1config HAVE_ARCH_KASAN 2 bool 3 4if HAVE_ARCH_KASAN 5 6config KASAN 7 bool "KASan: runtime memory debugger" 8 depends on SLUB || (SLAB && !DEBUG_SLAB) 9 select CONSTRUCTORS 10 select STACKDEPOT 11 help 12 Enables kernel address sanitizer - runtime memory debugger, 13 designed to find out-of-bounds accesses and use-after-free bugs. 14 This is strictly a debugging feature and it requires a gcc version 15 of 4.9.2 or later. Detection of out of bounds accesses to stack or 16 global variables requires gcc 5.0 or later. 17 This feature consumes about 1/8 of available memory and brings about 18 ~x3 performance slowdown. 19 For better error detection enable CONFIG_STACKTRACE. 20 Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB 21 (the resulting kernel does not boot). 22 23config KASAN_EXTRA 24 bool "KAsan: extra checks" 25 depends on KASAN && DEBUG_KERNEL && !COMPILE_TEST 26 help 27 This enables further checks in the kernel address sanitizer, for now 28 it only includes the address-use-after-scope check that can lead 29 to excessive kernel stack usage, frame size warnings and longer 30 compile time. 31 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 has more 32 33 34choice 35 prompt "Instrumentation type" 36 depends on KASAN 37 default KASAN_OUTLINE 38 39config KASAN_OUTLINE 40 bool "Outline instrumentation" 41 help 42 Before every memory access compiler insert function call 43 __asan_load*/__asan_store*. These functions performs check 44 of shadow memory. This is slower than inline instrumentation, 45 however it doesn't bloat size of kernel's .text section so 46 much as inline does. 47 48config KASAN_INLINE 49 bool "Inline instrumentation" 50 help 51 Compiler directly inserts code checking shadow memory before 52 memory accesses. This is faster than outline (in some workloads 53 it gives about x2 boost over outline instrumentation), but 54 make kernel's .text size much bigger. 55 This requires a gcc version of 5.0 or later. 56 57endchoice 58 59config TEST_KASAN 60 tristate "Module for testing kasan for bug detection" 61 depends on m && KASAN 62 help 63 This is a test module doing various nasty things like 64 out of bounds accesses, use after free. It is useful for testing 65 kernel debugging features like kernel address sanitizer. 66 67endif 68