Commit 0249c9c1 authored by Roland McGrath's avatar Roland McGrath Committed by Ingo Molnar

x86 vDSO: vdso32 build

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: default avatarRoland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 0c2f51a7
#
# 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 +65,74 @@ 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/
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)
KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
$(vdso32.so-y:%=$(obj)/vdso32-%.so.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
$(vdso32.so-y:%=$(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
$(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)
#
# Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
#
quiet_cmd_vdso_install = INSTALL $@
cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
vdso.so:
$(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
@mkdir -p $(MODLIB)/vdso
$(call cmd,vdso_install)
vdso_install: vdso.so
PHONY += vdso_install $(vdso-install-y)
vdso_install: $(vdso-install-y)
/*
* Linker script for 32-bit vDSO.
* We #include the file to define the layout details.
* Here we only choose the prelinked virtual address.
*
* This file defines the version script giving the user-exported symbols in
* the DSO. We can define local symbols here called VDSO* to make their
* values visible using the asm-x86/vdso.h macros from the kernel proper.
*/
#define VDSO_PRELINK 0
#include "../vdso-layout.lds.S"
/* The ELF entry point can be used to set the AT_SYSINFO value. */
ENTRY(__kernel_vsyscall);
/*
* This controls what userland symbols we export from the vDSO.
*/
VERSION
{
LINUX_2.5 {
global:
__kernel_vsyscall;
__kernel_sigreturn;
__kernel_rt_sigreturn;
local: *;
};
}
/*
* Symbols we define here called VDSO* get their values into vdso32-syms.h.
*/
VDSO32_PRELINK = VDSO_PRELINK;
VDSO32_vsyscall = __kernel_vsyscall;
VDSO32_sigreturn = __kernel_sigreturn;
VDSO32_rt_sigreturn = __kernel_rt_sigreturn;
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment