[linux-block.git] / lib / Kconfig.kmsan

# SPDX-License-Identifier: GPL-2.0-only
config HAVE_ARCH_KMSAN
	bool

config HAVE_KMSAN_COMPILER
	# Clang versions <14.0.0 also support -fsanitize=kernel-memory, but not
	# all the features necessary to build the kernel with KMSAN.
	depends on CC_IS_CLANG && CLANG_VERSION >= 140000
	def_bool $(cc-option,-fsanitize=kernel-memory -mllvm -msan-disable-checks=1)

config KMSAN
	bool "KMSAN: detector of uninitialized values use"
	depends on HAVE_ARCH_KMSAN && HAVE_KMSAN_COMPILER
	depends on SLUB && DEBUG_KERNEL && !KASAN && !KCSAN
	select STACKDEPOT
	select STACKDEPOT_ALWAYS_INIT
	help
	  KernelMemorySanitizer (KMSAN) is a dynamic detector of uses of
	  uninitialized values in the kernel. It is based on compiler
	  instrumentation provided by Clang and thus requires Clang to build.

	  An important note is that KMSAN is not intended for production use,
	  because it drastically increases kernel memory footprint and slows
	  the whole system down.

	  See <file:Documentation/dev-tools/kmsan.rst> for more details.

if KMSAN

config HAVE_KMSAN_PARAM_RETVAL
	# -fsanitize-memory-param-retval is supported only by Clang >= 14.
	depends on HAVE_KMSAN_COMPILER
	def_bool $(cc-option,-fsanitize=kernel-memory -fsanitize-memory-param-retval)

config KMSAN_CHECK_PARAM_RETVAL
	bool "Check for uninitialized values passed to and returned from functions"
	default y
	depends on HAVE_KMSAN_PARAM_RETVAL
	help
	  If the compiler supports -fsanitize-memory-param-retval, KMSAN will
	  eagerly check every function parameter passed by value and every
	  function return value.

	  Disabling KMSAN_CHECK_PARAM_RETVAL will result in tracking shadow for
	  function parameters and return values across function borders. This
	  is a more relaxed mode, but it generates more instrumentation code and
	  may potentially report errors in corner cases when non-instrumented
	  functions call instrumented ones.

endif
Commit	Line	Data
f80be457 AP	1	# SPDX-License-Identifier: GPL-2.0-only
	2	config HAVE_ARCH_KMSAN
	3	bool
	4
	5	config HAVE_KMSAN_COMPILER
	6	# Clang versions <14.0.0 also support -fsanitize=kernel-memory, but not
	7	# all the features necessary to build the kernel with KMSAN.
	8	depends on CC_IS_CLANG && CLANG_VERSION >= 140000
	9	def_bool $(cc-option,-fsanitize=kernel-memory -mllvm -msan-disable-checks=1)
	10
	11	config KMSAN
	12	bool "KMSAN: detector of uninitialized values use"
	13	depends on HAVE_ARCH_KMSAN && HAVE_KMSAN_COMPILER
	14	depends on SLUB && DEBUG_KERNEL && !KASAN && !KCSAN
	15	select STACKDEPOT
	16	select STACKDEPOT_ALWAYS_INIT
	17	help
	18	KernelMemorySanitizer (KMSAN) is a dynamic detector of uses of
	19	uninitialized values in the kernel. It is based on compiler
	20	instrumentation provided by Clang and thus requires Clang to build.
	21
	22	An important note is that KMSAN is not intended for production use,
	23	because it drastically increases kernel memory footprint and slows
	24	the whole system down.
	25
	26	See <file:Documentation/dev-tools/kmsan.rst> for more details.
	27
	28	if KMSAN
	29
	30	config HAVE_KMSAN_PARAM_RETVAL
	31	# -fsanitize-memory-param-retval is supported only by Clang >= 14.
	32	depends on HAVE_KMSAN_COMPILER
	33	def_bool $(cc-option,-fsanitize=kernel-memory -fsanitize-memory-param-retval)
	34
	35	config KMSAN_CHECK_PARAM_RETVAL
	36	bool "Check for uninitialized values passed to and returned from functions"
	37	default y
	38	depends on HAVE_KMSAN_PARAM_RETVAL
	39	help
	40	If the compiler supports -fsanitize-memory-param-retval, KMSAN will
	41	eagerly check every function parameter passed by value and every
	42	function return value.
	43
	44	Disabling KMSAN_CHECK_PARAM_RETVAL will result in tracking shadow for
	45	function parameters and return values across function borders. This
	46	is a more relaxed mode, but it generates more instrumentation code and
	47	may potentially report errors in corner cases when non-instrumented
	48	functions call instrumented ones.
	49
	50	endif