[PATCH 08/14] powerpc/vdso: Remove an unsupported flag from vgettimeofday-32.o with clang

[Nathan Chancellor]

When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it
warns:

  clang-16: error: argument unused during compilation: '-fno-stack-clash-protection' [-Werror,-Wunused-command-line-argument]

This flag is supported for 64-bit powerpc but not 32-bit, hence the warning.
Just remove the flag from vgettimeofday-32.o's CFLAGS when using clang, as has
been done for other flags previously.

Signed-off-by: Nathan Chancellor <nathan at kernel.org>
---
Cc: mpe at ellerman.id.au
Cc: npiggin at gmail.com
Cc: christophe.leroy at csgroup.eu
Cc: linuxppc-dev at lists.ozlabs.org
---
 arch/powerpc/kernel/vdso/Makefile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/vdso/Makefile b/arch/powerpc/kernel/vdso/Makefile
index 769b62832b38..4ee7d36ce752 100644
--- a/arch/powerpc/kernel/vdso/Makefile
+++ b/arch/powerpc/kernel/vdso/Makefile
@@ -16,6 +16,11 @@ ifneq ($(c-gettimeofday-y),)
   CFLAGS_vgettimeofday-32.o += -ffreestanding -fasynchronous-unwind-tables
   CFLAGS_REMOVE_vgettimeofday-32.o = $(CC_FLAGS_FTRACE)
   CFLAGS_REMOVE_vgettimeofday-32.o += -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
+  # This flag is supported by clang for 64-bit but not 32-bit so it will cause
+  # an unused command line flag warning for this file.
+  ifdef CONFIG_CC_IS_CLANG
+  CFLAGS_REMOVE_vgettimeofday-32.o += -fno-stack-clash-protection
+  endif
   CFLAGS_vgettimeofday-64.o += -include $(c-gettimeofday-y)
   CFLAGS_vgettimeofday-64.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
   CFLAGS_vgettimeofday-64.o += $(call cc-option, -fno-stack-protector)

-- 
2.39.0