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| author | Nathan Chancellor <nathan@kernel.org> | 2022-11-21 20:21:21 +0100 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2022-11-28 12:57:36 +0100 |
| commit | 59e2cf8d21e05391c42628eb9fb5bb40f9d9698f (patch) | |
| tree | 236ace165e381de6f30aed8b44a9c74fa2f6992e /arch/arm | |
| parent | ARM: 9274/1: Add hwcap for Speculative Store Bypassing Safe (diff) | |
| download | linux-59e2cf8d21e05391c42628eb9fb5bb40f9d9698f.tar.xz linux-59e2cf8d21e05391c42628eb9fb5bb40f9d9698f.zip | |
ARM: 9275/1: Drop '-mthumb' from AFLAGS_ISA
When building with CONFIG_THUMB2_KERNEL=y + a version of clang from
Debian using CROSS_COMPILE=arm-linux-gnueabihf-, the following warning
occurs frequently:
<built-in>:383:9: warning: '__thumb2__' macro redefined [-Wmacro-redefined]
#define __thumb2__ 2
^
<built-in>:353:9: note: previous definition is here
#define __thumb2__ 1
^
1 warning generated.
Debian carries a downstream patch that changes the default CPU of the
arm-linux-gnueabihf target from 'arm1176jzf-s' (v6) to 'cortex-a7' (v7).
As a result, '-mthumb' defines both '__thumb__' and '__thumb2__'. The
define of '__thumb2__' via the command line was purposefully added to
catch a situation like this.
In a similar vein as commit 26b12e084bce ("ARM: 9264/1: only use
-mtp=cp15 for the compiler"), do not add '-mthumb' to AFLAGS_ISA, as it
is already passed to the assembler via '-Wa,-mthumb' and '__thumb2__' is
already defined for preprocessing.
Link: https://salsa.debian.org/pkg-llvm-team/llvm-toolchain/-/raw/622dbcbd40b316ed3905a2d25d9623544a06e6b1/debian/patches/930008-arm.diff
Fixes: 1d2e9b67b001 ("ARM: 9265/1: pass -march= only to compiler")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/Makefile | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 357f0d9b8607..d1ebb746ff40 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -131,8 +131,9 @@ endif AFLAGS_NOWARN :=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W) ifeq ($(CONFIG_THUMB2_KERNEL),y) -CFLAGS_ISA :=-mthumb -Wa,-mimplicit-it=always $(AFLAGS_NOWARN) +CFLAGS_ISA :=-Wa,-mimplicit-it=always $(AFLAGS_NOWARN) AFLAGS_ISA :=$(CFLAGS_ISA) -Wa$(comma)-mthumb -D__thumb2__=2 +CFLAGS_ISA +=-mthumb else CFLAGS_ISA :=$(call cc-option,-marm,) $(AFLAGS_NOWARN) AFLAGS_ISA :=$(CFLAGS_ISA) |