[PATCH v3 00/12] kbuild: create *.mod with directory path and remove MODVERDIR

[PATCH v3 00/12] kbuild: create *.mod with directory path and remove MODVERDIR

[Masahiro Yamada]

This series kills the long standing MODVERDIR.

Since MODVERDIR has a flat structure, it cannot avoid a race
condition when somebody introduces a module name conflict.

Kbuild now reads modules.order to get the list of all modules.

The post-processing/installation stages will be more robust
and simpler.



Masahiro Yamada (12):
  kbuild: do not create empty modules.order in the prepare stage
  kbuild: get rid of kernel/ prefix from in-tree modules.{order,builtin}
  kbuild: remove duplication from modules.order in sub-directories
  scsi: remove pointless $(MODVERDIR)/$(obj)/53c700.ver
  kbuild: modinst: read modules.order instead of $(MODVERDIR)/*.mod
  kbuild: modsign: read modules.order instead of $(MODVERDIR)/*.mod
  kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod
  kbuild: export_report: read modules.order instead of
    .tmp_versions/*.mod
  kbuild: create *.mod with full directory path and remove MODVERDIR
  kbuild: remove the first line of *.mod files
  kbuild: remove 'prepare1' target
  kbuild: split out *.mod out of {single,multi}-used-m rules

 .gitignore                                 |  1 +
 Documentation/dontdiff                     |  1 +
 Makefile                                   | 36 ++++++-------------
 drivers/scsi/Makefile                      |  2 +-
 lib/Kconfig.debug                          | 12 +------
 scripts/Makefile.build                     | 40 +++++++++-------------
 scripts/Makefile.modbuiltin                |  2 +-
 scripts/Makefile.modinst                   |  5 +--
 scripts/Makefile.modpost                   | 19 +++++-----
 scripts/Makefile.modsign                   |  3 +-
 scripts/adjust_autoksyms.sh                | 14 +++-----
 scripts/export_report.pl                   | 11 +++---
 scripts/mod/sumversion.c                   | 23 +++----------
 scripts/modules-check.sh                   |  2 +-
 scripts/package/mkspec                     |  2 +-
 tools/power/cpupower/debug/kernel/Makefile |  4 +--
 16 files changed, 62 insertions(+), 115 deletions(-)

-- 
2.17.1

[PATCH v3 01/12] kbuild: do not create empty modules.order in the prepare stage

[Masahiro Yamada]

Currently, $(objtree)/modules.order is touched in two places.

In the 'prepare0' rule, scripts/Makefile.build creates an empty
modules.order while processing 'obj=.'

In the 'modules' rule, the top-level Makefile overwrites it with
the correct list of modules.

While this might be a good side-effect that modules.order is made
empty every time (probably this is not intended functionality),
I personally do not like this behavior.

Create modules.order only when it is sensible to do so.

This avoids creating the following pointless files:

  scripts/basic/modules.order
  scripts/dtc/modules.order
  scripts/gcc-plugins/modules.order
  scripts/genksyms/modules.order
  scripts/mod/modules.order
  scripts/modules.order
  scripts/selinux/genheaders/modules.order
  scripts/selinux/mdp/modules.order
  scripts/selinux/modules.order

Going forward, $(objtree)/modules.order lists the modules that
was built in the last successful build.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v3: None
Changes in v2:
  - inverted the logic "preparing" -> need-modorder

 Makefile               | 4 ++--
 scripts/Makefile.build | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index e43285786102..b74a6e9cefc8 100644
--- a/Makefile
+++ b/Makefile
@@ -1072,7 +1072,7 @@ $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
 
 PHONY += $(vmlinux-dirs)
 $(vmlinux-dirs): prepare
-	$(Q)$(MAKE) $(build)=$@ need-builtin=1
+	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1
 
 filechk_kernel.release = \
 	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
@@ -1616,7 +1616,7 @@ $(objtree)/Module.symvers:
 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
 PHONY += $(module-dirs) modules
 $(module-dirs): prepare $(objtree)/Module.symvers
-	$(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
+	$(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@) need-modorder=1
 
 modules: $(module-dirs)
 	@$(kecho) '  Building modules, stage 2.';
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 5829ccbc7dd0..631bb89524de 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -63,7 +63,7 @@ ifneq ($(strip $(real-obj-y) $(need-builtin)),)
 builtin-target := $(obj)/built-in.a
 endif
 
-ifdef CONFIG_MODULES
+ifeq ($(CONFIG_MODULES)$(need-modorder),y1)
 modorder-target := $(obj)/modules.order
 endif
 
-- 
2.17.1

[PATCH v3 02/12] kbuild: get rid of kernel/ prefix from in-tree modules.{order,builtin}

[Masahiro Yamada]

Removing the 'kernel/' prefix will make our life easier because we can
simply do 'cat modules.order' to get all built modules with full paths.

Currently, we parse the first line of '*.mod' files in $(MODVERDIR).
Since we have duplicated functionality here, I plan to remove MODVERDIR
entirely.

In fact, modules.order is generated also for external modules in a
broken format. It adds the 'kernel/' prefix to the absolute path of
the module, like this:

  kernel//path/to/your/external/module/foo.ko

This is fine for now since modules.order is not used for external
modules. However, I want to sanitize the format everywhere towards
the goal of removing MODVERDIR.

We cannot change the format of installed module.{order,builtin}.
So, 'make modules_install' will add the 'kernel/' prefix while copying
them to $(MODLIB)/.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v3: None
Changes in v2: None

 Makefile                    | 4 ++--
 scripts/Makefile.build      | 2 +-
 scripts/Makefile.modbuiltin | 2 +-
 scripts/modules-check.sh    | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/Makefile b/Makefile
index b74a6e9cefc8..396cd5e525d1 100644
--- a/Makefile
+++ b/Makefile
@@ -1329,8 +1329,8 @@ _modinst_:
 		rm -f $(MODLIB)/build ; \
 		ln -s $(CURDIR) $(MODLIB)/build ; \
 	fi
-	@cp -f $(objtree)/modules.order $(MODLIB)/
-	@cp -f $(objtree)/modules.builtin $(MODLIB)/
+	@sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
+	@sed 's:^:kernel/:' modules.builtin > $(MODLIB)/modules.builtin
 	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
 
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 631bb89524de..10e92a27ec20 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -426,7 +426,7 @@ endif # builtin-target
 modorder-cmds =						\
 	$(foreach m, $(modorder),			\
 		$(if $(filter %/modules.order, $m),	\
-			cat $m;, echo kernel/$m;))
+			cat $m;, echo $m;))
 
 $(modorder-target): $(subdir-ym) FORCE
 	$(Q)(cat /dev/null; $(modorder-cmds)) > $@
diff --git a/scripts/Makefile.modbuiltin b/scripts/Makefile.modbuiltin
index 50a9990760f3..7d4711b88656 100644
--- a/scripts/Makefile.modbuiltin
+++ b/scripts/Makefile.modbuiltin
@@ -40,7 +40,7 @@ __modbuiltin: $(modbuiltin-target) $(subdir-ym)
 	@:
 
 $(modbuiltin-target): $(subdir-ym) FORCE
-	$(Q)(for m in $(modbuiltin-mods); do echo kernel/$$m; done;	\
+	$(Q)(for m in $(modbuiltin-mods); do echo $$m; done;	\
 	cat /dev/null $(modbuiltin-subdirs)) > $@
 
 PHONY += FORCE
diff --git a/scripts/modules-check.sh b/scripts/modules-check.sh
index 39e8cb36ba19..f51f446707b8 100755
--- a/scripts/modules-check.sh
+++ b/scripts/modules-check.sh
@@ -9,7 +9,7 @@ check_same_name_modules()
 	for m in $(sed 's:.*/::' modules.order | sort | uniq -d)
 	do
 		echo "warning: same module names found:" >&2
-		sed -n "/\/$m/s:^kernel/:  :p" modules.order >&2
+		sed -n "/\/$m/s:^:  :p" modules.order >&2
 	done
 }
 
-- 
2.17.1

[PATCH v3 03/12] kbuild: remove duplication from modules.order in sub-directories

[Masahiro Yamada]

Currently, only the top-level modules.order drops duplicated entries.

The modules.order files in sub-directories potentially contain
duplication. To list out the paths of all modules, I want to use
modules.order instead of parsing *.mod files in $(MODVERDIR).

To achieve this, I want to rip off duplication from modules.order
of external modules too.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v3: None
Changes in v2: None

 scripts/Makefile.build | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 10e92a27ec20..be32a3752de4 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -423,13 +423,10 @@ endif # builtin-target
 #
 # Create commands to either record .ko file or cat modules.order from
 # a subdirectory
-modorder-cmds =						\
-	$(foreach m, $(modorder),			\
-		$(if $(filter %/modules.order, $m),	\
-			cat $m;, echo $m;))
-
 $(modorder-target): $(subdir-ym) FORCE
-	$(Q)(cat /dev/null; $(modorder-cmds)) > $@
+	$(Q){ $(foreach m, $(modorder), \
+	$(if $(filter %/modules.order, $m), cat $m, echo $m);) :; } \
+	| $(AWK) '!x[$$0]++' - > $@
 
 #
 # Rule to compile a set of .o files into one .a file (with symbol table)
-- 
2.17.1

[PATCH v3 04/12] scsi: remove pointless $(MODVERDIR)/$(obj)/53c700.ver

[Masahiro Yamada]

Nothing depends on this, so it is dead code.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v3: None
Changes in v2: None

 drivers/scsi/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index aeda53901064..c00e3dd57990 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -185,7 +185,7 @@ zalon7xx-objs	:= zalon.o ncr53c8xx.o
 # Files generated that shall be removed upon make clean
 clean-files :=	53c700_d.h 53c700_u.h scsi_devinfo_tbl.c
 
-$(obj)/53c700.o $(MODVERDIR)/$(obj)/53c700.ver: $(obj)/53c700_d.h
+$(obj)/53c700.o: $(obj)/53c700_d.h
 
 $(obj)/scsi_sysfs.o: $(obj)/scsi_devinfo_tbl.c
 
-- 
2.17.1

[PATCH v3 05/12] kbuild: modinst: read modules.order instead of $(MODVERDIR)/*.mod

[Masahiro Yamada]

Towards the goal of removing MODVERDIR, read out modules.order to get
the list of modules to be installed. This is simpler than parsing *.mod
files in $(MODVERDIR).

For external modules, $(KBUILD_EXTMOD)/modules.order should be read.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v3: None
Changes in v2: None

 scripts/Makefile.modinst | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst
index 0dae402661f3..5a4579e76485 100644
--- a/scripts/Makefile.modinst
+++ b/scripts/Makefile.modinst
@@ -8,10 +8,7 @@ __modinst:
 
 include scripts/Kbuild.include
 
-#
-
-__modules := $(sort $(shell grep -h '\.ko$$' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
-modules := $(patsubst %.o,%.ko,$(wildcard $(__modules:.ko=.o)))
+modules := $(sort $(shell cat $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)modules.order))
 
 PHONY += $(modules)
 __modinst: $(modules)
-- 
2.17.1

[PATCH v3 06/12] kbuild: modsign: read modules.order instead of $(MODVERDIR)/*.mod

[Masahiro Yamada]

Towards the goal of removing MODVERDIR, read out modules.order to get
the list of modules to be signed. This is simpler than parsing *.mod
files in $(MODVERDIR).

