1# SPDX-License-Identifier: GPL-2.0-only 2config ARCH_HAS_UBSAN_SANITIZE_ALL 3 bool 4 5menuconfig UBSAN 6 bool "Undefined behaviour sanity checker" 7 help 8 This option enables the Undefined Behaviour sanity checker. 9 Compile-time instrumentation is used to detect various undefined 10 behaviours at runtime. For more details, see: 11 Documentation/dev-tools/ubsan.rst 12 13if UBSAN 14 15config UBSAN_TRAP 16 bool "On Sanitizer warnings, abort the running kernel code" 17 depends on $(cc-option, -fsanitize-undefined-trap-on-error) 18 help 19 Building kernels with Sanitizer features enabled tends to grow 20 the kernel size by around 5%, due to adding all the debugging 21 text on failure paths. To avoid this, Sanitizer instrumentation 22 can just issue a trap. This reduces the kernel size overhead but 23 turns all warnings (including potentially harmless conditions) 24 into full exceptions that abort the running kernel code 25 (regardless of context, locks held, etc), which may destabilize 26 the system. For some system builders this is an acceptable 27 trade-off. 28 29config UBSAN_BOUNDS 30 bool "Perform array index bounds checking" 31 default UBSAN 32 help 33 This option enables detection of directly indexed out of bounds 34 array accesses, where the array size is known at compile time. 35 Note that this does not protect array overflows via bad calls 36 to the {str,mem}*cpy() family of functions (that is addressed 37 by CONFIG_FORTIFY_SOURCE). 38 39config UBSAN_MISC 40 bool "Enable all other Undefined Behavior sanity checks" 41 default UBSAN 42 help 43 This option enables all sanity checks that don't have their 44 own Kconfig options. Disable this if you only want to have 45 individually selected checks. 46 47config UBSAN_SANITIZE_ALL 48 bool "Enable instrumentation for the entire kernel" 49 depends on ARCH_HAS_UBSAN_SANITIZE_ALL 50 51 # We build with -Wno-maybe-uninitilzed, but we still want to 52 # use -Wmaybe-uninitilized in allmodconfig builds. 53 # So dependsy bellow used to disable this option in allmodconfig 54 depends on !COMPILE_TEST 55 default y 56 help 57 This option activates instrumentation for the entire kernel. 58 If you don't enable this option, you have to explicitly specify 59 UBSAN_SANITIZE := y for the files/directories you want to check for UB. 60 Enabling this option will get kernel image size increased 61 significantly. 62 63config UBSAN_ALIGNMENT 64 bool "Enable checks for pointers alignment" 65 default !HAVE_EFFICIENT_UNALIGNED_ACCESS 66 depends on !X86 || !COMPILE_TEST 67 help 68 This option enables the check of unaligned memory accesses. 69 Enabling this option on architectures that support unaligned 70 accesses may produce a lot of false positives. 71 72config TEST_UBSAN 73 tristate "Module for testing for undefined behavior detection" 74 depends on m 75 help 76 This is a test module for UBSAN. 77 It triggers various undefined behavior, and detect it. 78 79endif # if UBSAN 80