kbuild: replace $(if A,A,B) with $(or A,B)

$(or ...) is available since GNU Make 3.81, and useful to shorten the
code in some places.

Covert as follows:

$(if A,A,B) --> $(or A,B)

This patch also converts:

$(if A, A, B) --> $(or A, B)

Strictly speaking, the latter is not an equivalent conversion because
GNU Make keeps spaces after commas; if A is not empty, $(if A, A, B)
expands to " A", while $(or A, B) expands to "A".

Anyway, preceding spaces are not significant in the code hunks I touched.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

tools build: Fix feature detect clean for out of source builds

Currently the clean target when using O= isn't cleaning the feature
detect output. This is because O= and OUTPUT= are set to canonical
paths. For example in tools/perf/Makefile:

FULL_O := $(shell cd $(PWD); readlink -f $(O) || echo $(O))

This means that OUTPUT ends in a / and most usages prepend it to a file
without adding an extra /. This line that was changed adds an extra /
before the 'feature' folder but not to the end, resulting in a clean
command like this:

rm -f /tmp/build//featuretest-all.bin ...

After the change the clean command looks like this:

rm -f /tmp/build/feature/test-all.bin ...

Fixes: 762323eb39a257c3 ("perf build: Move feature cleanup under tools/build")
Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20210816130705.1331868-1-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf build: Move feature cleanup under tools/build

Arnaldo reported issue for following build command:

$ rm -rf /tmp/krava; mkdir /tmp/krava; make O=/tmp/krava clean
CLEAN config
/bin/sh: line 0: cd: /tmp/krava/feature/: No such file or directory
../../scripts/Makefile.include:17: *** output directory "/tmp/krava/feature/" does not exist. Stop.
make[1]: *** [Makefile.perf:1010: config-clean] Error 2
make: *** [Makefile:90: clean] Error 2

The problem is that now that we include scripts/Makefile.include
in feature's Makefile (which is fine and needed), we need to ensure
the OUTPUT directory exists, before executing (out of tree) clean
command.

Removing the feature's cleanup from perf Makefile and fixing
feature's cleanup under build Makefile, so it now checks that
there's existing OUTPUT directory before calling the clean.

Fixes: 211a741cd3e1 ("tools: Factor Clang, LLC and LLVM utils definitions")
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13-git
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210224150831.409639-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools: Factor HOSTCC, HOSTLD, HOSTAR definitions

Several Makefiles in tools/ need to define the host toolchain variables.
Move their definition to tools/scripts/Makefile.include

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/bpf/20201110164310.2600671-2-jean-philippe@linaro.org

tools, bpf/build: Cleanup feature files on make clean

The system for "Auto-detecting system features" located under
tools/build/ are (currently) used by perf, libbpf and bpftool. It can
contain stalled feature detection files, which are not cleaned up by
libbpf and bpftool on make clean (side-note: perf tool is correct).

Fix this by making the users invoke the make clean target.

Some details about the changes. The libbpf Makefile already had a
clean-config target (which seems to be copy-pasted from perf), but this
target was not "connected" (a make dependency) to clean target. Choose
not to rename target as someone might be using it. Did change the output
from "CLEAN config" to "CLEAN feature-detect", to make it more clear
what happens.

This is related to the complaint and troubleshooting in the following
link: https://lore.kernel.org/lkml/20200818122007.2d1cfe2d@carbon/

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/lkml/20200818122007.2d1cfe2d@carbon/
Link: https://lore.kernel.org/bpf/159851841661.1072907.13770213104521805592.stgit@firesoul

kbuild: Rename HOSTLDFLAGS to KBUILD_HOSTLDFLAGS

In preparation for enabling command line LDFLAGS, re-name HOSTLDFLAGS
to KBUILD_HOSTLDFLAGS as the internal use only flags. This should not
have any visible effects.

Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

tools: build: Use HOSTLDFLAGS with fixdep

The final link of fixdep uses LDFLAGS but not the existing HOSTLDFLAGS.
Fix this.

Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

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>

perf build: Add special fixdep cleaning rule

Ingo reported following build failure:

On Sat, Feb 11, 2017 at 12:12:34PM +0100, Ingo Molnar wrote:
>
> So I had this oldish 32-bit 15.10 Ubuntu installation around (fully updated), and
> trying to build perf gave me:
>
> deimos:~/tip/tools/perf> make
> BUILD: Doing 'make -j4' parallel build
> make[3]: *** No rule to make target '/usr/include/x86_64-linux-gnu/sys/types.h', needed by 'fixdep.o'. Stop.
> Makefile:42: recipe for target 'fixdep-in.o' failed
> make[2]: *** [fixdep-in.o] Error 2
> /home/mingo/tip/tools/build/Makefile.include:4: recipe for target 'fixdep' failed
> make[1]: *** [fixdep] Error 2
> Makefile:68: recipe for target 'all' failed
> make: *** [all] Error 2
>
> Now this got a bit better after I did a 'make mrproper' in the kernel tree:
>
> deimos:~/tip/tools/perf> make
> BUILD: Doing 'make -j4' parallel build
> HOSTCC fixdep.o
> /home/mingo/tip/tools/build/fixdep: 1: /home/mingo/tip/tools/build/fixdep: Syntax error: "(" unexpected
> /home/mingo/tip/tools/build/Makefile.build:101: recipe for target 'fixdep.o' failed
> make[3]: *** [fixdep.o] Error 2
> Makefile:42: recipe for target 'fixdep-in.o' failed
> make[2]: *** [fixdep-in.o] Error 2
> /home/mingo/tip/tools/build/Makefile.include:4: recipe for target 'fixdep' failed
> make[1]: *** [fixdep] Error 2
> Makefile:68: recipe for target 'all' failed
> make: *** [all] Error 2
>
> After some digging it turns out that my 'fixdep' binary was 64-bit:
>
> deimos:~/tip/tools/perf> file /home/mingo/tip/tools/build/fixdep
> /home/mingo/tip/tools/build/fixdep: ELF 64-bit LSB executable, x86-64, version 1
> (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux
> 2.6.32, BuildID[sha1]=d527f736b57b5ba47210fbcb562a3b52867d21c1, not stripped
>
> But it did not get cleaned out by 'make clean'.
>
> Only after I did a 'make clean' in tools/ itself, did it get built properly.

It shows we don't clean up properly the fixdep objects, so adding
special rule for that.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1487340058-10496-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

make use of make variable CURDIR instead of calling pwd

make already provides the current working directory in a variable, so make
use of it instead of forking a shell. Also replace usage of PWD by
CURDIR. PWD is provided by most shells, but not all, so this makes the
build system more robust.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Michal Marek <mmarek@suse.com>

tools build: Make fixdep a hostprog

It is used in the build process, so stop suppressing its build in tools
cross builds.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20160927141846.GA6589@krava
[ Use HOSTCC on the $(OUTPUT)fixdep target, it was using the x-compiler
to link fixdep-in.o, that was correctly built with HOSTCC and thus failing ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools build: Add support for host programs format

In some cases, like for fixdep and shortly for jevents, we need to build a tool
to run on the host that will be used in building a tool, such as perf, that is
being cross compiled, so do like the kernel and provide HOSTCC, HOSTLD and HOSTAR
to do that.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Requested-by: Andi Kleen <andi@firstfloor.org>
Requested-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20160927141846.GA6589@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools build: Use fixdep with OUTPUT path prefix

Adding OUTPUT path prefix for fixdep target so we use it properly in out
of tree builds.

If the fixdep already existed in the tree, the out of tree build would
see it already exist and did not build the out of tree version, as
reported by Arnaldo:

[acme@zoo linux]$ make O=/tmp/build/perf -C tools/perf
make: Entering directory '/home/git/linux/tools/perf'
BUILD: Doing 'make -j4' parallel build
make[2]: Nothing to be done for 'fixdep'.
make: Leaving directory '/home/git/linux/tools/perf'

Reported-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20151126185055.GC19410@krava.brq.redhat.com
[ Fixed conflict with 5725dd8fa888 ("tools build: Clean CFLAGS and LDFLAGS for fixdep") ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools build: Add fixdep dependency helper

For dependency tracking we currently use targets that fall out of the
gcc -MD command. We store this info in the .cmd file and include as
makefile during the build.

This format put object as target and all the c and header files as
dependencies, like:

util/abspath.o: util/abspath.c /usr/include/stdc-predef.h util/cache.h \
/usr/include/bits/wordsize.h /usr/include/gnu/stubs.h \
...

If any of those dependency header files (krava.h below) is removed the
build fails on:

make[1]: *** No rule to make target 'krava.h', needed by 'inc.o'. Stop.

This patch adds fixdep helper, that is used by kbuild to alter the shape
of the object dependencies like:

source_util/abspath.o := util/abspath.c

deps_util/abspath.o := \
/usr/include/stdc-predef.h \
util/cache.h \
...

util/abspath.o: $(deps_util/abspath.o)

$(deps_util/abspath.o):

With this format the header removal won't make the build fail, because
it'll be picked up by the last empty target defined for each header.

As previously mentioned the fixdep tool is taken from kbuild. It's not
complete backport, only the part that alters the standard dependency
info was taken, the part that adds the CONFIG_* dependency logic will be
probably taken later on.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Kai Germaschewski <kai.germaschewski@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1443004442-32660-4-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>