitfields
>> 109 in structures. This reduces the performance hit of RANDSTRUCT
>> 110 at the cost of weakened randomization.
>> 111
49 config GCC_PLUGIN_ARM_SSP_PER_TASK 112 config GCC_PLUGIN_ARM_SSP_PER_TASK
50 bool 113 bool
51 depends on GCC_PLUGINS && ARM 114 depends on GCC_PLUGINS && ARM
52 115
53 endif !! 116 endmenu
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