<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/include/linux/module.h, branch v5.1-rc1</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>Merge tag 'docs-5.1' of git://git.lwn.net/linux</title>
<updated>2019-03-09T17:56:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-09T17:56:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1a29e857507046e413ca7a4a7c9cd32fed9ea255'/>
<id>1a29e857507046e413ca7a4a7c9cd32fed9ea255</id>
<content type='text'>
Pull documentation updates from Jonathan Corbet:
 "A fairly routine cycle for docs - lots of typo fixes, some new
  documents, and more translations. There's also some LICENSES
  adjustments from Thomas"

* tag 'docs-5.1' of git://git.lwn.net/linux: (74 commits)
  docs: Bring some order to filesystem documentation
  Documentation/locking/lockdep: Drop last two chars of sample states
  doc: rcu: Suspicious RCU usage is a warning
  docs: driver-api: iio: fix errors in documentation
  Documentation/process/howto: Update for 4.x -&gt; 5.x versioning
  docs: Explicitly state that the 'Fixes:' tag shouldn't split lines
  doc: security: Add kern-doc for lsm_hooks.h
  doc: sctp: Merge and clean up rst files
  Docs: Correct /proc/stat path
  scripts/spdxcheck.py: fix C++ comment style detection
  doc: fix typos in license-rules.rst
  Documentation: fix admin-guide/README.rst minimum gcc version requirement
  doc: process: complete removal of info about -git patches
  doc: translations: sync translations 'remove info about -git patches'
  perf-security: wrap paragraphs on 72 columns
  perf-security: elaborate on perf_events/Perf privileged users
  perf-security: document collected perf_events/Perf data categories
  perf-security: document perf_events/Perf resource control
  sysfs.txt: add note on available attribute macros
  docs: kernel-doc: typo "if ... if" -&gt; "if ... is"
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull documentation updates from Jonathan Corbet:
 "A fairly routine cycle for docs - lots of typo fixes, some new
  documents, and more translations. There's also some LICENSES
  adjustments from Thomas"

* tag 'docs-5.1' of git://git.lwn.net/linux: (74 commits)
  docs: Bring some order to filesystem documentation
  Documentation/locking/lockdep: Drop last two chars of sample states
  doc: rcu: Suspicious RCU usage is a warning
  docs: driver-api: iio: fix errors in documentation
  Documentation/process/howto: Update for 4.x -&gt; 5.x versioning
  docs: Explicitly state that the 'Fixes:' tag shouldn't split lines
  doc: security: Add kern-doc for lsm_hooks.h
  doc: sctp: Merge and clean up rst files
  Docs: Correct /proc/stat path
  scripts/spdxcheck.py: fix C++ comment style detection
  doc: fix typos in license-rules.rst
  Documentation: fix admin-guide/README.rst minimum gcc version requirement
  doc: process: complete removal of info about -git patches
  doc: translations: sync translations 'remove info about -git patches'
  perf-security: wrap paragraphs on 72 columns
  perf-security: elaborate on perf_events/Perf privileged users
  perf-security: document collected perf_events/Perf data categories
  perf-security: document perf_events/Perf resource control
  sysfs.txt: add note on available attribute macros
  docs: kernel-doc: typo "if ... if" -&gt; "if ... is"
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>include/linux/module.h: copy __init/__exit attrs to init/cleanup_module</title>
<updated>2019-02-15T18:52:56+00:00</updated>
<author>
<name>Miguel Ojeda</name>
<email>miguel.ojeda.sandonis@gmail.com</email>
</author>
<published>2019-01-19T19:59:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a6e60d84989fa0e91db7f236eda40453b0e44afa'/>
<id>a6e60d84989fa0e91db7f236eda40453b0e44afa</id>
<content type='text'>
The upcoming GCC 9 release extends the -Wmissing-attributes warnings
(enabled by -Wall) to C and aliases: it warns when particular function
attributes are missing in the aliases but not in their target.

In particular, it triggers for all the init/cleanup_module
aliases in the kernel (defined by the module_init/exit macros),
ending up being very noisy.

These aliases point to the __init/__exit functions of a module,
which are defined as __cold (among other attributes). However,
the aliases themselves do not have the __cold attribute.

Since the compiler behaves differently when compiling a __cold
function as well as when compiling paths leading to calls
to __cold functions, the warning is trying to point out
the possibly-forgotten attribute in the alias.

In order to keep the warning enabled, we decided to silence
this case. Ideally, we would mark the aliases directly
as __init/__exit. However, there are currently around 132 modules
in the kernel which are missing __init/__exit in their init/cleanup
functions (either because they are missing, or for other reasons,
e.g. the functions being called from somewhere else); and
a section mismatch is a hard error.

A conservative alternative was to mark the aliases as __cold only.
However, since we would like to eventually enforce __init/__exit
to be always marked,  we chose to use the new __copy function
attribute (introduced by GCC 9 as well to deal with this).
With it, we copy the attributes used by the target functions
into the aliases. This way, functions that were not marked
as __init/__exit won't have their aliases marked either,
and therefore there won't be a section mismatch.

