LXR linux/lib/Kconfig.kasan

   1config HAVE_ARCH_KASAN
   2        bool
   3
   4if HAVE_ARCH_KASAN
   5
   6config KASAN
   7        bool "KASan: runtime memory debugger"
   8        depends on SLUB || (SLAB && !DEBUG_SLAB)
   9        select CONSTRUCTORS
  10        select STACKDEPOT
  11        help
  12          Enables kernel address sanitizer - runtime memory debugger,
  13          designed to find out-of-bounds accesses and use-after-free bugs.
  14          This is strictly a debugging feature and it requires a gcc version
  15          of 4.9.2 or later. Detection of out of bounds accesses to stack or
  16          global variables requires gcc 5.0 or later.
  17          This feature consumes about 1/8 of available memory and brings about
  18          ~x3 performance slowdown.
  19          For better error detection enable CONFIG_STACKTRACE.
  20          Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB
  21          (the resulting kernel does not boot).
  22
  23config KASAN_EXTRA
  24        bool "KAsan: extra checks"
  25        depends on KASAN && DEBUG_KERNEL && !COMPILE_TEST
  26        help
  27          This enables further checks in the kernel address sanitizer, for now
  28          it only includes the address-use-after-scope check that can lead
  29          to excessive kernel stack usage, frame size warnings and longer
  30          compile time.
  31          https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 has more
  32
  33
  34choice
  35        prompt "Instrumentation type"
  36        depends on KASAN
  37        default KASAN_OUTLINE
  38
  39config KASAN_OUTLINE
  40        bool "Outline instrumentation"
  41        help
  42          Before every memory access compiler insert function call
  43          __asan_load*/__asan_store*. These functions performs check
  44          of shadow memory. This is slower than inline instrumentation,
  45          however it doesn't bloat size of kernel's .text section so
  46          much as inline does.
  47
  48config KASAN_INLINE
  49        bool "Inline instrumentation"
  50        help
  51          Compiler directly inserts code checking shadow memory before
  52          memory accesses. This is faster than outline (in some workloads
  53          it gives about x2 boost over outline instrumentation), but
  54          make kernel's .text size much bigger.
  55          This requires a gcc version of 5.0 or later.
  56
  57endchoice
  58
  59config TEST_KASAN
  60        tristate "Module for testing kasan for bug detection"
  61        depends on m && KASAN
  62        help
  63          This is a test module doing various nasty things like
  64          out of bounds accesses, use after free. It is useful for testing
  65          kernel debugging features like kernel address sanitizer.
  66
  67endif
  68