From f73edc8951b2de515b5ecc8a357ccd47dd41077e Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 25 Sep 2022 03:19:13 +0900 Subject: kbuild: unify two modpost invocations Currently, modpost is executed twice; first for vmlinux, second for modules. This commit merges them. Current build flow ================== 1) build obj-y and obj-m objects 2) link vmlinux.o 3) modpost for vmlinux 4) link vmlinux 5) modpost for modules 6) link modules (*.ko) The build steps 1) through 6) are serialized, that is, modules are built after vmlinux. You do not get benefits of parallel builds when scripts/link-vmlinux.sh is being run. New build flow ============== 1) build obj-y and obj-m objects 2) link vmlinux.o 3) modpost for vmlinux and modules 4a) link vmlinux 4b) link modules (*.ko) In the new build flow, modpost is invoked just once. vmlinux and modules are built in parallel. One exception is CONFIG_DEBUG_INFO_BTF_MODULES=y, where modules depend on vmlinux. Signed-off-by: Masahiro Yamada Tested-by: Nick Desaulniers Reviewed-by: Nicolas Schier --- scripts/Makefile.modfinal | 2 +- scripts/Makefile.modpost | 93 ++++++++++++++--------------------------------- scripts/link-vmlinux.sh | 3 -- 3 files changed, 29 insertions(+), 69 deletions(-) (limited to 'scripts') diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index 35100e981f4a..a3cf9e3647c9 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -55,7 +55,7 @@ if_changed_except = $(if $(call newer_prereqs_except,$(2))$(cmd-check), \ printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) # Re-generate module BTFs if either module's .ko or vmlinux changed -$(modules): %.ko: %.o %.mod.o scripts/module.lds $(if $(KBUILD_BUILTIN),vmlinux) FORCE +$(modules): %.ko: %.o %.mod.o scripts/module.lds $(and $(CONFIG_DEBUG_INFO_BTF_MODULES),$(KBUILD_BUILTIN),vmlinux) FORCE +$(call if_changed_except,ld_ko_o,vmlinux) ifdef CONFIG_DEBUG_INFO_BTF_MODULES +$(if $(newer-prereqs),$(call cmd,btf_ko)) diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost index 04ad00917b2f..2daf760eeb25 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -32,9 +32,6 @@ # Step 4 is solely used to allow module versioning in external modules, # where the CRC of each module is retrieved from the Module.symvers file. -# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. -# This is solely useful to speed up test compiles - PHONY := __modpost __modpost: @@ -45,24 +42,23 @@ MODPOST = scripts/mod/modpost \ $(if $(CONFIG_MODVERSIONS),-m) \ $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ + $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \ + $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) \ -o $@ -ifdef MODPOST_VMLINUX - -quiet_cmd_modpost = MODPOST $@ - cmd_modpost = $(MODPOST) $< - -vmlinux.symvers: vmlinux.o - $(call cmd,modpost) +# 'make -i -k' ignores compile errors, and builds as many modules as possible. +ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),) +MODPOST += -n +endif -__modpost: vmlinux.symvers +ifeq ($(KBUILD_EXTMOD),) # Generate the list of in-tree objects in vmlinux # --------------------------------------------------------------------------- # This is used to retrieve symbol versions generated by genksyms. ifdef CONFIG_MODVERSIONS -vmlinux.symvers: .vmlinux.objs +vmlinux.symvers Module.symvers: .vmlinux.objs endif # Ignore libgcc.a @@ -83,24 +79,12 @@ targets += .vmlinux.objs .vmlinux.objs: $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS) FORCE $(call if_changed,vmlinux_objs) -else - -ifeq ($(KBUILD_EXTMOD),) - -input-symdump := vmlinux.symvers -output-symdump := modules-only.symvers - -quiet_cmd_cat = GEN $@ - cmd_cat = cat $(real-prereqs) > $@ - -ifneq ($(wildcard vmlinux.symvers),) - -__modpost: Module.symvers -Module.symvers: vmlinux.symvers modules-only.symvers FORCE - $(call if_changed,cat) - -targets += Module.symvers +vmlinux.o-if-present := $(wildcard vmlinux.o) +output-symdump := vmlinux.symvers +ifdef KBUILD_MODULES +output-symdump := $(if $(vmlinux.o-if-present), Module.symvers, modules-only.symvers) +missing-input := $(filter-out $(vmlinux.o-if-present),vmlinux.o) endif else @@ -112,56 +96,35 @@ src := $(obj) # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS include $(or $(wildcard $(src)/Kbuild), $(src)/Makefile) -# modpost option for external modules -MODPOST += -e - -input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS) +module.symvers-if-present := $(wildcard Module.symvers) output-symdump := $(KBUILD_EXTMOD)/Module.symvers +missing-input := $(filter-out $(module.symvers-if-present), Module.symvers) -endif - -existing-input-symdump := $(wildcard $(input-symdump)) - -# modpost options for modules (both in-kernel and external) -MODPOST += \ - $(addprefix -i ,$(existing-input-symdump)) \ - $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \ - $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) - -# 'make -i -k' ignores compile errors, and builds as many modules as possible. -ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),) -MODPOST += -n -endif +MODPOST += -e $(addprefix -i ,$(module.symvers-if-present) $(KBUILD_EXTRA_SYMBOLS)) -# Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree). -VPATH := -$(input-symdump): - @echo >&2 'WARNING: Symbol version dump "$@" is missing.' - @echo >&2 ' Modules may not have dependencies or modversions.' - @echo >&2 ' You may get many unresolved symbol warnings.' +endif # ($(KBUILD_EXTMOD),) -# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined symbols -ifneq ($(KBUILD_MODPOST_WARN)$(filter-out $(existing-input-symdump), $(input-symdump)),) +ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),) MODPOST += -w endif +modorder-if-needed := $(if $(KBUILD_MODULES), $(MODORDER)) + # Read out modules.order to pass in modpost. # Otherwise, allmodconfig would fail with "Argument list too long". quiet_cmd_modpost = MODPOST $@ - cmd_modpost = sed 's/ko$$/o/' $< | $(MODPOST) -T - - -$(output-symdump): $(MODORDER) $(input-symdump) FORCE - $(call if_changed,modpost) + cmd_modpost = \ + $(if $(missing-input), \ + echo >&2 "WARNING: $(missing-input) is missing."; \ + echo >&2 " Modules may not have dependencies or modversions."; \ + echo >&2 " You may get many unresolved symbol warnings.";) \ + sed 's/ko$$/o/' $(or $(modorder-if-needed), /dev/null) | $(MODPOST) $(vmlinux.o-if-present) -T - targets += $(output-symdump) +$(output-symdump): $(modorder-if-needed) $(vmlinux.o-if-present) $(moudle.symvers-if-present) FORCE + $(call if_changed,modpost) __modpost: $(output-symdump) -ifneq ($(KBUILD_MODPOST_NOFINAL),1) - $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal -endif - -endif - PHONY += FORCE FORCE: diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 07486f90d5e2..6a197d8a88ac 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -214,9 +214,6 @@ if [ "$1" = "clean" ]; then exit 0 fi -# modpost vmlinux.o to check for section mismatches -${MAKE} -f "${srctree}/scripts/Makefile.modpost" MODPOST_VMLINUX=1 - info MODINFO modules.builtin.modinfo ${OBJCOPY} -j .modinfo -O binary vmlinux.o modules.builtin.modinfo info GEN modules.builtin -- cgit v1.2.3-59-g8ed1b