164 lines
6.2 KiB
Plaintext
164 lines
6.2 KiB
Plaintext
# 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 "Abort on Sanitizer warnings (smaller kernel but less verbose)"
|
|
depends on !COMPILE_TEST
|
|
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.
|
|
|
|
Also note that selecting Y will cause your kernel to Oops
|
|
with an "illegal instruction" error with no further details
|
|
when a UBSAN violation occurs. (Except on arm64, which will
|
|
report which Sanitizer failed.) This may make it hard to
|
|
determine whether an Oops was caused by UBSAN or to figure
|
|
out the details of a UBSAN violation. It makes the kernel log
|
|
output less useful for bug reports.
|
|
|
|
config CC_HAS_UBSAN_BOUNDS_STRICT
|
|
def_bool $(cc-option,-fsanitize=bounds-strict)
|
|
help
|
|
The -fsanitize=bounds-strict option is only available on GCC,
|
|
but uses the more strict handling of arrays that includes knowledge
|
|
of flexible arrays, which is comparable to Clang's regular
|
|
-fsanitize=bounds.
|
|
|
|
config CC_HAS_UBSAN_ARRAY_BOUNDS
|
|
def_bool $(cc-option,-fsanitize=array-bounds)
|
|
help
|
|
Under Clang, the -fsanitize=bounds option is actually composed
|
|
of two more specific options, -fsanitize=array-bounds and
|
|
-fsanitize=local-bounds. However, -fsanitize=local-bounds can
|
|
only be used when trap mode is enabled. (See also the help for
|
|
CONFIG_LOCAL_BOUNDS.) Explicitly check for -fsanitize=array-bounds
|
|
so that we can build up the options needed for UBSAN_BOUNDS
|
|
with or without UBSAN_TRAP.
|
|
|
|
config UBSAN_BOUNDS
|
|
bool "Perform array index bounds checking"
|
|
default UBSAN
|
|
depends on CC_HAS_UBSAN_ARRAY_BOUNDS || CC_HAS_UBSAN_BOUNDS_STRICT
|
|
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_BOUNDS_STRICT
|
|
def_bool UBSAN_BOUNDS && CC_HAS_UBSAN_BOUNDS_STRICT
|
|
help
|
|
GCC's bounds sanitizer. This option is used to select the
|
|
correct options in Makefile.ubsan.
|
|
|
|
config UBSAN_ARRAY_BOUNDS
|
|
def_bool UBSAN_BOUNDS && CC_HAS_UBSAN_ARRAY_BOUNDS
|
|
help
|
|
Clang's array bounds sanitizer. This option is used to select
|
|
the correct options in Makefile.ubsan.
|
|
|
|
config UBSAN_LOCAL_BOUNDS
|
|
def_bool UBSAN_ARRAY_BOUNDS && UBSAN_TRAP
|
|
help
|
|
This option enables Clang's -fsanitize=local-bounds which traps
|
|
when an access 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. Since this option is
|
|
trap-only, it depends on CONFIG_UBSAN_TRAP.
|
|
|
|
config UBSAN_SHIFT
|
|
bool "Perform checking for bit-shift overflows"
|
|
default UBSAN
|
|
depends on $(cc-option,-fsanitize=shift)
|
|
help
|
|
This option enables -fsanitize=shift which checks for bit-shift
|
|
operations that overflow to the left or go switch to negative
|
|
for signed types.
|
|
|
|
config UBSAN_DIV_ZERO
|
|
bool "Perform checking for integer divide-by-zero"
|
|
depends on $(cc-option,-fsanitize=integer-divide-by-zero)
|
|
# https://github.com/ClangBuiltLinux/linux/issues/1657
|
|
# https://github.com/llvm/llvm-project/issues/56289
|
|
depends on !CC_IS_CLANG
|
|
help
|
|
This option enables -fsanitize=integer-divide-by-zero which checks
|
|
for integer division by zero. This is effectively redundant with the
|
|
kernel's existing exception handling, though it can provide greater
|
|
debugging information under CONFIG_UBSAN_REPORT_FULL.
|
|
|
|
config UBSAN_UNREACHABLE
|
|
bool "Perform checking for unreachable code"
|
|
# objtool already handles unreachable checking and gets angry about
|
|
# seeing UBSan instrumentation located in unreachable places.
|
|
depends on !(OBJTOOL && (STACK_VALIDATION || UNWINDER_ORC || HAVE_UACCESS_VALIDATION))
|
|
depends on $(cc-option,-fsanitize=unreachable)
|
|
help
|
|
This option enables -fsanitize=unreachable which checks for control
|
|
flow reaching an expected-to-be-unreachable position.
|
|
|
|
config UBSAN_BOOL
|
|
bool "Perform checking for non-boolean values used as boolean"
|
|
default UBSAN
|
|
depends on $(cc-option,-fsanitize=bool)
|
|
help
|
|
This option enables -fsanitize=bool which checks for boolean values being
|
|
loaded that are neither 0 nor 1.
|
|
|
|
config UBSAN_ENUM
|
|
bool "Perform checking for out of bounds enum values"
|
|
default UBSAN
|
|
depends on $(cc-option,-fsanitize=enum)
|
|
help
|
|
This option enables -fsanitize=enum which checks for values being loaded
|
|
into an enum that are outside the range of given values for the given enum.
|
|
|
|
config UBSAN_ALIGNMENT
|
|
bool "Perform checking for misaligned pointer usage"
|
|
default !HAVE_EFFICIENT_UNALIGNED_ACCESS
|
|
depends on !UBSAN_TRAP && !COMPILE_TEST
|
|
depends on $(cc-option,-fsanitize=alignment)
|
|
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 UBSAN_SANITIZE_ALL
|
|
bool "Enable instrumentation for the entire kernel"
|
|
depends on ARCH_HAS_UBSAN_SANITIZE_ALL
|
|
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 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
|