xref: /openbmc/linux/arch/riscv/kernel/vdso/Makefile (revision 82df5b73)
1# SPDX-License-Identifier: GPL-2.0-only
2# Copied from arch/tile/kernel/vdso/Makefile
3
4# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
5# the inclusion of generic Makefile.
6ARCH_REL_TYPE_ABS := R_RISCV_32|R_RISCV_64|R_RISCV_JUMP_SLOT
7include $(srctree)/lib/vdso/Makefile
8# Symbols present in the vdso
9vdso-syms  = rt_sigreturn
10ifdef CONFIG_64BIT
11vdso-syms += vgettimeofday
12endif
13vdso-syms += getcpu
14vdso-syms += flush_icache
15
16# Files to link into the vdso
17obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
18
19ifneq ($(c-gettimeofday-y),)
20  CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y)
21endif
22
23# Build rules
24targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o
25obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
26
27obj-y += vdso.o vdso-syms.o
28CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
29
30# Disable gcov profiling for VDSO code
31GCOV_PROFILE := n
32
33# Force dependency
34$(obj)/vdso.o: $(obj)/vdso.so
35
36# link rule for the .so file, .lds has to be first
37SYSCFLAGS_vdso.so.dbg = $(c_flags)
38$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
39	$(call if_changed,vdsold)
40
41# We also create a special relocatable object that should mirror the symbol
42# table and layout of the linked DSO. With ld --just-symbols we can then
43# refer to these symbols in the kernel code rather than hand-coded addresses.
44
45SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
46	-Wl,--build-id -Wl,--hash-style=both
47$(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
48	$(call if_changed,vdsold)
49
50LDFLAGS_vdso-syms.o := -r --just-symbols
51$(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
52	$(call if_changed,ld)
53
54# strip rule for the .so file
55$(obj)/%.so: OBJCOPYFLAGS := -S
56$(obj)/%.so: $(obj)/%.so.dbg FORCE
57	$(call if_changed,objcopy)
58
59# actual build commands
60# The DSO images are built using a special linker script
61# Add -lgcc so rv32 gets static muldi3 and lshrdi3 definitions.
62# Make sure only to export the intended __vdso_xxx symbol offsets.
63quiet_cmd_vdsold = VDSOLD  $@
64      cmd_vdsold = $(CC) $(KBUILD_CFLAGS) $(call cc-option, -no-pie) -nostdlib -nostartfiles $(SYSCFLAGS_$(@F)) \
65                           -Wl,-T,$(filter-out FORCE,$^) -o $@.tmp && \
66                   $(CROSS_COMPILE)objcopy \
67                           $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
68                   rm $@.tmp
69
70# install commands for the unstripped file
71quiet_cmd_vdso_install = INSTALL $@
72      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
73
74vdso.so: $(obj)/vdso.so.dbg
75	@mkdir -p $(MODLIB)/vdso
76	$(call cmd,vdso_install)
77
78vdso_install: vdso.so
79