The modules_sign target is only supported for in-kernel modules.
So, this commit does not take care of external modules.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v3: None
Changes in v2: None

 scripts/Makefile.modsign | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/scripts/Makefile.modsign b/scripts/Makefile.modsign
index da56aa78d245..d7325cefe709 100644
--- a/scripts/Makefile.modsign
+++ b/scripts/Makefile.modsign
@@ -8,8 +8,7 @@ __modsign:
 
 include scripts/Kbuild.include
 
-__modules := $(sort $(shell grep -h '\.ko$$' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
-modules := $(patsubst %.o,%.ko,$(wildcard $(__modules:.ko=.o)))
+modules := $(sort $(shell cat modules.order))
 
 PHONY += $(modules)
 __modsign: $(modules)
-- 
2.17.1

[PATCH v3 07/12] kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod

[Masahiro Yamada]

Towards the goal of removing MODVERDIR, read out modules.order to get
the list of modules to be processed. This is simpler than parsing *.mod
files in $(MODVERDIR).

For external modules, $(KBUILD_EXTMOD)/modules.order should be read.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v3:
  - Add ifdef CONFIG_MODULES to avoid warning

Changes in v2: None

 scripts/Makefile.modpost | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index fec6ec2ffa47..5841508ffca9 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -8,9 +8,10 @@
 # b) A <module>.o file which is the .o files above linked together
 # c) A <module>.mod file in $(MODVERDIR)/, listing the name of the
 #    the preliminary <module>.o file, plus all .o files
+# d) modules.order, which lists all the modules
 
 # Stage 2 is handled by this file and does the following
-# 1) Find all modules from the files listed in $(MODVERDIR)/
+# 1) Find all modules listed in modules.order
 # 2) modpost is then used to
 # 3)  create one <module>.mod.c file pr. module
 # 4)  create one Module.symvers file with CRC for all exported symbols
@@ -60,10 +61,12 @@ include scripts/Makefile.lib
 kernelsymfile := $(objtree)/Module.symvers
 modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
 
-# Step 1), find all modules listed in $(MODVERDIR)/
-MODLISTCMD := find $(MODVERDIR) -name '*.mod' | xargs -r grep -h '\.ko$$' | sort -u
-__modules := $(shell $(MODLISTCMD))
-modules   := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))
+modorder := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)modules.order
+
+# Step 1), find all modules listed in modules.order
+ifdef CONFIG_MODULES
+modules := $(sort $(shell cat $(modorder)))
+endif
 
 # Stop after building .o files if NOFINAL is set. Makes compile tests quicker
 _modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
@@ -84,7 +87,7 @@ MODPOST_OPT=$(subst -i,-n,$(filter -i,$(MAKEFLAGS)))
 
 # We can go over command line length here, so be careful.
 quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
-      cmd_modpost = $(MODLISTCMD) | sed 's/\.ko$$/.o/' | $(modpost) $(MODPOST_OPT) -s -T -
+      cmd_modpost = sed 's/ko$$/o/' $(modorder) | $(modpost) $(MODPOST_OPT) -s -T -
 
 PHONY += __modpost
 __modpost: $(modules:.ko=.o) FORCE
-- 
2.17.1

Re: [PATCH v3 07/12] kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod

[Jan Kiszka]

On 17.07.19 08:17, Masahiro Yamada wrote:
> Towards the goal of removing MODVERDIR, read out modules.order to get
> the list of modules to be processed. This is simpler than parsing *.mod
> files in $(MODVERDIR).
> 
> For external modules, $(KBUILD_EXTMOD)/modules.order should be read.
> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
> 
> Changes in v3:
>   - Add ifdef CONFIG_MODULES to avoid warning
> 
> Changes in v2: None
> 
>  scripts/Makefile.modpost | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
> index fec6ec2ffa47..5841508ffca9 100644
> --- a/scripts/Makefile.modpost
> +++ b/scripts/Makefile.modpost
> @@ -8,9 +8,10 @@
>  # b) A <module>.o file which is the .o files above linked together
>  # c) A <module>.mod file in $(MODVERDIR)/, listing the name of the
>  #    the preliminary <module>.o file, plus all .o files
> +# d) modules.order, which lists all the modules
>  
>  # Stage 2 is handled by this file and does the following
> -# 1) Find all modules from the files listed in $(MODVERDIR)/
> +# 1) Find all modules listed in modules.order
>  # 2) modpost is then used to
>  # 3)  create one <module>.mod.c file pr. module
>  # 4)  create one Module.symvers file with CRC for all exported symbols
> @@ -60,10 +61,12 @@ include scripts/Makefile.lib
>  kernelsymfile := $(objtree)/Module.symvers
>  modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
>  
> -# Step 1), find all modules listed in $(MODVERDIR)/
> -MODLISTCMD := find $(MODVERDIR) -name '*.mod' | xargs -r grep -h '\.ko$$' | sort -u
> -__modules := $(shell $(MODLISTCMD))
> -modules   := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))
> +modorder := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)modules.order
> +
> +# Step 1), find all modules listed in modules.order
> +ifdef CONFIG_MODULES
> +modules := $(sort $(shell cat $(modorder)))
> +endif
>  
>  # Stop after building .o files if NOFINAL is set. Makes compile tests quicker
>  _modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
> @@ -84,7 +87,7 @@ MODPOST_OPT=$(subst -i,-n,$(filter -i,$(MAKEFLAGS)))
>  
>  # We can go over command line length here, so be careful.
>  quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
> -      cmd_modpost = $(MODLISTCMD) | sed 's/\.ko$$/.o/' | $(modpost) $(MODPOST_OPT) -s -T -
> +      cmd_modpost = sed 's/ko$$/o/' $(modorder) | $(modpost) $(MODPOST_OPT) -s -T -
>  
>  PHONY += __modpost
>  __modpost: $(modules:.ko=.o) FORCE
> 