Note that the warning would go away marking either the extern
declaration, the definition, or both. However, we only mark
the definition of the alias, since we do not want callers
(which only see the declaration) to be compiled as if the function
was __cold (and therefore the paths leading to those calls
would be assumed to be unlikely).

Link: https://lore.kernel.org/lkml/20190123173707.GA16603@gmail.com/
Link: https://lore.kernel.org/lkml/20190206175627.GA20399@gmail.com/
Suggested-by: Martin Sebor &lt;msebor@gcc.gnu.org&gt;
Acked-by: Jessica Yu &lt;jeyu@kernel.org&gt;
Signed-off-by: Miguel Ojeda &lt;miguel.ojeda.sandonis@gmail.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The upcoming GCC 9 release extends the -Wmissing-attributes warnings
(enabled by -Wall) to C and aliases: it warns when particular function
attributes are missing in the aliases but not in their target.

In particular, it triggers for all the init/cleanup_module
aliases in the kernel (defined by the module_init/exit macros),
ending up being very noisy.

These aliases point to the __init/__exit functions of a module,
which are defined as __cold (among other attributes). However,
the aliases themselves do not have the __cold attribute.

Since the compiler behaves differently when compiling a __cold
function as well as when compiling paths leading to calls
to __cold functions, the warning is trying to point out
the possibly-forgotten attribute in the alias.

In order to keep the warning enabled, we decided to silence
this case. Ideally, we would mark the aliases directly
as __init/__exit. However, there are currently around 132 modules
in the kernel which are missing __init/__exit in their init/cleanup
functions (either because they are missing, or for other reasons,
e.g. the functions being called from somewhere else); and
a section mismatch is a hard error.

A conservative alternative was to mark the aliases as __cold only.
However, since we would like to eventually enforce __init/__exit
to be always marked,  we chose to use the new __copy function
attribute (introduced by GCC 9 as well to deal with this).
With it, we copy the attributes used by the target functions
into the aliases. This way, functions that were not marked
as __init/__exit won't have their aliases marked either,
and therefore there won't be a section mismatch.

Note that the warning would go away marking either the extern
declaration, the definition, or both. However, we only mark
the definition of the alias, since we do not want callers
(which only see the declaration) to be compiled as if the function
was __cold (and therefore the paths leading to those calls
would be assumed to be unlikely).

Link: https://lore.kernel.org/lkml/20190123173707.GA16603@gmail.com/
Link: https://lore.kernel.org/lkml/20190206175627.GA20399@gmail.com/
Suggested-by: Martin Sebor &lt;msebor@gcc.gnu.org&gt;
Acked-by: Jessica Yu &lt;jeyu@kernel.org&gt;
Signed-off-by: Miguel Ojeda &lt;miguel.ojeda.sandonis@gmail.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>module: Cure the MODULE_LICENSE "GPL" vs. "GPL v2" bogosity</title>
<updated>2019-02-11T15:17:43+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-02-08T16:02:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bf7fbeeae6db644ef5995085de2bc5c6121f8c8d'/>
<id>bf7fbeeae6db644ef5995085de2bc5c6121f8c8d</id>
<content type='text'>
The original MODULE_LICENSE string for kernel modules licensed under the
GPL v2 (only / or later) was simply "GPL", which was - and still is -
completely sufficient for the purpose of module loading and checking
whether the module is free software or proprietary.

In January 2003 this was changed with commit 3344ea3ad4b7 ("[PATCH]
MODULE_LICENSE and EXPORT_SYMBOL_GPL support"). This commit can be found in
the history git repository which holds the 1:1 import of Linus' bitkeeper
repository:

  https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=3344ea3ad4b7c302c846a680dbaeedf96ed45c02

The main intention of the patch was to refuse linking proprietary modules
against symbols exported with EXPORT_SYMBOL_GPL() at module load time.

As a completely undocumented side effect it also introduced the distinction
between "GPL" and "GPL v2" MODULE_LICENSE() strings:

 *      "GPL"                           [GNU Public License v2 or later]
 *      "GPL v2"                        [GNU Public License v2]
 *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 *      "Dual BSD/GPL"                  [GNU Public License v2
 *                                       or BSD license choice]
 *      "Dual MPL/GPL"                  [GNU Public License v2
 *                                       or Mozilla license choice]

This distinction was and still is wrong in several aspects:

 1) It broke all modules which were using the "GPL" string in the
    MODULE_LICENSE() already and were licensed under GPL v2 only.

    A quick license scan over the tree at that time shows that at least 480
    out of 1484 modules have been affected by this change back then. The
    number is probably way higher as this was just a quick check for
    clearly identifiable license information.

