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 && SYSFS) || (SLAB && !DEBUG_SLAB)
   9        select SLUB_DEBUG if SLUB
  10        select CONSTRUCTORS
  11        select STACKDEPOT
  12        help
  13          Enables kernel address sanitizer - runtime memory debugger,
  14          designed to find out-of-bounds accesses and use-after-free bugs.
  15          This is strictly a debugging feature and it requires a gcc version
  16          of 4.9.2 or later. Detection of out of bounds accesses to stack or
  17          global variables requires gcc 5.0 or later.
  18          This feature consumes about 1/8 of available memory and brings about
  19          ~x3 performance slowdown.
  20          For better error detection enable CONFIG_STACKTRACE.
  21          Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB
  22          (the resulting kernel does not boot).
  23
  24config KASAN_EXTRA
  25        bool "KAsan: extra checks"
  26        depends on KASAN && DEBUG_KERNEL && !COMPILE_TEST
  27        help
  28          This enables further checks in the kernel address sanitizer, for now
  29          it only includes the address-use-after-scope check that can lead
  30          to excessive kernel stack usage, frame size warnings and longer
  31          compile time.
  32          https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 has more
  33
  34
  35choice
  36        prompt "Instrumentation type"
  37        depends on KASAN
  38        default KASAN_OUTLINE
  39
  40config KASAN_OUTLINE
  41        bool "Outline instrumentation"
  42        help
  43          Before every memory access compiler insert function call
  44          __asan_load*/__asan_store*. These functions performs check
  45          of shadow memory. This is slower than inline instrumentation,
  46          however it doesn't bloat size of kernel's .text section so
  47          much as inline does.
  48
  49config KASAN_INLINE
  50        bool "Inline instrumentation"
  51        help
  52          Compiler directly inserts code checking shadow memory before
  53          memory accesses. This is faster than outline (in some workloads
  54          it gives about x2 boost over outline instrumentation), but
  55          make kernel's .text size much bigger.
  56          This requires a gcc version of 5.0 or later.
  57
  58endchoice
  59
  60config TEST_KASAN
  61        tristate "Module for testing kasan for bug detection"
  62        depends on m && KASAN
  63        help
  64          This is a test module doing various nasty things like
  65          out of bounds accesses, use after free. It is useful for testing
  66          kernel debugging features like kernel address sanitizer.
  67
  68endif
  69