ubsan: move cc-option tests into Kconfig

Instead of doing if/endif blocks with cc-option calls in the UBSAN
Makefile, move all the tests into Kconfig and use the Makefile to collect
the results.

Link: https://lkml.kernel.org/r/20201203004437.389959-3-keescook@chromium.org
Link: https://lore.kernel.org/lkml/CAHk-=wjPasyJrDuwDnpHJS2TuQfExwe=px-SzLeN8GFMAQJPmQ@mail.gmail.com/
Signed-off-by: Kees Cook <keescook@chromium.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kees Cook 2020-12-15 20:46:24 -08:00 committed by Linus Torvalds
parent d8a7f62b6e
commit cdf8a76fda
2 changed files with 73 additions and 33 deletions

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@ -36,10 +36,17 @@ config UBSAN_KCOV_BROKEN
See https://bugs.llvm.org/show_bug.cgi?id=45831 for the status
in newer releases.
config CC_HAS_UBSAN_BOUNDS
def_bool $(cc-option,-fsanitize=bounds)
config CC_HAS_UBSAN_ARRAY_BOUNDS
def_bool $(cc-option,-fsanitize=array-bounds)
config UBSAN_BOUNDS
bool "Perform array index bounds checking"
default UBSAN
depends on !UBSAN_KCOV_BROKEN
depends on CC_HAS_UBSAN_ARRAY_BOUNDS || CC_HAS_UBSAN_BOUNDS
help
This option enables detection of directly indexed out of bounds
array accesses, where the array size is known at compile time.
@ -47,15 +54,30 @@ config UBSAN_BOUNDS
to the {str,mem}*cpy() family of functions (that is addressed
by CONFIG_FORTIFY_SOURCE).
config UBSAN_ONLY_BOUNDS
def_bool CC_HAS_UBSAN_BOUNDS && !CC_HAS_UBSAN_ARRAY_BOUNDS
depends on UBSAN_BOUNDS
help
This is a weird case: Clang's -fsanitize=bounds includes
-fsanitize=local-bounds, but it's trapping-only, so for
Clang, we must use -fsanitize=array-bounds when we want
traditional array bounds checking enabled. For GCC, we
want -fsanitize=bounds.
config UBSAN_ARRAY_BOUNDS
def_bool CC_HAS_UBSAN_ARRAY_BOUNDS
depends on UBSAN_BOUNDS
config UBSAN_LOCAL_BOUNDS
bool "Perform array local bounds checking"
depends on UBSAN_TRAP
depends on CC_IS_CLANG
depends on !UBSAN_KCOV_BROKEN
depends on $(cc-option,-fsanitize=local-bounds)
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.
exception/error is detected. Therefore, it may only be enabled
with CONFIG_UBSAN_TRAP.
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
@ -69,6 +91,38 @@ config UBSAN_MISC
own Kconfig options. Disable this if you only want to have
individually selected checks.
config UBSAN_SHIFT
def_bool UBSAN_MISC
depends on $(cc-option,-fsanitize=shift)
config UBSAN_DIV_ZERO
def_bool UBSAN_MISC
depends on $(cc-option,-fsanitize=integer-divide-by-zero)
config UBSAN_UNREACHABLE
def_bool UBSAN_MISC
depends on $(cc-option,-fsanitize=unreachable)
config UBSAN_SIGNED_OVERFLOW
def_bool UBSAN_MISC
depends on $(cc-option,-fsanitize=signed-integer-overflow)
config UBSAN_UNSIGNED_OVERFLOW
def_bool UBSAN_MISC
depends on $(cc-option,-fsanitize=unsigned-integer-overflow)
config UBSAN_OBJECT_SIZE
def_bool UBSAN_MISC
depends on $(cc-option,-fsanitize=object-size)
config UBSAN_BOOL
def_bool UBSAN_MISC
depends on $(cc-option,-fsanitize=bool)
config UBSAN_ENUM
def_bool UBSAN_MISC
depends on $(cc-option,-fsanitize=enum)
config UBSAN_SANITIZE_ALL
bool "Enable instrumentation for the entire kernel"
depends on ARCH_HAS_UBSAN_SANITIZE_ALL
@ -85,6 +139,7 @@ config UBSAN_ALIGNMENT
bool "Enable checks for pointers alignment"
default !HAVE_EFFICIENT_UNALIGNED_ACCESS
depends on !UBSAN_TRAP
depends on $(cc-option,-fsanitize=alignment)
help
This option enables the check of unaligned memory accesses.
Enabling this option on architectures that support unaligned

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@ -1,33 +1,18 @@
# SPDX-License-Identifier: GPL-2.0
export CFLAGS_UBSAN :=
# Enable available and selected UBSAN features.
ubsan-cflags-$(CONFIG_UBSAN_ALIGNMENT) += -fsanitize=alignment
ubsan-cflags-$(CONFIG_UBSAN_ONLY_BOUNDS) += -fsanitize=bounds
ubsan-cflags-$(CONFIG_UBSAN_ARRAY_BOUNDS) += -fsanitize=array-bounds
ubsan-cflags-$(CONFIG_UBSAN_LOCAL_BOUNDS) += -fsanitize=local-bounds
ubsan-cflags-$(CONFIG_UBSAN_SHIFT) += -fsanitize=shift
ubsan-cflags-$(CONFIG_UBSAN_DIV_ZERO) += -fsanitize=integer-divide-by-zero
ubsan-cflags-$(CONFIG_UBSAN_UNREACHABLE) += -fsanitize=unreachable
ubsan-cflags-$(CONFIG_UBSAN_SIGNED_OVERFLOW) += -fsanitize=signed-integer-overflow
ubsan-cflags-$(CONFIG_UBSAN_UNSIGNED_OVERFLOW) += -fsanitize=unsigned-integer-overflow
ubsan-cflags-$(CONFIG_UBSAN_OBJECT_SIZE) += -fsanitize=object-size
ubsan-cflags-$(CONFIG_UBSAN_BOOL) += -fsanitize=bool
ubsan-cflags-$(CONFIG_UBSAN_ENUM) += -fsanitize=enum
ubsan-cflags-$(CONFIG_UBSAN_TRAP) += -fsanitize-undefined-trap-on-error
ifdef CONFIG_UBSAN_ALIGNMENT
CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment)
endif
ifdef CONFIG_UBSAN_BOUNDS
ifdef CONFIG_CC_IS_CLANG
CFLAGS_UBSAN += -fsanitize=array-bounds
else
CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds)
endif
endif
ifdef CONFIG_UBSAN_LOCAL_BOUNDS
CFLAGS_UBSAN += -fsanitize=local-bounds
endif
ifdef CONFIG_UBSAN_MISC
CFLAGS_UBSAN += $(call cc-option, -fsanitize=shift)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=integer-divide-by-zero)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=unreachable)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=signed-integer-overflow)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=object-size)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=bool)
CFLAGS_UBSAN += $(call cc-option, -fsanitize=enum)
endif
ifdef CONFIG_UBSAN_TRAP
CFLAGS_UBSAN += $(call cc-option, -fsanitize-undefined-trap-on-error)
endif
export CFLAGS_UBSAN := $(ubsan-cflags-y)