This affects also external modules builds: I have patterns here that do

[Makefile]
subdir-y := some-module

[some-module/Makefile]
obj-m := some-module.o

and since this patch, the final some-module.ko is no longer built. Am I missing
something in the kbuild makefiles, or is this a regression?

Jan

-- 
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux

Re: [PATCH v3 07/12] kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod

[Masahiro Yamada]

Hi Jan,

On Thu, Jul 25, 2019 at 5:39 PM Jan Kiszka <jan.kiszka@siemens.com> wrote:
> >
>
> This affects also external modules builds: I have patterns here that do
>
> [Makefile]
> subdir-y := some-module
>
> [some-module/Makefile]
> obj-m := some-module.o
>
> and since this patch, the final some-module.ko is no longer built. Am I missing
> something in the kbuild makefiles, or is this a regression?

Thanks for the report.
Interesting. I have never imagined that Makefiles were written like that.

I just wrote a fix-up, but I have not determined to apply it.
https://patchwork.kernel.org/patch/11059033/

It is easy to fixup your Makefile, though.

--
Best Regards
Masahiro Yamada

Re: [PATCH v3 07/12] kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod

[Jan Kiszka]

On 25.07.19 17:18, Masahiro Yamada wrote:
> Hi Jan,
> 
> On Thu, Jul 25, 2019 at 5:39 PM Jan Kiszka <jan.kiszka@siemens.com> wrote:
>>>
>>
>> This affects also external modules builds: I have patterns here that do
>>
>> [Makefile]
>> subdir-y := some-module
>>
>> [some-module/Makefile]
>> obj-m := some-module.o
>>
>> and since this patch, the final some-module.ko is no longer built. Am I missing
>> something in the kbuild makefiles, or is this a regression?
> 
> Thanks for the report.
> Interesting. I have never imagined that Makefiles were written like that.
> 
> I just wrote a fix-up, but I have not determined to apply it.
> https://patchwork.kernel.org/patch/11059033/
> 
> It is easy to fixup your Makefile, though.

Thanks for addressing this quickly! I'm happy to adjust our code [1]. Is the
suggested pattern usable with recent stable kernels as well, say down to 4.4 at
least?

Jan

[1] https://github.com/siemens/jailhouse/blob/master/Kbuild#L54

-- 
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux

Re: [PATCH v3 07/12] kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod

[Masahiro Yamada]

On Fri, Jul 26, 2019 at 12:27 AM Jan Kiszka <jan.kiszka@siemens.com> wrote:
>
> On 25.07.19 17:18, Masahiro Yamada wrote:
> > Hi Jan,
> >
> > On Thu, Jul 25, 2019 at 5:39 PM Jan Kiszka <jan.kiszka@siemens.com> wrote:
> >>>
> >>
> >> This affects also external modules builds: I have patterns here that do
> >>
> >> [Makefile]
> >> subdir-y := some-module
> >>
> >> [some-module/Makefile]
> >> obj-m := some-module.o
> >>
> >> and since this patch, the final some-module.ko is no longer built. Am I missing
> >> something in the kbuild makefiles, or is this a regression?
> >
> > Thanks for the report.
> > Interesting. I have never imagined that Makefiles were written like that.
> >
> > I just wrote a fix-up, but I have not determined to apply it.
> > https://patchwork.kernel.org/patch/11059033/
> >
> > It is easy to fixup your Makefile, though.
>
> Thanks for addressing this quickly! I'm happy to adjust our code [1]. Is the
> suggested pattern usable with recent stable kernels as well, say down to 4.4 at
> least?

Yes, should work for any kernel version.



> Jan
>
> [1] https://github.com/siemens/jailhouse/blob/master/Kbuild#L54

Maybe,

obj-m := driver/ hypervisor/ configs/ inmates/ tools/

   and

$(patsubst %/,$(obj)/%,$(obj-m)): $(GEN_CONFIG_MK)


Not tested at all.


-- 
Best Regards
Masahiro Yamada

[PATCH v3 08/12] kbuild: export_report: read modules.order instead of .tmp_versions/*.mod

[Masahiro Yamada]

Towards the goal of removing MODVERDIR aka .tmp_versions, read out
modules.order to get the list of modules to be processed. This is
simpler than parsing *.mod files in .tmp_versions.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v3:
  - New patch

Changes in v2: None

 scripts/export_report.pl | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/scripts/export_report.pl b/scripts/export_report.pl
index 0f604f62f067..7d3030d03a25 100755
--- a/scripts/export_report.pl
+++ b/scripts/export_report.pl
@@ -52,13 +52,12 @@ sub usage {
 
 sub collectcfiles {
     my @file;
-    while (<.tmp_versions/*.mod>) {
-	open my $fh, '<', $_ or die "cannot open $_: $!\n";
-	push (@file,
-	      grep s/\.ko/.mod.c/,	# change the suffix
-	      grep m/.+\.ko/,		# find the .ko path
-	      <$fh>);			# lines in opened file
+    open my $fh, '< modules.order' or die "cannot open modules.order: $!\n";
+    while (<$fh>) {
+	s/\.ko$/.mod.c/;
+	push (@file, $_)
     }
+    close($fh);
     chomp @file;
     return @file;
 }
-- 
2.17.1

[PATCH v3 09/12] kbuild: create *.mod with full directory path and remove MODVERDIR

[Masahiro Yamada]

While descending directories, Kbuild produces objects for modules,
but do not link final *.ko files; it is done in the modpost.

