* why scripts/link-vmlinux.sh has a final build of init/
@ 2018-02-12 4:22 Cao jin
2018-02-12 14:48 ` Masahiro Yamada
0 siblings, 1 reply; 5+ messages in thread
From: Cao jin @ 2018-02-12 4:22 UTC (permalink / raw)
To: Masahiro Yamada; +Cc: Michal Marek, Linux Kbuild mailing list, linux-kernel
Hi Masahiro-san,
As I remember, init/ is already built during recursive make, and I did
a clean build(make mrproper, make localmodconfig) with all plugins
included on x86_64 with following patch, the kernel can boot without any
obvious problem. So, I don't figure out why we need this final build?
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index e6818b8e7141..086b2efd4d53 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -247,9 +247,6 @@ else
expr 0$(cat .old_version) + 1 >.version;
fi;
-# final build of init/
-${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
-
archive_builtin
#link vmlinux.o
--
Sincerely,
Cao jin
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: why scripts/link-vmlinux.sh has a final build of init/
2018-02-12 4:22 why scripts/link-vmlinux.sh has a final build of init/ Cao jin
@ 2018-02-12 14:48 ` Masahiro Yamada
2018-02-13 7:08 ` Cao jin
0 siblings, 1 reply; 5+ messages in thread
From: Masahiro Yamada @ 2018-02-12 14:48 UTC (permalink / raw)
To: Cao jin; +Cc: Michal Marek, Linux Kbuild mailing list, linux-kernel
2018-02-12 13:22 GMT+09:00 Cao jin <caoj.fnst@cn.fujitsu.com>:
> Hi Masahiro-san,
>
> As I remember, init/ is already built during recursive make, and I did
> a clean build(make mrproper, make localmodconfig) with all plugins
> included on x86_64 with following patch, the kernel can boot without any
> obvious problem. So, I don't figure out why we need this final build?
>
>
> diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
> index e6818b8e7141..086b2efd4d53 100755
> --- a/scripts/link-vmlinux.sh
> +++ b/scripts/link-vmlinux.sh
> @@ -247,9 +247,6 @@ else
> expr 0$(cat .old_version) + 1 >.version;
> fi;
>
> -# final build of init/
> -${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
> GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
> -
> archive_builtin
>
> #link vmlinux.o
>
link-vmlinux.sh increments '.version'
so it must descend into init/
to update include/generated/compile.h
and re-compile init/version.o
We do not increment '.version'
at the first descend into init/
because we never know whether the kernel
is updated or not before the final link stage.
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: why scripts/link-vmlinux.sh has a final build of init/
2018-02-12 14:48 ` Masahiro Yamada
@ 2018-02-13 7:08 ` Cao jin
2018-02-14 11:31 ` Masahiro Yamada
0 siblings, 1 reply; 5+ messages in thread
From: Cao jin @ 2018-02-13 7:08 UTC (permalink / raw)
To: Masahiro Yamada; +Cc: Michal Marek, Linux Kbuild mailing list, linux-kernel
On 02/12/2018 10:48 PM, Masahiro Yamada wrote:
> 2018-02-12 13:22 GMT+09:00 Cao jin <caoj.fnst@cn.fujitsu.com>:
>> Hi Masahiro-san,
>>
>> As I remember, init/ is already built during recursive make, and I did
>> a clean build(make mrproper, make localmodconfig) with all plugins
>> included on x86_64 with following patch, the kernel can boot without any
>> obvious problem. So, I don't figure out why we need this final build?
>>
>>
>> diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
>> index e6818b8e7141..086b2efd4d53 100755
>> --- a/scripts/link-vmlinux.sh
>> +++ b/scripts/link-vmlinux.sh
>> @@ -247,9 +247,6 @@ else
>> expr 0$(cat .old_version) + 1 >.version;
>> fi;
>>
>> -# final build of init/
>> -${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
>> GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
>> -
>> archive_builtin
>>
>> #link vmlinux.o
>>
>
>
> link-vmlinux.sh increments '.version'
> so it must descend into init/
> to update include/generated/compile.h
> and re-compile init/version.o
>
> We do not increment '.version'
> at the first descend into init/
> because we never know whether the kernel
> is updated or not before the final link stage.
>
Oh, I wasn't aware of this process, now understood. Thanks Masahiro-san.
BTW, I still have 2 questions.
1. In final build, why need
GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
Doesn't GCC_PLUGINS_CFLAGS already exist in the environment?
I also tested the Randomizing Structure Layout plugin with this patch,
the plugin seems works in my test.
