[linux-2.6-block.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.

config KASAN_SHADOW_OFFSET
	hex
	default 0xdffffc0000000000 if X86_64

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
	21	config KASAN_SHADOW_OFFSET
	22	hex
ef7f0d6a	23	default 0xdffffc0000000000 if X86_64
0b24becc AR	24
	25	choice
	26	prompt "Instrumentation type"
	27	depends on KASAN
	28	default KASAN_OUTLINE
	29
	30	config 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
	39	config 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.
01e76903	46	This requires a gcc version of 5.0 or later.
0b24becc AR	47
	48	endchoice
	49
3f15801c AR	50	config 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
0b24becc	58	endif