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 $(KBUILD_VMLINUX_OBJS) $(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 38# Reuse objtool_args defined in scripts/Makefile.lib if LTO or IBT is enabled. 39# 40# Add some more flags as needed. 41# --no-unreachable and --link might be added twice, but it is fine. 42# 43# Expand objtool_args to a simple variable to avoid circular reference. 44 45objtool_args := \ 46 $(if $(delay-objtool),$(objtool_args)) \ 47 $(if $(CONFIG_NOINSTR_VALIDATION), --noinstr) \ 48 $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) \ 49 --link 50 51# Link of vmlinux.o used for section mismatch analysis 52# --------------------------------------------------------------------------- 53 54quiet_cmd_ld_vmlinux.o = LD $@ 55 cmd_ld_vmlinux.o = \ 56 $(LD) ${KBUILD_LDFLAGS} -r -o $@ \ 57 $(addprefix -T , $(initcalls-lds)) \ 58 --whole-archive $(KBUILD_VMLINUX_OBJS) --no-whole-archive \ 59 --start-group $(KBUILD_VMLINUX_LIBS) --end-group \ 60 $(cmd_objtool) 61 62define rule_ld_vmlinux.o 63 $(call cmd_and_savecmd,ld_vmlinux.o) 64 $(call cmd,gen_objtooldep) 65endef 66 67vmlinux.o: $(initcalls-lds) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS) FORCE 68 $(call if_changed_rule,ld_vmlinux.o) 69 70targets += vmlinux.o 71 72# Add FORCE to the prequisites of a target to force it to be always rebuilt. 73# --------------------------------------------------------------------------- 74 75PHONY += FORCE 76FORCE: 77 78# Read all saved command lines and dependencies for the $(targets) we 79# may be building above, using $(if_changed{,_dep}). As an 80# optimization, we don't need to read them if the target does not 81# exist, we will rebuild anyway in that case. 82 83existing-targets := $(wildcard $(sort $(targets))) 84 85-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) 86 87.PHONY: $(PHONY) 88