mm: slub: introduce metadata_access_enable()/metadata_access_disable()

[linux-2.6-block.git] / lib / Kconfig.kasan

config HAVE_ARCH_KASAN
	bool

if HAVE_ARCH_KASAN

config KASAN
	bool "KASan: runtime memory debugger"
	help
	  Enables kernel address sanitizer - runtime memory debugger,
	  designed to find out-of-bounds accesses and use-after-free bugs.
	  This is strictly debugging feature. It 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.

endchoice

endif