When building the boot wrapper assembly files with clang after commit 648a1783fe25 ("powerpc/boot: Fix boot wrapper code generation with CONFIG_POWER10_CPU"), the following warnings appear for each file built:
'-prefixed' is not a recognized feature for this target (ignoring feature) '-pcrel' is not a recognized feature for this target (ignoring feature)
While it is questionable whether or not LLVM should be emitting a warning when passed negative versions of code generation flags when building assembly files (since it does not emit a warning for the altivec and vsx flags), it is easy enough to work around this by just moving the disabled flags to BOOTCFLAGS after the assignment of BOOTAFLAGS, so that they are not added when building assembly files. Do so to silence the warnings.
Cc: stable@vger.kernel.org Fixes: 648a1783fe25 ("powerpc/boot: Fix boot wrapper code generation with CONFIG_POWER10_CPU") Link: https://github.com/ClangBuiltLinux/linux/issues/1839 Reviewed-by: Nicholas Piggin npiggin@gmail.com Signed-off-by: Nathan Chancellor nathan@kernel.org --- I do not think that 648a1783fe25 is truly to blame for this but the Fixes tag will help the stable team ensure that this change gets backported with 648a1783fe25. This is the minimal fix for the problem but the true fix is separating AFLAGS and CFLAGS, which should be done by this in-flight series by Nick:
https://lore.kernel.org/20230426055848.402993-1-npiggin@gmail.com/ --- arch/powerpc/boot/Makefile | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile index 85cde5bf04b7..771b79423bbc 100644 --- a/arch/powerpc/boot/Makefile +++ b/arch/powerpc/boot/Makefile @@ -34,8 +34,6 @@ endif
BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -O2 -msoft-float -mno-altivec -mno-vsx \ - $(call cc-option,-mno-prefixed) $(call cc-option,-mno-pcrel) \ - $(call cc-option,-mno-mma) \ $(call cc-option,-mno-spe) $(call cc-option,-mspe=no) \ -pipe -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \ $(LINUXINCLUDE) @@ -71,6 +69,10 @@ BOOTAFLAGS := -D__ASSEMBLY__ $(BOOTCFLAGS) -nostdinc
BOOTARFLAGS := -crD
+BOOTCFLAGS += $(call cc-option,-mno-prefixed) \ + $(call cc-option,-mno-pcrel) \ + $(call cc-option,-mno-mma) + ifdef CONFIG_CC_IS_CLANG BOOTCFLAGS += $(CLANG_FLAGS) BOOTAFLAGS += $(CLANG_FLAGS)
--- base-commit: 169f8997968ab620d750d9a45e15c5288d498356 change-id: 20230427-remove-power10-args-from-boot-aflags-clang-268c43e8c1fc
Best regards,