kbuild: add kbuild-file macro

While building, installing, cleaning, Kbuild visits sub-directories
and includes 'Kbuild' or 'Makefile' that exists there.

Add 'kbuild-file' macro, and reuse it from s

kbuild: add kbuild-file macro

While building, installing, cleaning, Kbuild visits sub-directories
and includes 'Kbuild' or 'Makefile' that exists there.

Add 'kbuild-file' macro, and reuse it from scripts/Makefie.*

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Tested-by: Alexander Lobakin <alobakin@pm.me>

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kbuild: prefix $(srctree)/ to some included Makefiles

VPATH is used in Kbuild to make pattern rules search for prerequisites
in both $(objtree) and $(srctree). Some of *.c, *.S files are not real
so

kbuild: prefix $(srctree)/ to some included Makefiles

VPATH is used in Kbuild to make pattern rules search for prerequisites
in both $(objtree) and $(srctree). Some of *.c, *.S files are not real
sources, but generated by tools such as flex, bison, perl.

In contrast, I doubt the benefit of --include-dir=$(abs_srctree) because
it is always clear which Makefiles are real sources, and which are not.

So, my hope is to add $(srctree)/ prefix to all check-in Makefiles,
then remove --include-dir=$(abs_srctree) flag in the future.

I am touching only some Kbuild core parts for now. Treewide fixes will
be needed to achieve this goal.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

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kbuild: force all architectures except um to include mandatory-y

Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes
the common Kbuild.asm file. Factor out the duplicated include dir

kbuild: force all architectures except um to include mandatory-y

Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes
the common Kbuild.asm file. Factor out the duplicated include directives
to scripts/Makefile.asm-generic so that no architecture would opt out
of the mandatory-y mechanism.

um is not forced to include mandatory-y since it is a very exceptional
case which does not support UAPI.

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

show more ...

kbuild: warn redundant generic-y

The generic-y is redundant under the following condition:

- arch has its own implementation

- the same header is added to generated-y

- the same header is adde

kbuild: warn redundant generic-y

The generic-y is redundant under the following condition:

- arch has its own implementation

- the same header is added to generated-y

- the same header is added to mandatory-y

If a redundant generic-y is found, the warning like follows is displayed:

scripts/Makefile.asm-generic:20: redundant generic-y found in arch/arm/include/asm/Kbuild: timex.h

I fixed up arch Kbuild files found by this.

Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

show more ...

kbuild: generate asm-generic wrappers if mandatory headers are missing

Some time ago, Sam pointed out a certain degree of overwrap between
generic-y and mandatory-y. (https://lkml.org/lkml/2017/7/10

kbuild: generate asm-generic wrappers if mandatory headers are missing

Some time ago, Sam pointed out a certain degree of overwrap between
generic-y and mandatory-y. (https://lkml.org/lkml/2017/7/10/121)

I tweaked the meaning of mandatory-y a little bit; now it defines the
minimum set of ASM headers that all architectures must have.

If arch does not have specific implementation of a mandatory header,
Kbuild will let it fallback to the asm-generic one by automatically
generating a wrapper. This will allow to drop lots of redundant
generic-y defines.

Previously, "mandatory" was used in the context of UAPI, but I guess
this can be extended to kernel space ASM headers.

Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

show more ...

kbuild: refactor Makefile.asm-generic

- Use conventional $(MAKE) $(asm-generic)=<dir> style
for directory descending

- Remove unneeded FORCE since "all" is a phony target

- Remove unneeded "

kbuild: refactor Makefile.asm-generic

- Use conventional $(MAKE) $(asm-generic)=<dir> style
for directory descending

- Remove unneeded FORCE since "all" is a phony target

- Remove unneeded "_dummy :=" assignment

- Skip $(shell mkdir ...) when headers exist in the directory

- Misc cleanups

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

show more ...

kbuild: add forward declaration of default target to Makefile.asm-generic

$(kbuild-file) and Kbuild.include are included before the default
target "all".

We will add a target into Kbuild.include.

kbuild: add forward declaration of default target to Makefile.asm-generic

$(kbuild-file) and Kbuild.include are included before the default
target "all".

We will add a target into Kbuild.include. In advance, add a forward
declaration of the default target.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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kbuild: update comments of Makefile.asm-generic

Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

kbuild: replace genhdr-y with generated-y

Originally, generated-y and genhdr-y had different meaning, like
follows:

- generated-y: generated headers (other than asm-generic wrappers)
- header-y :

kbuild: replace genhdr-y with generated-y

Originally, generated-y and genhdr-y had different meaning, like
follows:

- generated-y: generated headers (other than asm-generic wrappers)
- header-y : headers to be exported
- genhdr-y : generated headers to be exported (generated-y + header-y)

Since commit fcc8487d477a ("uapi: export all headers under uapi
directories"), headers under UAPI directories are all exported.
So, there is no more difference between generated-y and genhdr-y.

We see two users of genhdr-y, arch/{arm,x86}/include/uapi/asm/Kbuild.
They generate some headers in arch/{arm,x86}/include/generated/uapi/asm
directories, which are obviously exported.

Replace them with generated-y, and abolish genhdr-y.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>

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kbuild: Remove stale asm-generic wrappers

When a header file is removed from generic-y (often accompanied by the
addition of an arch specific header), the generated wrapper file will
persist, and in

kbuild: Remove stale asm-generic wrappers

When a header file is removed from generic-y (often accompanied by the
addition of an arch specific header), the generated wrapper file will
persist, and in some cases may still take precedence over the new arch
header.

For example commit f1fe2d21f4e1 ("MIPS: Add definitions for extended
context") removed ucontext.h from generic-y in arch/mips/include/asm/,
and added an arch/mips/include/uapi/asm/ucontext.h. The continued use of
the wrapper when reusing a dirty build tree resulted in build failures
in arch/mips/kernel/signal.c:

arch/mips/kernel/signal.c: In function ‘sc_to_extcontext’:
arch/mips/kernel/signal.c:142:12: error: ‘struct ucontext’ has no member named ‘uc_extcontext’
return &uc->uc_extcontext;
^
Fix by detecting and removing wrapper headers in generated header
directories that do not correspond to a filename in generic-y, genhdr-y,
or the newly introduced generated-y.

Reported-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Reported-by: Hauke Mehrtens <hauke@hauke-m.de>
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-kbuild@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Michal Marek <mmarek@suse.com>
Link: http://lkml.kernel.org/r/1466808144-23209-3-git-send-email-james.hogan@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

show more ...

kbuild: trivial - remove trailing empty lines

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

uapi: Allow automatic generation of uapi/asm/ header files

Several arch/*/include/uapi/asm/* header simply include the
corresponding <asm-generic/*> file. This patch allows such files to be
specifie

uapi: Allow automatic generation of uapi/asm/ header files

Several arch/*/include/uapi/asm/* header simply include the
corresponding <asm-generic/*> file. This patch allows such files to be
specified in uapi/asm/Kbuild via "generic-y += ..." to be automatically
generated (similar to asm/Kbuild).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>

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kbuild: silence Nothing to be done for 'all' message

This patch silences a Makefile.asm-generic message
by defining a dummy rule for all.

make -f /usr/src/git/scripts/Makefile.asm-generic \

kbuild: silence Nothing to be done for 'all' message

This patch silences a Makefile.asm-generic message
by defining a dummy rule for all.

make -f /usr/src/git/scripts/Makefile.asm-generic \
obj=arch/x86/include/generated/asm
make[1]: Nothing to be done for `all'.

Signed-off-by: Peter Foley <pefoley2@verizon.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>

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kbuild: Fix Makefile.asm-generic for um

Do nothing if arch/$(SRCARCH)/include/asm/Kbuild does not exist, which
is the case of um.

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Mic

kbuild: Fix Makefile.asm-generic for um

Do nothing if arch/$(SRCARCH)/include/asm/Kbuild does not exist, which
is the case of um.

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

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kbuild: asm-generic support

There is an increasing amount of header files
shared between individual architectures in asm-generic.
To avoid a lot of dummy wrapper files that just
include the correspo

kbuild: asm-generic support

There is an increasing amount of header files
shared between individual architectures in asm-generic.
To avoid a lot of dummy wrapper files that just
include the corresponding file in asm-generic provide
some basic support in kbuild for this.

With the following patch an architecture can maintain
a list of files in the file arch/$(ARCH)/include/asm/Kbuild

To use a generic file just add:

generic-y += <name-of-header-file.h>

For each file listed kbuild will generate the necessary
wrapper in arch/$(ARCH)/include/generated/asm.

When installing userspace headers a wrapper is likewise created.

The original inspiration for this came from the unicore32
patchset - although a different method is used.

The patch includes several improvements from Arnd Bergmann.
Michael Marek contributed Makefile.asm-generic.

Remis Baima did an intial implementation along to achive
the same - see https://patchwork.kernel.org/patch/13352/

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Guan Xuetao <guanxuetao@mprc.pku.edu.cn>
Tested-by: Guan Xuetao <guanxuetao@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

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kbuild: force all architectures except um to include mandatory-y

Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes
the common Kbuild.asm file. Factor out the duplicated

kbuild: force all architectures except um to include mandatory-y

Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes
the common Kbuild.asm file. Factor out the duplicated include directives
to scripts/Makefile.asm-generic so that no architecture would opt out
of the mandatory-y mechanism.

um is not forced to include mandatory-y since it is a very exceptional
case which does not support UAPI.

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

show more ...

kbuild: warn redundant generic-y

The generic-y is redundant under the following condition:

- arch has its own implementation

- the same header is added to generated-y

kbuild: warn redundant generic-y

The generic-y is redundant under the following condition:

- arch has its own implementation

- the same header is added to generated-y

- the same header is added to mandatory-y

If a redundant generic-y is found, the warning like follows is displayed:

scripts/Makefile.asm-generic:20: redundant generic-y found in arch/arm/include/asm/Kbuild: timex.h

I fixed up arch Kbuild files found by this.

Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

show more ...

kbuild: generate asm-generic wrappers if mandatory headers are missing

Some time ago, Sam pointed out a certain degree of overwrap between
generic-y and mandatory-y. (https://lkml.org/lk

kbuild: generate asm-generic wrappers if mandatory headers are missing

Some time ago, Sam pointed out a certain degree of overwrap between
generic-y and mandatory-y. (https://lkml.org/lkml/2017/7/10/121)

I tweaked the meaning of mandatory-y a little bit; now it defines the
minimum set of ASM headers that all architectures must have.

If arch does not have specific implementation of a mandatory header,
Kbuild will let it fallback to the asm-generic one by automatically
generating a wrapper. This will allow to drop lots of redundant
generic-y defines.

Previously, "mandatory" was used in the context of UAPI, but I guess
this can be extended to kernel space ASM headers.

Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

show more ...

kbuild: refactor Makefile.asm-generic

- Use conventional $(MAKE) $(asm-generic)=<dir> style
for directory descending

- Remove unneeded FORCE since "all" is a phony target

kbuild: refactor Makefile.asm-generic

- Use conventional $(MAKE) $(asm-generic)=<dir> style
for directory descending

- Remove unneeded FORCE since "all" is a phony target

- Remove unneeded "_dummy :=" assignment

- Skip $(shell mkdir ...) when headers exist in the directory

- Misc cleanups

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

show more ...

Merge tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:
"One of the most remarkable improvements in th

Merge tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:
"One of the most remarkable improvements in this cycle is, Kbuild is
now able to cache the result of shell commands. Some variables are
expensive to compute, for example, $(call cc-option,...) invokes the
compiler. It is not efficient to redo this computation every time,
even when we are not actually building anything. Kbuild creates a
hidden file ".cache.mk" that contains invoked shell commands and their
results. The speed-up should be noticeable.

Summary:

- Fix arch build issues (hexagon, sh)

- Clean up various Makefiles and scripts

- Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles

- Cache variables that are expensive to compute

- Improve cc-ldopton and ld-option for Clang

- Optimize output directory creation"

* tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits)
kbuild: move coccicheck help from scripts/Makefile.help to top Makefile
sh: decompressor: add shipped files to .gitignore
frv: .gitignore: ignore vmlinux.lds
selinux: remove unnecessary assignment to subdir-
kbuild: specify FORCE in Makefile.headersinst as .PHONY target
kbuild: remove redundant mkdir from ./Kbuild
kbuild: optimize object directory creation for incremental build
kbuild: create object directories simpler and faster
kbuild: filter-out PHONY targets from "targets"
kbuild: remove redundant $(wildcard ...) for cmd_files calculation
kbuild: create directory for make cache only when necessary
sh: select KBUILD_DEFCONFIG depending on ARCH
kbuild: fix linker feature test macros when cross compiling with Clang
kbuild: shrink .cache.mk when it exceeds 1000 lines
kbuild: do not call cc-option before KBUILD_CFLAGS initialization
kbuild: Cache a few more calls to the compiler
kbuild: Add a cache for generated variables
kbuild: add forward declaration of default target to Makefile.asm-generic
kbuild: remove KBUILD_SUBDIR_ASFLAGS and KBUILD_SUBDIR_CCFLAGS
hexagon/kbuild: replace CFLAGS_MODULE with KBUILD_CFLAGS_MODULE
...

show more ...

kbuild: add forward declaration of default target to Makefile.asm-generic

$(kbuild-file) and Kbuild.include are included before the default
target "all".

We will add a target in

kbuild: add forward declaration of default target to Makefile.asm-generic

$(kbuild-file) and Kbuild.include are included before the default
target "all".

We will add a target into Kbuild.include. In advance, add a forward
declaration of the default target.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>

show more ...

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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kbuild: update comments of Makefile.asm-generic

Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

kbuild: replace genhdr-y with generated-y

Originally, generated-y and genhdr-y had different meaning, like
follows:

- generated-y: generated headers (other than asm-generic wrap

kbuild: replace genhdr-y with generated-y

Originally, generated-y and genhdr-y had different meaning, like
follows:

- generated-y: generated headers (other than asm-generic wrappers)
- header-y : headers to be exported
- genhdr-y : generated headers to be exported (generated-y + header-y)

Since commit fcc8487d477a ("uapi: export all headers under uapi
directories"), headers under UAPI directories are all exported.
So, there is no more difference between generated-y and genhdr-y.

We see two users of genhdr-y, arch/{arm,x86}/include/uapi/asm/Kbuild.
They generate some headers in arch/{arm,x86}/include/generated/uapi/asm
directories, which are obviously exported.

Replace them with generated-y, and abolish genhdr-y.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>

show more ...