To keep track of modules, Kbuild creates a *.mod file in $(MODVERDIR)
for every module it is building. Some post-processing steps read the
necessary information from *.mod files. This avoids descending into
directories again. This mechanism was introduced in 2003 or so.

Later, commit 551559e13af1 ("kbuild: implement modules.order") added
modules.order. So, we can simply read it out to know all the modules
with directory paths. This is easier than parsing the first line of
*.mod files.

$(MODVERDIR) has a flat directory structure, that is, *.mod files
are named only with base names. This is based on the assumption that
the module name is unique across the tree. This assumption is really
fragile.

Stephen Rothwell reported a race condition caused by a module name
conflict:

  https://lkml.org/lkml/2019/5/13/991

In parallel building, two different threads could write to the same
$(MODVERDIR)/*.mod simultaneously.

Non-unique module names are the source of all kind of troubles, hence
commit 3a48a91901c5 ("kbuild: check uniqueness of module names")
introduced a new checker script.

However, it is still fragile in the build system point of view because
this race happens before scripts/modules-check.sh is invoked. If it
happens again, the modpost will emit unclear error messages.

To fix this issue completely, create *.mod with full directory path
so that two threads never attempt to write to the same file.

$(MODVERDIR) is no longer needed.

Since modules with directory paths are listed in modules.order, Kbuild
is still able to find *.mod files without additional descending.

I also killed cmd_secanalysis; scripts/mod/sumversion.c computes MD4 hash
for modules with MODULE_VERSION(). When CONFIG_DEBUG_SECTION_MISMATCH=y,
it occurs not only in the modpost stage, but also during directory
descending, where sumversion.c may parse stale *.mod files. It would emit
'No such file or directory' warning when an object consisting a module is
renamed, or when a single-obj module is turned into a multi-obj module or
vice versa.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
---

Changes in v3:
  - Fix build error of allnoconfig
  - Remove cmd_secanalysis
  - Fix up comment in scripts/adjust_autoksyms.sh
  - Fix up tools/power/cpupower/debug/kernel/Makefile

Changes in v2:
  - Remove -r of xargs, which is a GNU extension
  - Add '--' for extra safety

 .gitignore                                 |  1 +
 Documentation/dontdiff                     |  1 +
 Makefile                                   | 20 +++-----------------
 lib/Kconfig.debug                          | 12 +-----------
 scripts/Makefile.build                     | 15 +++------------
 scripts/Makefile.modpost                   |  4 ++--
 scripts/adjust_autoksyms.sh                | 14 +++++---------
 scripts/mod/sumversion.c                   | 16 +++-------------
 scripts/package/mkspec                     |  2 +-
 tools/power/cpupower/debug/kernel/Makefile |  4 ++--
 10 files changed, 22 insertions(+), 67 deletions(-)

diff --git a/.gitignore b/.gitignore
index 7587ef56b92d..8f5422cba6e2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,6 +30,7 @@
 *.lz4
 *.lzma
 *.lzo
+*.mod
 *.mod.c
 *.o
 *.o.*
diff --git a/Documentation/dontdiff b/Documentation/dontdiff
index 5eba889ea84d..9f4392876099 100644
--- a/Documentation/dontdiff
+++ b/Documentation/dontdiff
@@ -30,6 +30,7 @@
 *.lzo
 *.mo
 *.moc
+*.mod
 *.mod.c
 *.o
 *.o.*
diff --git a/Makefile b/Makefile
index 396cd5e525d1..9ad9f8d1130d 100644
--- a/Makefile
+++ b/Makefile
@@ -486,11 +486,6 @@ export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
 export KBUILD_ARFLAGS
 
-# When compiling out-of-tree modules, put MODVERDIR in the module
-# tree rather than in the kernel tree. The kernel tree might
-# even be read-only.
-export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
-
 # Files to ignore in find ... statements
 
 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
@@ -1029,8 +1024,8 @@ vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
 
 # Recurse until adjust_autoksyms.sh is satisfied
 PHONY += autoksyms_recursive
-autoksyms_recursive: $(vmlinux-deps)
 ifdef CONFIG_TRIM_UNUSED_KSYMS
+autoksyms_recursive: $(vmlinux-deps) modules.order
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
 	  "$(MAKE) -f $(srctree)/Makefile vmlinux"
 endif
@@ -1113,7 +1108,6 @@ endif
 
 prepare1: prepare3 outputmakefile asm-generic $(version_h) $(autoksyms_h) \
 						include/generated/utsrelease.h
-	$(cmd_crmodverdir)
 
 archprepare: archheaders archscripts prepare1 scripts
 
@@ -1371,7 +1365,7 @@ endif # CONFIG_MODULES
 # make distclean Remove editor backup files, patch leftover files and the like
 
 # Directories & files removed with 'make clean'
-CLEAN_DIRS  += $(MODVERDIR) include/ksym
+CLEAN_DIRS  += include/ksym
 CLEAN_FILES += modules.builtin.modinfo
 
 # Directories & files removed with 'make mrproper'
@@ -1641,7 +1635,6 @@ PHONY += $(clean-dirs) clean
 $(clean-dirs):
 	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
 
-clean:	rm-dirs := $(MODVERDIR)
 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
 
