From: Jan Hendrik Farr Date: Wed, 30 Apr 2025 18:42:31 +0000 (+0200) Subject: hardening: simplify CONFIG_CC_HAS_COUNTED_BY X-Git-Tag: v6.16-rc1~151^2~11 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=5106c6506c51aa93198908b094228a7143292b9e;p=users%2Fgriffoul%2Flinux.git hardening: simplify CONFIG_CC_HAS_COUNTED_BY Simplifies CONFIG_CC_HAS_COUNTED_BY by removing the build test and relying solely on gcc/clang version numbering (GCC_VERSION >= 150100 and CLANG_VERSION >= 190103). The build test was used to allow unreleased gcc 15.0 builds to use the __counted_by attribute. Now that gcc 15.1.0 has been released, this is not needed anymore. Note: This will disable __counted_by on unreleased gcc 15.0 builds. clang version support for __counted_by remains unchanged. Link: https://lore.kernel.org/all/Zw8iawAF5W2uzGuh@archlinux/T/#m204c09f63c076586a02d194b87dffc7e81b8de7b Link: https://lore.kernel.org/r/20241029140036.577804-2-kernel@jfarr.cc Suggested-by: Nathan Chancellor Signed-off-by: Jan Hendrik Farr Link: https://lore.kernel.org/r/20250430184231.671365-2-kernel@jfarr.cc Reviewed-by: Nathan Chancellor Signed-off-by: Kees Cook --- diff --git a/init/Kconfig b/init/Kconfig index 63f5974b9fa6..017fde21d0ba 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -121,13 +121,14 @@ 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) + bool # 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) + default y if CC_IS_CLANG && CLANG_VERSION >= 190103 + # supported since gcc 15.1.0 + # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896 + default y if CC_IS_GCC && GCC_VERSION >= 150100 config CC_HAS_MULTIDIMENSIONAL_NONSTRING def_bool $(success,echo 'char tag[][4] __attribute__((__nonstring__)) = { };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror)