[PATCH 1/4] kbuild: remove cc-option test of -fno-strict-overflow

From: Masahiro Yamada
Date: Thu Sep 10 2020 - 10:23:01 EST


The minimal compiler versions, GCC 4.9 and Clang 10 support this flag.

Here is the godbolt:
https://godbolt.org/z/odq8h9

Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---

Makefile | 2 +-
arch/arm64/kernel/vdso32/Makefile | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 4b5a305e30d2..059b36f2ea53 100644
--- a/Makefile
+++ b/Makefile
@@ -922,7 +922,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)

# disable invalid "can't wrap" optimizations for signed / pointers
-KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
+KBUILD_CFLAGS += -fno-strict-overflow

# clang sets -fmerge-all-constants by default as optimization, but this
# is non-conforming behavior for C and in fact breaks the kernel, so we
diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile
index d6adb4677c25..dfffd55175a3 100644
--- a/arch/arm64/kernel/vdso32/Makefile
+++ b/arch/arm64/kernel/vdso32/Makefile
@@ -90,7 +90,7 @@ VDSO_CFLAGS += -O2
# Some useful compiler-dependent flags from top-level Makefile
VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,)
VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign)
-VDSO_CFLAGS += $(call cc32-option,-fno-strict-overflow)
+VDSO_CFLAGS += -fno-strict-overflow
VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes)
VDSO_CFLAGS += $(call cc32-option,-Werror=date-time)
VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types)
--
2.25.1