Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

torvalds · torvalds · commit 6e54df001ac9 · 2018-12-26T16:57:27.000-08:00
Pull x86 build updates from Ingo Molnar:

 - Resolve LLVM build bug by removing redundant GNU specific flag

 - Remove obsolete -funit-at-a-time and -fno-unit-at-a-time use from x86
   PowerPC and UM.

   The UML change was seen and acked by UML maintainer Richard
   Weinberger.

* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/um/vdso: Drop implicit common-page-size linker flag
  x86, powerpc: Remove -funit-at-a-time compiler option entirely
  x86/um: Remove -fno-unit-at-a-time workaround for pre-4.0 GCC
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
@@ -228,10 +228,6 @@ KBUILD_CFLAGS += $(call cc-option,-mno-vsx)
 KBUILD_CFLAGS += $(call cc-option,-mno-spe)
 KBUILD_CFLAGS += $(call cc-option,-mspe=no)
 
-# Enable unit-at-a-time mode when possible. It shrinks the
-# kernel considerably.
-KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
-
 # FIXME: the module load should be taught about the additional relocs
 # generated by this.
 # revert to pre-gcc-4.4 behaviour of .eh_frame
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
@@ -130,10 +130,6 @@ else
 
         KBUILD_CFLAGS += -mno-red-zone
         KBUILD_CFLAGS += -mcmodel=kernel
-
-        # -funit-at-a-time shrinks the kernel .text considerably
-        # unfortunately it makes reading oopses harder.
-        KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
 endif
 
 ifdef CONFIG_X86_X32
diff --git a/arch/x86/Makefile.um b/arch/x86/Makefile.um
@@ -26,13 +26,6 @@ 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 [ $(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)
 
 else
@@ -54,6 +47,4 @@ ELF_FORMAT := elf64-x86-64
 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)
 endif
diff --git a/arch/x86/um/vdso/Makefile b/arch/x86/um/vdso/Makefile
@@ -26,7 +26,7 @@ targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
 CPPFLAGS_vdso.lds += -P -C
 
 VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
-       -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
+       -Wl,-z,max-page-size=4096
 
 $(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
 
