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Andrey Ryabinin0b24bec2015-02-13 14:39:17 -08001config HAVE_ARCH_KASAN
2 bool
3
4if HAVE_ARCH_KASAN
5
6config KASAN
7 bool "KASan: runtime memory debugger"
Alexander Potapenko7ed2f9e2016-03-25 14:21:59 -07008 depends on SLUB_DEBUG || (SLAB && !DEBUG_SLAB)
Andrey Ryabininbebf56a2015-02-13 14:40:17 -08009 select CONSTRUCTORS
Alexander Potapenkocd110162016-03-25 14:22:08 -070010 select STACKDEPOT if SLAB
Andrey Ryabinin0b24bec2015-02-13 14:39:17 -080011 help
12 Enables kernel address sanitizer - runtime memory debugger,
13 designed to find out-of-bounds accesses and use-after-free bugs.
Joe Perches01e76902015-05-05 16:23:38 -070014 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.
Andrey Ryabinin89d3c872015-11-05 18:51:23 -080019 For better error detection enable CONFIG_STACKTRACE.
Alexander Potapenko7ed2f9e2016-03-25 14:21:59 -070020 Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB
21 (the resulting kernel does not boot).
Andrey Ryabinin0b24bec2015-02-13 14:39:17 -080022
Andrey Ryabinin0b24bec2015-02-13 14:39:17 -080023choice
24 prompt "Instrumentation type"
25 depends on KASAN
26 default KASAN_OUTLINE
27
28config KASAN_OUTLINE
29 bool "Outline instrumentation"
30 help
31 Before every memory access compiler insert function call
32 __asan_load*/__asan_store*. These functions performs check
33 of shadow memory. This is slower than inline instrumentation,
34 however it doesn't bloat size of kernel's .text section so
35 much as inline does.
36
37config KASAN_INLINE
38 bool "Inline instrumentation"
39 help
40 Compiler directly inserts code checking shadow memory before
41 memory accesses. This is faster than outline (in some workloads
42 it gives about x2 boost over outline instrumentation), but
43 make kernel's .text size much bigger.
Joe Perches01e76902015-05-05 16:23:38 -070044 This requires a gcc version of 5.0 or later.
Andrey Ryabinin0b24bec2015-02-13 14:39:17 -080045
46endchoice
47
Andrey Ryabinin3f158012015-02-13 14:39:53 -080048config TEST_KASAN
49 tristate "Module for testing kasan for bug detection"
50 depends on m && KASAN
51 help
52 This is a test module doing various nasty things like
53 out of bounds accesses, use after free. It is useful for testing
54 kernel debugging features like kernel address sanitizer.
55
Andrey Ryabinin0b24bec2015-02-13 14:39:17 -080056endif