1# SPDX-License-Identifier: GPL-2.0-only
2#
3# Makefile for compat_vdso
4#
5
6# Symbols present in the compat_vdso
7compat_vdso-syms  = rt_sigreturn
8compat_vdso-syms += getcpu
9compat_vdso-syms += flush_icache
10
11COMPAT_CC := $(CC)
12COMPAT_LD := $(LD)
13
14COMPAT_CC_FLAGS := -march=rv32g -mabi=ilp32
15COMPAT_LD_FLAGS := -melf32lriscv
16
17# Files to link into the compat_vdso
18obj-compat_vdso = $(patsubst %, %.o, $(compat_vdso-syms)) note.o
19
20# Build rules
21targets := $(obj-compat_vdso) compat_vdso.so compat_vdso.so.dbg compat_vdso.lds
22obj-compat_vdso := $(addprefix $(obj)/, $(obj-compat_vdso))
23
24obj-y += compat_vdso.o
25CPPFLAGS_compat_vdso.lds += -P -C -U$(ARCH)
26
27# Disable profiling and instrumentation for VDSO code
28GCOV_PROFILE := n
29KCOV_INSTRUMENT := n
30KASAN_SANITIZE := n
31UBSAN_SANITIZE := n
32
33# Force dependency
34$(obj)/compat_vdso.o: $(obj)/compat_vdso.so
35
36# link rule for the .so file, .lds has to be first
37$(obj)/compat_vdso.so.dbg: $(obj)/compat_vdso.lds $(obj-compat_vdso) FORCE
38	$(call if_changed,compat_vdsold)
39LDFLAGS_compat_vdso.so.dbg = -shared -S -soname=linux-compat_vdso.so.1 \
40	--build-id=sha1 --hash-style=both --eh-frame-hdr
41
42$(obj-compat_vdso): %.o: %.S FORCE
43	$(call if_changed_dep,compat_vdsoas)
44
45# strip rule for the .so file
46$(obj)/%.so: OBJCOPYFLAGS := -S
47$(obj)/%.so: $(obj)/%.so.dbg FORCE
48	$(call if_changed,objcopy)
49
50# Generate VDSO offsets using helper script
51gen-compat_vdsosym := $(srctree)/$(src)/gen_compat_vdso_offsets.sh
52quiet_cmd_compat_vdsosym = VDSOSYM $@
53	cmd_compat_vdsosym = $(NM) $< | $(gen-compat_vdsosym) | LC_ALL=C sort > $@
54
55include/generated/compat_vdso-offsets.h: $(obj)/compat_vdso.so.dbg FORCE
56	$(call if_changed,compat_vdsosym)
57
58# actual build commands
59# The DSO images are built using a special linker script
60# Make sure only to export the intended __compat_vdso_xxx symbol offsets.
61quiet_cmd_compat_vdsold = VDSOLD  $@
62      cmd_compat_vdsold = $(COMPAT_LD) $(ld_flags) $(COMPAT_LD_FLAGS) -T $(filter-out FORCE,$^) -o $@.tmp && \
63                   $(OBJCOPY) $(patsubst %, -G __compat_vdso_%, $(compat_vdso-syms)) $@.tmp $@ && \
64                   rm $@.tmp
65
66# actual build commands
67quiet_cmd_compat_vdsoas = VDSOAS $@
68      cmd_compat_vdsoas = $(COMPAT_CC) $(a_flags) $(COMPAT_CC_FLAGS) -c -o $@ $<
69
70# install commands for the unstripped file
71quiet_cmd_compat_vdso_install = INSTALL $@
72      cmd_compat_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/compat_vdso/$@
73
74compat_vdso.so: $(obj)/compat_vdso.so.dbg
75	@mkdir -p $(MODLIB)/compat_vdso
76	$(call cmd,compat_vdso_install)
77
78compat_vdso_install: compat_vdso.so
79