Commit bbb56c27 authored Dec 06, 2016 by Marc Zyngier Committed by Catalin Marinas Dec 06, 2016

arm64: Add detection code for broken .inst support in binutils



Binutils version up to (and including) 2.25 have a pathological
behaviour when it comes to mixing .inst directive and arithmetic
involving labels. The assembler complains about non-constant
expressions and compilation stops pretty quickly.

In order to detect this and work around it, let's add a bit of
detection code that will set the CONFIG_BROKEN_GAS_INST option
should a broken gas be detected.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

parent 49f5522e

arch/arm64/Makefile

+8 −2

Original line number	Diff line number	Diff line
		@@ -37,10 +37,16 @@ $(warning LSE atomics not supported by binutils)
		endif
		endif

		KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr)
		brokengasinst := $(call as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n,,-DCONFIG_BROKEN_GAS_INST=1)

		ifneq ($(brokengasinst),)
		$(warning Detected assembler with broken .inst; disassembly will be unreliable)
		endif

		KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst)
		KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
		KBUILD_CFLAGS += $(call cc-option, -mpc-relative-literal-loads)
		KBUILD_AFLAGS += $(lseinstr)
		KBUILD_AFLAGS += $(lseinstr) $(brokengasinst)

		ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
		KBUILD_CPPFLAGS += -mbig-endian