<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/tools/build, branch v5.9</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>perf build-ids: Fall back to debuginfod query if debuginfo not found</title>
<updated>2020-08-14T12:51:14+00:00</updated>
<author>
<name>Frank Ch. Eigler</name>
<email>fche@redhat.com</email>
</author>
<published>2020-08-13T08:22:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c7a14fdcb3fa77368273b3daab52ad8e86d358b6'/>
<id>c7a14fdcb3fa77368273b3daab52ad8e86d358b6</id>
<content type='text'>
During a perf-record, use the -ldebuginfod API to query a debuginfod
server, should the debug data not be found in the usual system
locations.  If successful, the usual $HOME/.debug dir is populated.

Tested with:

  $ find .
  .
  ./ctags-debuginfo-5.8-26.fc31.x86_64.rpm
  ./usr
  ./usr/lib
  ./usr/lib/debug
  ./usr/lib/debug/.build-id
  ./usr/lib/debug/.build-id/ca
  ./usr/lib/debug/.build-id/ca/46f6ae6a0cee57d85abc1d461c49074248908d
  ./usr/lib/debug/.build-id/ca/46f6ae6a0cee57d85abc1d461c49074248908d.debug
  ./usr/lib/debug/usr
  ./usr/lib/debug/usr/bin
  ./usr/lib/debug/usr/bin/ctags-5.8-26.fc31.x86_64.debug

  $ debuginfod  -F .
  ...

  $ rm -rf ~/.debug/ ; mkdir ~/.debug

  $ perf record make tags
    BUILD:   Doing 'make -j8' parallel build
    GEN      tags
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.107 MB perf.data (1483 samples) ]

  $ find ~/.debug | grep ctags
  /home/jolsa/.debug/usr/bin/ctags
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/elf
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/probes

  $ rm -rf ~/.debug/ ; mkdir ~/.debug

  $ DEBUGINFOD_URLS=http://localhost:8002 perf record make tags
    BUILD:   Doing 'make -j8' parallel build
    GEN      tags
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.108 MB perf.data (1531 samples) ]

  $ find ~/.debug | grep ctag
  /home/jolsa/.debug/usr/bin/ctags
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/debug
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/elf
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/probes

Note the 'debug' file is created in the last run.

Note that currently the debuginfo data are downloaded only on record path,
we still need add this support to perf build-id/report.. and test ;-)

Tested-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Signed-off-by: Frank Ch. Eigler &lt;fche@redhat.com&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
During a perf-record, use the -ldebuginfod API to query a debuginfod
server, should the debug data not be found in the usual system
locations.  If successful, the usual $HOME/.debug dir is populated.

Tested with:

  $ find .
  .
  ./ctags-debuginfo-5.8-26.fc31.x86_64.rpm
  ./usr
  ./usr/lib
  ./usr/lib/debug
  ./usr/lib/debug/.build-id
  ./usr/lib/debug/.build-id/ca
  ./usr/lib/debug/.build-id/ca/46f6ae6a0cee57d85abc1d461c49074248908d
  ./usr/lib/debug/.build-id/ca/46f6ae6a0cee57d85abc1d461c49074248908d.debug
  ./usr/lib/debug/usr
  ./usr/lib/debug/usr/bin
  ./usr/lib/debug/usr/bin/ctags-5.8-26.fc31.x86_64.debug

  $ debuginfod  -F .
  ...

  $ rm -rf ~/.debug/ ; mkdir ~/.debug

  $ perf record make tags
    BUILD:   Doing 'make -j8' parallel build
    GEN      tags
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.107 MB perf.data (1483 samples) ]

  $ find ~/.debug | grep ctags
  /home/jolsa/.debug/usr/bin/ctags
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/elf
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/probes

  $ rm -rf ~/.debug/ ; mkdir ~/.debug

  $ DEBUGINFOD_URLS=http://localhost:8002 perf record make tags
    BUILD:   Doing 'make -j8' parallel build
    GEN      tags
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.108 MB perf.data (1531 samples) ]

  $ find ~/.debug | grep ctag
  /home/jolsa/.debug/usr/bin/ctags
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/debug
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/elf
  /home/jolsa/.debug/usr/bin/ctags/ca46f6ae6a0cee57d85abc1d461c49074248908d/probes

Note the 'debug' file is created in the last run.

Note that currently the debuginfo data are downloaded only on record path,
we still need add this support to perf build-id/report.. and test ;-)

Tested-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Signed-off-by: Frank Ch. Eigler &lt;fche@redhat.com&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools build feature: Quote CC and CXX for their arguments</title>
<updated>2020-08-13T13:00:19+00:00</updated>
<author>
<name>Daniel Díaz</name>
<email>daniel.diaz@linaro.org</email>
</author>
<published>2020-08-12T22:15:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fa5c893181ed2ca2f96552f50073786d2cfce6c0'/>
<id>fa5c893181ed2ca2f96552f50073786d2cfce6c0</id>
<content type='text'>
When using a cross-compilation environment, such as OpenEmbedded,
the CC an CXX variables are set to something more than just a
command: there are arguments (such as --sysroot) that need to be
passed on to the compiler so that the right set of headers and
libraries are used.

For the particular case that our systems detected, CC is set to
the following:

  export CC="aarch64-linaro-linux-gcc  --sysroot=/oe/build/tmp/work/machine/perf/1.0-r9/recipe-sysroot"

Without quotes, detection is as follows:

  Auto-detecting system features:
  ...                         dwarf: [ OFF ]
  ...            dwarf_getlocations: [ OFF ]
  ...                         glibc: [ OFF ]
  ...                          gtk2: [ OFF ]
  ...                        libbfd: [ OFF ]
  ...                        libcap: [ OFF ]
  ...                        libelf: [ OFF ]
  ...                       libnuma: [ OFF ]
  ...        numa_num_possible_cpus: [ OFF ]
  ...                       libperl: [ OFF ]
  ...                     libpython: [ OFF ]
  ...                     libcrypto: [ OFF ]
  ...                     libunwind: [ OFF ]
  ...            libdw-dwarf-unwind: [ OFF ]
  ...                          zlib: [ OFF ]
  ...                          lzma: [ OFF ]
  ...                     get_cpuid: [ OFF ]
  ...                           bpf: [ OFF ]
  ...                        libaio: [ OFF ]
  ...                       libzstd: [ OFF ]
  ...        disassembler-four-args: [ OFF ]

  Makefile.config:414: *** No gnu/libc-version.h found, please install glibc-dev[el].  Stop.
  Makefile.perf:230: recipe for target 'sub-make' failed
  make[1]: *** [sub-make] Error 2
  Makefile:69: recipe for target 'all' failed
  make: *** [all] Error 2

With CC and CXX quoted, some of those features are now detected.

Fixes: e3232c2f39ac ("tools build feature: Use CC and CXX from parent")
Signed-off-by: Daniel Díaz &lt;daniel.diaz@linaro.org&gt;
Reviewed-by: Thomas Hebb &lt;tommyhebb@gmail.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Andrii Nakryiko &lt;andriin@fb.com&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Fastabend &lt;john.fastabend@gmail.com&gt;
Cc: KP Singh &lt;kpsingh@chromium.org&gt;
Cc: Martin KaFai Lau &lt;kafai@fb.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Yonghong Song &lt;yhs@fb.com&gt;
Link: http://lore.kernel.org/lkml/20200812221518.2869003-1-daniel.diaz@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When using a cross-compilation environment, such as OpenEmbedded,
the CC an CXX variables are set to something more than just a
command: there are arguments (such as --sysroot) that need to be
passed on to the compiler so that the right set of headers and
libraries are used.

For the particular case that our systems detected, CC is set to
the following:

  export CC="aarch64-linaro-linux-gcc  --sysroot=/oe/build/tmp/work/machine/perf/1.0-r9/recipe-sysroot"

Without quotes, detection is as follows:

  Auto-detecting system features:
  ...                         dwarf: [ OFF ]
  ...            dwarf_getlocations: [ OFF ]
  ...                         glibc: [ OFF ]
  ...                          gtk2: [ OFF ]
  ...                        libbfd: [ OFF ]
  ...                        libcap: [ OFF ]
  ...                        libelf: [ OFF ]
  ...                       libnuma: [ OFF ]
  ...        numa_num_possible_cpus: [ OFF ]
  ...                       libperl: [ OFF ]
  ...                     libpython: [ OFF ]
  ...                     libcrypto: [ OFF ]
  ...                     libunwind: [ OFF ]
  ...            libdw-dwarf-unwind: [ OFF ]
  ...                          zlib: [ OFF ]
  ...                          lzma: [ OFF ]
  ...                     get_cpuid: [ OFF ]
  ...                           bpf: [ OFF ]
  ...                        libaio: [ OFF ]
  ...                       libzstd: [ OFF ]
  ...        disassembler-four-args: [ OFF ]

  Makefile.config:414: *** No gnu/libc-version.h found, please install glibc-dev[el].  Stop.
  Makefile.perf:230: recipe for target 'sub-make' failed
  make[1]: *** [sub-make] Error 2
  Makefile:69: recipe for target 'all' failed
  make: *** [all] Error 2

With CC and CXX quoted, some of those features are now detected.

