From: Nathan Chancellor natechancellor@gmail.com
[ Upstream commit 465bfd9c44dea6b55962b5788a23ac87a467c923 ]
When building pseries_defconfig, building vdso32 errors out:
error: unknown target ABI 'elfv1'
This happens because -m32 in clang changes the target to 32-bit, which does not allow the ABI to be changed.
Commit 4dc831aa8813 ("powerpc: Fix compiling a BE kernel with a powerpc64le toolchain") added these flags to fix building big endian kernels with a little endian GCC.
Clang doesn't need -mabi because the target triple controls the default value. -mlittle-endian and -mbig-endian manipulate the triple into either powerpc64-* or powerpc64le-*, which properly sets the default ABI.
Adding a debug print out in the PPC64TargetInfo constructor after line 383 above shows this:
$ echo | ./clang -E --target=powerpc64-linux -mbig-endian -o /dev/null - Default ABI: elfv1
$ echo | ./clang -E --target=powerpc64-linux -mlittle-endian -o /dev/null - Default ABI: elfv2
$ echo | ./clang -E --target=powerpc64le-linux -mbig-endian -o /dev/null - Default ABI: elfv1
$ echo | ./clang -E --target=powerpc64le-linux -mlittle-endian -o /dev/null - Default ABI: elfv2
Don't specify -mabi when building with clang to avoid the build error with -m32 and not change any code generation.
-mcall-aixdesc is not an implemented flag in clang so it can be safely excluded as well, see commit 238abecde8ad ("powerpc: Don't use gcc specific options on clang").
pseries_defconfig successfully builds after this patch and powernv_defconfig and ppc44x_defconfig don't regress.
Reviewed-by: Daniel Axtens dja@axtens.net Signed-off-by: Nathan Chancellor natechancellor@gmail.com [mpe: Trim clang links in change log] Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20191119045712.39633-2-natechancellor@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/Makefile | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index dfcb698ec8f3..e43321f46a3b 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -90,11 +90,13 @@ MULTIPLEWORD := -mmultiple endif
ifdef CONFIG_PPC64 +ifndef CONFIG_CC_IS_CLANG cflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mabi=elfv1) cflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mcall-aixdesc) aflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mabi=elfv1) aflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mabi=elfv2 endif +endif
ifneq ($(cc-name),clang) cflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mno-strict-align @@ -134,6 +136,7 @@ endif endif
CFLAGS-$(CONFIG_PPC64) := $(call cc-option,-mtraceback=no) +ifndef CONFIG_CC_IS_CLANG ifdef CONFIG_CPU_LITTLE_ENDIAN CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv2,$(call cc-option,-mcall-aixdesc)) AFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv2) @@ -142,6 +145,7 @@ CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv1) CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcall-aixdesc) AFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv1) endif +endif CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcmodel=medium,$(call cc-option,-mminimal-toc)) CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mno-pointers-to-nested-functions)