xref: /linux/scripts/Makefile.vmlinux_o (revision 7f7072574127c9e971cad83a0274e86f6275c0d5)
1# SPDX-License-Identifier: GPL-2.0-only
2
3PHONY := __default
4__default: vmlinux.o
5
6include include/config/auto.conf
7include $(srctree)/scripts/Kbuild.include
8
9# for objtool
10include $(srctree)/scripts/Makefile.lib
11
12# Generate a linker script to ensure correct ordering of initcalls for Clang LTO
13# ---------------------------------------------------------------------------
14
15quiet_cmd_gen_initcalls_lds = GEN     $@
16      cmd_gen_initcalls_lds = \
17	$(PYTHON3) $(srctree)/scripts/jobserver-exec \
18	$(PERL) $(real-prereqs) > $@
19
20.tmp_initcalls.lds: $(srctree)/scripts/generate_initcall_order.pl \
21		vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
22	$(call if_changed,gen_initcalls_lds)
23
24targets := .tmp_initcalls.lds
25
26ifdef CONFIG_LTO_CLANG
27initcalls-lds := .tmp_initcalls.lds
28endif
29
30# objtool for vmlinux.o
31# ---------------------------------------------------------------------------
32#
33# For delay-objtool (IBT or LTO), objtool doesn't run on individual translation
34# units.  Instead it runs on vmlinux.o.
35#
36# For !delay-objtool + CONFIG_NOINSTR_VALIDATION, it runs on both translation
37# units and vmlinux.o, with the latter only used for noinstr/unret validation.
38
39objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION))
40
41ifeq ($(delay-objtool),y)
42vmlinux-objtool-args-y					+= $(objtool-args-y)
43else
44vmlinux-objtool-args-$(CONFIG_OBJTOOL_WERROR)		+= --Werror
45endif
46
47vmlinux-objtool-args-$(CONFIG_NOINSTR_VALIDATION)	+= --noinstr \
48							   $(if $(or $(CONFIG_MITIGATION_UNRET_ENTRY),$(CONFIG_MITIGATION_SRSO)), --unret)
49
50objtool-args = $(vmlinux-objtool-args-y) --link
51
52# Link of vmlinux.o used for section mismatch analysis
53# ---------------------------------------------------------------------------
54
55vmlinux-o-ld-args-$(CONFIG_BUILTIN_MODULE_RANGES)	+= -Map=$@.map
56
57quiet_cmd_ld_vmlinux.o = LD      $@
58      cmd_ld_vmlinux.o = \
59	$(LD) ${KBUILD_LDFLAGS} -r -o $@ \
60	$(vmlinux-o-ld-args-y) \
61	$(addprefix -T , $(initcalls-lds)) \
62	--whole-archive vmlinux.a --no-whole-archive \
63	--start-group $(KBUILD_VMLINUX_LIBS) --end-group \
64	$(cmd_objtool)
65
66define rule_ld_vmlinux.o
67	$(call cmd_and_savecmd,ld_vmlinux.o)
68	$(call cmd,gen_objtooldep)
69endef
70
71vmlinux.o: $(initcalls-lds) vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
72	$(call if_changed_rule,ld_vmlinux.o)
73
74targets += vmlinux.o
75
76# Add FORCE to the prerequisites of a target to force it to be always rebuilt.
77# ---------------------------------------------------------------------------
78
79PHONY += FORCE
80FORCE:
81
82# Read all saved command lines and dependencies for the $(targets) we
83# may be building above, using $(if_changed{,_dep}). As an
84# optimization, we don't need to read them if the target does not
85# exist, we will rebuild anyway in that case.
86
87existing-targets := $(wildcard $(sort $(targets)))
88
89-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
90
91.PHONY: $(PHONY)
92