    There was exactly ONE instance of a "GPL v2" module license string in
    the kernel back then - drivers/net/tulip/xircom_tulip_cb.c which
    otherwise had no license information at all. There is no indication
    that the change above is any way related to this driver. The change
    happend with the 2.4.11 release which was on Oct. 9 2001 - so quite
    some time before the above commit. Unfortunately there is no trace on
    the intertubes to any discussion of this.

 2) The dual licensed strings became ill defined as well because following
    the "GPL" vs. "GPL v2" distinction all dual licensed (or additional
    rights) MODULE_LICENSE strings would either require those dual licensed
    modules to be licensed under GPL v2 or later or just be unspecified for
    the dual licensing case. Neither choice is coherent with the GPL
    distinction.

Due to the lack of a proper changelog and no real discussion on the patch
submission other than a few implementation details, it's completely unclear
why this distinction was introduced at all. Other than the comment in the
module header file exists no documentation for this at all.

From a license compliance and license scanning POV this distinction is a
total nightmare.

As of 5.0-rc2 2873 out of 9200 instances of MODULE_LICENSE() strings are
conflicting with the actual license in the source code (either SPDX or
license boilerplate/reference). A comparison between the scan of the
history tree and a scan of current Linus tree shows to the extent that the
git rename detection over Linus tree grafted with the history tree is
halfways complete that almost none of the files which got broken in 2003
have been cleaned up vs. the MODULE_LICENSE string. So subtracting those
480 known instances from the conflicting 2800 of today more than 25% of the
module authors got it wrong and it's a high propability that a large
portion of the rest just got it right by chance.

There is no value for the module loader to convey the detailed license
information as the only decision to be made is whether the module is free
software or not.

The "and additional rights", "BSD" and "MPL" strings are not conclusive
license information either. So there is no point in trying to make the GPL
part conclusive and exact. As shown above it's already non conclusive for
dual licensing and incoherent with a large portion of the module source.

As an unintended side effect this distinction causes a major headache for
license compliance, license scanners and the ongoing effort to clean up the
license mess of the kernel.

Therefore remove the well meant, but ill defined, distinction between "GPL"
and "GPL v2" and document that:

  - "GPL" and "GPL v2" both express that the module is licensed under GPLv2
    (without a distinction of 'only' and 'or later') and is therefore kernel
    license compliant.

  - None of the MODULE_LICENSE strings can be used for expressing or
    determining the exact license

  - Their sole purpose is to decide whether the module is free software or
    not.

Add a MODULE_LICENSE subsection to the license rule documentation as well.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Acked-by: Joe Perches &lt;joe@perches.com&gt;
[jc: Did s/merily/merely/ ]
Acked-by: Jessica Yu &lt;jeyu@kernel.org&gt;
Signed-off-by: Jonathan Corbet &lt;corbet@lwn.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The original MODULE_LICENSE string for kernel modules licensed under the
GPL v2 (only / or later) was simply "GPL", which was - and still is -
completely sufficient for the purpose of module loading and checking
whether the module is free software or proprietary.

In January 2003 this was changed with commit 3344ea3ad4b7 ("[PATCH]
MODULE_LICENSE and EXPORT_SYMBOL_GPL support"). This commit can be found in
the history git repository which holds the 1:1 import of Linus' bitkeeper
repository:

  https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=3344ea3ad4b7c302c846a680dbaeedf96ed45c02

The main intention of the patch was to refuse linking proprietary modules
against symbols exported with EXPORT_SYMBOL_GPL() at module load time.

As a completely undocumented side effect it also introduced the distinction
between "GPL" and "GPL v2" MODULE_LICENSE() strings:

 *      "GPL"                           [GNU Public License v2 or later]
 *      "GPL v2"                        [GNU Public License v2]
 *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 *      "Dual BSD/GPL"                  [GNU Public License v2
 *                                       or BSD license choice]
 *      "Dual MPL/GPL"                  [GNU Public License v2
 *                                       or Mozilla license choice]

This distinction was and still is wrong in several aspects:

 1) It broke all modules which were using the "GPL" string in the
    MODULE_LICENSE() already and were licensed under GPL v2 only.

    A quick license scan over the tree at that time shows that at least 480
    out of 1484 modules have been affected by this change back then. The
    number is probably way higher as this was just a quick check for
    clearly identifiable license information.

    There was exactly ONE instance of a "GPL v2" module license string in
    the kernel back then - drivers/net/tulip/xircom_tulip_cb.c which
    otherwise had no license information at all. There is no indication
    that the change above is any way related to this driver. The change
    happend with the 2.4.11 release which was on Oct. 9 2001 - so quite
    some time before the above commit. Unfortunately there is no trace on
    the intertubes to any discussion of this.

 2) The dual licensed strings became ill defined as well because following
    the "GPL" vs. "GPL v2" distinction all dual licensed (or additional
    rights) MODULE_LICENSE strings would either require those dual licensed
    modules to be licensed under GPL v2 or later or just be unspecified for
    the dual licensing case. Neither choice is coherent with the GPL
    distinction.

Due to the lack of a proper changelog and no real discussion on the patch
submission other than a few implementation details, it's completely unclear
why this distinction was introduced at all. Other than the comment in the
module header file exists no documentation for this at all.

From a license compliance and license scanning POV this distinction is a
total nightmare.

As of 5.0-rc2 2873 out of 9200 instances of MODULE_LICENSE() strings are
conflicting with the actual license in the source code (either SPDX or
license boilerplate/reference). A comparison between the scan of the
history tree and a scan of current Linus tree shows to the extent that the
git rename detection over Linus tree grafted with the history tree is
halfways complete that almost none of the files which got broken in 2003
have been cleaned up vs. the MODULE_LICENSE string. So subtracting those
480 known instances from the conflicting 2800 of today more than 25% of the
module authors got it wrong and it's a high propability that a large
portion of the rest just got it right by chance.

There is no value for the module loader to convey the detailed license
information as the only decision to be made is whether the module is free
software or not.

The "and additional rights", "BSD" and "MPL" strings are not conclusive
license information either. So there is no point in trying to make the GPL
part conclusive and exact. As shown above it's already non conclusive for
dual licensing and incoherent with a large portion of the module source.

As an unintended side effect this distinction causes a major headache for
license compliance, license scanners and the ongoing effort to clean up the
license mess of the kernel.

Therefore remove the well meant, but ill defined, distinction between "GPL"
and "GPL v2" and document that:

  - "GPL" and "GPL v2" both express that the module is licensed under GPLv2
    (without a distinction of 'only' and 'or later') and is therefore kernel
    license compliant.

  - None of the MODULE_LICENSE strings can be used for expressing or
    determining the exact license

  - Their sole purpose is to decide whether the module is free software or
    not.

Add a MODULE_LICENSE subsection to the license rule documentation as well.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Acked-by: Joe Perches &lt;joe@perches.com&gt;
[jc: Did s/merily/merely/ ]
Acked-by: Jessica Yu &lt;jeyu@kernel.org&gt;
Signed-off-by: Jonathan Corbet &lt;corbet@lwn.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86, modpost: Replace last remnants of RETPOLINE with CONFIG_RETPOLINE</title>
<updated>2019-01-09T09:35:56+00:00</updated>
<author>
<name>WANG Chao</name>
<email>chao.wang@ucloud.cn</email>
</author>
<published>2018-12-10T16:37:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e4f358916d528d479c3c12bd2fd03f2d5a576380'/>
<id>e4f358916d528d479c3c12bd2fd03f2d5a576380</id>
<content type='text'>
Commit

  4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")

replaced the RETPOLINE define with CONFIG_RETPOLINE checks. Remove the
remaining pieces.

 [ bp: Massage commit message. ]

Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")
Signed-off-by: WANG Chao &lt;chao.wang@ucloud.cn&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Zhenzhong Duan &lt;zhenzhong.duan@oracle.com&gt;
Reviewed-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: David Woodhouse &lt;dwmw@amazon.co.uk&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Jessica Yu &lt;jeyu@kernel.org&gt;
Cc: Jiri Kosina &lt;jkosina@suse.cz&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Cc: Luc Van Oostenryck &lt;luc.vanoostenryck@gmail.com&gt;
Cc: Michal Marek &lt;michal.lkml@markovi.net&gt;
Cc: Miguel Ojeda &lt;miguel.ojeda.sandonis@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Tim Chen &lt;tim.c.chen@linux.intel.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: linux-kbuild@vger.kernel.org
Cc: srinivas.eeda@oracle.com
Cc: stable &lt;stable@vger.kernel.org&gt;
Cc: x86-ml &lt;x86@kernel.org&gt;
Link: https://lkml.kernel.org/r/20181210163725.95977-1-chao.wang@ucloud.cn
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit

  4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")

replaced the RETPOLINE define with CONFIG_RETPOLINE checks. Remove the
remaining pieces.

 [ bp: Massage commit message. ]

Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")
Signed-off-by: WANG Chao &lt;chao.wang@ucloud.cn&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Zhenzhong Duan &lt;zhenzhong.duan@oracle.com&gt;
Reviewed-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: David Woodhouse &lt;dwmw@amazon.co.uk&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Jessica Yu &lt;jeyu@kernel.org&gt;
Cc: Jiri Kosina &lt;jkosina@suse.cz&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Cc: Luc Van Oostenryck &lt;luc.vanoostenryck@gmail.com&gt;
Cc: Michal Marek &lt;michal.lkml@markovi.net&gt;
Cc: Miguel Ojeda &lt;miguel.ojeda.sandonis@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Tim Chen &lt;tim.c.chen@linux.intel.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: linux-kbuild@vger.kernel.org
Cc: srinivas.eeda@oracle.com
Cc: stable &lt;stable@vger.kernel.org&gt;
Cc: x86-ml &lt;x86@kernel.org&gt;
Link: https://lkml.kernel.org/r/20181210163725.95977-1-chao.wang@ucloud.cn
</pre>
</div>
</content>
</entry>
<entry>
<title>jump_label: move 'asm goto' support test to Kconfig</title>
<updated>2019-01-06T00:46:51+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2018-12-30T15:14:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e9666d10a5677a494260d60d1fa0b73cc7646eb3'/>
<id>e9666d10a5677a494260d60d1fa0b73cc7646eb3</id>
<content type='text'>
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) &amp;&amp; defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt; (powerpc)
Tested-by: Sedat Dilek &lt;sedat.dilek@gmail.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) &amp;&amp; defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt; (powerpc)
Tested-by: Sedat Dilek &lt;sedat.dilek@gmail.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next</title>
<updated>2018-12-27T21:04:52+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-12-27T21:04:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e0c38a4d1f196a4b17d2eba36afff8f656a4f1de'/>
<id>e0c38a4d1f196a4b17d2eba36afff8f656a4f1de</id>
<content type='text'>
Pull networking updates from David Miller:

 1) New ipset extensions for matching on destination MAC addresses, from
    Stefano Brivio.

 2) Add ipv4 ttl and tos, plus ipv6 flow label and hop limit offloads to
    nfp driver. From Stefano Brivio.

 3) Implement GRO for plain UDP sockets, from Paolo Abeni.

 4) Lots of work from Michał Mirosław to eliminate the VLAN_TAG_PRESENT
    bit so that we could support the entire vlan_tci value.

 5) Rework the IPSEC policy lookups to better optimize more usecases,
    from Florian Westphal.

 6) Infrastructure changes eliminating direct manipulation of SKB lists
    wherever possible, and to always use the appropriate SKB list
    helpers. This work is still ongoing...

 7) Lots of PHY driver and state machine improvements and
    simplifications, from Heiner Kallweit.

 8) Various TSO deferral refinements, from Eric Dumazet.

 9) Add ntuple filter support to aquantia driver, from Dmitry Bogdanov.

10) Batch dropping of XDP packets in tuntap, from Jason Wang.

11) Lots of cleanups and improvements to the r8169 driver from Heiner
    Kallweit, including support for -&gt;xmit_more. This driver has been
    getting some much needed love since he started working on it.

12) Lots of new forwarding selftests from Petr Machata.

13) Enable VXLAN learning in mlxsw driver, from Ido Schimmel.

14) Packed ring support for virtio, from Tiwei Bie.

15) Add new Aquantia AQtion USB driver, from Dmitry Bezrukov.

16) Add XDP support to dpaa2-eth driver, from Ioana Ciocoi Radulescu.

17) Implement coalescing on TCP backlog queue, from Eric Dumazet.

18) Implement carrier change in tun driver, from Nicolas Dichtel.

19) Support msg_zerocopy in UDP, from Willem de Bruijn.

20) Significantly improve garbage collection of neighbor objects when
    the table has many PERMANENT entries, from David Ahern.

21) Remove egdev usage from nfp and mlx5, and remove the facility
    completely from the tree as it no longer has any users. From Oz
    Shlomo and others.

22) Add a NETDEV_PRE_CHANGEADDR so that drivers can veto the change and
    therefore abort the operation before the commit phase (which is the
    NETDEV_CHANGEADDR event). From Petr Machata.

23) Add indirect call wrappers to avoid retpoline overhead, and use them
    in the GRO code paths. From Paolo Abeni.

24) Add support for netlink FDB get operations, from Roopa Prabhu.

25) Support bloom filter in mlxsw driver, from Nir Dotan.

26) Add SKB extension infrastructure. This consolidates the handling of
    the auxiliary SKB data used by IPSEC and bridge netfilter, and is
    designed to support the needs to MPTCP which could be integrated in
    the future.

27) Lots of XDP TX optimizations in mlx5 from Tariq Toukan.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1845 commits)
  net: dccp: fix kernel crash on module load
  drivers/net: appletalk/cops: remove redundant if statement and mask
  bnx2x: Fix NULL pointer dereference in bnx2x_del_all_vlans() on some hw
  net/net_namespace: Check the return value of register_pernet_subsys()
  net/netlink_compat: Fix a missing check of nla_parse_nested
  ieee802154: lowpan_header_create check must check daddr
  net/mlx4_core: drop useless LIST_HEAD
  mlxsw: spectrum: drop useless LIST_HEAD
  net/mlx5e: drop useless LIST_HEAD
  iptunnel: Set tun_flags in the iptunnel_metadata_reply from src
  net/mlx5e: fix semicolon.cocci warnings
  staging: octeon: fix build failure with XFRM enabled
  net: Revert recent Spectre-v1 patches.
  can: af_can: Fix Spectre v1 vulnerability
  packet: validate address length if non-zero
  nfc: af_nfc: Fix Spectre v1 vulnerability
  phonet: af_phonet: Fix Spectre v1 vulnerability
  net: core: Fix Spectre v1 vulnerability
  net: minor cleanup in skb_ext_add()
  net: drop the unused helper skb_ext_get()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking updates from David Miller:

 1) New ipset extensions for matching on destination MAC addresses, from
    Stefano Brivio.

 2) Add ipv4 ttl and tos, plus ipv6 flow label and hop limit offloads to
    nfp driver. From Stefano Brivio.

 3) Implement GRO for plain UDP sockets, from Paolo Abeni.

 4) Lots of work from Michał Mirosław to eliminate the VLAN_TAG_PRESENT
    bit so that we could support the entire vlan_tci value.

 5) Rework the IPSEC policy lookups to better optimize more usecases,
    from Florian Westphal.

 6) Infrastructure changes eliminating direct manipulation of SKB lists
    wherever possible, and to always use the appropriate SKB list
    helpers. This work is still ongoing...

 7) Lots of PHY driver and state machine improvements and
    simplifications, from Heiner Kallweit.

 8) Various TSO deferral refinements, from Eric Dumazet.

 9) Add ntuple filter support to aquantia driver, from Dmitry Bogdanov.

10) Batch dropping of XDP packets in tuntap, from Jason Wang.

11) Lots of cleanups and improvements to the r8169 driver from Heiner
    Kallweit, including support for -&gt;xmit_more. This driver has been
    getting some much needed love since he started working on it.

12) Lots of new forwarding selftests from Petr Machata.

13) Enable VXLAN learning in mlxsw driver, from Ido Schimmel.

14) Packed ring support for virtio, from Tiwei Bie.

15) Add new Aquantia AQtion USB driver, from Dmitry Bezrukov.

16) Add XDP support to dpaa2-eth driver, from Ioana Ciocoi Radulescu.

17) Implement coalescing on TCP backlog queue, from Eric Dumazet.

18) Implement carrier change in tun driver, from Nicolas Dichtel.

19) Support msg_zerocopy in UDP, from Willem de Bruijn.

20) Significantly improve garbage collection of neighbor objects when
    the table has many PERMANENT entries, from David Ahern.

21) Remove egdev usage from nfp and mlx5, and remove the facility
    completely from the tree as it no longer has any users. From Oz
    Shlomo and others.

22) Add a NETDEV_PRE_CHANGEADDR so that drivers can veto the change and
    therefore abort the operation before the commit phase (which is the
    NETDEV_CHANGEADDR event). From Petr Machata.

23) Add indirect call wrappers to avoid retpoline overhead, and use them
    in the GRO code paths. From Paolo Abeni.

24) Add support for netlink FDB get operations, from Roopa Prabhu.

25) Support bloom filter in mlxsw driver, from Nir Dotan.

26) Add SKB extension infrastructure. This consolidates the handling of
    the auxiliary SKB data used by IPSEC and bridge netfilter, and is
    designed to support the needs to MPTCP which could be integrated in
    the future.

27) Lots of XDP TX optimizations in mlx5 from Tariq Toukan.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1845 commits)
  net: dccp: fix kernel crash on module load
  drivers/net: appletalk/cops: remove redundant if statement and mask
  bnx2x: Fix NULL pointer dereference in bnx2x_del_all_vlans() on some hw
  net/net_namespace: Check the return value of register_pernet_subsys()
  net/netlink_compat: Fix a missing check of nla_parse_nested
  ieee802154: lowpan_header_create check must check daddr
  net/mlx4_core: drop useless LIST_HEAD
  mlxsw: spectrum: drop useless LIST_HEAD
  net/mlx5e: drop useless LIST_HEAD
  iptunnel: Set tun_flags in the iptunnel_metadata_reply from src
  net/mlx5e: fix semicolon.cocci warnings
  staging: octeon: fix build failure with XFRM enabled
  net: Revert recent Spectre-v1 patches.
  can: af_can: Fix Spectre v1 vulnerability
  packet: validate address length if non-zero
  nfc: af_nfc: Fix Spectre v1 vulnerability
  phonet: af_phonet: Fix Spectre v1 vulnerability
  net: core: Fix Spectre v1 vulnerability
  net: minor cleanup in skb_ext_add()
  net: drop the unused helper skb_ext_get()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: support raw tracepoints in modules</title>
<updated>2018-12-18T22:08:12+00:00</updated>
<author>
<name>Matt Mullins</name>
<email>mmullins@fb.com</email>
</author>
<published>2018-12-13T00:42:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a38d1107f937ca95dcf820161ef44ea683d6a0b1'/>
<id>a38d1107f937ca95dcf820161ef44ea683d6a0b1</id>
<content type='text'>
Distributions build drivers as modules, including network and filesystem
drivers which export numerous tracepoints.  This enables
bpf(BPF_RAW_TRACEPOINT_OPEN) to attach to those tracepoints.

Signed-off-by: Matt Mullins &lt;mmullins@fb.com&gt;
Acked-by: Martin KaFai Lau &lt;kafai@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Distributions build drivers as modules, including network and filesystem
drivers which export numerous tracepoints.  This enables
bpf(BPF_RAW_TRACEPOINT_OPEN) to attach to those tracepoints.

Signed-off-by: Matt Mullins &lt;mmullins@fb.com&gt;
Acked-by: Martin KaFai Lau &lt;kafai@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: module: Fix function kallsyms on Thumb-2</title>
<updated>2018-12-14T19:27:29+00:00</updated>
<author>
<name>Vincent Whitchurch</name>
<email>vincent.whitchurch@axis.com</email>
</author>
<published>2018-12-14T16:05:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=93d77e7f1410c366050d6035dcba1a5167c7cf0b'/>
<id>93d77e7f1410c366050d6035dcba1a5167c7cf0b</id>
<content type='text'>
Thumb-2 functions have the lowest bit set in the symbol value in the
symtab.  When kallsyms are generated for the vmlinux, the kallsyms are
generated from the output of nm, and nm clears the lowest bit.

 $ arm-linux-gnueabihf-readelf -a vmlinux | grep show_interrupts
  95947: 8015dc89   686 FUNC    GLOBAL DEFAULT    2 show_interrupts
 $ arm-linux-gnueabihf-nm vmlinux | grep show_interrupts
 8015dc88 T show_interrupts
 $ cat /proc/kallsyms | grep show_interrupts
 8015dc88 T show_interrupts

However, for modules, the kallsyms uses the values in the symbol table
without modification, so for functions in modules, the lowest bit is set
in kallsyms.

 $ arm-linux-gnueabihf-readelf -a drivers/net/tun.ko | grep tun_get_socket
    333: 00002d4d    36 FUNC    GLOBAL DEFAULT    1 tun_get_socket
 $ arm-linux-gnueabihf-nm drivers/net/tun.ko | grep tun_get_socket
 00002d4c T tun_get_socket
 $ cat /proc/kallsyms | grep tun_get_socket
 7f802d4d t tun_get_socket      [tun]

Because of this, the symbol+offset of the crashing instruction shown in
oopses is incorrect when the crash is in a module.  For example, given a
tun_get_socket which starts like this,

 00002d4c &lt;tun_get_socket&gt;:
     2d4c:       6943            ldr     r3, [r0, #20]
     2d4e:       4a07            ldr     r2, [pc, #28]
     2d50:       4293            cmp     r3, r2

a crash when tun_get_socket is called with NULL results in:

 PC is at tun_xdp+0xa3/0xa4 [tun]
 pc : [&lt;7f802d4c&gt;]

As can be seen, the "PC is at" line reports the wrong symbol name, and
the symbol+offset will point to the wrong source line if it is passed to
gdb.

To solve this, add a way for archs to fixup the reading of these module
kallsyms values, and use that to clear the lowest bit for function
symbols on Thumb-2.

After the fix:

 # cat /proc/kallsyms | grep tun_get_socket
 7f802d4c t tun_get_socket       [tun]

 PC is at tun_get_socket+0x0/0x24 [tun]
 pc : [&lt;7f802d4c&gt;]

Signed-off-by: Vincent Whitchurch &lt;vincent.whitchurch@axis.com&gt;
Signed-off-by: Jessica Yu &lt;jeyu@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Thumb-2 functions have the lowest bit set in the symbol value in the
symtab.  When kallsyms are generated for the vmlinux, the kallsyms are
generated from the output of nm, and nm clears the lowest bit.

 $ arm-linux-gnueabihf-readelf -a vmlinux | grep show_interrupts
  95947: 8015dc89   686 FUNC    GLOBAL DEFAULT    2 show_interrupts
 $ arm-linux-gnueabihf-nm vmlinux | grep show_interrupts
 8015dc88 T show_interrupts
 $ cat /proc/kallsyms | grep show_interrupts
 8015dc88 T show_interrupts

However, for modules, the kallsyms uses the values in the symbol table
without modification, so for functions in modules, the lowest bit is set
in kallsyms.

 $ arm-linux-gnueabihf-readelf -a drivers/net/tun.ko | grep tun_get_socket
    333: 00002d4d    36 FUNC    GLOBAL DEFAULT    1 tun_get_socket
 $ arm-linux-gnueabihf-nm drivers/net/tun.ko | grep tun_get_socket
 00002d4c T tun_get_socket
 $ cat /proc/kallsyms | grep tun_get_socket
 7f802d4d t tun_get_socket      [tun]

Because of this, the symbol+offset of the crashing instruction shown in
oopses is incorrect when the crash is in a module.  For example, given a
tun_get_socket which starts like this,

 00002d4c &lt;tun_get_socket&gt;:
     2d4c:       6943            ldr     r3, [r0, #20]
     2d4e:       4a07            ldr     r2, [pc, #28]
     2d50:       4293            cmp     r3, r2

a crash when tun_get_socket is called with NULL results in:

 PC is at tun_xdp+0xa3/0xa4 [tun]
 pc : [&lt;7f802d4c&gt;]

As can be seen, the "PC is at" line reports the wrong symbol name, and
the symbol+offset will point to the wrong source line if it is passed to
gdb.

