From 0bf6276392e990dd0da0ccd8e10f42597d503f29 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 27 Feb 2012 14:09:10 -0800 Subject: [PATCH] x32: Warn and disable rather than error if binutils too old If X32 is enabled in .config, but the binutils can't build it, issue a warning and disable the feature rather than erroring out. In order to support this, have CONFIG_X86_X32 be the option set in Kconfig, and CONFIG_X86_X32_ABI be the option set by the Makefile when it is enabled and binutils has been found to be functional. Requested-by: Ingo Molnar Signed-off-by: H. Peter Anvin Cc: H. J. Lu Link: http://lkml.kernel.org/r/1329696488-16970-1-git-send-email-hpa@zytor.com --- arch/x86/Kconfig | 4 ++-- arch/x86/Makefile | 16 ++++++++++++++++ 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c9d6c9e..e2b38b4 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2175,7 +2175,7 @@ config IA32_AOUT ---help--- Support old a.out binaries in the 32bit emulation. -config X86_X32_ABI +config X86_X32 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)" depends on X86_64 && IA32_EMULATION && EXPERIMENTAL ---help--- @@ -2190,7 +2190,7 @@ config X86_X32_ABI config COMPAT def_bool y - depends on IA32_EMULATION || X86_X32_ABI + depends on IA32_EMULATION || X86_X32 config COMPAT_FOR_U64_ALIGNMENT def_bool COMPAT diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 209ba12..31bb1eb 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -82,6 +82,22 @@ ifdef CONFIG_CC_STACKPROTECTOR endif endif +ifdef CONFIG_X86_X32 + x32_ld_ok := $(call try-run,\ + /bin/echo -e '1: .quad 1b' | \ + $(CC) $(KBUILD_AFLAGS) -c -xassembler -o "$$TMP" - && \ + $(OBJCOPY) -O elf32-x86-64 "$$TMP" "$$TMPO" && \ + $(LD) -m elf32_x86_64 "$$TMPO" -o "$$TMP",y,n) + ifeq ($(x32_ld_ok),y) + CONFIG_X86_X32_ABI := y + KBUILD_AFLAGS += -DCONFIG_X86_X32_ABI + KBUILD_CFLAGS += -DCONFIG_X86_X32_ABI + else + $(warning CONFIG_X86_X32 enabled but no binutils support) + endif +endif +export CONFIG_X86_X32_ABI + # Don't unroll struct assignments with kmemcheck enabled ifeq ($(CONFIG_KMEMCHECK),y) KBUILD_CFLAGS += $(call cc-option,-fno-builtin-memcpy) -- 2.7.4