1 # SPDX-License-Identifier: GPL-2.0-only
2 # Copied from arch/tile/kernel/vdso/Makefile
4 # Symbols present in the vdso
5 vdso-syms = rt_sigreturn
7 vdso-syms += gettimeofday
8 vdso-syms += clock_gettime
9 vdso-syms += clock_getres
12 vdso-syms += flush_icache
14 # Files to link into the vdso
15 obj-vdso = $(patsubst %, %.o, $(vdso-syms))
18 targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o
19 obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
21 obj-y += vdso.o vdso-syms.o
22 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
24 # Disable gcov profiling for VDSO code
28 $(obj)/vdso.o: $(obj)/vdso.so
30 # link rule for the .so file, .lds has to be first
31 SYSCFLAGS_vdso.so.dbg = $(c_flags)
32 $(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
33 $(call if_changed,vdsold)
35 # We also create a special relocatable object that should mirror the symbol
36 # table and layout of the linked DSO. With ld -R we can then refer to
37 # these symbols in the kernel code rather than hand-coded addresses.
39 SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
41 $(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
42 $(call if_changed,vdsold)
44 LDFLAGS_vdso-syms.o := -r -R
45 $(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
48 # strip rule for the .so file
49 $(obj)/%.so: OBJCOPYFLAGS := -S
50 $(obj)/%.so: $(obj)/%.so.dbg FORCE
51 $(call if_changed,objcopy)
53 # actual build commands
54 # The DSO images are built using a special linker script
55 # Add -lgcc so rv32 gets static muldi3 and lshrdi3 definitions.
56 # Make sure only to export the intended __vdso_xxx symbol offsets.
57 quiet_cmd_vdsold = VDSOLD $@
58 cmd_vdsold = $(CC) $(KBUILD_CFLAGS) $(call cc-option, -no-pie) -nostdlib -nostartfiles $(SYSCFLAGS_$(@F)) \
59 -Wl,-T,$(filter-out FORCE,$^) -o $@.tmp && \
60 $(CROSS_COMPILE)objcopy \
61 $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@
63 # install commands for the unstripped file
64 quiet_cmd_vdso_install = INSTALL $@
65 cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
67 vdso.so: $(obj)/vdso.so.dbg
68 @mkdir -p $(MODLIB)/vdso
69 $(call cmd,vdso_install)