<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/mips/include, branch v4.14.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge tag 'mips_fixes_4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips</title>
<updated>2017-11-04T18:31:02+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-11-04T18:31:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dab30d5531c9ee7c42c4448afa0030c86e55df19'/>
<id>dab30d5531c9ee7c42c4448afa0030c86e55df19</id>
<content type='text'>
Pull MIPS fixes from James Hogan:
 "A selection of important MIPS fixes for 4.14, and some MAINTAINERS /
  email address updates:

  Maintainership updates:
   - imgtec.com -&gt; mips.com email addresses (this trivially updates
     comments in quite a few files, as well as MAINTAINERS)
   - Pistachio SoC maintainership update

  Fixes:
   - NI 169445 build (new platform in 4.14)
   - EVA regression (4.14)
   - SMP-CPS build &amp; preemption regressions (4.14)
   - SMP/hotplug deadlock &amp; race (deadlock reintroduced 4.13)
   - ebpf_jit error return (4.13)
   - SMP-CMP build regressions (4.11 and 4.14)
   - bad UASM microMIPS encoding (3.16)
   - CM definitions (3.15)"

[ I had taken the email address updates separately, because I didn't
  expect James to send a pull request, so those got applied twice.   - Linus]

* tag 'mips_fixes_4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
  MIPS: Update email address for Marcin Nowakowski
  MIPS: smp-cmp: Fix vpe_id build error
  MAINTAINERS: Update Pistachio platform maintainers
  MIPS: smp-cmp: Use right include for task_struct
  MIPS: Update Goldfish RTC driver maintainer email address
  MIPS: Update RINT emulation maintainer email address
  MIPS: CPS: Fix use of current_cpu_data in preemptible code
  MIPS: SMP: Fix deadlock &amp; online race
  MIPS: bpf: Fix a typo in build_one_insn()
  MIPS: microMIPS: Fix incorrect mask in insn_table_MM
  MIPS: Fix CM region target definitions
  MIPS: generic: Fix compilation error from include asm/mips-cpc.h
  MIPS: Fix exception entry when CONFIG_EVA enabled
  MIPS: generic: Fix NI 169445 its build
  Update MIPS email addresses
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull MIPS fixes from James Hogan:
 "A selection of important MIPS fixes for 4.14, and some MAINTAINERS /
  email address updates:

  Maintainership updates:
   - imgtec.com -&gt; mips.com email addresses (this trivially updates
     comments in quite a few files, as well as MAINTAINERS)
   - Pistachio SoC maintainership update

  Fixes:
   - NI 169445 build (new platform in 4.14)
   - EVA regression (4.14)
   - SMP-CPS build &amp; preemption regressions (4.14)
   - SMP/hotplug deadlock &amp; race (deadlock reintroduced 4.13)
   - ebpf_jit error return (4.13)
   - SMP-CMP build regressions (4.11 and 4.14)
   - bad UASM microMIPS encoding (3.16)
   - CM definitions (3.15)"

[ I had taken the email address updates separately, because I didn't
  expect James to send a pull request, so those got applied twice.   - Linus]

* tag 'mips_fixes_4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
  MIPS: Update email address for Marcin Nowakowski
  MIPS: smp-cmp: Fix vpe_id build error
  MAINTAINERS: Update Pistachio platform maintainers
  MIPS: smp-cmp: Use right include for task_struct
  MIPS: Update Goldfish RTC driver maintainer email address
  MIPS: Update RINT emulation maintainer email address
  MIPS: CPS: Fix use of current_cpu_data in preemptible code
  MIPS: SMP: Fix deadlock &amp; online race
  MIPS: bpf: Fix a typo in build_one_insn()
  MIPS: microMIPS: Fix incorrect mask in insn_table_MM
  MIPS: Fix CM region target definitions
  MIPS: generic: Fix compilation error from include asm/mips-cpc.h
  MIPS: Fix exception entry when CONFIG_EVA enabled
  MIPS: generic: Fix NI 169445 its build
  Update MIPS email addresses
</pre>
</div>
</content>
</entry>
<entry>
<title>Update MIPS email addresses</title>
<updated>2017-11-03T16:02:30+00:00</updated>
<author>
<name>Paul Burton</name>
<email>paul.burton@mips.com</email>
</author>
<published>2017-10-26T00:04:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fb615d61b5583db92e3793709b97e35dc9499c2a'/>
<id>fb615d61b5583db92e3793709b97e35dc9499c2a</id>
<content type='text'>
MIPS will soon not be a part of Imagination Technologies, and as such
many @imgtec.com email addresses will no longer be valid. This patch
updates the addresses for those who:

 - Have 10 or more patches in mainline authored using an @imgtec.com
   email address, or any patches dated within the past year.

 - Are still with Imagination but leaving as part of the MIPS business
   unit, as determined from an internal email address list.

 - Haven't already updated their email address (ie. JamesH) or expressed
   a desire to be excluded (ie. Maciej).

 - Acked v2 or earlier of this patch, which leaves Deng-Cheng, Matt &amp;
   myself.

New addresses are of the form firstname.lastname@mips.com, and all
verified against an internal email address list.  An entry is added to
.mailmap for each person such that get_maintainer.pl will report the new
addresses rather than @imgtec.com addresses which will soon be dead.

Instances of the affected addresses throughout the tree are then
mechanically replaced with the new @mips.com address.

Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Deng-Cheng Zhu &lt;dengcheng.zhu@imgtec.com&gt;
Cc: Deng-Cheng Zhu &lt;dengcheng.zhu@mips.com&gt;
Acked-by: Dengcheng Zhu &lt;dengcheng.zhu@mips.com&gt;
Cc: Matt Redfearn &lt;matt.redfearn@imgtec.com&gt;
Cc: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Acked-by: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
MIPS will soon not be a part of Imagination Technologies, and as such
many @imgtec.com email addresses will no longer be valid. This patch
updates the addresses for those who:

 - Have 10 or more patches in mainline authored using an @imgtec.com
   email address, or any patches dated within the past year.

 - Are still with Imagination but leaving as part of the MIPS business
   unit, as determined from an internal email address list.

 - Haven't already updated their email address (ie. JamesH) or expressed
   a desire to be excluded (ie. Maciej).

 - Acked v2 or earlier of this patch, which leaves Deng-Cheng, Matt &amp;
   myself.

New addresses are of the form firstname.lastname@mips.com, and all
verified against an internal email address list.  An entry is added to
.mailmap for each person such that get_maintainer.pl will report the new
addresses rather than @imgtec.com addresses which will soon be dead.

Instances of the affected addresses throughout the tree are then
mechanically replaced with the new @mips.com address.

Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Deng-Cheng Zhu &lt;dengcheng.zhu@imgtec.com&gt;
Cc: Deng-Cheng Zhu &lt;dengcheng.zhu@mips.com&gt;
Acked-by: Dengcheng Zhu &lt;dengcheng.zhu@mips.com&gt;
Cc: Matt Redfearn &lt;matt.redfearn@imgtec.com&gt;
Cc: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Acked-by: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>License cleanup: add SPDX license identifier to uapi header files with a license</title>
<updated>2017-11-02T10:20:11+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2017-11-01T14:09:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e2be04c7f9958dde770eeb8b30e829ca969b37bb'/>
<id>e2be04c7f9958dde770eeb8b30e829ca969b37bb</id>
<content type='text'>
Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be.  This makes it hard for
compliance tools to determine the correct license.

Update these files with an SPDX license identifier.  The identifier was
chosen based on the license information in the file.

GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.

Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier.  The format
is:
        ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)

SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text.  The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be.  This makes it hard for
compliance tools to determine the correct license.

Update these files with an SPDX license identifier.  The identifier was
chosen based on the license information in the file.

GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.

Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier.  The format
is:
        ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)

SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text.  The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>License cleanup: add SPDX license identifier to uapi header files with no license</title>
<updated>2017-11-02T10:19:54+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2017-11-01T14:08:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6f52b16c5b29b89d92c0e7236f4655dc8491ad70'/>
<id>6f52b16c5b29b89d92c0e7236f4655dc8491ad70</id>
<content type='text'>
Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.

