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 LTO and IBT, objtool doesn't run on individual translation units. 34# Run everything on vmlinux instead. 35 36objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION)) 37 38vmlinux-objtool-args-$(delay-objtool) += $(objtool-args-y) 39vmlinux-objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable 40vmlinux-objtool-args-$(CONFIG_NOINSTR_VALIDATION) += --noinstr $(if $(CONFIG_CPU_UNRET_ENTRY), --unret) 41 42objtool-args = $(vmlinux-objtool-args-y) --link 43 44# Link of vmlinux.o used for section mismatch analysis 45# --------------------------------------------------------------------------- 46 47quiet_cmd_ld_vmlinux.o = LD $@ 48 cmd_ld_vmlinux.o = \ 49 $(LD) ${KBUILD_LDFLAGS} -r -o $@ \ 50 $(addprefix -T , $(initcalls-lds)) \ 51 --whole-archive vmlinux.a --no-whole-archive \ 52 --start-group $(KBUILD_VMLINUX_LIBS) --end-group \ 53 $(cmd_objtool) 54 55define rule_ld_vmlinux.o 56 $(call cmd_and_savecmd,ld_vmlinux.o) 57 $(call cmd,gen_objtooldep) 58endef 59 60vmlinux.o: $(initcalls-lds) vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE 61 $(call if_changed_rule,ld_vmlinux.o) 62 63targets += vmlinux.o 64 65# Add FORCE to the prequisites of a target to force it to be always rebuilt. 66# --------------------------------------------------------------------------- 67 68PHONY += FORCE 69FORCE: 70 71# Read all saved command lines and dependencies for the $(targets) we 72# may be building above, using $(if_changed{,_dep}). As an 73# optimization, we don't need to read them if the target does not 74# exist, we will rebuild anyway in that case. 75 76existing-targets := $(wildcard $(sort $(targets))) 77 78-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) 79 80.PHONY: $(PHONY) 81