[linux.git] / lib / Kconfig.kasan

config HAVE_ARCH_KASAN
	bool

if HAVE_ARCH_KASAN

config KASAN
	bool "KASan: runtime memory debugger"
	depends on SLUB_DEBUG
	select CONSTRUCTORS
	help
	  Enables kernel address sanitizer - runtime memory debugger,
	  designed to find out-of-bounds accesses and use-after-free bugs.
	  This is strictly a debugging feature and it requires a gcc version
	  of 4.9.2 or later. Detection of out of bounds accesses to stack or
	  global variables requires gcc 5.0 or later.
	  This feature consumes about 1/8 of available memory and brings about
	  ~x3 performance slowdown.
	  For better error detection enable CONFIG_STACKTRACE,
	  and add slub_debug=U to boot cmdline.

choice
	prompt "Instrumentation type"
	depends on KASAN
	default KASAN_OUTLINE

config KASAN_OUTLINE
	bool "Outline instrumentation"
	help
	  Before every memory access compiler insert function call
	  __asan_load*/__asan_store*. These functions performs check
	  of shadow memory. This is slower than inline instrumentation,
	  however it doesn't bloat size of kernel's .text section so
	  much as inline does.

config KASAN_INLINE
	bool "Inline instrumentation"
	help
	  Compiler directly inserts code checking shadow memory before
	  memory accesses. This is faster than outline (in some workloads
	  it gives about x2 boost over outline instrumentation), but
	  make kernel's .text size much bigger.
	  This requires a gcc version of 5.0 or later.

endchoice

config TEST_KASAN
	tristate "Module for testing kasan for bug detection"
	depends on m && KASAN
	help
	  This is a test module doing various nasty things like
	  out of bounds accesses, use after free. It is useful for testing
	  kernel debugging features like kernel address sanitizer.

endif
Commit	Line	Data
0b24becc AR	1	config HAVE_ARCH_KASAN
	2	bool
	3
	4	if HAVE_ARCH_KASAN
	5
	6	config KASAN
	7	bool "KASan: runtime memory debugger"
0316bec2	8	depends on SLUB_DEBUG
bebf56a1	9	select CONSTRUCTORS
0b24becc AR	10	help
	11	Enables kernel address sanitizer - runtime memory debugger,
	12	designed to find out-of-bounds accesses and use-after-free bugs.
01e76903 JP	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.
0b24becc AR	18	For better error detection enable CONFIG_STACKTRACE,
	19	and add slub_debug=U to boot cmdline.
	20
0b24becc AR	21	choice
	22	prompt "Instrumentation type"
	23	depends on KASAN
	24	default KASAN_OUTLINE
	25
	26	config KASAN_OUTLINE
	27	bool "Outline instrumentation"
	28	help
	29	Before every memory access compiler insert function call
	30	__asan_load/__asan_store. These functions performs check
	31	of shadow memory. This is slower than inline instrumentation,
	32	however it doesn't bloat size of kernel's .text section so
	33	much as inline does.
	34
	35	config KASAN_INLINE
	36	bool "Inline instrumentation"
	37	help
	38	Compiler directly inserts code checking shadow memory before
	39	memory accesses. This is faster than outline (in some workloads
	40	it gives about x2 boost over outline instrumentation), but
	41	make kernel's .text size much bigger.
01e76903	42	This requires a gcc version of 5.0 or later.
0b24becc AR	43
	44	endchoice
	45
3f15801c AR	46	config TEST_KASAN
	47	tristate "Module for testing kasan for bug detection"
	48	depends on m && KASAN
	49	help
	50	This is a test module doing various nasty things like
	51	out of bounds accesses, use after free. It is useful for testing
	52	kernel debugging features like kernel address sanitizer.
	53
0b24becc	54	endif