By default are files without license information under the default
license of the kernel, which is GPLV2.  Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

otherwise syscall usage would not be possible.

Update the files which contain no license information with an SPDX
license identifier.  The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception.  SPDX license identifiers are 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.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.

By default are files without license information under the default
license of the kernel, which is GPLV2.  Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

otherwise syscall usage would not be possible.

Update the files which contain no license information with an SPDX
license identifier.  The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception.  SPDX license identifiers are 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.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>License cleanup: add SPDX GPL-2.0 license identifier to files with no license</title>
<updated>2017-11-02T10:10:55+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2017-11-01T14:07:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b24413180f5600bcb3bb70fbed5cf186b60864bd'/>
<id>b24413180f5600bcb3bb70fbed5cf186b60864bd</id>
<content type='text'>
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 &amp; 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 &gt;5
   lines of source
 - File already had some variant of a license header in it (even if &lt;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 &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &amp; 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 &gt;5
   lines of source
 - File already had some variant of a license header in it (even if &lt;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 &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Fix CM region target definitions</title>
<updated>2017-10-31T23:54:20+00:00</updated>
<author>
<name>Paul Burton</name>
<email>paul.burton@mips.com</email>
</author>
<published>2017-10-31T22:09:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6a6cba1d945a7511cdfaf338526871195e420762'/>
<id>6a6cba1d945a7511cdfaf338526871195e420762</id>
<content type='text'>
The default CM target field in the GCR_BASE register is encoded with 0
meaning memory &amp; 1 being reserved. However the definitions we use for
those bits effectively get these two values backwards - likely because
they were copied from the definitions for the CM regions where the
target is encoded differently. This results in use setting up GCR_BASE
with the reserved target value by default, rather than targeting memory
as intended. Although we currently seem to get away with this it's not a
great idea to rely upon.

Fix this by changing our macros to match the documentated target values.

The incorrect encoding became used as of commit 9f98f3dd0c51 ("MIPS: Add
generic CM probe &amp; access code") in the Linux v3.15 cycle, and was
likely carried forwards from older but unused code introduced by
commit 39b8d5254246 ("[MIPS] Add support for MIPS CMP platform.") in the
v2.6.26 cycle.

Fixes: 9f98f3dd0c51 ("MIPS: Add generic CM probe &amp; access code")
Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Reported-by: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Reviewed-by: James Hogan &lt;jhogan@kernel.org&gt;
Cc: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: linux-mips@linux-mips.org
Cc: &lt;stable@vger.kernel.org&gt; # v3.15+
Patchwork: https://patchwork.linux-mips.org/patch/17562/
Signed-off-by: James Hogan &lt;jhogan@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The default CM target field in the GCR_BASE register is encoded with 0
meaning memory &amp; 1 being reserved. However the definitions we use for
those bits effectively get these two values backwards - likely because
they were copied from the definitions for the CM regions where the
target is encoded differently. This results in use setting up GCR_BASE
with the reserved target value by default, rather than targeting memory
as intended. Although we currently seem to get away with this it's not a
great idea to rely upon.

Fix this by changing our macros to match the documentated target values.

The incorrect encoding became used as of commit 9f98f3dd0c51 ("MIPS: Add
generic CM probe &amp; access code") in the Linux v3.15 cycle, and was
likely carried forwards from older but unused code introduced by
commit 39b8d5254246 ("[MIPS] Add support for MIPS CMP platform.") in the
v2.6.26 cycle.