 PHONY += help
@@ -1655,8 +1648,6 @@ help:
 	@echo  ''
 
 PHONY += prepare
-prepare:
-	$(cmd_crmodverdir)
 endif # KBUILD_EXTMOD
 
 clean: $(clean-dirs)
@@ -1667,7 +1658,7 @@ clean: $(clean-dirs)
 		-o -name '*.ko.*' \
 		-o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
 		-o -name '*.dwo' -o -name '*.lst' \
-		-o -name '*.su'  \
+		-o -name '*.su' -o -name '*.mod' \
 		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
 		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
 		-o -name '*.asn1.[ch]' \
@@ -1796,11 +1787,6 @@ quiet_cmd_depmod = DEPMOD  $(KERNELRELEASE)
       cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
                    $(KERNELRELEASE)
 
-# Create temporary dir for module support files
-# clean it up only when building all modules
-cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
-                  $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
-
 # read saved command lines for existing targets
 existing-targets := $(wildcard $(sort $(targets)))
 
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 4ac4ca21a30a..cde5675340ba 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -353,23 +353,13 @@ config DEBUG_SECTION_MISMATCH
 	  which results in the code/data being placed in specific sections.
 	  The section mismatch analysis is always performed after a full
 	  kernel build, and enabling this option causes the following
-	  additional steps to occur:
+	  additional step to occur:
 	  - Add the option -fno-inline-functions-called-once to gcc commands.
 	    When inlining a function annotated with __init in a non-init
 	    function, we would lose the section information and thus
 	    the analysis would not catch the illegal reference.
 	    This option tells gcc to inline less (but it does result in
 	    a larger kernel).
-	  - Run the section mismatch analysis for each module/built-in.a file.
-	    When we run the section mismatch analysis on vmlinux.o, we
-	    lose valuable information about where the mismatch was
-	    introduced.
-	    Running the analysis for each module/built-in.a file
-	    tells where the mismatch happens much closer to the
-	    source. The drawback is that the same mismatch is
-	    reported at least twice.
-	  - Enable verbose reporting from modpost in order to help resolve
-	    the section mismatches that are reported.
 
 config SECTION_MISMATCH_WARN_ONLY
 	bool "Make section mismatch errors non-fatal"
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index be32a3752de4..c6dfcc028f56 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -67,8 +67,6 @@ ifeq ($(CONFIG_MODULES)$(need-modorder),y1)
 modorder-target := $(obj)/modules.order
 endif
 
-# We keep a list of all modules in $(MODVERDIR)
-
 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
 	 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
 	 $(subdir-ym) $(always)
@@ -87,11 +85,6 @@ ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
   cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
 endif
 
-# Do section mismatch analysis for each module/built-in.a
-ifdef CONFIG_DEBUG_SECTION_MISMATCH
-  cmd_secanalysis = ; scripts/mod/modpost $@
-endif
-
 # Compile C sources (.c)
 # ---------------------------------------------------------------------------
 
@@ -278,13 +271,11 @@ $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
 	$(call cmd,force_checksrc)
 	$(call if_changed_rule,cc_o_c)
 
-# Single-part modules are special since we need to mark them in $(MODVERDIR)
-
 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
 	$(call cmd,force_checksrc)
 	$(call if_changed_rule,cc_o_c)
 	@{ echo $(@:.o=.ko); echo $@; \
-	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
+	   $(cmd_undef_syms); } > $(patsubst %.o,%.mod,$@)
 
 quiet_cmd_cc_lst_c = MKLST   $@
       cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
@@ -461,12 +452,12 @@ endif
 # module is turned into a multi object module, $^ will contain header file
 # dependencies recorded in the .*.cmd file.
 quiet_cmd_link_multi-m = LD [M]  $@
-cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^) $(cmd_secanalysis)
+      cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
 
 $(multi-used-m): FORCE
 	$(call if_changed,link_multi-m)
 	@{ echo $(@:.o=.ko); echo $(filter %.o,$^); \
-	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
+	   $(cmd_undef_syms); } > $(patsubst %.o,%.mod,$@)
 $(call multi_depend, $(multi-used-m), .o, -objs -y -m)
 
 targets += $(multi-used-m)
diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index 5841508ffca9..6b19c1a4eae5 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -6,8 +6,8 @@
 # Stage one of module building created the following:
 # a) The individual .o files used for the module
 # b) A <module>.o file which is the .o files above linked together
-# c) A <module>.mod file in $(MODVERDIR)/, listing the name of the
-#    the preliminary <module>.o file, plus all .o files
+# c) A <module>.mod file, listing the name of the preliminary <module>.o file,
+#    plus all .o files
 # d) modules.order, which lists all the modules
 
 # Stage 2 is handled by this file and does the following
diff --git a/scripts/adjust_autoksyms.sh b/scripts/adjust_autoksyms.sh
index aab4e299d7a2..2e4a7320bfb4 100755
--- a/scripts/adjust_autoksyms.sh
+++ b/scripts/adjust_autoksyms.sh
@@ -8,8 +8,7 @@
 #
 
 # Create/update the include/generated/autoksyms.h file from the list
-# of all module's needed symbols as recorded on the third line of
-# .tmp_versions/*.mod files.
+# of all module's needed symbols as recorded on the third line of *.mod files.
 #
 # For each symbol being added or removed, the corresponding dependency
 # file's timestamp is updated to force a rebuild of the affected source
@@ -47,13 +46,10 @@ cat > "$new_ksyms_file" << EOT
  */
 
