<feed xmlns='http://www.w3.org/2005/Atom'>
<title>talos-op-linux/Documentation/kbuild, branch master</title>
<subtitle>Talos™ II Linux sources for OpenPOWER</subtitle>
<id>https://git.raptorcs.com/git/talos-op-linux/atom?h=master</id>
<link rel='self' href='https://git.raptorcs.com/git/talos-op-linux/atom?h=master'/>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-op-linux/'/>
<updated>2020-02-03T16:53:07+00:00</updated>
<entry>
<title>kbuild: rename hostprogs-y/always to hostprogs/always-y</title>
<updated>2020-02-03T16:53:07+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2020-02-01T16:49:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-op-linux/commit/?id=5f2fb52fac15a8a8e10ce020dd532504a8abfc4e'/>
<id>urn:sha1:5f2fb52fac15a8a8e10ce020dd532504a8abfc4e</id>
<content type='text'>
In old days, the "host-progs" syntax was used for specifying host
programs. It was renamed to the current "hostprogs-y" in 2004.

It is typically useful in scripts/Makefile because it allows Kbuild to
selectively compile host programs based on the kernel configuration.

This commit renames like follows:

  always       -&gt;  always-y
  hostprogs-y  -&gt;  hostprogs

So, scripts/Makefile will look like this:

  always-$(CONFIG_BUILD_BIN2C) += ...
  always-$(CONFIG_KALLSYMS)    += ...
      ...
  hostprogs := $(always-y) $(always-m)

I think this makes more sense because a host program is always a host
program, irrespective of the kernel configuration. We want to specify
which ones to compile by CONFIG options, so always-y will be handier.

The "always", "hostprogs-y", "hostprogs-m" will be kept for backward
compatibility for a while.

Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</content>
</entry>
<entry>
<title>kbuild: fix the document to use extra-y for vmlinux.lds</title>
<updated>2020-02-03T16:50:52+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2020-02-01T16:49:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-op-linux/commit/?id=faa7bdd7e9e1441ed82819b8db8bb43d3d3fd818'/>
<id>urn:sha1:faa7bdd7e9e1441ed82819b8db8bb43d3d3fd818</id>
<content type='text'>
The difference between "always" and "extra-y" is that the targets
listed in $(always) are always built, whereas the ones in $(extra-y)
are built only when KBUILD_BUILTIN is set.

So, "make modules" does not build the targets in $(extra-y).

vmlinux.lds is only needed for linking vmlinux. So, adding it to extra-y
is more correct. In fact, arch/x86/kernel/Makefile does this.

Fix the example code.

Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'kconfig-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild</title>
<updated>2020-02-01T18:25:55+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-02-01T18:25:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-op-linux/commit/?id=14cd0bd04907df79b36a31e55f18768172230987'/>
<id>urn:sha1:14cd0bd04907df79b36a31e55f18768172230987</id>
<content type='text'>
Pull Kconfig updates from Masahiro Yamada:

 - add 'yes2modconfig' and 'mod2yesconfig' targets (useful mainly for
   turning syzbot configs into more modular ones as a step to minimizing
   the result)

 - sanitize help text

 - various code cleanups

* tag 'kconfig-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: fix documentation typos
  kconfig: fix an "implicit declaration of function" warning
  kconfig: fix nesting of symbol help text
  kconfig: distinguish between dependencies and visibility in help text
  kconfig: list all definitions of a symbol in help text
  kconfig: Add yes2modconfig and mod2yesconfig targets.
  kconfig: use $(PERL) in Makefile
  kconfig: fix too deep indentation in Makefile
  kconfig: localmodconfig: fix indentation for closing brace
  kconfig: localmodconfig: remove unused $config
  kconfig: squash prop_alloc() into menu_add_prop()
  kconfig: remove sym from struct property
  kconfig: remove 'prompt' argument from menu_add_prop()
  kconfig: move prompt handling to menu_add_prompt() from menu_add_prop()
  kconfig: remove 'prompt' symbol
  kconfig: drop T_WORD from the RHS of 'prompt' symbol
  kconfig: use parent-&gt;dep as the parentdep of 'menu'
  kconfig: remove the rootmenu check in menu_add_prop()
</content>
</entry>
<entry>
<title>kconfig: fix documentation typos</title>
<updated>2020-01-21T15:54:35+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2020-01-17T16:18:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-op-linux/commit/?id=2b5072b9dfab1bc9e4f605bba19b4470e429c60c'/>
<id>urn:sha1:2b5072b9dfab1bc9e4f605bba19b4470e429c60c</id>
<content type='text'>
Fix a couple typos in kconfig-language documentation.

Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</content>
</entry>
<entry>
<title>kbuild: create modules.builtin without Makefile.modbuiltin or tristate.conf</title>
<updated>2020-01-06T17:18:39+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2019-12-19T08:33:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-op-linux/commit/?id=8b41fc4454e36fbfdbb23f940d023d4dece2de29'/>
<id>urn:sha1:8b41fc4454e36fbfdbb23f940d023d4dece2de29</id>
<content type='text'>
Commit bc081dd6e9f6 ("kbuild: generate modules.builtin") added
infrastructure to generate modules.builtin, the list of all
builtin modules.

Basically, it works like this:

  - Kconfig generates include/config/tristate.conf, the list of
    tristate CONFIG options with a value in a capital letter.

  - scripts/Makefile.modbuiltin makes Kbuild descend into
    directories to collect the information of builtin modules.

I am not a big fan of it because Kbuild ends up with traversing
the source tree twice.

I am not sure how perfectly it should work, but this approach cannot
avoid false positives; even if the relevant CONFIG option is tristate,
some Makefiles forces obj-m to obj-y.

Some examples are:

  arch/powerpc/platforms/powermac/Makefile:
    obj-$(CONFIG_NVRAM:m=y)         += nvram.o

  net/ipv6/Makefile:
    obj-$(subst m,y,$(CONFIG_IPV6)) += inet6_hashtables.o

  net/netlabel/Makefile:
    obj-$(subst m,y,$(CONFIG_IPV6)) += netlabel_calipso.o

Nobody has complained about (or noticed) it, so it is probably fine to
have false positives in modules.builtin.

This commit simplifies the implementation. Let's exploit the fact
that every module has MODULE_LICENSE(). (modpost shows a warning if
MODULE_LICENSE is missing. If so, 0-day bot would already have blocked
such a module.)

I added MODULE_FILE to &lt;linux/module.h&gt;. When the code is being compiled
as builtin, it will be filled with the file path of the module, and
collected into modules.builtin.info. Then, scripts/link-vmlinux.sh
extracts the list of builtin modules out of it.

This new approach fixes the false-positives above, but adds another
type of false-positives; non-modular code may have MODULE_LICENSE()
by mistake. This is not a big deal, it is just the code is always
orphan. We can clean it up if we like. You can see cleanup examples by:

  $ git log --grep='make.* explicitly non-modular'

To sum up, this commits deletes lots of code, but still produces almost
equivalent results. Please note it does not increase the vmlinux size at
all. As you can see in include/asm-generic/vmlinux.lds.h, the .modinfo
section is discarded in the link stage.

Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</content>
</entry>
<entry>
<title>kbuild: clarify the difference between obj-y and obj-m w.r.t. descending</title>
<updated>2019-12-21T15:25:35+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2019-12-19T11:51:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-op-linux/commit/?id=28f94a44298c99c0db85539874b62f21d94fcaa7'/>
<id>urn:sha1:28f94a44298c99c0db85539874b62f21d94fcaa7</id>
<content type='text'>
Kbuild descends into a directory by either 'y' or 'm', but there is an
important difference.

Kbuild combines the built-in objects into built-in.a in each directory.
The built-in.a in the directory visited by obj-y is merged into the
built-in.a in the parent directory. This merge happens recursively
when Kbuild is ascending back towards the top directory, then built-in
objects are linked into vmlinux eventually. This works properly only
when the Makefile specifying obj-y is reachable by the chain of obj-y.

On the other hand, Kbuild does not take built-in.a from the directory
visited by obj-m. This it, all the objects in that directory are
supposed to be modular. If Kbuild descends into a directory by obj-m,
but the Makefile in the sub-directory specifies obj-y, those objects
are just left orphan.

The current statement "Kbuild only uses this information to decide that
it needs to visit the directory" is misleading. Clarify the difference.