Fixes: 9f98f3dd0c51 ("MIPS: Add generic CM probe &amp; access code")
Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Reported-by: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Reviewed-by: James Hogan &lt;jhogan@kernel.org&gt;
Cc: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: linux-mips@linux-mips.org
Cc: &lt;stable@vger.kernel.org&gt; # v3.15+
Patchwork: https://patchwork.linux-mips.org/patch/17562/
Signed-off-by: James Hogan &lt;jhogan@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Fix exception entry when CONFIG_EVA enabled</title>
<updated>2017-10-31T23:49:33+00:00</updated>
<author>
<name>Matt Redfearn</name>
<email>matt.redfearn@mips.com</email>
</author>
<published>2017-10-11T08:59:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c496f3c08a83e57359509828e5b19eeb920b81b1'/>
<id>c496f3c08a83e57359509828e5b19eeb920b81b1</id>
<content type='text'>
Commit 9fef68686317b ("MIPS: Make SAVE_SOME more standard") made several
changes to the order in which registers are saved in the SAVE_SOME
macro, used by exception handlers to save the processor state. In
particular, it removed the
move   k1, sp
in the delay slot of the branch testing if the processor is already in
kernel mode. This is replaced later in the macro by a
move   k0, sp
When CONFIG_EVA is disabled, this instruction actually appears in the
delay slot of the branch. However, when CONFIG_EVA is enabled, instead
the RPS workaround of
MFC0	k0, CP0_ENTRYHI
appears in the delay slot. This results in k0 not containing the stack
pointer, but some unrelated value, which is then saved to the kernel
stack. On exit from the exception, this bogus value is restored to the
stack pointer, resulting in an OOPS.

Fix this by moving the save of SP in k0 explicitly in the delay slot of
the branch, outside of the CONFIG_EVA section, restoring the expected
instruction ordering when CONFIG_EVA is active.

Fixes: 9fef68686317b ("MIPS: Make SAVE_SOME more standard")
Signed-off-by: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Reported-by: Vladimir Kondratiev &lt;vladimir.kondratiev@intel.com&gt;
Reviewed-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Reviewed-by: James Hogan &lt;jhogan@kernel.org&gt;
Patchwork: https://patchwork.linux-mips.org/patch/17471/
Signed-off-by: James Hogan &lt;jhogan@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 9fef68686317b ("MIPS: Make SAVE_SOME more standard") made several
changes to the order in which registers are saved in the SAVE_SOME
macro, used by exception handlers to save the processor state. In
particular, it removed the
move   k1, sp
in the delay slot of the branch testing if the processor is already in
kernel mode. This is replaced later in the macro by a
move   k0, sp
When CONFIG_EVA is disabled, this instruction actually appears in the
delay slot of the branch. However, when CONFIG_EVA is enabled, instead
the RPS workaround of
MFC0	k0, CP0_ENTRYHI
appears in the delay slot. This results in k0 not containing the stack
pointer, but some unrelated value, which is then saved to the kernel
stack. On exit from the exception, this bogus value is restored to the
stack pointer, resulting in an OOPS.

Fix this by moving the save of SP in k0 explicitly in the delay slot of
the branch, outside of the CONFIG_EVA section, restoring the expected
instruction ordering when CONFIG_EVA is active.

Fixes: 9fef68686317b ("MIPS: Make SAVE_SOME more standard")
Signed-off-by: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Reported-by: Vladimir Kondratiev &lt;vladimir.kondratiev@intel.com&gt;
Reviewed-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Reviewed-by: James Hogan &lt;jhogan@kernel.org&gt;
Patchwork: https://patchwork.linux-mips.org/patch/17471/
Signed-off-by: James Hogan &lt;jhogan@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Update MIPS email addresses</title>
<updated>2017-10-31T22:42:39+00:00</updated>
<author>
<name>Paul Burton</name>
<email>paul.burton@mips.com</email>
</author>
<published>2017-10-26T00:04:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=48c834be170bb1060e14092ff1c7967ea72b2e97'/>
<id>48c834be170bb1060e14092ff1c7967ea72b2e97</id>
<content type='text'>
MIPS will soon not be a part of Imagination Technologies, and as such
many @imgtec.com email addresses will no longer be valid. This patch
updates the addresses for those who:

 - Have 10 or more patches in mainline authored using an @imgtec.com
   email address, or any patches dated within the past year.

 - Are still with Imagination but leaving as part of the MIPS business
   unit, as determined from an internal email address list.

 - Haven't already updated their email address (ie. JamesH) or expressed
   a desire to be excluded (ie. Maciej).

