diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index b080eb2335eb..032c889c7f02 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -415,8 +415,8 @@ static void lkdtm_FAM_BOUNDS(void) pr_err("FAIL: survived access of invalid flexible array member index!\n"); - if (!__has_attribute(__counted_by__)) - pr_warn("This is expected since this %s was built a compiler supporting __counted_by\n", + if (!IS_ENABLED(CONFIG_CC_HAS_COUNTED_BY)) + pr_warn("This is expected since this %s was built with a compiler that does not support __counted_by\n", lkdtm_kernel_info); else if (IS_ENABLED(CONFIG_UBSAN_BOUNDS)) pr_expected_config(CONFIG_UBSAN_TRAP); diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index f5859b8c68b4..7e0a2efd90ca 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -94,19 +94,6 @@ # define __copy(symbol) #endif -/* - * Optional: only supported since gcc >= 14 - * Optional: only supported since clang >= 18 - * - * gcc: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896 - * clang: https://reviews.llvm.org/D148381 - */ -#if __has_attribute(__counted_by__) -# define __counted_by(member) __attribute__((__counted_by__(member))) -#else -# define __counted_by(member) -#endif - /* * Optional: not supported by gcc * Optional: only supported since clang >= 14.0 diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 454d942384a4..8faf6c7786ad 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -304,6 +304,25 @@ struct ftrace_likely_data { #define __counted_by_be(member) __counted_by(member) #endif +/* + * Optional: only supported since gcc >= 15 + * Optional: only supported since clang >= 18 + * + * gcc: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896 + * clang: https://github.com/llvm/llvm-project/pull/76348 + * + * __bdos on clang < 19.1.2 can erroneously return 0: + * https://github.com/llvm/llvm-project/pull/110497 + * + * __bdos on clang < 19.1.3 can be off by 4: + * https://github.com/llvm/llvm-project/pull/112636 + */ +#ifdef CONFIG_CC_HAS_COUNTED_BY +# define __counted_by(member) __attribute__((__counted_by__(member))) +#else +# define __counted_by(member) +#endif + /* Section for code which can't be instrumented at all */ #define __noinstr_section(section) \ noinline notrace __attribute((__section__(section))) \ diff --git a/init/Kconfig b/init/Kconfig index 8fd42e425ef5..227b0d8b4d76 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -107,6 +107,15 @@ config CC_HAS_ASM_INLINE config CC_HAS_NO_PROFILE_FN_ATTR def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror) +config CC_HAS_COUNTED_BY + # TODO: when gcc 15 is released remove the build test and add + # a gcc version check + def_bool $(success,echo 'struct flex { int count; int array[] __attribute__((__counted_by__(count))); };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror) + # clang needs to be at least 19.1.3 to avoid __bdos miscalculations + # https://github.com/llvm/llvm-project/pull/110497 + # https://github.com/llvm/llvm-project/pull/112636 + depends on !(CC_IS_CLANG && CLANG_VERSION < 190103) + config PAHOLE_VERSION int default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE))