config HAVE_ARCH_KASAN bool if HAVE_ARCH_KASAN config KASAN bool "KASan: runtime memory debugger" depends on (SLUB && SYSFS) || (SLAB && !DEBUG_SLAB) select SLUB_DEBUG if SLUB select CONSTRUCTORS select STACKDEPOT help Enables kernel address sanitizer - runtime memory debugger, designed to find out-of-bounds accesses and use-after-free bugs. This is strictly a debugging feature and it requires a gcc version of 4.9.2 or later. Detection of out of bounds accesses to stack or global variables requires gcc 5.0 or later. This feature consumes about 1/8 of available memory and brings about ~x3 performance slowdown. For better error detection enable CONFIG_STACKTRACE. Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB (the resulting kernel does not boot). config KASAN_EXTRA bool "KAsan: extra checks" depends on KASAN && DEBUG_KERNEL && !COMPILE_TEST help This enables further checks in the kernel address sanitizer, for now it only includes the address-use-after-scope check that can lead to excessive kernel stack usage, frame size warnings and longer compile time. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 has more choice prompt "Instrumentation type" depends on KASAN default KASAN_OUTLINE config KASAN_OUTLINE bool "Outline instrumentation" help Before every memory access compiler insert function call __asan_load*/__asan_store*. These functions performs check of shadow memory. This is slower than inline instrumentation, however it doesn't bloat size of kernel's .text section so much as inline does. config KASAN_INLINE bool "Inline instrumentation" help Compiler directly inserts code checking shadow memory before memory accesses. This is faster than outline (in some workloads it gives about x2 boost over outline instrumentation), but make kernel's .text size much bigger. This requires a gcc version of 5.0 or later. endchoice config KASAN_S390_4_LEVEL_PAGING bool "KASan: use 4-level paging" depends on KASAN && S390 help Compiling the kernel with KASan disables automatic 3-level vs 4-level paging selection. 3-level paging is used by default (up to 3TB of RAM with KASan enabled). This options allows to force 4-level paging instead. config TEST_KASAN tristate "Module for testing kasan for bug detection" depends on m && KASAN help This is a test module doing various nasty things like out of bounds accesses, use after free. It is useful for testing kernel debugging features like kernel address sanitizer. endif