 - Acked v2 or earlier of this patch, which leaves Deng-Cheng, Matt &amp;
   myself.

New addresses are of the form firstname.lastname@mips.com, and all
verified against an internal email address list. An entry is added to
.mailmap for each person such that get_maintainer.pl will report the new
addresses rather than @imgtec.com addresses which will soon be dead.

Instances of the affected addresses throughout the tree are then
mechanically replaced with the new @mips.com address.

Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Deng-Cheng Zhu &lt;dengcheng.zhu@imgtec.com&gt;
Cc: Deng-Cheng Zhu &lt;dengcheng.zhu@mips.com&gt;
Acked-by: Dengcheng Zhu &lt;dengcheng.zhu@mips.com&gt;
Cc: Matt Redfearn &lt;matt.redfearn@imgtec.com&gt;
Cc: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Acked-by: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17540/
Signed-off-by: James Hogan &lt;jhogan@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
MIPS will soon not be a part of Imagination Technologies, and as such
many @imgtec.com email addresses will no longer be valid. This patch
updates the addresses for those who:

 - Have 10 or more patches in mainline authored using an @imgtec.com
   email address, or any patches dated within the past year.

 - Are still with Imagination but leaving as part of the MIPS business
   unit, as determined from an internal email address list.

 - Haven't already updated their email address (ie. JamesH) or expressed
   a desire to be excluded (ie. Maciej).

 - Acked v2 or earlier of this patch, which leaves Deng-Cheng, Matt &amp;
   myself.

New addresses are of the form firstname.lastname@mips.com, and all
verified against an internal email address list. An entry is added to
.mailmap for each person such that get_maintainer.pl will report the new
addresses rather than @imgtec.com addresses which will soon be dead.

Instances of the affected addresses throughout the tree are then
mechanically replaced with the new @mips.com address.

Signed-off-by: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Deng-Cheng Zhu &lt;dengcheng.zhu@imgtec.com&gt;
Cc: Deng-Cheng Zhu &lt;dengcheng.zhu@mips.com&gt;
Acked-by: Dengcheng Zhu &lt;dengcheng.zhu@mips.com&gt;
Cc: Matt Redfearn &lt;matt.redfearn@imgtec.com&gt;
Cc: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Acked-by: Matt Redfearn &lt;matt.redfearn@mips.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17540/
Signed-off-by: James Hogan &lt;jhogan@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Fix cmpxchg on 32b signed ints for 64b kernel with !kernel_uses_llsc</title>
<updated>2017-10-09T14:31:32+00:00</updated>
<author>
<name>Paul Burton</name>
<email>paul.burton@imgtec.com</email>
</author>
<published>2017-09-01T21:46:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=133d68e0ed4d822ccfa276ff7d2d1753477de1a8'/>
<id>133d68e0ed4d822ccfa276ff7d2d1753477de1a8</id>
<content type='text'>
Commit 8263db4d7768 ("MIPS: cmpxchg: Implement __cmpxchg() as a
function") refactored our implementation of __cmpxchg() to be a function
rather than a macro, with the aim of making it easier to read &amp; modify.
Unfortunately the commit breaks use of cmpxchg() for signed 32 bit
values when we have a 64 bit kernel with kernel_uses_llsc == false,
because:

 - In cmpxchg_local() we cast the old value to the type the pointer
   points to, and then to an unsigned long. If the pointer points to a
   signed type smaller than 64 bits then the old value will be sign
   extended to 64 bits. That is, bits beyond the size of the pointed to
   type will be set to 1 if the old value is negative. In the case of a
   signed 32 bit integer with a negative value, bits 63:32 will all be
   set.

 - In __cmpxchg_asm() we load the value from memory, ie. dereference the
   pointer, and store the value as an unsigned integer (__ret) whose
   size matches the pointer. For a 32 bit cmpxchg() this means we store
   the value in a u32, because the pointer provided to __cmpxchg_asm()
   by __cmpxchg() is of type volatile u32 *.

 - __cmpxchg_asm() then checks whether the value in memory (__ret)
   matches the provided old value, by comparing the two values. This
   results in the u32 being promoted to a 64 bit unsigned long to match
   the old argument - however because both types are unsigned the value
   is zero extended, which does not match the sign extension performed
   on the old value in cmpxchg_local() earlier.

This mismatch means that unfortunate cmpxchg() calls can incorrectly
fail for 64 bit kernels with kernel_uses_llsc == false. This is the case
on at least non-SMP Cavium Octeon kernels, which hardcode
kernel_uses_llsc in their cpu-feature-overrides.h header. Using a
v4.13-rc7 kernel configured using cavium_octeon_defconfig with SMP
manually disabled, this presents itself as oddity when we reach
userland - for example:

  can't run '/bin/mount': Text file busy
  can't run '/bin/mkdir': Text file busy
  can't run '/bin/mkdir': Text file busy
  can't run '/bin/mount': Text file busy
  can't run '/bin/hostname': Text file busy
  can't run '/etc/init.d/rcS': Text file busy
  can't run '/sbin/getty': Text file busy
  can't run '/sbin/getty': Text file busy

It appears that some part of the init process, which is in this case
buildroot's busybox init, is running successfully. It never manages to
reach the login prompt though, and complains about /sbin/getty being
busy repeatedly and indefinitely.

Fix this by casting the old value provided to __cmpxchg_asm() to an
appropriately sized unsigned integer, such that we consistently
zero-extend avoiding the mismatch. The __cmpxchg_small() case for 8 &amp; 16
bit values is unaffected because __cmpxchg_small() already masks
provided values appropriately.

Signed-off-by: Paul Burton &lt;paul.burton@imgtec.com&gt;
Fixes: 8263db4d7768 ("MIPS: cmpxchg: Implement __cmpxchg() as a function")
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17226/
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 8263db4d7768 ("MIPS: cmpxchg: Implement __cmpxchg() as a
function") refactored our implementation of __cmpxchg() to be a function
rather than a macro, with the aim of making it easier to read &amp; modify.
Unfortunately the commit breaks use of cmpxchg() for signed 32 bit
values when we have a 64 bit kernel with kernel_uses_llsc == false,
because:

 - In cmpxchg_local() we cast the old value to the type the pointer
   points to, and then to an unsigned long. If the pointer points to a
   signed type smaller than 64 bits then the old value will be sign
   extended to 64 bits. That is, bits beyond the size of the pointed to
   type will be set to 1 if the old value is negative. In the case of a
   signed 32 bit integer with a negative value, bits 63:32 will all be
   set.

 - In __cmpxchg_asm() we load the value from memory, ie. dereference the
   pointer, and store the value as an unsigned integer (__ret) whose
   size matches the pointer. For a 32 bit cmpxchg() this means we store
   the value in a u32, because the pointer provided to __cmpxchg_asm()
   by __cmpxchg() is of type volatile u32 *.

 - __cmpxchg_asm() then checks whether the value in memory (__ret)
   matches the provided old value, by comparing the two values. This
   results in the u32 being promoted to a 64 bit unsigned long to match
   the old argument - however because both types are unsigned the value
   is zero extended, which does not match the sign extension performed
   on the old value in cmpxchg_local() earlier.

This mismatch means that unfortunate cmpxchg() calls can incorrectly
fail for 64 bit kernels with kernel_uses_llsc == false. This is the case
on at least non-SMP Cavium Octeon kernels, which hardcode
kernel_uses_llsc in their cpu-feature-overrides.h header. Using a
v4.13-rc7 kernel configured using cavium_octeon_defconfig with SMP
manually disabled, this presents itself as oddity when we reach
userland - for example:

  can't run '/bin/mount': Text file busy
  can't run '/bin/mkdir': Text file busy
  can't run '/bin/mkdir': Text file busy
  can't run '/bin/mount': Text file busy
  can't run '/bin/hostname': Text file busy
  can't run '/etc/init.d/rcS': Text file busy
  can't run '/sbin/getty': Text file busy
  can't run '/sbin/getty': Text file busy

It appears that some part of the init process, which is in this case
buildroot's busybox init, is running successfully. It never manages to
reach the login prompt though, and complains about /sbin/getty being
busy repeatedly and indefinitely.

Fix this by casting the old value provided to __cmpxchg_asm() to an
appropriately sized unsigned integer, such that we consistently
zero-extend avoiding the mismatch. The __cmpxchg_small() case for 8 &amp; 16
bit values is unaffected because __cmpxchg_small() already masks
provided values appropriately.

Signed-off-by: Paul Burton &lt;paul.burton@imgtec.com&gt;
Fixes: 8263db4d7768 ("MIPS: cmpxchg: Implement __cmpxchg() as a function")
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17226/
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Fix input modify in __write_64bit_c0_split()</title>
<updated>2017-09-21T14:26:42+00:00</updated>
<author>
<name>James Hogan</name>
<email>james.hogan@imgtec.com</email>
</author>
<published>2017-09-19T13:11:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c22c8043105591a8b74142cf837604087cdba40b'/>
<id>c22c8043105591a8b74142cf837604087cdba40b</id>
<content type='text'>
The inline asm in __write_64bit_c0_split() modifies the 64-bit input
operand by shifting the high register left by 32, and constructing the
full 64-bit value in the low register (even on a 32-bit kernel), so if
that value is used again it could cause breakage as GCC would assume the
registers haven't changed when they have.

To quote the GCC extended asm documentation:
&gt; Warning: Do not modify the contents of input-only operands (except for
&gt; inputs tied to outputs). The compiler assumes that on exit from the
&gt; asm statement these operands contain the same values as they had
&gt; before executing the statement.

Avoid modifying the input by using a temporary variable as an output
which is modified instead of the input and not otherwise used. The asm
is always __volatile__ so GCC shouldn't optimise it out. The low
register of the temporary output is written before the high register of
the input is read, so we have two constraint alternatives, one where
both use the same registers (for when the input value isn't subsequently
used), and one with an early clobber on the output in case the low
output uses the same register as the high input. This allows the
resulting assembly to remain mostly unchanged.

A diff of a MIPS32r6 kernel reveals only three differences, two in
relation to write_c0_r10k_diag() in cpu_probe() (register allocation
rearranged slightly but otherwise identical), and one in relation to
write_c0_cvmmemctl2() in kvm_vz_local_flush_guesttlb_all(), but the
octeon CPU is only supported on 64-bit kernels where
__write_64bit_c0_split() isn't used so that shouldn't matter in
practice. So there currently doesn't appear to be anything broken by
this bug.

Signed-off-by: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17315/
Signed-off-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The inline asm in __write_64bit_c0_split() modifies the 64-bit input
operand by shifting the high register left by 32, and constructing the
full 64-bit value in the low register (even on a 32-bit kernel), so if
that value is used again it could cause breakage as GCC would assume the
registers haven't changed when they have.

To quote the GCC extended asm documentation:
&gt; Warning: Do not modify the contents of input-only operands (except for
&gt; inputs tied to outputs). The compiler assumes that on exit from the
&gt; asm statement these operands contain the same values as they had
&gt; before executing the statement.

Avoid modifying the input by using a temporary variable as an output
which is modified instead of the input and not otherwise used. The asm
is always __volatile__ so GCC shouldn't optimise it out. The low
register of the temporary output is written before the high register of
the input is read, so we have two constraint alternatives, one where
both use the same registers (for when the input value isn't subsequently
used), and one with an early clobber on the output in case the low
output uses the same register as the high input. This allows the
resulting assembly to remain mostly unchanged.

A diff of a MIPS32r6 kernel reveals only three differences, two in
relation to write_c0_r10k_diag() in cpu_probe() (register allocation
rearranged slightly but otherwise identical), and one in relation to
write_c0_cvmmemctl2() in kvm_vz_local_flush_guesttlb_all(), but the
octeon CPU is only supported on 64-bit kernels where
__write_64bit_c0_split() isn't used so that shouldn't matter in
practice. So there currently doesn't appear to be anything broken by
this bug.

Signed-off-by: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17315/
Signed-off-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;
</pre>
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