 EOT
-[ "$(ls -A "$MODVERDIR")" ] &&
-for mod in "$MODVERDIR"/*.mod; do
-	sed -n -e '3{s/ /\n/g;/^$/!p;}' "$mod"
-done | sort -u |
-while read sym; do
-	echo "#define __KSYM_${sym} 1"
-done >> "$new_ksyms_file"
+sed 's/ko$/mod/' modules.order |
+xargs -n1 sed -n -e '3{s/ /\n/g;/^$/!p;}' -- |
+sort -u |
+sed -e 's/\(.*\)/#define __KSYM_\1 1/' >> "$new_ksyms_file"
 
 # Special case for modversions (see modpost.c)
 if [ -n "$CONFIG_MODVERSIONS" ]; then
diff --git a/scripts/mod/sumversion.c b/scripts/mod/sumversion.c
index 0f6dcb4011a8..166f3fa247a9 100644
--- a/scripts/mod/sumversion.c
+++ b/scripts/mod/sumversion.c
@@ -396,21 +396,11 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen)
 	unsigned long len;
 	struct md4_ctx md;
 	char *sources, *end, *fname;
-	const char *basename;
 	char filelist[PATH_MAX + 1];
-	char *modverdir = getenv("MODVERDIR");
 
-	if (!modverdir)
-		modverdir = ".";
-
-	/* Source files for module are in .tmp_versions/modname.mod,
-	   after the first line. */
-	if (strrchr(modname, '/'))
-		basename = strrchr(modname, '/') + 1;
-	else
-		basename = modname;
-	snprintf(filelist, sizeof(filelist), "%s/%.*s.mod", modverdir,
-		(int) strlen(basename) - 2, basename);
+	/* objects for a module are listed in the second line of *.mod file. */
+	snprintf(filelist, sizeof(filelist), "%.*smod",
+		 (int)strlen(modname) - 1, modname);
 
 	file = grab_file(filelist, &len);
 	if (!file)
diff --git a/scripts/package/mkspec b/scripts/package/mkspec
index 2d29df4a0a53..8640c278f1aa 100755
--- a/scripts/package/mkspec
+++ b/scripts/package/mkspec
@@ -29,7 +29,7 @@ fi
 
 PROVIDES="$PROVIDES kernel-$KERNELRELEASE"
 __KERNELRELEASE=$(echo $KERNELRELEASE | sed -e "s/-/_/g")
-EXCLUDES="$RCS_TAR_IGNORE --exclude=.tmp_versions --exclude=*vmlinux* \
+EXCLUDES="$RCS_TAR_IGNORE --exclude=*vmlinux* --exclude=*.mod \
 --exclude=*.o --exclude=*.ko --exclude=*.cmd --exclude=Documentation \
 --exclude=.config.old --exclude=.missing-syscalls.d --exclude=*.s"
 
diff --git a/tools/power/cpupower/debug/kernel/Makefile b/tools/power/cpupower/debug/kernel/Makefile
index c23e5a6ceb7e..7b5c43684be1 100644
--- a/tools/power/cpupower/debug/kernel/Makefile
+++ b/tools/power/cpupower/debug/kernel/Makefile
@@ -12,8 +12,8 @@ default:
 	$(MAKE) -C $(KDIR) M=$(CURDIR)
 
 clean:
-	- rm -rf *.o *.ko .tmp-versions .*.cmd .*.mod.* *.mod.c
-	- rm -rf .tmp_versions* Module.symvers modules.order
+	- rm -rf *.o *.ko .*.cmd .*.mod.* *.mod.c
+	- rm -rf Module.symvers modules.order
 
 install: default
 	install -d $(KMISC)
-- 
2.17.1

[PATCH v3 10/12] kbuild: remove the first line of *.mod files

[Masahiro Yamada]

The current format of *.mod is like this:

  line 1: directory path to the .ko file
  line 2: a list of objects linked into this module
  line 3: unresolved symbols (only when CONFIG_TRIM_UNUSED_KSYMS=y)

Now that *.mod and *.ko are created in the same directory, the line 1
provides no valuable information. It can be derived by replacing the
extension .mod with .ko. In fact, nobody uses the first line any more.

Cut down the first line.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v3: None
Changes in v2: None

 scripts/Makefile.build      | 4 ++--
 scripts/adjust_autoksyms.sh | 4 ++--
 scripts/mod/sumversion.c    | 9 ++-------
 3 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index c6dfcc028f56..9f37f203882f 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -274,7 +274,7 @@ $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
 	$(call cmd,force_checksrc)
 	$(call if_changed_rule,cc_o_c)
-	@{ echo $(@:.o=.ko); echo $@; \
+	@{ echo $@; \
 	   $(cmd_undef_syms); } > $(patsubst %.o,%.mod,$@)
 
 quiet_cmd_cc_lst_c = MKLST   $@
@@ -456,7 +456,7 @@ quiet_cmd_link_multi-m = LD [M]  $@
 
 $(multi-used-m): FORCE
 	$(call if_changed,link_multi-m)
-	@{ echo $(@:.o=.ko); echo $(filter %.o,$^); \
+	@{ echo $(filter %.o,$^); \
 	   $(cmd_undef_syms); } > $(patsubst %.o,%.mod,$@)
 $(call multi_depend, $(multi-used-m), .o, -objs -y -m)
 
diff --git a/scripts/adjust_autoksyms.sh b/scripts/adjust_autoksyms.sh
index 2e4a7320bfb4..a904bf1f5e67 100755
--- a/scripts/adjust_autoksyms.sh
+++ b/scripts/adjust_autoksyms.sh
@@ -8,7 +8,7 @@
 #
 