Reported-by: Johan Hovold &lt;johan@kernel.org&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Reviewed-by: Johan Hovold &lt;johan@kernel.org&gt;
</content>
</entry>
<entry>
<title>kconfig: remove ---help--- from documentation</title>
<updated>2019-12-18T14:17:29+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2019-12-17T11:51:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-op-linux/commit/?id=8f268881d7d278047b00eed54bbb9288dbd6ab23'/>
<id>urn:sha1:8f268881d7d278047b00eed54bbb9288dbd6ab23</id>
<content type='text'>
Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), scripts/checkpatch.pl warns the use of ---help---.

Kconfig still supports ---help---, but new code should avoid using it.
Let's stop advertising it in documentation.

Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</content>
</entry>
<entry>
<title>kbuild: remove header compile test</title>
<updated>2019-11-14T15:22:35+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2019-11-07T07:14:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-op-linux/commit/?id=fcbb8461fd2376ba3782b5b8bd440c929b8e4980'/>
<id>urn:sha1:fcbb8461fd2376ba3782b5b8bd440c929b8e4980</id>
<content type='text'>
There are both positive and negative options about this feature.
At first, I thought it was a good idea, but actually Linus stated a
negative opinion (https://lkml.org/lkml/2019/9/29/227). I admit it
is ugly and annoying.

The baseline I'd like to keep is the compile-test of uapi headers.
(Otherwise, kernel developers have no way to ensure the correctness
of the exported headers.)

I will maintain a small build rule in usr/include/Makefile.
Remove the other header test functionality.

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
</content>
</entry>
<entry>
<title>kbuild: do not read $(KBUILD_EXTMOD)/Module.symvers</title>
<updated>2019-11-11T11:07:03+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2019-10-03T10:29:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-op-linux/commit/?id=39808e451fdf30d20099a92e5185a0acb028d826'/>
<id>urn:sha1:39808e451fdf30d20099a92e5185a0acb028d826</id>
<content type='text'>
Since commit 040fcc819a2e ("kbuild: improved modversioning support for
external modules"), the external module build reads Module.symvers in
the directory of the module itself, then dumps symbols back into it.
It accumulates stale symbols in the file when you build an external
module incrementally.

The idea behind it was, as the commit log explained, you can copy
Modules.symvers from one module to another when you need to pass symbol
information between two modules. However, the manual copy of the file
sounds questionable to me, and containing stale symbols is a downside.

Some time later, commit 0d96fb20b7ed ("kbuild: Add new Kbuild variable
KBUILD_EXTRA_SYMBOLS") introduced a saner approach.

So, this commit removes the former one. Going forward, the external
module build dumps symbols into Module.symvers to be carried via
KBUILD_EXTRA_SYMBOLS, but never reads it automatically.

With the -I option removed, there is no one to set the external_module
flag unless KBUILD_EXTRA_SYMBOLS is passed. Now the -i option does it
instead.

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'modules-for-v5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux</title>
<updated>2019-10-11T17:19:24+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-10-11T17:19:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-op-linux/commit/?id=c6f6ebd77ce1bb8931f78412a841dd1371820181'/>
<id>urn:sha1:c6f6ebd77ce1bb8931f78412a841dd1371820181</id>
<content type='text'>
Pull module fixes from Jessica Yu:
 "Code cleanups and kbuild/namespace related fixups from Masahiro.

  Most importantly, it fixes a namespace-related modpost issue for
  external module builds

   - Fix broken external module builds due to a modpost bug in
     read_dump(), where the namespace was not being strdup'd and
     sym-&gt;namespace would be set to bogus data.

   - Various namespace-related kbuild fixes and cleanups thanks to
     Masahiro Yamada"

* tag 'modules-for-v5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  doc: move namespaces.rst from kbuild/ to core-api/
  nsdeps: make generated patches independent of locale
  nsdeps: fix hashbang of scripts/nsdeps
  kbuild: fix build error of 'make nsdeps' in clean tree
  module: rename __kstrtab_ns_* to __kstrtabns_* to avoid symbol conflict
  modpost: fix broken sym-&gt;namespace for external module builds
  module: swap the order of symbol.namespace
  scripts: add_namespace: Fix coccicheck failed
</content>
</entry>
</feed>
