lib/Kconfig.kasan

   1 config HAVE_ARCH_KASAN
   2         bool
   3
   4 if HAVE_ARCH_KASAN
   5
   6 config 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 debugging feature. It consumes about 1/8
  14           of available memory and brings about ~x3 performance slowdown.
  15           For better error detection enable CONFIG_STACKTRACE,
  16           and add slub_debug=U to boot cmdline.
  17
  18 config KASAN_SHADOW_OFFSET
  19         hex
  20         default 0xdffffc0000000000 if X86_64
  21
  22 choice
  23         prompt "Instrumentation type"
  24         depends on KASAN
  25         default KASAN_OUTLINE
  26
  27 config KASAN_OUTLINE
  28         bool "Outline instrumentation"
  29         help
  30           Before every memory access compiler insert function call
  31           __asan_load*/__asan_store*. These functions performs check
  32           of shadow memory. This is slower than inline instrumentation,
  33           however it doesn't bloat size of kernel's .text section so
  34           much as inline does.
  35
  36 config KASAN_INLINE
  37         bool "Inline instrumentation"
  38         help
  39           Compiler directly inserts code checking shadow memory before
  40           memory accesses. This is faster than outline (in some workloads
  41           it gives about x2 boost over outline instrumentation), but
  42           make kernel's .text size much bigger.
  43
  44 endchoice
  45
  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
  54 endif