diff options
| -rw-r--r-- | arch/x86/vdso/Makefile | 78 | ||||
| -rw-r--r-- | arch/x86/vdso/vdso32/vdso32.lds.S | 37 |
2 files changed, 112 insertions, 3 deletions
diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile index 6a665dd0984..a02e1ca2a1b 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 +65,74 @@ 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) diff --git a/arch/x86/vdso/vdso32/vdso32.lds.S b/arch/x86/vdso/vdso32/vdso32.lds.S new file mode 100644 index 00000000000..976124bb5f9 --- /dev/null +++ b/arch/x86/vdso/vdso32/vdso32.lds.S @@ -0,0 +1,37 @@ +/* + * 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; |