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authorJeff Dike <jdike@addtoit.com>2008-07-07 13:36:56 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-07 10:53:10 -0700
commit4f81c5350b44bcc501ab6f8a089b16d064b4d2f6 (patch)
tree69a3e0f0758f114d1faa6a3242c02ec26f4a2ddc
parentb2798bf0ec2cb5a17bfc1430c5ba6d971c436a03 (diff)
[UML] fix gcc ICEs and unresolved externs
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 c0a18111e571138747a98af18b3a2124df56a0d1 Ingo reported a gcc internal error with gcc 4.3 with no-unit-at-a-timem, resulting in 22eecde2f9034764a3fd095eecfa3adfb8ec9a98 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>
-rw-r--r--arch/um/Makefile1
-rw-r--r--arch/um/Makefile-i3867
-rw-r--r--arch/um/Makefile-x86_643
3 files changed, 10 insertions, 1 deletions
diff --git a/arch/um/Makefile b/arch/um/Makefile
index dbeab15e7bb..ca40397017b 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -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
diff --git a/arch/um/Makefile-i386 b/arch/um/Makefile-i386
index 561e373bd85..302cbe50454 100644
--- a/arch/um/Makefile-i386
+++ b/arch/um/Makefile-i386
@@ -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 += $(cflags-y)
diff --git a/arch/um/Makefile-x86_64 b/arch/um/Makefile-x86_64
index 8ed362f9358..a9cd7e77a7a 100644
--- a/arch/um/Makefile-x86_64
+++ b/arch/um/Makefile-x86_64
@@ -21,3 +21,6 @@ HEADER_ARCH := x86
LINK-$(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)