# SPDX-License-Identifier: GPL-2.0-only

  config ARCH_HAS_UBSAN_SANITIZE_ALL
  	bool

  menuconfig UBSAN

  	bool "Undefined behaviour sanity checker"
  	help

  	  This option enables the Undefined Behaviour sanity checker.

  	  Compile-time instrumentation is used to detect various undefined

  	  behaviours at runtime. For more details, see:
  	  Documentation/dev-tools/ubsan.rst

  if UBSAN

  config UBSAN_TRAP
  	bool "On Sanitizer warnings, abort the running kernel code"

  	depends on $(cc-option, -fsanitize-undefined-trap-on-error)
  	help
  	  Building kernels with Sanitizer features enabled tends to grow
  	  the kernel size by around 5%, due to adding all the debugging
  	  text on failure paths. To avoid this, Sanitizer instrumentation
  	  can just issue a trap. This reduces the kernel size overhead but
  	  turns all warnings (including potentially harmless conditions)
  	  into full exceptions that abort the running kernel code
  	  (regardless of context, locks held, etc), which may destabilize
  	  the system. For some system builders this is an acceptable
  	  trade-off.

  config UBSAN_KCOV_BROKEN
  	def_bool KCOV && CC_HAS_SANCOV_TRACE_PC
  	depends on CC_IS_CLANG
  	depends on !$(cc-option,-Werror=unused-command-line-argument -fsanitize=bounds -fsanitize-coverage=trace-pc)
  	help
  	  Some versions of clang support either UBSAN or KCOV but not the
  	  combination of the two.
  	  See https://bugs.llvm.org/show_bug.cgi?id=45831 for the status
  	  in newer releases.

  config UBSAN_BOUNDS
  	bool "Perform array index bounds checking"
  	default UBSAN

  	depends on !UBSAN_KCOV_BROKEN

  	help
  	  This option enables detection of directly indexed out of bounds
  	  array accesses, where the array size is known at compile time.
  	  Note that this does not protect array overflows via bad calls
  	  to the {str,mem}*cpy() family of functions (that is addressed
  	  by CONFIG_FORTIFY_SOURCE).

  config UBSAN_LOCAL_BOUNDS
  	bool "Perform array local bounds checking"
  	depends on UBSAN_TRAP
  	depends on CC_IS_CLANG
  	depends on !UBSAN_KCOV_BROKEN
  	help
  	  This option enables -fsanitize=local-bounds which traps when an
  	  exception/error is detected. Therefore, it should be enabled only
  	  if trapping is expected.
  	  Enabling this option detects errors due to accesses through a
  	  pointer that is derived from an object of a statically-known size,
  	  where an added offset (which may not be known statically) is
  	  out-of-bounds.

  config UBSAN_MISC
  	bool "Enable all other Undefined Behavior sanity checks"
  	default UBSAN
  	help
  	  This option enables all sanity checks that don't have their
  	  own Kconfig options. Disable this if you only want to have
  	  individually selected checks.

  config UBSAN_SANITIZE_ALL
  	bool "Enable instrumentation for the entire kernel"

  	depends on ARCH_HAS_UBSAN_SANITIZE_ALL

  
  	# We build with -Wno-maybe-uninitilzed, but we still want to
  	# use -Wmaybe-uninitilized in allmodconfig builds.
  	# So dependsy bellow used to disable this option in allmodconfig
  	depends on !COMPILE_TEST

  	default y
  	help
  	  This option activates instrumentation for the entire kernel.
  	  If you don't enable this option, you have to explicitly specify
  	  UBSAN_SANITIZE := y for the files/directories you want to check for UB.

  	  Enabling this option will get kernel image size increased
  	  significantly.

  config UBSAN_ALIGNMENT
  	bool "Enable checks for pointers alignment"
  	default !HAVE_EFFICIENT_UNALIGNED_ACCESS

  	depends on !UBSAN_TRAP

  	help

  	  This option enables the check of unaligned memory accesses.
  	  Enabling this option on architectures that support unaligned

  	  accesses may produce a lot of false positives.

  config TEST_UBSAN
  	tristate "Module for testing for undefined behavior detection"

  	depends on m

  	help
  	  This is a test module for UBSAN.
  	  It triggers various undefined behavior, and detect it.

  
  endif	# if UBSAN