diff options
| -rw-r--r-- | Documentation/dev-tools/ubsan.rst | 1 | ||||
| -rw-r--r-- | lib/Kconfig.ubsan | 82 |
2 files changed, 57 insertions, 26 deletions
diff --git a/Documentation/dev-tools/ubsan.rst b/Documentation/dev-tools/ubsan.rst index 655e6b63c227..1be6618e232d 100644 --- a/Documentation/dev-tools/ubsan.rst +++ b/Documentation/dev-tools/ubsan.rst @@ -86,3 +86,4 @@ References .. _1: https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html .. _2: https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html +.. _3: https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan index fa78f0f3c1dc..8b635fd75fe4 100644 --- a/lib/Kconfig.ubsan +++ b/lib/Kconfig.ubsan @@ -84,48 +84,88 @@ config UBSAN_LOCAL_BOUNDS 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_SHIFT - def_bool UBSAN_MISC + 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 - def_bool UBSAN_MISC + bool "Perform checking for integer divide-by-zero" depends on $(cc-option,-fsanitize=integer-divide-by-zero) + 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 - def_bool UBSAN_MISC + bool "Perform checking for unreachable code" + # objtool already handles unreachable checking and gets angry about + # seeing UBSan instrumentation located in unreachable places. + depends on !STACK_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_SIGNED_OVERFLOW - def_bool UBSAN_MISC + bool "Perform checking for signed arithmetic overflow" + default UBSAN depends on $(cc-option,-fsanitize=signed-integer-overflow) + help + This option enables -fsanitize=signed-integer-overflow which checks + for overflow of any arithmetic operations with signed integers. config UBSAN_UNSIGNED_OVERFLOW - def_bool UBSAN_MISC + bool "Perform checking for unsigned arithmetic overflow" depends on $(cc-option,-fsanitize=unsigned-integer-overflow) + help + This option enables -fsanitize=unsigned-integer-overflow which checks + for overflow of any arithmetic operations with unsigned integers. This + currently causes x86 to fail to boot. config UBSAN_OBJECT_SIZE - def_bool UBSAN_MISC + bool "Perform checking for accesses beyond the end of objects" + default UBSAN # gcc hugely expands stack usage with -fsanitize=object-size # https://lore.kernel.org/lkml/CAHk-=wjPasyJrDuwDnpHJS2TuQfExwe=px-SzLeN8GFMAQJPmQ@mail.gmail.com/ depends on !CC_IS_GCC depends on $(cc-option,-fsanitize=object-size) + help + This option enables -fsanitize=object-size which checks for accesses + beyond the end of objects where the optimizer can determine both the + object being operated on and its size, usually seen with bad downcasts, + or access to struct members from NULL pointers. config UBSAN_BOOL - def_bool UBSAN_MISC + 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 - def_bool UBSAN_MISC + 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" @@ -138,16 +178,6 @@ config UBSAN_SANITIZE_ALL 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 && !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 TEST_UBSAN tristate "Module for testing for undefined behavior detection" depends on m |