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 <mingo@elte.hu>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: H. J. Lu <hjl.tools@gmail.com>
Link: http://lkml.kernel.org/r/1329696488-16970-1-git-send-email-hpa@zytor.com
This commit is contained in:
H. Peter Anvin 2012-02-27 14:09:10 -08:00
parent e0a449cab5
commit 0bf6276392
2 changed files with 18 additions and 2 deletions

View File

@ -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

View File

@ -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)