diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 02197cb8e3a7718a98003f85ca819eb8d10f9f99..ea549579bfb77e3b5f7c6f36cc318956604fc36f 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -88,6 +88,10 @@ endif
targets-for-modules := $(patsubst %.o, %.mod, $(filter %.o, $(obj-m)))
+ifdef CONFIG_LTO_CLANG
+targets-for-modules += $(patsubst %.o, %.lto.o, $(filter %.o, $(obj-m)))
+endif
+
ifdef need-modorder
targets-for-modules += $(obj)/modules.order
endif
@@ -271,12 +275,33 @@ $(obj)/%.o: $(src)/%.c $(recordmcount_source) $$(objtool_dep) FORCE
$(call if_changed_rule,cc_o_c)
$(call cmd,force_checksrc)
+ifdef CONFIG_LTO_CLANG
+# Module .o files may contain LLVM bitcode, compile them into native code
+# before ELF processing
+quiet_cmd_cc_lto_link_modules = LTO [M] $@
+cmd_cc_lto_link_modules = \
+ $(LD) $(ld_flags) -r -o $@ \
+ $(shell [ -s $(@:.lto.o=.o.symversions) ] && \
+ echo -T $(@:.lto.o=.o.symversions)) \
+ --whole-archive $(filter-out FORCE,$^)
+
+ifdef CONFIG_STACK_VALIDATION
+# objtool was skipped for LLVM bitcode, run it now that we have compiled
+# modules into native code
+cmd_cc_lto_link_modules += ; \
+ $(objtree)/tools/objtool/objtool $(objtool_args) --module $@
+endif
+
+$(obj)/%.lto.o: $(obj)/%.o FORCE
+ $(call if_changed,cc_lto_link_modules)
+endif
+
cmd_mod = { \
echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
$(undefined_syms) echo; \
} > $@
-$(obj)/%.mod: $(obj)/%.o FORCE
+$(obj)/%.mod: $(obj)/%$(mod-prelink-ext).o FORCE
$(call if_changed,mod)
quiet_cmd_cc_lst_c = MKLST $@
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 10950559b223b906ee73093f7da1fab1bc34db37..af1c920a585c1fc1e4f8042599e13acbc02f3022 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -225,6 +225,13 @@ dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \
$(addprefix -I,$(DTC_INCLUDE)) \
-undef -D__DTS__
+ifeq ($(CONFIG_LTO_CLANG),y)
+# With CONFIG_LTO_CLANG, .o files in modules might be LLVM bitcode, so we
+# need to run LTO to compile them into native code (.lto.o) before further
+# processing.
+mod-prelink-ext := .lto
+endif
+
# Objtool arguments are also needed for modfinal with LTO, so we define
# then here to avoid duplication.
objtool_args = \
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 5e9b8057fb24113a560894f2da1352857b7a4080..ff805777431ce7c11a0ab2f1d00067cd0fbe8181 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -9,7 +9,7 @@ __modfinal:
include include/config/auto.conf
include $(srctree)/scripts/Kbuild.include
-# for c_flags and objtool_args
+# for c_flags and mod-prelink-ext
include $(srctree)/scripts/Makefile.lib
# find all modules listed in modules.order
@@ -30,23 +30,6 @@ quiet_cmd_cc_o_c = CC [M] $@
ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
-ifdef CONFIG_LTO_CLANG
-# With CONFIG_LTO_CLANG, reuse the object file we compiled for modpost to
-# avoid a second slow LTO link
-prelink-ext := .lto
-
-# ELF processing was skipped earlier because we didn't have native code,
-# so let's now process the prelinked binary before we link the module.
-
-ifdef CONFIG_STACK_VALIDATION
-cmd_ld_ko_o += \
- $(objtree)/tools/objtool/objtool $(objtool_args) \
- $(@:.ko=$(prelink-ext).o);
-
-endif # CONFIG_STACK_VALIDATION
-
-endif # CONFIG_LTO_CLANG
-
quiet_cmd_ld_ko_o = LD [M] $@
cmd_ld_ko_o += \
$(LD) -r $(KBUILD_LDFLAGS) \
@@ -72,7 +55,7 @@ if_changed_except = $(if $(call newer_prereqs_except,$(2))$(cmd-check), \
# Re-generate module BTFs if either module's .ko or vmlinux changed
-$(modules): %.ko: %$(prelink-ext).o %.mod.o scripts/module.lds $(if $(KBUILD_BUILTIN),vmlinux) FORCE
+$(modules): %.ko: %$(mod-prelink-ext).o %.mod.o scripts/module.lds $(if $(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 c383ba33d837f8f38888a98eb382d34286594d9e..eef56d629799a0e5e5d91196dd2b6ce07785a985 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -41,7 +41,7 @@ __modpost:
include include/config/auto.conf
include $(srctree)/scripts/Kbuild.include
-# for ld_flags
+# for mod-prelink-ext
include $(srctree)/scripts/Makefile.lib
MODPOST = scripts/mod/modpost \
@@ -118,22 +118,6 @@ $(input-symdump):
@echo >&2 ' Modules may not have dependencies or modversions.'
@echo >&2 ' You may get many unresolved symbol warnings.'
-ifdef CONFIG_LTO_CLANG
-# With CONFIG_LTO_CLANG, .o files might be LLVM bitcode, so we need to run
-# LTO to compile them into native code before running modpost
-prelink-ext := .lto
-
-quiet_cmd_cc_lto_link_modules = LTO [M] $@
-cmd_cc_lto_link_modules = \
- $(LD) $(ld_flags) -r -o $@ \
- $(shell [ -s $(@:.lto.o=.o.symversions) ] && \
- echo -T $(@:.lto.o=.o.symversions)) \
- --whole-archive $^
-
-%.lto.o: %.o
- $(call if_changed,cc_lto_link_modules)
-endif
-
modules := $(sort $(shell cat $(MODORDER)))
# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined symbols
@@ -144,9 +128,9 @@ endif
# 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$$/$(prelink-ext)\.o/' $< | $(MODPOST) -T -
+ cmd_modpost = sed 's/\.ko$$/$(mod-prelink-ext)\.o/' $< | $(MODPOST) -T -
-$(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(prelink-ext).o) FORCE
+$(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(mod-prelink-ext).o) FORCE
$(call if_changed,modpost)
targets += $(output-symdump)
diff --git a/scripts/gen_autoksyms.sh b/scripts/gen_autoksyms.sh
index da320151e7c39cd900dabac81c0ab0202c500bfb..6ed0d225c8b1c877abfc4256ddc1ee5e2e96516f 100755
--- a/scripts/gen_autoksyms.sh
+++ b/scripts/gen_autoksyms.sh
@@ -26,18 +26,6 @@ if [ -n "$CONFIG_MODVERSIONS" ]; then
needed_symbols="$needed_symbols module_layout"
fi
-# With CONFIG_LTO_CLANG, LLVM bitcode has not yet been compiled into a binary
-# when the .mod files are generated, which means they don't yet contain
-# references to certain symbols that will be present in the final binaries.
-if [ -n "$CONFIG_LTO_CLANG" ]; then
- # intrinsic functions
- needed_symbols="$needed_symbols memcpy memmove memset"
- # ftrace
- needed_symbols="$needed_symbols _mcount"
- # stack protector symbols
- needed_symbols="$needed_symbols __stack_chk_fail __stack_chk_guard"
-fi
-
ksym_wl=
if [ -n "$CONFIG_UNUSED_KSYMS_WHITELIST" ]; then
# Use 'eval' to expand the whitelist path and check if it is relative