 # Create/update the include/generated/autoksyms.h file from the list
-# of all module's needed symbols as recorded on the third line of *.mod files.
+# of all module's needed symbols as recorded on the second line of *.mod files.
 #
 # For each symbol being added or removed, the corresponding dependency
 # file's timestamp is updated to force a rebuild of the affected source
@@ -47,7 +47,7 @@ cat > "$new_ksyms_file" << EOT
 
 EOT
 sed 's/ko$/mod/' modules.order |
-xargs -n1 sed -n -e '3{s/ /\n/g;/^$/!p;}' -- |
+xargs -n1 sed -n -e '2{s/ /\n/g;/^$/!p;}' -- |
 sort -u |
 sed -e 's/\(.*\)/#define __KSYM_\1 1/' >> "$new_ksyms_file"
 
diff --git a/scripts/mod/sumversion.c b/scripts/mod/sumversion.c
index 166f3fa247a9..63062024ce0e 100644
--- a/scripts/mod/sumversion.c
+++ b/scripts/mod/sumversion.c
@@ -398,7 +398,7 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen)
 	char *sources, *end, *fname;
 	char filelist[PATH_MAX + 1];
 
-	/* objects for a module are listed in the second line of *.mod file. */
+	/* objects for a module are listed in the first line of *.mod file. */
 	snprintf(filelist, sizeof(filelist), "%.*smod",
 		 (int)strlen(modname) - 1, modname);
 
@@ -407,13 +407,8 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen)
 		/* not a module or .mod file missing - ignore */
 		return;
 
-	sources = strchr(file, '\n');
-	if (!sources) {
-		warn("malformed versions file for %s\n", modname);
-		goto release;
-	}
+	sources = file;
 
-	sources++;
 	end = strchr(sources, '\n');
 	if (!end) {
 		warn("bad ending versions file for %s\n", modname);
-- 
2.17.1

[PATCH v3 11/12] kbuild: remove 'prepare1' target

[Masahiro Yamada]

Now that there is no rule for 'prepare1', it can go away.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v3: None
Changes in v2: None

 Makefile | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/Makefile b/Makefile
index 9ad9f8d1130d..14458ab3d6a8 100644
--- a/Makefile
+++ b/Makefile
@@ -1089,7 +1089,7 @@ scripts: scripts_basic scripts_dtc
 # archprepare is used in arch Makefiles and when processed asm symlink,
 # version.h and scripts_basic is processed / created.
 
-PHONY += prepare archprepare prepare1 prepare3
+PHONY += prepare archprepare prepare3
 
 # prepare3 is used to check if we are building in a separate output directory,
 # and if so do:
@@ -1106,10 +1106,8 @@ ifdef building_out_of_srctree
 	fi;
 endif
 
-prepare1: prepare3 outputmakefile asm-generic $(version_h) $(autoksyms_h) \
-						include/generated/utsrelease.h
-
-archprepare: archheaders archscripts prepare1 scripts
+archprepare: archheaders archscripts scripts prepare3 outputmakefile \
+	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h
 
 prepare0: archprepare
 	$(Q)$(MAKE) $(build)=scripts/mod
-- 
2.17.1

[PATCH v3 12/12] kbuild: split out *.mod out of {single,multi}-used-m rules

[Masahiro Yamada]

Currently, *.mod is created as a side-effect of obj-m.

Split out *.mod as a dedicated build rule, which allows to unify
the %.c -> %.o rule, and remove the single-used-m rule.

This also makes the incremental build of allmodconfig faster because
it saves $(NM) invocation when there is no change in the module.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v3: None
Changes in v2: None

 scripts/Makefile.build | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 9f37f203882f..0d434d0afc0b 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -67,8 +67,10 @@ ifeq ($(CONFIG_MODULES)$(need-modorder),y1)
 modorder-target := $(obj)/modules.order
 endif
 
+mod-targets := $(patsubst %.o, %.mod, $(obj-m))
+
 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
-	 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
+	 $(if $(KBUILD_MODULES),$(obj-m) $(mod-targets) $(modorder-target)) \
 	 $(subdir-ym) $(always)
 	@:
 
@@ -261,7 +263,7 @@ endef
 
 # List module undefined symbols (or empty line if not enabled)
 ifdef CONFIG_TRIM_UNUSED_KSYMS
-cmd_undef_syms = $(NM) $@ | sed -n 's/^  *U //p' | xargs echo
+cmd_undef_syms = $(NM) $< | sed -n 's/^  *U //p' | xargs echo
 else
 cmd_undef_syms = echo
 endif
@@ -271,11 +273,15 @@ $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
 	$(call cmd,force_checksrc)
 	$(call if_changed_rule,cc_o_c)
 
-$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
-	$(call cmd,force_checksrc)
-	$(call if_changed_rule,cc_o_c)
-	@{ echo $@; \
-	   $(cmd_undef_syms); } > $(patsubst %.o,%.mod,$@)
+cmd_mod = { \
+	echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
+	$(cmd_undef_syms); \
+	} > $@
+
+$(obj)/%.mod: $(obj)/%.o FORCE
+	$(call if_changed,mod)
+
+targets += $(mod-targets)
 
 quiet_cmd_cc_lst_c = MKLST   $@
       cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
@@ -456,8 +462,6 @@ quiet_cmd_link_multi-m = LD [M]  $@
 
 $(multi-used-m): FORCE
 	$(call if_changed,link_multi-m)
-	@{ echo $(filter %.o,$^); \
-	   $(cmd_undef_syms); } > $(patsubst %.o,%.mod,$@)
 $(call multi_depend, $(multi-used-m), .o, -objs -y -m)
 
 targets += $(multi-used-m)
-- 
2.17.1