From: Luis Chamberlain <mcgrof@xxxxxxxxxx>
The file modules.builtin names all modules that are built into the
kernel; this is checked by modprobe to not fail when trying to load
something built-in. But for tools which want to see which object files
make up each module, we want to help them with such a mapping as it is
not easy to get this otherwise.
We do this by just extending scripts/Makefile.lib with a new variable
and define to capture all object files included in this module, store it
in a new objs= modinfo stanza, then extract it just before linking into
a new file modules.builtin.objs with a layout roughly modelled on a
makefile:
path/to/module.o: path/to/constituent.o path/to/other-constituent.o
Single-file built-in modules get a line reading
path/to/module.o:
Note that the .modinfo section is discarded at the link stage, so the
kernel is not bloated at all (see include/asm-generic/vmlinux.lds.h).
Orabug: 29891866
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Signed-off-by: Nick Alcock <nick.alcock@xxxxxxxxxx>
Reviewed-by: Nick Alcock <nick.alcock@xxxxxxxxxx>
Reviewed-by: Kris Van Hees <kris.van.hees@xxxxxxxxxx>
---
Changes since v1:
- None
---
.gitignore | 2 +-
Documentation/dontdiff | 2 +-
Documentation/kbuild/kbuild.rst | 5 +++++
Makefile | 8 ++++++--
include/linux/module.h | 4 +++-
scripts/Makefile.lib | 5 ++++-
scripts/Makefile.modinst | 6 +++---
scripts/Makefile.vmlinux_o | 15 ++++++++++++++-
8 files changed, 37 insertions(+), 10 deletions(-)
diff --git a/.gitignore b/.gitignore
index c59dc60ba62ef..62ede8565a2aa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -69,7 +69,7 @@ modules.order
/System.map
/Module.markers
/modules.builtin
-/modules.builtin.modinfo
+/modules.builtin.*
/modules.nsdeps
#
diff --git a/Documentation/dontdiff b/Documentation/dontdiff
index 3c399f132e2db..75b9655e57914 100644
--- a/Documentation/dontdiff
+++ b/Documentation/dontdiff
@@ -179,7 +179,7 @@ mkutf8data
modpost
modules-only.symvers
modules.builtin
-modules.builtin.modinfo
+modules.builtin.*
modules.nsdeps
modules.order
modversions.h*
diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst
index 9c8d1d046ea56..79e104ffee715 100644
--- a/Documentation/kbuild/kbuild.rst
+++ b/Documentation/kbuild/kbuild.rst
@@ -17,6 +17,11 @@ modules.builtin
This file lists all modules that are built into the kernel. This is used
by modprobe to not fail when trying to load something builtin.
+modules.builtin.objs
+-----------------------
+This file contains object mapping of modules that are built into the kernel
+to their corresponding object files used to build the module.
+
modules.builtin.modinfo
-----------------------
This file contains modinfo from all modules that are built into the kernel.
