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  1. 06 9月, 2019 1 次提交
  3. 04 9月, 2019 3 次提交
    • M
      kbuild: add $(BASH) to run scripts with bash-extension · 858805b3
      由 Masahiro Yamada 提交于 
      CONFIG_SHELL falls back to sh when bash is not installed on the system,
but nobody is testing such a case since bash is usually installed.
So, shell scripts invoked by CONFIG_SHELL are only tested with bash.

It makes it difficult to test whether the hashbang #!/bin/sh is real.
For example, #!/bin/sh in arch/powerpc/kernel/prom_init_check.sh is
false. (I fixed it up)

Besides, some shell scripts invoked by CONFIG_SHELL use bash-extension
and #!/bin/bash is specified as the hashbang, while CONFIG_SHELL may
not always be set to bash.

Probably, the right thing to do is to introduce BASH, which is bash by
default, and always set CONFIG_SHELL to sh. Replace $(CONFIG_SHELL)
with $(BASH) for bash scripts.

If somebody tries to add bash-extension to a #!/bin/sh script, it will
be caught in testing because /bin/sh is a symlink to dash on some major
distributions.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      858805b3
    • M
      kbuild: remove ARCH_{CPP,A,C}FLAGS · 8cc7af75
      由 Masahiro Yamada 提交于 
      These flags were added by commit 61754c18 ("kbuild: Allow arch
Makefiles to override {cpp,ld,c}flags") to allow ARC to override -O2.

We did not see any other usage after all. Now that ARC switched to
CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3, there is no more user of
these variables.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      8cc7af75
    • M
      kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC · 15f5db60
      由 Masahiro Yamada 提交于 
      arch/arc/Makefile overrides -O2 with -O3. This is the only user of
ARCH_CFLAGS. There is no user of ARCH_CPPFLAGS or ARCH_AFLAGS.
My plan is to remove ARCH_{CPP,A,C}FLAGS after refactoring the ARC
Makefile.

Currently, ARC has no way to enable -Wmaybe-uninitialized because both
-O3 and -Os disable it. Enabling it will be useful for compile-testing.
This commit allows allmodconfig (, which defaults to -O2) to enable it.

Add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y to all the defconfig files
in arch/arc/configs/ in order to keep the current config settings.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NVineet Gupta <vgupta@synopsys.com>
      15f5db60
  5. 30 8月, 2019 1 次提交
  7. 29 8月, 2019 7 次提交
  9. 25 8月, 2019 3 次提交
  11. 22 8月, 2019 1 次提交
  13. 21 8月, 2019 6 次提交
    • M
      kbuild: rebuild modules when module linker scripts are updated · 10df0638
      由 Masahiro Yamada 提交于 
      Currently, the timestamp of module linker scripts are not checked.
Add them to the dependency of modules so they are correctly rebuilt.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      10df0638
    • M
      kbuild: make single targets work more correctly · 394053f4
      由 Masahiro Yamada 提交于 
      Currently, the single target build directly descends into the directory
of the target. For example,

  $ make foo/bar/baz.o

... directly descends into foo/bar/.

On the other hand, the normal build usually descends one directory at
a time, i.e. descends into foo/, and then foo/bar/.

This difference causes some problems.

[1] miss subdir-asflags-y, subdir-ccflags-y in upper Makefiles

    The options in subdir-{as,cc}flags-y take effect in the current
    and its sub-directories. In other words, they are inherited
    downward. In the example above, the single target will miss
    subdir-{as,cc}flags-y if they are defined in foo/Makefile.

[2] could be built in a different directory

    As Documentation/kbuild/modules.rst section 4.3 says, Kbuild can
    handle files that are spread over several sub-directories.

    The build rule of foo/bar/baz.o may not necessarily be specified in
    foo/bar/Makefile. It might be specifies in foo/Makefile as follows:

    [foo/Makefile]
    obj-y := bar/baz.o

    This often happens when a module is so big that its source files
    are divided into sub-directories.

    In this case, there is no Makefile in the foo/bar/ directory, yet
    the single target descends into foo/bar/, then fails due to the
    missing Makefile. You can still do 'make foo/bar/' for partial
    building, but cannot do 'make foo/bar/baz.s'. I believe the single
    target '%.s' is a useful feature for inspecting the compiler output.

    Some modules work around this issue by putting an empty Makefile
    in every sub-directory.

This commit fixes those problems by making the single target build
descend in the same way as the normal build does.

Another change is the single target build will observe the CONFIG
options. Previously, it allowed users to build the foo.o even when
the corresponding CONFIG_FOO is disabled:

   obj-$(CONFIG_FOO) += foo.o

In the new behavior, the single target build will just fail and show
"No rule to make target ..." (or "Nothing to be done for ..." if the
stale object already exists, but cannot be updated).

The disadvantage of this commit is the build speed. Now that the
single target build visits every directory and parses lots of
Makefiles, it is slower than before. (But, I hope it will not be
too slow.)
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      394053f4
    • M
      kbuild: unify clean-dirs rule for in-kernel and external module · 76cd306d
      由 Masahiro Yamada 提交于 
      Factor out the duplicated code for in-kernel and external module
cleaning.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      76cd306d
    • M
      kbuild: unify vmlinux-dirs and module-dirs rules · c99f3918
      由 Masahiro Yamada 提交于 
      The in-kernel build and external module build have similar code
for descending into sub-directories.

Factor out the code into the common place.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      c99f3918
    • M
      kbuild: unset variables in top Makefile instead of setting 0 · 2042b548
      由 Masahiro Yamada 提交于 
      There is no need to set 0 to variables such as config-targets,
mixed-targets, etc.

Unset instead of setting 0 in order to use 'ifdef' to test them.

I also renamed:

  config-targets  ->  config-build
  mixed-targets   ->  mixed-build
  dot-config      ->  need-config

to clarify what we are doing.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      2042b548
    • M
      kbuild: do not descend to ./Kbuild when cleaning · 125d059b
      由 Masahiro Yamada 提交于 
      'make clean' descends into ./Kbuild, but does not clean anything
since everything is added to no-clean-files.

There is no need to descend to ./Kbuild in the first place.
We can drop the no-clean-files assignment.

With this, there is no more user of no-clean-files. I will keep it
for a while to see whether a new user will appear.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      125d059b
  15. 15 8月, 2019 2 次提交
  17. 12 8月, 2019 1 次提交
  19. 11 8月, 2019 1 次提交
  21. 10 8月, 2019 2 次提交
    • M
      kbuild: show hint if subdir-y/m is used to visit module Makefile · c07d8d47
      由 Masahiro Yamada 提交于 
      Since commit ff9b45c5 ("kbuild: modpost: read modules.order instead
of $(MODVERDIR)/*.mod"), a module is no longer built in the following
pattern:

  [Makefile]
  subdir-y := some-module

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

You cannot write Makefile this way in upstream because modules.order is
not correctly generated. subdir-y is used to descend to a sub-directory
that builds tools, device trees, etc.

For external modules, the modules order does not matter. So, the
Makefile above was known to work.

I believe the Makefile should be re-written as follows:

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

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

However, people will have no idea if their Makefile suddenly stops
working. In fact, I received questions from multiple people.

Show a warning for a while if obj-m is specified in a Makefile visited
by subdir-y or subdir-m.

I touched the %/ rule to avoid false-positive warnings for the single
target.

Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Tom Stonecypher <thomas.edwardx.stonecypher@intel.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: NJan Kiszka <jan.kiszka@siemens.com>
      c07d8d47
    • M
      kbuild: revive single target %.ko · 47801c97
      由 Masahiro Yamada 提交于 
      I removed the single target %.ko in commit ff9b45c5 ("kbuild:
modpost: read modules.order instead of $(MODVERDIR)/*.mod") because
the modpost stage does not work reliably. For instance, the module
dependency, modversion, etc. do not work if we lack symbol information
from the other modules.

Yet, some people still want to build only one module in their interest,
and it may be still useful if it is used within those limitations.

Fixes: ff9b45c5 ("kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod")
Reported-by: NDon Brace <don.brace@microsemi.com>
Reported-by: NArend Van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      47801c97
  23. 08 8月, 2019 1 次提交
  25. 05 8月, 2019 1 次提交
  27. 31 7月, 2019 1 次提交
  29. 29 7月, 2019 1 次提交
  31. 26 7月, 2019 1 次提交
    • G
      Makefile: Globally enable fall-through warning · a035d552
      由 Gustavo A. R. Silva 提交于 
      Now that all the fall-through warnings have been addressed in the
kernel, enable the fall-through warning globally.

Also, update the deprecated.rst file to include implicit fall-through
as 'deprecated' so people can be pointed to a single location for
justification.

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
      a035d552
  33. 22 7月, 2019 1 次提交
  35. 20 7月, 2019 1 次提交
  37. 18 7月, 2019 3 次提交
    • M
      kbuild: remove 'prepare1' target · 30527cef
      由 Masahiro Yamada 提交于 
      Now that there is no rule for 'prepare1', it can go away.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      30527cef
    • M
      kbuild: create *.mod with full directory path and remove MODVERDIR · b7dca6dd
      由 Masahiro Yamada 提交于 
      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 551559e1 ("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 3a48a919 ("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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NNicolas Pitre <nico@fluxnic.net>
      b7dca6dd
    • M
      kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod · ff9b45c5
      由 Masahiro Yamada 提交于 
      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.

I removed the single target %.ko from the top Makefile. To make sure
modpost works correctly, vmlinux and the other modules must be built.
You cannot build a particular .ko file alone.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      ff9b45c5
  39. 17 7月, 2019 2 次提交
    • M
      kbuild: get rid of kernel/ prefix from in-tree modules.{order,builtin} · 1bd9a468
      由 Masahiro Yamada 提交于 
      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: NMasahiro Yamada <yamada.masahiro@socionext.com>
      1bd9a468
    • M
      kbuild: do not create empty modules.order in the prepare stage · 7e131918
      由 Masahiro Yamada 提交于 
      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: NMasahiro Yamada <yamada.masahiro@socionext.com>
      7e131918