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 || (SLAB && !DEBUG_SLAB)
   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           Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB
  20           (the resulting kernel does not boot).
  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           This requires a gcc version of 5.0 or later.
  44
  45 endchoice
  46
  47 config TEST_KASAN
  48         tristate "Module for testing kasan for bug detection"
  49         depends on m && KASAN
  50         help
  51           This is a test module doing various nasty things like
  52           out of bounds accesses, use after free. It is useful for testing
  53           kernel debugging features like kernel address sanitizer.
  54
  55 endif