arm/Makefile: Fix systemtap

Currently systemtap fails to operate correctly on armv7 systems such as beaglebone and
soon, qemuarm.

root@qemuarm:/usr/src/kernel# env -uARCH -uKBUILD_EXTMOD -uCROSS_COMPILE -uKBUILD_IMAGE -uKCONFIG_CONFIG -uINSTALL_PATH -uLD_LIBRARY_PATH PATH=/usr/bin:/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin make -C /lib/modules/4.19.19-yocto-standard/build M=/tmp/staptcNU6M modules CONFIG_DEBUG_INFO= CONFIG_STACK_VALIDATION= ARCH=arm stap_4321_src.i --no-print-directory -j2 V=1
test -e include/generated/autoconf.h -a -e include/config/auto.conf || (		\
echo >&2;							\
echo >&2 "  ERROR: Kernel configuration is invalid.";		\
echo >&2 "         include/generated/autoconf.h or include/config/auto.conf are missing.";\
echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
echo >&2 ;							\
/bin/false)
mkdir -p /tmp/staptcNU6M/.tmp_versions ; rm -f /tmp/staptcNU6M/.tmp_versions/*
make -f ./scripts/Makefile.build obj=/tmp/staptcNU6M
(cat /dev/null;   echo kernel//tmp/staptcNU6M/stap_4321.ko;) > /tmp/staptcNU6M/modules.order
  gcc -Wp,-MD,/tmp/staptcNU6M/.stap_4321_src.o.d  -nostdinc -isystem /usr/lib/gcc/arm-poky-linux-gnueabi/8.3.0/include -I./arch/arm/include -I./arch/arm/include/generated  -I./include -I./arch/arm/include/uapi -I./arch/arm/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h -include ./include/linux/compiler_types.h -D__KERNEL__ -mlittle-endian -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -fshort-wchar -Werror-implicit-function-declaration -Wno-format-security -std=gnu89 -fno-PIE -DCC_HAVE_ASM_GOTO -fno-dwarf2-cfi-asm -fno-omit-frame-pointer -mapcs -mno-sched-prolog -fno-ipa-sra -mabi=aapcs-linux -mfpu=vfp -funwind-tables -marm -Wa,-mno-warn-deprecated -D__LINUX_ARM_ARCH__=7 -march=armv5t -Wa,-march=armv7-a -msoft-float -Uarm -fno-delete-null-pointer-checks -Wno-frame-address -Wno-format-truncation -Wno-format-overflow -Wno-int-in-bool-context -Os -Wno-maybe-uninitialized --param=allow-store-data-races=0 -Wframe-larger-than=1024 -fstack-protector-strong -Wno-unused-but-set-variable -Wno-unused-const-variable -fno-omit-frame-pointer -fno-optimize-sibling-calls -fno-var-tracking-assignments -pg -Wdeclaration-after-statement -Wno-pointer-sign -Wno-stringop-truncation -fno-strict-overflow -fno-merge-all-constants -fmerge-constants -fno-stack-check -fconserve-stack -Werror=implicit-int -Werror=strict-prototypes -Werror=date-time -Werror=incompatible-pointer-types -Werror=designated-init -fmacro-prefix-map=./= -Wno-packed-not-aligned -Iinclude2/asm/mach-default -I/lib/modules/4.19.19-yocto-standard/build -include /tmp/staptcNU6M/stapconf_4321.h -D "STP_NO_VELREL_CHECK" -freorder-blocks -fasynchronous-unwind-tables -Wframe-larger-than=512 -fno-ipa-icf -Wno-unused -Wno-tautological-compare -Werror -I/usr/share/systemtap/runtime  -DMODULE  -DKBUILD_BASENAME='"stap_4321_src"' -DKBUILD_MODNAME='"stap_4321"' -c -o /tmp/staptcNU6M/stap_4321_src.o /tmp/staptcNU6M/stap_4321_src.c
/tmp/ccaE9CMG.s: Assembler messages:
/tmp/ccaE9CMG.s:49: Error: selected processor does not support `dmb ish' in ARM mode
/tmp/ccaE9CMG.s:52: Error: architectural extension `mp' is not allowed for the current b

(which was from running the stap command with -v -v -v -k and then being able to run the command individually)

Note that it says armv5t above.

That comes from the code this patch changes

root@qemuarm:/usr/src/kernel# gcc -march=armv7-a /tmp/staptcNU6M/stap_4321_aux_0.c
cc1: error: -mfloat-abi=hard: selected processor lacks an FPU

which makes me wonder if cc-option fails unless -mfpu-vfp is on the commandline too.

Since we have a gcc which accepts the armv7-a arch, just remove the cc-option
wrapper unconditionally here.

Signed-off-by: Richard Purdie <[email protected]>
Signed-off-by: Bruce Ashfield <[email protected]>

arch/arm/Makefile

@@ -61,7 +61,7 @@ KBUILD_CFLAGS	+= $(call cc-option,-fno-ipa-sra)
 # macro, but instead defines a whole series of macros which makes
 # testing for a specific architecture or later rather impossible.
 arch-$(CONFIG_CPU_32v7M)	=-D__LINUX_ARM_ARCH__=7 -march=armv7-m -Wa,-march=armv7-m
-arch-$(CONFIG_CPU_32v7)		=-D__LINUX_ARM_ARCH__=7 $(call cc-option,-march=armv7-a,-march=armv5t -Wa$(comma)-march=armv7-a)
+arch-$(CONFIG_CPU_32v7)		=-D__LINUX_ARM_ARCH__=7 -march=armv7-a -Wa$(comma)-march=armv7-a
 arch-$(CONFIG_CPU_32v6)		=-D__LINUX_ARM_ARCH__=6 $(call cc-option,-march=armv6,-march=armv5t -Wa$(comma)-march=armv6)
 # Only override the compiler option if ARMv6. The ARMv6K extensions are
 # always available in ARMv7