Hi Roland.
Some minor things below.
In general I like the simplification of this
area and having it moved out of kernel/Makefile is the-right-thing.
Sam
On Mon, Nov 19, 2007 at 02:05:32PM -0800, Roland McGrath wrote:
>
> This builds the 32-bit vDSO images in the arch/x86/vdso subdirectory.
> Nothing uses the images yet, but this paves the way for consolidating
> the vDSO build logic all in one place. The new images use a linker
> script sharing the layout parts from vdso-layout.lds.S with the 64-bit
> vDSO. A new vdso32-syms.lds is generated in the style of vdso-syms.lds.
>
> Signed-off-by: Roland McGrath <[EMAIL PROTECTED]>
> ---
> arch/x86/vdso/Makefile | 76 +++++++++++++++++++++++++++++++++++-
> arch/x86/vdso/vdso32/vdso32.lds.S | 37 ++++++++++++++++++
> 2 files changed, 110 insertions(+), 3 deletions(-)
> create mode 100644 arch/x86/vdso/vdso32/vdso32.lds.S
>
> diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile
> index 6a665dd..a1e0418 100644
> --- a/arch/x86/vdso/Makefile
> +++ b/arch/x86/vdso/Makefile
> @@ -1,7 +1,15 @@
> #
> -# x86-64 vDSO.
> +# Building vDSO images for x86.
> #
>
> +VDSO64-$(CONFIG_X86_64) := y
> +VDSO32-$(CONFIG_X86_32) := y
> +VDSO32-$(CONFIG_COMPAT) := y
> +
> +vdso-install-$(VDSO64-y) += vdso.so
> +vdso-install-$(VDSO32-y) += $(vdso32-y:=.so)
> +
> +
> # files to link into the vdso
> vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vvar.o
>
> @@ -57,10 +65,72 @@ quiet_cmd_vdsosym = VDSOSYM $@
> $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
> $(call if_changed,vdsosym)
>
> +#
> +# Build multiple 32-bit vDSO images to choose from at boot time.
> +#
> +vdso32.so-$(CONFIG_X86_32) += int80
> +vdso32.so-$(VDSO32-y) += sysenter
> +
> +CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
> +VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -Wl,-soname=linux-gate.so.1
> +
> +# This makes sure the $(obj) subdirectory exists even though vdso32/
> +# is not a kbuild sub-make subdirectory.
> +override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
Should we teach kbuild to create dirs specified in targets?
Or we could 'fix' it so you do not need the override.
> +
> +targets += vdso32/vdso32.lds
> +targets += $(vdso32.so-y:%=vdso32-%.so.dbg) $(vdso32.so-y:%=vdso32-%.so)
> +targets += vdso32/note.o $(vdso32.so-y:%=vdso32/%.o)
> +
> +extra-y += $(vdso32.so-y:%=vdso32-%.so)
> +
> +$(vdso32.so-y:%=$(obj)/vdso32-%.so.dbg): asflags-$(CONFIG_X86_64) += -m32
> +
> +$(vdso32.so-y:%=$(obj)/vdso32-%.so.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
> + $(obj)/vdso32/vdso32.lds \
> + $(obj)/vdso32/note.o \
> + $(obj)/vdso32/%.o
> + $(call if_changed,vdso)
> +
> +# Make vdso32-*-syms.lds from each image, and then make sure they match.
> +# The only difference should be that some do not define
> VDSO32_SYSENTER_RETURN.
> +
> +targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
> +
> +quiet_cmd_vdso32sym = VDSOSYM $@
> +define cmd_vdso32sym
> + if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \
> + $(foreach H,$(filter-out FORCE,$^),\
> + if grep -q VDSO32_SYSENTER_RETURN $H; \
> + then diff -u $(@D)/.tmp_$(@F) $H; \
> + else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \
> + diff -u - $H; fi &&) : ;\
> + then mv -f $(@D)/.tmp_$(@F) $@; \
> + else rm -f $(@D)/.tmp_$(@F); exit 1; \
> + fi
> +endef
use "set -e; in front of this shell script to bail out early
in case of errors.
> +
> +$(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
> + $(call if_changed,vdso32sym)
> +
> +#
> +# The DSO images are built using a special linker script.
> +#
> +quiet_cmd_vdso = VDSO $@
> + cmd_vdso = $(CC) -nostdlib -o $@ \
> + $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
> + -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^)
> +
> +VDSO_LDFLAGS = -fPIC -shared $(call ld-option, -Wl$(comma)--hash-style=sysv)
Do you need to specify soname for 64-bit - seems missing?
> +
> +#
> +# Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
> +#
> quiet_cmd_vdso_install = INSTALL $@
> cmd_vdso_install = cp $(obj)/[EMAIL PROTECTED] $(MODLIB)/vdso/$@
> -vdso.so:
> +$(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
> @mkdir -p $(MODLIB)/vdso
> $(call cmd,vdso_install)
Please use $(Q) in preference for @
Then it is easier to debug using make V=1
> -vdso_install: vdso.so
> +PHONY += vdso_install $(vdso-install-y)
> +vdso_install: $(vdso-install-y)
-
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