init: Kconfig: Disable -Wstringop-overflow for GCC-11 -Wstringop-overflow is buggy in GCC-11. Therefore, we should disable this option specifically for that compiler version. To achieve this, we introduce a new configuration option: GCC11_NO_STRINGOP_OVERFLOW. The compiler option related to string operation overflow is now managed under configuration CC_STRINGOP_OVERFLOW. This option is enabled by default for all other versions of GCC that support it. Link: https://lore.kernel.org/lkml/b3c99290-40bc-426f-b3d2-1aa903f95c4e@embeddedor.com/ Link: https://lore.kernel.org/lkml/20231128091351.2bfb38dd@canb.auug.org.au/ Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/linux-hardening/ZWj1+jkweEDWbmAR@work/ Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
diff --git a/Makefile b/Makefile index c01cbbb..9f9b76d 100644 --- a/Makefile +++ b/Makefile
@@ -986,7 +986,9 @@ # perform bounds checking. KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3) -KBUILD_CFLAGS += $(call cc-option, -Wstringop-overflow) +#Currently, disable -Wstringop-overflow for GCC 11, globally. +KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow) +KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow) # disable invalid "can't wrap" optimizations for signed / pointers KBUILD_CFLAGS += -fno-strict-overflow
diff --git a/init/Kconfig b/init/Kconfig index 8df18f3a..8d4e836 100644 --- a/init/Kconfig +++ b/init/Kconfig
@@ -876,6 +876,18 @@ bool default y if CC_IS_GCC && GCC_VERSION >= 110000 && GCC11_NO_ARRAY_BOUNDS +# Currently, disable -Wstringop-overflow for GCC 11, globally. +config GCC11_NO_STRINGOP_OVERFLOW + def_bool y + +config CC_NO_STRINGOP_OVERFLOW + bool + default y if CC_IS_GCC && GCC_VERSION >= 110000 && GCC_VERSION < 120000 && GCC11_NO_STRINGOP_OVERFLOW + +config CC_STRINGOP_OVERFLOW + bool + default y if CC_IS_GCC && !CC_NO_STRINGOP_OVERFLOW + # # For architectures that know their GCC __int128 support is sound #