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>
This commit is contained in:
Gustavo A. R. Silva 2023-11-30 14:29:34 -06:00
parent 113a61863e
commit a5e0ace04f
2 changed files with 15 additions and 1 deletions

View File

@ -986,7 +986,9 @@ NOSTDINC_FLAGS += -nostdinc
# 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

View File

@ -876,6 +876,18 @@ config CC_NO_ARRAY_BOUNDS
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
#