| # SPDX-License-Identifier: GPL-2.0-only |
| |
| # Include the generic Makefile to check the built vdso. |
| include $(srctree)/lib/vdso/Makefile |
| |
| # Symbols present in the vdso |
| vdso-syms += rt_sigreturn |
| vdso-syms += vgettimeofday |
| |
| # Files to link into the vdso |
| obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o |
| |
| ifneq ($(c-gettimeofday-y),) |
| CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) |
| endif |
| |
| ccflags-y := -fno-stack-protector -DBUILD_VDSO32 |
| |
| # Build rules |
| targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o |
| obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) |
| |
| obj-y += vdso.o vdso-syms.o |
| CPPFLAGS_vdso.lds += -P -C -U$(ARCH) |
| |
| # Disable gcov profiling for VDSO code |
| GCOV_PROFILE := n |
| KCOV_INSTRUMENT := n |
| |
| # Force dependency |
| $(obj)/vdso.o: $(obj)/vdso.so |
| |
| SYSCFLAGS_vdso.so.dbg = $(c_flags) |
| $(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE |
| $(call if_changed,vdsold) |
| SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \ |
| -Wl,--build-id=sha1 -Wl,--hash-style=both |
| |
| $(obj)/vdso-syms.S: $(obj)/vdso.so FORCE |
| $(call if_changed,so2s) |
| |
| # strip rule for the .so file |
| $(obj)/%.so: OBJCOPYFLAGS := -S |
| $(obj)/%.so: $(obj)/%.so.dbg FORCE |
| $(call if_changed,objcopy) |
| |
| # actual build commands |
| # The DSO images are built using a special linker script |
| # Make sure only to export the intended __vdso_xxx symbol offsets. |
| quiet_cmd_vdsold = VDSOLD $@ |
| cmd_vdsold = $(CC) $(KBUILD_CFLAGS) $(call cc-option, -no-pie) -nostdlib -nostartfiles $(SYSCFLAGS_$(@F)) \ |
| -Wl,-T,$(filter-out FORCE,$^) -o $@.tmp && \ |
| $(CROSS_COMPILE)objcopy \ |
| $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \ |
| rm $@.tmp |
| |
| # Extracts symbol offsets from the VDSO, converting them into an assembly file |
| # that contains the same symbols at the same offsets. |
| quiet_cmd_so2s = SO2S $@ |
| cmd_so2s = $(NM) -D $< | $(srctree)/$(src)/so2s.sh > $@ |
| |
| # install commands for the unstripped file |
| quiet_cmd_vdso_install = INSTALL $@ |
| cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@ |
| |
| vdso.so: $(obj)/vdso.so.dbg |
| @mkdir -p $(MODLIB)/vdso |
| $(call cmd,vdso_install) |
| |
| vdso_install: vdso.so |