1config HAVE_ARCH_KASAN
2	bool
3
4if HAVE_ARCH_KASAN
5
6config KASAN
7	bool "KASan: runtime memory debugger"
8	depends on SLUB_DEBUG
9	select CONSTRUCTORS
10	help
11	  Enables kernel address sanitizer - runtime memory debugger,
12	  designed to find out-of-bounds accesses and use-after-free bugs.
13	  This is strictly a debugging feature and it requires a gcc version
14	  of 4.9.2 or later. Detection of out of bounds accesses to stack or
15	  global variables requires gcc 5.0 or later.
16	  This feature consumes about 1/8 of available memory and brings about
17	  ~x3 performance slowdown.
18	  For better error detection enable CONFIG_STACKTRACE,
19	  and add slub_debug=U to boot cmdline.
20
21config KASAN_SHADOW_OFFSET
22	hex
23	default 0xdffffc0000000000 if X86_64
24
25choice
26	prompt "Instrumentation type"
27	depends on KASAN
28	default KASAN_OUTLINE
29
30config KASAN_OUTLINE
31	bool "Outline instrumentation"
32	help
33	  Before every memory access compiler insert function call
34	  __asan_load*/__asan_store*. These functions performs check
35	  of shadow memory. This is slower than inline instrumentation,
36	  however it doesn't bloat size of kernel's .text section so
37	  much as inline does.
38
39config KASAN_INLINE
40	bool "Inline instrumentation"
41	help
42	  Compiler directly inserts code checking shadow memory before
43	  memory accesses. This is faster than outline (in some workloads
44	  it gives about x2 boost over outline instrumentation), but
45	  make kernel's .text size much bigger.
46	  This requires a gcc version of 5.0 or later.
47
48endchoice
49
50config TEST_KASAN
51	tristate "Module for testing kasan for bug detection"
52	depends on m && KASAN
53	help
54	  This is a test module doing various nasty things like
55	  out of bounds accesses, use after free. It is useful for testing
56	  kernel debugging features like kernel address sanitizer.
57
58endif
59