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 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.
  18           For better error detection enable CONFIG_STACKTRACE.
  19
  20 choice
  21         prompt "Instrumentation type"
  22         depends on KASAN
  23         default KASAN_OUTLINE
  24
  25 config KASAN_OUTLINE
  26         bool "Outline instrumentation"
  27         help
  28           Before every memory access compiler insert function call
  29           __asan_load*/__asan_store*. These functions performs check
  30           of shadow memory. This is slower than inline instrumentation,
  31           however it doesn't bloat size of kernel's .text section so
  32           much as inline does.
  33
  34 config KASAN_INLINE
  35         bool "Inline instrumentation"
  36         help
  37           Compiler directly inserts code checking shadow memory before
  38           memory accesses. This is faster than outline (in some workloads
  39           it gives about x2 boost over outline instrumentation), but
  40           make kernel's .text size much bigger.
  41           This requires a gcc version of 5.0 or later.
  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