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         help
  10           Enables kernel address sanitizer - runtime memory debugger,
  11           designed to find out-of-bounds accesses and use-after-free bugs.
  12           This is strictly debugging feature. It consumes about 1/8
  13           of available memory and brings about ~x3 performance slowdown.
  14           For better error detection enable CONFIG_STACKTRACE,
  15           and add slub_debug=U to boot cmdline.
  16
  17 config KASAN_SHADOW_OFFSET
  18         hex
  19         default 0xdffffc0000000000 if X86_64
  20
  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.
  42
  43 endchoice
  44
  45 config TEST_KASAN
  46         tristate "Module for testing kasan for bug detection"
  47         depends on m && KASAN
  48         help
  49           This is a test module doing various nasty things like
  50           out of bounds accesses, use after free. It is useful for testing
  51           kernel debugging features like kernel address sanitizer.
  52
  53 endif