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 66cmd_check_function_names = $(srctree)/scripts/check-function-names.sh $@ 67 68define rule_ld_vmlinux.o 69 $(call cmd_and_savecmd,ld_vmlinux.o) 70 $(call cmd,gen_objtooldep) 71 $(call cmd,check_function_names) 72endef 73 74 75vmlinux.o: $(initcalls-lds) vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE 76 $(call if_changed_rule,ld_vmlinux.o) 77 78targets += vmlinux.o 79 80# Add FORCE to the prerequisites of a target to force it to be always rebuilt. 81# --------------------------------------------------------------------------- 82 83PHONY += FORCE 84FORCE: 85 86# Read all saved command lines and dependencies for the $(targets) we 87# may be building above, using $(if_changed{,_dep}). As an 88# optimization, we don't need to read them if the target does not 89# exist, we will rebuild anyway in that case. 90 91existing-targets := $(wildcard $(sort $(targets))) 92 93-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) 94 95.PHONY: $(PHONY) 96