2. scripts/link-vmlinux.sh seems just handle only one argument: clean.
So why shouldn't it be:
diff --git a/Makefile b/Makefile
index ccd981892ef2..21d93b545381 100644
--- a/Makefile
+++ b/Makefile
@@ -998,7 +998,7 @@ ARCH_POSTLINK := $(wildcard
$(srctree)/arch/$(SRCARCH)/Makefile.postlink)
# Final link of vmlinux with optional arch pass after final link
cmd_link-vmlinux = \
- $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) ; \
+ $(CONFIG_SHELL) $<; \
$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
vmlinux: scripts/link-vmlinux.sh vmlinux_prereq $(vmlinux-deps) FORCE
--
Sincerely,
Cao jin
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: why scripts/link-vmlinux.sh has a final build of init/
2018-02-13 7:08 ` Cao jin
@ 2018-02-14 11:31 ` Masahiro Yamada
2018-02-21 3:20 ` Cao jin
0 siblings, 1 reply; 5+ messages in thread
From: Masahiro Yamada @ 2018-02-14 11:31 UTC (permalink / raw)
To: Cao jin; +Cc: Michal Marek, Linux Kbuild mailing list, linux-kernel
2018-02-13 16:08 GMT+09:00 Cao jin <caoj.fnst@cn.fujitsu.com>:
> BTW, I still have 2 questions.
>
> 1. In final build, why need
>
> GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
>
> Doesn't GCC_PLUGINS_CFLAGS already exist in the environment?
>
> I also tested the Randomizing Structure Layout plugin with this patch,
> the plugin seems works in my test.
I have not tested, but GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
is probably unnecessary.
> 2. scripts/link-vmlinux.sh seems just handle only one argument: clean.
> So why shouldn't it be:
To detect the change of $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux)
because link-vmlinux.sh depends on them.
> diff --git a/Makefile b/Makefile
> index ccd981892ef2..21d93b545381 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -998,7 +998,7 @@ ARCH_POSTLINK := $(wildcard
> $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
>
> # Final link of vmlinux with optional arch pass after final link
> cmd_link-vmlinux = \
> - $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) ; \
> + $(CONFIG_SHELL) $<; \
> $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
>
> vmlinux: scripts/link-vmlinux.sh vmlinux_prereq $(vmlinux-deps) FORCE
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: why scripts/link-vmlinux.sh has a final build of init/
2018-02-14 11:31 ` Masahiro Yamada
@ 2018-02-21 3:20 ` Cao jin
0 siblings, 0 replies; 5+ messages in thread
From: Cao jin @ 2018-02-21 3:20 UTC (permalink / raw)
To: Masahiro Yamada; +Cc: Michal Marek, Linux Kbuild mailing list, linux-kernel
Sorry for late.
On 02/14/2018 07:31 PM, Masahiro Yamada wrote:
> 2018-02-13 16:08 GMT+09:00 Cao jin <caoj.fnst@cn.fujitsu.com>:
>
>> BTW, I still have 2 questions.
>>
>> 1. In final build, why need
>>
>> GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
>>
>> Doesn't GCC_PLUGINS_CFLAGS already exist in the environment?
>>
>> I also tested the Randomizing Structure Layout plugin with this patch,
>> the plugin seems works in my test.
>
>
> I have not tested, but GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
> is probably unnecessary.
>
>
>
>> 2. scripts/link-vmlinux.sh seems just handle only one argument: clean.
>> So why shouldn't it be:
>
>
> To detect the change of $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux)
> because link-vmlinux.sh depends on them.
>
I understood, I missed the existence of .vmlinux.cmd file.
Thanks very much, Masahiro-san.
--
Sincerely,
Cao jin
>
>> diff --git a/Makefile b/Makefile
>> index ccd981892ef2..21d93b545381 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -998,7 +998,7 @@ ARCH_POSTLINK := $(wildcard
>> $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
>>
>> # Final link of vmlinux with optional arch pass after final link
>> cmd_link-vmlinux = \
>> - $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) ; \
>> + $(CONFIG_SHELL) $<; \
>> $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
>>
>> vmlinux: scripts/link-vmlinux.sh vmlinux_prereq $(vmlinux-deps) FORCE
>
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-02-21 3:20 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-02-12 4:22 why scripts/link-vmlinux.sh has a final build of init/ Cao jin
2018-02-12 14:48 ` Masahiro Yamada
2018-02-13 7:08 ` Cao jin
2018-02-14 11:31 ` Masahiro Yamada
2018-02-21 3:20 ` Cao jin
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