diff --git a/Makefile b/Makefile
index d51d411d44a82..cc979f9874f5a 100644
--- a/Makefile
+++ b/Makefile
@@ -1140,7 +1140,11 @@ PHONY += vmlinux_o
vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
-vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
+MODULES_BUILTIN := modules.builtin.modinfo
+MODULES_BUILTIN += modules.builtin
+MODULES_BUILTIN += modules.builtin.objs
+
+vmlinux.o $(MODULES_BUILTIN): vmlinux_o
@:
PHONY += vmlinux
@@ -1476,7 +1480,7 @@ endif # CONFIG_MODULES
# Directories & files removed with 'make clean'
CLEAN_FILES += vmlinux.symvers modules-only.symvers \
- modules.builtin modules.builtin.modinfo modules.nsdeps \
+ modules.builtin modules.builtin.* modules.nsdeps \
compile_commands.json .thinlto-cache rust/test \
rust-project.json .vmlinux.objs .vmlinux.export.c
diff --git a/include/linux/module.h b/include/linux/module.h
index 1153b0d99a808..cbfff06e00cd6 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -180,7 +180,9 @@ extern void cleanup_module(void);
#ifdef MODULE
#define MODULE_FILE
#else
-#define MODULE_FILE MODULE_INFO(file, KBUILD_MODFILE);
+#define MODULE_FILE \
+ MODULE_INFO(file, KBUILD_MODFILE); \
+ MODULE_INFO(objs, KBUILD_MODOBJS);
#endif
/*
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 3179747cbd2cc..3b3baa78d4fbd 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -118,6 +118,8 @@ modname-multi = $(sort $(foreach m,$(multi-obj-ym),\
__modname = $(or $(modname-multi),$(basetarget))
modname = $(subst $(space),:,$(__modname))
+modname-objs = $($(modname)-objs) $($(modname)-y) $($(modname)-Y)
+modname-objs-prefixed = $(sort $(strip $(addprefix $(obj)/, $(modname-objs))))
modfile = $(addprefix $(obj)/,$(__modname))
# target with $(obj)/ and its suffix stripped
@@ -131,7 +133,8 @@ name-fix = $(call stringify,$(call name-fix-token,$1))
basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \
-D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname))
-modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))
+modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile)) \
+ -DKBUILD_MODOBJS=$(call stringify,$(modfile).o:$(subst $(space),|,$(modname-objs-prefixed)))
_c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
$(filter-out $(ccflags-remove-y), \
diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst
index 0afd75472679f..b45586aa1de49 100644
--- a/scripts/Makefile.modinst
+++ b/scripts/Makefile.modinst
@@ -30,10 +30,10 @@ $(MODLIB)/modules.order: modules.order FORCE
quiet_cmd_install_modorder = INSTALL $@
cmd_install_modorder = sed 's:^\(.*\)\.o$$:kernel/\1.ko:' $< > $@
-# Install modules.builtin(.modinfo) even when CONFIG_MODULES is disabled.
-install-y += $(addprefix $(MODLIB)/, modules.builtin modules.builtin.modinfo)
+# Install modules.builtin(.modinfo,.objs) even when CONFIG_MODULES is disabled.
+install-y += $(addprefix $(MODLIB)/, modules.builtin modules.builtin.modinfo modules.builtin.objs)
-$(addprefix $(MODLIB)/, modules.builtin modules.builtin.modinfo): $(MODLIB)/%: % FORCE
+$(addprefix $(MODLIB)/, modules.builtin modules.builtin.modinfo modules.builtin.objs): $(MODLIB)/%: % FORCE
$(call cmd,install)
endif
diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o
index 6de297916ce68..508b3294e2cf1 100644
--- a/scripts/Makefile.vmlinux_o
+++ b/scripts/Makefile.vmlinux_o
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
PHONY := __default
-__default: vmlinux.o modules.builtin.modinfo modules.builtin
+__default: vmlinux.o modules.builtin.modinfo modules.builtin modules.builtin.objs
include include/config/auto.conf
include $(srctree)/scripts/Kbuild.include
@@ -87,6 +87,19 @@ targets += modules.builtin
modules.builtin: modules.builtin.modinfo FORCE
$(call if_changed,modules_builtin)
+# module.builtin.objs
+# ---------------------------------------------------------------------------
+quiet_cmd_modules_builtin_objs = GEN $@
+ cmd_modules_builtin_objs = \
+ tr '\0' '\n' < $< | \
+ sed -n 's/^[[:alnum:]:_]*\.objs=//p' | \
+ tr ' ' '\n' | uniq | sed -e 's|:|: |' -e 's:|: :g' | \
+ tr -s ' ' > $@
+
+targets += modules.builtin.objs
+modules.builtin.objs: modules.builtin.modinfo FORCE
+ $(call if_changed,modules_builtin_objs)
+
# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------
--
2.43.0
