xref: /openbmc/linux/arch/riscv/kernel/vdso/Makefile (revision b23bf21f) 
1# SPDX-License-Identifier: GPL-2.0-only
2# Copied from arch/tile/kernel/vdso/Makefile
3
4# Symbols present in the vdso
5vdso-syms  = rt_sigreturn
6ifdef CONFIG_64BIT
7vdso-syms += gettimeofday
8vdso-syms += clock_gettime
9vdso-syms += clock_getres
10endif
11vdso-syms += getcpu
12vdso-syms += flush_icache
13
14# Files to link into the vdso
15obj-vdso = $(patsubst %, %.o, $(vdso-syms))
16
17# Build rules
18targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o
19obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
20
21obj-y += vdso.o vdso-syms.o
22CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
23
24# Disable gcov profiling for VDSO code
25GCOV_PROFILE := n
26
27# Force dependency
28$(obj)/vdso.o: $(obj)/vdso.so
29
30# link rule for the .so file, .lds has to be first
31SYSCFLAGS_vdso.so.dbg = $(c_flags)
32$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
33	$(call if_changed,vdsold)
34
35# We also create a special relocatable object that should mirror the symbol
36# table and layout of the linked DSO.  With ld -R we can then refer to
37# these symbols in the kernel code rather than hand-coded addresses.
38
39SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
40	-Wl,--build-id -Wl,--hash-style=both
41$(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
42	$(call if_changed,vdsold)
43
44LDFLAGS_vdso-syms.o := -r -R
45$(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
46	$(call if_changed,ld)
47
48# strip rule for the .so file
49$(obj)/%.so: OBJCOPYFLAGS := -S
50$(obj)/%.so: $(obj)/%.so.dbg FORCE
51	$(call if_changed,objcopy)
52
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.
57quiet_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 $@
62
63# install commands for the unstripped file
64quiet_cmd_vdso_install = INSTALL $@
65      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
66
67vdso.so: $(obj)/vdso.so.dbg
68	@mkdir -p $(MODLIB)/vdso
69	$(call cmd,vdso_install)
70
71vdso_install: vdso.so
72