Fixes: e3232c2f39ac ("tools build feature: Use CC and CXX from parent")
Signed-off-by: Daniel Díaz &lt;daniel.diaz@linaro.org&gt;
Reviewed-by: Thomas Hebb &lt;tommyhebb@gmail.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Andrii Nakryiko &lt;andriin@fb.com&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Fastabend &lt;john.fastabend@gmail.com&gt;
Cc: KP Singh &lt;kpsingh@chromium.org&gt;
Cc: Martin KaFai Lau &lt;kafai@fb.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Yonghong Song &lt;yhs@fb.com&gt;
Link: http://lore.kernel.org/lkml/20200812221518.2869003-1-daniel.diaz@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Mgerge remote-tracking branch 'torvalds/master' into perf/core</title>
<updated>2020-08-06T11:15:47+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2020-08-06T11:15:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=94fb1afb14c4f0ceb8c5508ddddac6819f662e95'/>
<id>94fb1afb14c4f0ceb8c5508ddddac6819f662e95</id>
<content type='text'>
To sync headers, for instance, in this case tools/perf was ahead of
upstream till Linus merged tip/perf/core to get the
PERF_RECORD_TEXT_POKE changes:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h'
  diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h

Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
To sync headers, for instance, in this case tools/perf was ahead of
upstream till Linus merged tip/perf/core to get the
PERF_RECORD_TEXT_POKE changes:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h'
  diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h

Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools, build: Propagate build failures from tools/build/Makefile.build</title>
<updated>2020-08-03T14:15:40+00:00</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andriin@fb.com</email>
</author>
<published>2020-07-31T02:42:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a278f3d8191228212c553a5d4303fa603214b717'/>
<id>a278f3d8191228212c553a5d4303fa603214b717</id>
<content type='text'>
The '&amp;&amp;' command seems to have a bad effect when $(cmd_$(1)) exits with
non-zero effect: the command failure is masked (despite `set -e`) and all but
the first command of $(dep-cmd) is executed (successfully, as they are mostly
printfs), thus overall returning 0 in the end.

This means in practice that despite compilation errors, tools's build Makefile
will return success. We see this very reliably with libbpf's Makefile, which
doesn't get compilation error propagated properly. This in turns causes issues
with selftests build, as well as bpftool and other projects that rely on
building libbpf.

The fix is simple: don't use &amp;&amp;. Given `set -e`, we don't need to chain
commands with &amp;&amp;. The shell will exit on first failure, giving desired
behavior and propagating error properly.

Fixes: 275e2d95591e ("tools build: Move dependency copy into function")
Signed-off-by: Andrii Nakryiko &lt;andriin@fb.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Link: https://lore.kernel.org/bpf/20200731024244.872574-1-andriin@fb.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The '&amp;&amp;' command seems to have a bad effect when $(cmd_$(1)) exits with
non-zero effect: the command failure is masked (despite `set -e`) and all but
the first command of $(dep-cmd) is executed (successfully, as they are mostly
printfs), thus overall returning 0 in the end.

This means in practice that despite compilation errors, tools's build Makefile
will return success. We see this very reliably with libbpf's Makefile, which
doesn't get compilation error propagated properly. This in turns causes issues
with selftests build, as well as bpftool and other projects that rely on
building libbpf.

The fix is simple: don't use &amp;&amp;. Given `set -e`, we don't need to chain
commands with &amp;&amp;. The shell will exit on first failure, giving desired
behavior and propagating error properly.

Fixes: 275e2d95591e ("tools build: Move dependency copy into function")
Signed-off-by: Andrii Nakryiko &lt;andriin@fb.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Link: https://lore.kernel.org/bpf/20200731024244.872574-1-andriin@fb.com
</pre>
</div>
</content>
</entry>
<entry>
<title>tools build feature: Use CC and CXX from parent</title>
<updated>2020-07-31T12:27:58+00:00</updated>
<author>
<name>Thomas Hebb</name>
<email>tommyhebb@gmail.com</email>
</author>
<published>2020-07-27T04:08:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e3232c2f39acafd5a29128425bc30b9884642cfa'/>
<id>e3232c2f39acafd5a29128425bc30b9884642cfa</id>
<content type='text'>
commit c8c188679ccf ("tools build: Use the same CC for feature detection
and actual build") changed these assignments from unconditional (:=) to
conditional (?=) so that they wouldn't clobber values from the
environment. However, conditional assignment does not work properly for
variables that Make implicitly sets, among which are CC and CXX. To
quote tools/scripts/Makefile.include, which handles this properly:

  # Makefiles suck: This macro sets a default value of $(2) for the
  # variable named by $(1), unless the variable has been set by
  # environment or command line. This is necessary for CC and AR
  # because make sets default values, so the simpler ?= approach
  # won't work as expected.

In other words, the conditional assignments will not run even if the
variables are not overridden in the environment; Make will set CC to
"cc" and CXX to "g++" when it starts[1], meaning the variables are not
empty by the time the conditional assignments are evaluated. This breaks
cross-compilation when CROSS_COMPILE is set but CC isn't, since "cc"
gets used for feature detection instead of the cross compiler (and
likewise for CXX).

To fix the issue, just pass down the values of CC and CXX computed by
the parent Makefile, which gets included by the Makefile that actually
builds whatever we're detecting features for and so is guaranteed to
have good values. This is a better solution anyway, since it means we
aren't trying to replicate the logic of the parent build system and so
don't risk it getting out of sync.

Leave PKG_CONFIG alone, since 1) there's no common logic to compute it
in Makefile.include, and 2) it's not an implicit variable, so
conditional assignment works properly.

[1] https://www.gnu.org/software/make/manual/html_node/Implicit-Variables.html

Fixes: c8c188679ccf ("tools build: Use the same CC for feature detection and actual build")
Signed-off-by: Thomas Hebb &lt;tommyhebb@gmail.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: David Carrillo-Cisneros &lt;davidcc@google.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Igor Lubashev &lt;ilubashe@akamai.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Quentin Monnet &lt;quentin@isovalent.com&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: thomas hebb &lt;tommyhebb@gmail.com&gt;
Link: http://lore.kernel.org/lkml/0a6e69d1736b0fa231a648f50b0cce5d8a6734ef.1595822871.git.tommyhebb@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c8c188679ccf ("tools build: Use the same CC for feature detection
and actual build") changed these assignments from unconditional (:=) to
conditional (?=) so that they wouldn't clobber values from the
environment. However, conditional assignment does not work properly for
variables that Make implicitly sets, among which are CC and CXX. To
quote tools/scripts/Makefile.include, which handles this properly:

  # Makefiles suck: This macro sets a default value of $(2) for the
  # variable named by $(1), unless the variable has been set by
  # environment or command line. This is necessary for CC and AR
  # because make sets default values, so the simpler ?= approach
  # won't work as expected.

In other words, the conditional assignments will not run even if the
variables are not overridden in the environment; Make will set CC to
"cc" and CXX to "g++" when it starts[1], meaning the variables are not
empty by the time the conditional assignments are evaluated. This breaks
cross-compilation when CROSS_COMPILE is set but CC isn't, since "cc"
gets used for feature detection instead of the cross compiler (and
likewise for CXX).

To fix the issue, just pass down the values of CC and CXX computed by
the parent Makefile, which gets included by the Makefile that actually
builds whatever we're detecting features for and so is guaranteed to
have good values. This is a better solution anyway, since it means we
aren't trying to replicate the logic of the parent build system and so
don't risk it getting out of sync.

Leave PKG_CONFIG alone, since 1) there's no common logic to compute it
in Makefile.include, and 2) it's not an implicit variable, so
conditional assignment works properly.

[1] https://www.gnu.org/software/make/manual/html_node/Implicit-Variables.html

Fixes: c8c188679ccf ("tools build: Use the same CC for feature detection and actual build")
Signed-off-by: Thomas Hebb &lt;tommyhebb@gmail.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: David Carrillo-Cisneros &lt;davidcc@google.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Igor Lubashev &lt;ilubashe@akamai.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Quentin Monnet &lt;quentin@isovalent.com&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: thomas hebb &lt;tommyhebb@gmail.com&gt;
Link: http://lore.kernel.org/lkml/0a6e69d1736b0fa231a648f50b0cce5d8a6734ef.1595822871.git.tommyhebb@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools/bpftool: Generalize BPF skeleton support and generate vmlinux.h</title>
<updated>2020-06-23T00:01:48+00:00</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andriin@fb.com</email>
</author>
<published>2020-06-19T23:17:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=05aca6da3b5ab3c5c6003dbbefc9580d9a6a308b'/>
<id>05aca6da3b5ab3c5c6003dbbefc9580d9a6a308b</id>
<content type='text'>
Adapt Makefile to support BPF skeleton generation beyond single profiler.bpf.c
case. Also add vmlinux.h generation and switch profiler.bpf.c to use it.

clang-bpf-global-var feature is extended and renamed to clang-bpf-co-re to
check for support of preserve_access_index attribute, which, together with BTF
for global variables, is the minimum requirement for modern BPF programs.

Signed-off-by: Andrii Nakryiko &lt;andriin@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Reviewed-by: Quentin Monnet &lt;quentin@isovalent.com&gt;
Link: https://lore.kernel.org/bpf/20200619231703.738941-7-andriin@fb.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Adapt Makefile to support BPF skeleton generation beyond single profiler.bpf.c
case. Also add vmlinux.h generation and switch profiler.bpf.c to use it.

clang-bpf-global-var feature is extended and renamed to clang-bpf-co-re to
check for support of preserve_access_index attribute, which, together with BTF
for global variables, is the minimum requirement for modern BPF programs.

Signed-off-by: Andrii Nakryiko &lt;andriin@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Reviewed-by: Quentin Monnet &lt;quentin@isovalent.com&gt;
Link: https://lore.kernel.org/bpf/20200619231703.738941-7-andriin@fb.com
</pre>
</div>
</content>
</entry>
<entry>
<title>perf build: Remove libaudit from the default feature checks</title>
<updated>2020-05-29T19:51:13+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2020-05-29T14:11:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a88f70de1b5024db75e8dab42bcce5d648d81957'/>
<id>a88f70de1b5024db75e8dab42bcce5d648d81957</id>
<content type='text'>
Ingo reported that the libaudit was always appearing as OFF:

  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...            dwarf_getlocations: [ on  ]
  ...                         glibc: [ on  ]
  ...                          gtk2: [ on  ]
  ...                      libaudit: [ OFF ]

And everything seemed to work, i.e. we were checking for a feature that
we don't use, causing confusion for people building perf, so work to
remove that nuisance while making sure that it works when an arch
doesn't provide the alternative method to generate the syscall id/name
conversion tables.

Longer explanation of the new modus operandi:

  $ make -C tools/perf O=/tmp/build/perf NO_SYSCALL_TABLE=1
  &lt;SNIP&gt;
  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...            dwarf_getlocations: [ on  ]
  ...                         glibc: [ on  ]
  ...                          gtk2: [ on  ]
  ...                        libbfd: [ on  ]
  ...                        libcap: [ on  ]
  ...                        libelf: [ on  ]
  ...                       libnuma: [ on  ]
  ...        numa_num_possible_cpus: [ on  ]
  ...                       libperl: [ on  ]
  ...                     libpython: [ on  ]
  ...                     libcrypto: [ on  ]
  ...                     libunwind: [ on  ]
  ...            libdw-dwarf-unwind: [ on  ]
  ...                          zlib: [ on  ]
  ...                          lzma: [ on  ]
  ...                     get_cpuid: [ on  ]
  ...                           bpf: [ on  ]
  ...                        libaio: [ on  ]
  ...                       libzstd: [ on  ]
  ...        disassembler-four-args: [ on  ]

  Makefile.config:665: No libaudit.h found, disables 'trace' tool, please install audit-libs-devel or libaudit-dev
    GEN      /tmp/build/perf/common-cmds.h
    MKDIR    /tmp/build/perf/fd/
    MKDIR    /tmp/build/perf/fs/
  &lt;SNIP&gt;
  $

The libaudit test is forced and it fails when audit-libs-devel isn't available:

  $ cat /tmp/build/perf/feature/test-libaudit.make.output
  test-libaudit.c:2:10: fatal error: libaudit.h: No such file or directory
      2 | #include &lt;libaudit.h&gt;
        |          ^~~~~~~~~~~~
  compilation terminated.
  $

If we install audit-libs-devel and rebuild it continues not to be shown as OFF
in the main auto-detection summary, but again gets tested and this time:

  $ rpm -q audit-libs-devel
  audit-libs-devel-3.0-0.15.20191104git1c2f876.fc31.x86_64
  $

The make output for the feature detection comes clean:

  $ cat /tmp/build/perf/feature/test-libaudit.make.output

And the feature detection binary is successfully built and is dynamicly linked
with libaudit:

  $ ldd /tmp/build/perf/feature/test-libaudit.bin | grep audit
  	libaudit.so.1 =&gt; /lib64/libaudit.so.1 (0x00007f5bf5177000)
  $

As well as the resulting perf binary:

  $ ldd /tmp/build/perf/perf | grep audit
  	libaudit.so.1 =&gt; /lib64/libaudit.so.1 (0x00007fad511c7000)
  $

And 'perf trace' works using the libaudit method:

  $ sudo /tmp/build/perf/perf trace -e nanosleep sleep 1
       0.000 (1000.067 ms): sleep/281872 nanosleep(rqtp: 0x7ffedbbe69d0) = 0
  $

If we leave audit-libs-devel installed but don't disable the use of the best
method, the one using SYSCALL_TABLE, the default for architectures that provide
the script to build the syscall id/name mapping using the .tbl files copied
from the kernel sources, we get:

  $ rm -rf /tmp/build/perf ; mkdir -p /tmp/build/perf
  $ make -C tools/perf O=/tmp/build/perf
  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...            dwarf_getlocations: [ on  ]
  ...                         glibc: [ on  ]
  ...                          gtk2: [ on  ]
  ...                        libbfd: [ on  ]
  ...                        libcap: [ on  ]
  ...                        libelf: [ on  ]
  ...                       libnuma: [ on  ]
  ...        numa_num_possible_cpus: [ on  ]
  ...                       libperl: [ on  ]
  ...                     libpython: [ on  ]
  ...                     libcrypto: [ on  ]
  ...                     libunwind: [ on  ]
  ...            libdw-dwarf-unwind: [ on  ]
  ...                          zlib: [ on  ]
  ...                          lzma: [ on  ]
  ...                     get_cpuid: [ on  ]
  ...                           bpf: [ on  ]
  ...                        libaio: [ on  ]
  ...                       libzstd: [ on  ]
  ...        disassembler-four-args: [ on  ]

    GEN      /tmp/build/perf/common-cmds.h
  &lt;SNIP&gt;
  $

Again, no mention of libaudit being on or OFF and:

  $ cat /tmp/build/perf/feature/test-libaudit.make.output
  cat: /tmp/build/perf/feature/test-libaudit.make.output: No such file or directory
  $

We didn't even bother checking for its availability, slightly speeding up the
build process and:

  $ ldd /tmp/build/perf/perf | grep libaudit
  $

We don't link with it, also:

  $ sudo /tmp/build/perf/perf trace -e nanosleep sleep 1
       0.000 (1000.053 ms): sleep/299125 nanosleep(rqtp: 0x7ffc24611b50) = 0
  $

And globs become available:

  $ sudo /tmp/build/perf/perf trace -e *sleep sleep 1
       0.000 (1000.072 ms): sleep/299136 nanosleep(rqtp: 0x7ffe7a3c4ff0) = 0
  $

Reported-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Ingo reported that the libaudit was always appearing as OFF:

  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...            dwarf_getlocations: [ on  ]
  ...                         glibc: [ on  ]
  ...                          gtk2: [ on  ]
  ...                      libaudit: [ OFF ]

And everything seemed to work, i.e. we were checking for a feature that
we don't use, causing confusion for people building perf, so work to
remove that nuisance while making sure that it works when an arch
doesn't provide the alternative method to generate the syscall id/name
conversion tables.

Longer explanation of the new modus operandi:

  $ make -C tools/perf O=/tmp/build/perf NO_SYSCALL_TABLE=1
  &lt;SNIP&gt;
  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...            dwarf_getlocations: [ on  ]
  ...                         glibc: [ on  ]
  ...                          gtk2: [ on  ]
  ...                        libbfd: [ on  ]
  ...                        libcap: [ on  ]
  ...                        libelf: [ on  ]
  ...                       libnuma: [ on  ]
  ...        numa_num_possible_cpus: [ on  ]
  ...                       libperl: [ on  ]
  ...                     libpython: [ on  ]
  ...                     libcrypto: [ on  ]
  ...                     libunwind: [ on  ]
  ...            libdw-dwarf-unwind: [ on  ]
  ...                          zlib: [ on  ]
  ...                          lzma: [ on  ]
  ...                     get_cpuid: [ on  ]
  ...                           bpf: [ on  ]
  ...                        libaio: [ on  ]
  ...                       libzstd: [ on  ]
  ...        disassembler-four-args: [ on  ]

  Makefile.config:665: No libaudit.h found, disables 'trace' tool, please install audit-libs-devel or libaudit-dev
    GEN      /tmp/build/perf/common-cmds.h
    MKDIR    /tmp/build/perf/fd/
    MKDIR    /tmp/build/perf/fs/
  &lt;SNIP&gt;
  $

The libaudit test is forced and it fails when audit-libs-devel isn't available:

  $ cat /tmp/build/perf/feature/test-libaudit.make.output
  test-libaudit.c:2:10: fatal error: libaudit.h: No such file or directory
      2 | #include &lt;libaudit.h&gt;
        |          ^~~~~~~~~~~~
  compilation terminated.
  $

If we install audit-libs-devel and rebuild it continues not to be shown as OFF
in the main auto-detection summary, but again gets tested and this time:

  $ rpm -q audit-libs-devel
  audit-libs-devel-3.0-0.15.20191104git1c2f876.fc31.x86_64
  $

The make output for the feature detection comes clean:

  $ cat /tmp/build/perf/feature/test-libaudit.make.output

And the feature detection binary is successfully built and is dynamicly linked
with libaudit:

  $ ldd /tmp/build/perf/feature/test-libaudit.bin | grep audit
  	libaudit.so.1 =&gt; /lib64/libaudit.so.1 (0x00007f5bf5177000)
  $

As well as the resulting perf binary:

  $ ldd /tmp/build/perf/perf | grep audit
  	libaudit.so.1 =&gt; /lib64/libaudit.so.1 (0x00007fad511c7000)
  $

And 'perf trace' works using the libaudit method:

  $ sudo /tmp/build/perf/perf trace -e nanosleep sleep 1
       0.000 (1000.067 ms): sleep/281872 nanosleep(rqtp: 0x7ffedbbe69d0) = 0
  $

If we leave audit-libs-devel installed but don't disable the use of the best
method, the one using SYSCALL_TABLE, the default for architectures that provide
the script to build the syscall id/name mapping using the .tbl files copied
from the kernel sources, we get:

  $ rm -rf /tmp/build/perf ; mkdir -p /tmp/build/perf
  $ make -C tools/perf O=/tmp/build/perf
  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...            dwarf_getlocations: [ on  ]
  ...                         glibc: [ on  ]
  ...                          gtk2: [ on  ]
  ...                        libbfd: [ on  ]
  ...                        libcap: [ on  ]
  ...                        libelf: [ on  ]
  ...                       libnuma: [ on  ]
  ...        numa_num_possible_cpus: [ on  ]
  ...                       libperl: [ on  ]
  ...                     libpython: [ on  ]
  ...                     libcrypto: [ on  ]
  ...                     libunwind: [ on  ]
  ...            libdw-dwarf-unwind: [ on  ]
  ...                          zlib: [ on  ]
  ...                          lzma: [ on  ]
  ...                     get_cpuid: [ on  ]
  ...                           bpf: [ on  ]
  ...                        libaio: [ on  ]
  ...                       libzstd: [ on  ]
  ...        disassembler-four-args: [ on  ]

    GEN      /tmp/build/perf/common-cmds.h
  &lt;SNIP&gt;
  $

Again, no mention of libaudit being on or OFF and:

  $ cat /tmp/build/perf/feature/test-libaudit.make.output
  cat: /tmp/build/perf/feature/test-libaudit.make.output: No such file or directory
  $

We didn't even bother checking for its availability, slightly speeding up the
build process and:

  $ ldd /tmp/build/perf/perf | grep libaudit
  $

We don't link with it, also:

  $ sudo /tmp/build/perf/perf trace -e nanosleep sleep 1
       0.000 (1000.053 ms): sleep/299125 nanosleep(rqtp: 0x7ffc24611b50) = 0
  $

And globs become available:

  $ sudo /tmp/build/perf/perf trace -e *sleep sleep 1
       0.000 (1000.072 ms): sleep/299136 nanosleep(rqtp: 0x7ffe7a3c4ff0) = 0
  $

Reported-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: cs-etm: Update to build with latest opencsd version.</title>
<updated>2020-05-05T19:35:32+00:00</updated>
<author>
<name>Mike Leach</name>
<email>mike.leach@linaro.org</email>
</author>
<published>2020-05-01T14:36:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=29e2eb2a9e1fac8b320bf2b4c628c336afbdd84f'/>
<id>29e2eb2a9e1fac8b320bf2b4c628c336afbdd84f</id>
<content type='text'>
OpenCSD version v0.14.0 adds in a new output element. This is represented
by a new value in the generic element type enum, which must be added to
the handling code in perf cs-etm-decoder to prevent build errors due to
build options on the perf project.

This element is not currently used by the perf decoder.

Perf build feature test updated to require a minimum of 0.14.0

Tested on Linux 5.7-rc3.

Signed-off-by: Mike Leach &lt;mike.leach@linaro.org&gt;
Reviewed-by: Leo Yan &lt;leo.yan@linaro.org&gt;
Reviewed-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Suzuki Poulouse &lt;suzuki.poulose@arm.com&gt;
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lore.kernel.org/lkml/20200501143615.1180-1-mike.leach@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
OpenCSD version v0.14.0 adds in a new output element. This is represented
by a new value in the generic element type enum, which must be added to
the handling code in perf cs-etm-decoder to prevent build errors due to
build options on the perf project.

This element is not currently used by the perf decoder.

Perf build feature test updated to require a minimum of 0.14.0

Tested on Linux 5.7-rc3.

Signed-off-by: Mike Leach &lt;mike.leach@linaro.org&gt;
Reviewed-by: Leo Yan &lt;leo.yan@linaro.org&gt;
Reviewed-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Suzuki Poulouse &lt;suzuki.poulose@arm.com&gt;
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lore.kernel.org/lkml/20200501143615.1180-1-mike.leach@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools feature: Add support for detecting libpfm4</title>
<updated>2020-05-05T19:35:31+00:00</updated>
<author>
<name>Stephane Eranian</name>
<email>eranian@google.com</email>
</author>
<published>2020-04-29T23:14:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5ef86146de941f273d669a8e018036f549bf058c'/>
<id>5ef86146de941f273d669a8e018036f549bf058c</id>
<content type='text'>
libpfm4 provides an alternate command line encoding of perf events.

Signed-off-by: Stephane Eranian &lt;eranian@google.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Andrii Nakryiko &lt;andriin@fb.com&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Igor Lubashev &lt;ilubashe@akamai.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Jiwei Sun &lt;jiwei.sun@windriver.com&gt;
Cc: John Garry &lt;john.garry@huawei.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Martin KaFai Lau &lt;kafai@fb.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Yonghong Song &lt;yhs@fb.com&gt;
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: yuzhoujian &lt;yuzhoujian@didichuxing.com&gt;
Link: http://lore.kernel.org/lkml/20200429231443.207201-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
libpfm4 provides an alternate command line encoding of perf events.

Signed-off-by: Stephane Eranian &lt;eranian@google.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Andrii Nakryiko &lt;andriin@fb.com&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Igor Lubashev &lt;ilubashe@akamai.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Jiwei Sun &lt;jiwei.sun@windriver.com&gt;
Cc: John Garry &lt;john.garry@huawei.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Martin KaFai Lau &lt;kafai@fb.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Yonghong Song &lt;yhs@fb.com&gt;
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: yuzhoujian &lt;yuzhoujian@didichuxing.com&gt;
Link: http://lore.kernel.org/lkml/20200429231443.207201-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools/build: tweak unused value workaround</title>
<updated>2020-04-21T18:11:55+00:00</updated>
<author>
<name>George Burgess IV</name>
<email>gbiv@google.com</email>
</author>
<published>2020-04-21T01:14:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a21151b9d81a69ce334f409e7f98e50e3b8fa984'/>
<id>a21151b9d81a69ce334f409e7f98e50e3b8fa984</id>
<content type='text'>
Clang has -Wself-assign enabled by default under -Wall, which always
gets -Werror'ed on this file, causing sync-compare-and-swap to be
disabled by default.

The generally-accepted way to spell "this value is intentionally
unused," is casting it to `void`.  This is accepted by both GCC and
Clang with -Wall enabled: https://godbolt.org/z/qqZ9r3

Signed-off-by: George Burgess IV &lt;gbiv@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Link: http://lkml.kernel.org/r/20200414195638.156123-1-gbiv@google.com
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Clang has -Wself-assign enabled by default under -Wall, which always
gets -Werror'ed on this file, causing sync-compare-and-swap to be
disabled by default.

The generally-accepted way to spell "this value is intentionally
unused," is casting it to `void`.  This is accepted by both GCC and
Clang with -Wall enabled: https://godbolt.org/z/qqZ9r3

Signed-off-by: George Burgess IV &lt;gbiv@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Link: http://lkml.kernel.org/r/20200414195638.156123-1-gbiv@google.com
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
