From b42d2306502419688190aa6dd4dab4a6def24b3d Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 29 May 2022 00:47:04 +0900 Subject: [PATCH] kbuild: factor out the common objtool arguments scripts/Makefile.build and scripts/link-vmlinux.sh have similar setups for the objtool arguments. It was difficult to factor out them because all the vmlinux build rules were written in a shell script. It is somewhat tedious to touch the two files every time a new objtool option is supported. To reduce the code duplication, move the objtool for vmlinux.o into scripts/Makefile.vmlinux_o. Then, move the common macros to Makefile.lib so they are shared between Makefile.build and Makefile.vmlinux_o. Signed-off-by: Masahiro Yamada Tested-by: Sedat Dilek # LLVM-14 (x86-64) --- scripts/Makefile.build | 26 ----------------- scripts/Makefile.lib | 26 +++++++++++++++++ scripts/Makefile.vmlinux_o | 26 +++++++++++++++++ scripts/link-vmlinux.sh | 71 ---------------------------------------------- 4 files changed, 52 insertions(+), 97 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 4cb7145..1f01ac6 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -210,38 +210,12 @@ cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), $(sub_cmd_record_mcount)) endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT -ifdef CONFIG_OBJTOOL - -objtool := $(objtree)/tools/objtool/objtool - -objtool_args = \ - $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \ - $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \ - $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \ - $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \ - $(if $(CONFIG_UNWINDER_ORC), --orc) \ - $(if $(CONFIG_RETPOLINE), --retpoline) \ - $(if $(CONFIG_SLS), --sls) \ - $(if $(CONFIG_STACK_VALIDATION), --stackval) \ - $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \ - --uaccess \ - $(if $(delay-objtool), --link) \ - $(if $(part-of-module), --module) \ - $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) - -cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@) -cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd) - -endif # CONFIG_OBJTOOL - # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y) -delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT)) - $(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y)) ifdef CONFIG_TRIM_UNUSED_KSYMS diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index f751383..f691fb2 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -225,6 +225,32 @@ dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \ $(addprefix -I,$(DTC_INCLUDE)) \ -undef -D__DTS__ +ifdef CONFIG_OBJTOOL + +objtool := $(objtree)/tools/objtool/objtool + +objtool_args = \ + $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \ + $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \ + $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \ + $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \ + $(if $(CONFIG_UNWINDER_ORC), --orc) \ + $(if $(CONFIG_RETPOLINE), --retpoline) \ + $(if $(CONFIG_SLS), --sls) \ + $(if $(CONFIG_STACK_VALIDATION), --stackval) \ + $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \ + --uaccess \ + $(if $(delay-objtool), --link) \ + $(if $(part-of-module), --module) \ + $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) + +delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT)) + +cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@) +cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd) + +endif # CONFIG_OBJTOOL + # Useful for describing the dependency of composite objects # Usage: # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add) diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o index a9b375c..3c97a15 100644 --- a/scripts/Makefile.vmlinux_o +++ b/scripts/Makefile.vmlinux_o @@ -6,6 +6,9 @@ __default: vmlinux.o include include/config/auto.conf include $(srctree)/scripts/Kbuild.include +# for objtool +include $(srctree)/scripts/Makefile.lib + # Generate a linker script to ensure correct ordering of initcalls for Clang LTO # --------------------------------------------------------------------------- @@ -24,6 +27,27 @@ ifdef CONFIG_LTO_CLANG initcalls-lds := .tmp_initcalls.lds endif +# objtool for vmlinux.o +# --------------------------------------------------------------------------- +# +# For LTO and IBT, objtool doesn't run on individual translation units. +# Run everything on vmlinux instead. + +objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION)) + +# Reuse objtool_args defined in scripts/Makefile.lib if LTO or IBT is enabled. +# +# Add some more flags as needed. +# --no-unreachable and --link might be added twice, but it is fine. +# +# Expand objtool_args to a simple variable to avoid circular reference. + +objtool_args := \ + $(if $(delay-objtool),$(objtool_args)) \ + $(if $(CONFIG_NOINSTR_VALIDATION), --noinstr) \ + $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) \ + --link + # Link of vmlinux.o used for section mismatch analysis # --------------------------------------------------------------------------- @@ -33,9 +57,11 @@ quiet_cmd_ld_vmlinux.o = LD $@ $(addprefix -T , $(initcalls-lds)) \ --whole-archive $(KBUILD_VMLINUX_OBJS) --no-whole-archive \ --start-group $(KBUILD_VMLINUX_LIBS) --end-group \ + $(cmd_objtool) define rule_ld_vmlinux.o $(call cmd_and_savecmd,ld_vmlinux.o) + $(call cmd,gen_objtooldep) endef vmlinux.o: $(initcalls-lds) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS) FORCE diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index bf685d4..eecc186 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -45,76 +45,6 @@ info() printf " %-7s %s\n" "${1}" "${2}" } -objtool_link() -{ - local objtoolcmd; - local objtoolopt; - - if ! is_enabled CONFIG_OBJTOOL; then - return; - fi - - if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then - - # For LTO and IBT, objtool doesn't run on individual - # translation units. Run everything on vmlinux instead. - - if is_enabled CONFIG_HAVE_JUMP_LABEL_HACK; then - objtoolopt="${objtoolopt} --hacks=jump_label" - fi - - if is_enabled CONFIG_HAVE_NOINSTR_HACK; then - objtoolopt="${objtoolopt} --hacks=noinstr" - fi - - if is_enabled CONFIG_X86_KERNEL_IBT; then - objtoolopt="${objtoolopt} --ibt" - fi - - if is_enabled CONFIG_FTRACE_MCOUNT_USE_OBJTOOL; then - objtoolopt="${objtoolopt} --mcount" - fi - - if is_enabled CONFIG_UNWINDER_ORC; then - objtoolopt="${objtoolopt} --orc" - fi - - if is_enabled CONFIG_RETPOLINE; then - objtoolopt="${objtoolopt} --retpoline" - fi - - if is_enabled CONFIG_SLS; then - objtoolopt="${objtoolopt} --sls" - fi - - if is_enabled CONFIG_STACK_VALIDATION; then - objtoolopt="${objtoolopt} --stackval" - fi - - if is_enabled CONFIG_HAVE_STATIC_CALL_INLINE; then - objtoolopt="${objtoolopt} --static-call" - fi - - objtoolopt="${objtoolopt} --uaccess" - fi - - if is_enabled CONFIG_NOINSTR_VALIDATION; then - objtoolopt="${objtoolopt} --noinstr" - fi - - if [ -n "${objtoolopt}" ]; then - - if is_enabled CONFIG_GCOV_KERNEL; then - objtoolopt="${objtoolopt} --no-unreachable" - fi - - objtoolopt="${objtoolopt} --link" - - info OBJTOOL ${1} - tools/objtool/objtool ${objtoolopt} ${1} - fi -} - # Link of vmlinux # ${1} - output file # ${2}, ${3}, ... - optional extra .o files @@ -298,7 +228,6 @@ ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1 #link vmlinux.o ${MAKE} -f "${srctree}/scripts/Makefile.vmlinux_o" -objtool_link vmlinux.o # Generate the list of in-tree objects in vmlinux # -- 2.7.4