[UML] fix gcc ICEs and unresolved externs (4f81c535) · Commits · 戴 / test

There are various constraints on the use of unit-at-a-time: - i386 uses no-unit-at-a-time for pre-4.0 (not 4.3) - x86_64 uses unit-at-a-time always Uli reported a crash on x86_64 with gcc 4.1.2 with unit-at-a-time, resulting in commit Ingo reported a gcc internal error with gcc 4.3 with no-unit-at-a-timem, resulting in Benny Halevy is seeing extern inlines not resolved with gcc 4.3 with no-unit-at-a-time This patch reintroduces unit-at-a-time for gcc >= 4.0, bringing back the possibility of Uli's crash. If that happens, we'll debug it. I started seeing both the internal compiler errors and unresolved inlines on Fedora 9. This patch fixes both problems, without so far reintroducing the crash reported by Uli. Signed-off-by:

Jeff Dike <jdike@linux.intel.com> Cc: Benny Halevy <bhalevy@panasas.com> Cc: Adrian Bunk <bunk@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ulrich Drepper <drepper@redhat.com> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

arch/um/Makefile

+0 −1

Original line number	Diff line number	Diff line
		@@ -77,7 +77,6 @@ include $(srctree)/$(ARCH_DIR)/Makefile-os-$(OS)
		KERNEL_DEFINES = $(strip -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask \
		-Dmktime=kernel_mktime $(ARCH_KERNEL_DEFINES))
		KBUILD_CFLAGS += $(KERNEL_DEFINES)
		KBUILD_CFLAGS += $(call cc-option,-fno-unit-at-a-time,)

		PHONY += linux

arch/um/Makefile-i386

+7 −0

Original line number	Diff line number	Diff line
		@@ -32,4 +32,11 @@ cflags-y += $(call cc-option,-mpreferred-stack-boundary=2)
		# an unresolved reference.
		cflags-y += -ffreestanding

		# Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
		# a lot more stack due to the lack of sharing of stacklots. Also, gcc
		# 4.3.0 needs -funit-at-a-time for extern inline functions.
		KBUILD_CFLAGS += $(shell if [ $(call cc-version) -lt 0400 ] ; then \
		echo $(call cc-option,-fno-unit-at-a-time); \
		else echo $(call cc-option,-funit-at-a-time); fi ;)

		KBUILD_CFLAGS += $(cflags-y)

arch/um/Makefile-x86_64

+3 −0

Original line number	Diff line number	Diff line
		@@ -21,3 +21,6 @@ HEADER_ARCH := x86

		LINK-$(CONFIG_LD_SCRIPT_DYN) += -Wl,-rpath,/lib64
		LINK-y += -m64

		# Do unit-at-a-time unconditionally on x86_64, following the host
		KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)

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