To solve this, add a way for archs to fixup the reading of these module
kallsyms values, and use that to clear the lowest bit for function
symbols on Thumb-2.

After the fix:

 # cat /proc/kallsyms | grep tun_get_socket
 7f802d4c t tun_get_socket       [tun]

 PC is at tun_get_socket+0x0/0x24 [tun]
 pc : [&lt;7f802d4c&gt;]

Signed-off-by: Vincent Whitchurch &lt;vincent.whitchurch@axis.com&gt;
Signed-off-by: Jessica Yu &lt;jeyu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security</title>
<updated>2018-10-24T10:49:35+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-10-24T10:49:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=638820d8da8ededd6dc609beaef02d5396599c03'/>
<id>638820d8da8ededd6dc609beaef02d5396599c03</id>
<content type='text'>
Pull security subsystem updates from James Morris:
 "In this patchset, there are a couple of minor updates, as well as some
  reworking of the LSM initialization code from Kees Cook (these prepare
  the way for ordered stackable LSMs, but are a valuable cleanup on
  their own)"

* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  LSM: Don't ignore initialization failures
  LSM: Provide init debugging infrastructure
  LSM: Record LSM name in struct lsm_info
  LSM: Convert security_initcall() into DEFINE_LSM()
  vmlinux.lds.h: Move LSM_TABLE into INIT_DATA
  LSM: Convert from initcall to struct lsm_info
  LSM: Remove initcall tracing
  LSM: Rename .security_initcall section to .lsm_info
  vmlinux.lds.h: Avoid copy/paste of security_init section
  LSM: Correctly announce start of LSM initialization
  security: fix LSM description location
  keys: Fix the use of the C++ keyword "private" in uapi/linux/keyctl.h
  seccomp: remove unnecessary unlikely()
  security: tomoyo: Fix obsolete function
  security/capabilities: remove check for -EINVAL
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull security subsystem updates from James Morris:
 "In this patchset, there are a couple of minor updates, as well as some
  reworking of the LSM initialization code from Kees Cook (these prepare
  the way for ordered stackable LSMs, but are a valuable cleanup on
  their own)"

* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  LSM: Don't ignore initialization failures
  LSM: Provide init debugging infrastructure
  LSM: Record LSM name in struct lsm_info
  LSM: Convert security_initcall() into DEFINE_LSM()
  vmlinux.lds.h: Move LSM_TABLE into INIT_DATA
  LSM: Convert from initcall to struct lsm_info
  LSM: Remove initcall tracing
  LSM: Rename .security_initcall section to .lsm_info
  vmlinux.lds.h: Avoid copy/paste of security_init section
  LSM: Correctly announce start of LSM initialization
  security: fix LSM description location
  keys: Fix the use of the C++ keyword "private" in uapi/linux/keyctl.h
  seccomp: remove unnecessary unlikely()
  security: tomoyo: Fix obsolete function
  security/capabilities: remove check for -EINVAL
</pre>
</div>
</content>
</entry>
<entry>
<title>tracepoint: Fix tracepoint array element size mismatch</title>
<updated>2018-10-17T19:35:29+00:00</updated>
<author>
<name>Mathieu Desnoyers</name>
<email>mathieu.desnoyers@efficios.com</email>
</author>
<published>2018-10-13T19:10:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9c0be3f6b5d776dfe3ed249862c244a4486414dc'/>
<id>9c0be3f6b5d776dfe3ed249862c244a4486414dc</id>
<content type='text'>
commit 46e0c9be206f ("kernel: tracepoints: add support for relative
references") changes the layout of the __tracepoint_ptrs section on
architectures supporting relative references. However, it does so
without turning struct tracepoint * const into const int elsewhere in
the tracepoint code, which has the following side-effect:

Setting mod-&gt;num_tracepoints is done in by module.c:

    mod-&gt;tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
                                         sizeof(*mod-&gt;tracepoints_ptrs),
                                         &amp;mod-&gt;num_tracepoints);

Basically, since sizeof(*mod-&gt;tracepoints_ptrs) is a pointer size
(rather than sizeof(int)), num_tracepoints is erroneously set to half the
size it should be on 64-bit arch. So a module with an odd number of
tracepoints misses the last tracepoint due to effect of integer
division.

So in the module going notifier:

        for_each_tracepoint_range(mod-&gt;tracepoints_ptrs,
                mod-&gt;tracepoints_ptrs + mod-&gt;num_tracepoints,
                tp_module_going_check_quiescent, NULL);

the expression (mod-&gt;tracepoints_ptrs + mod-&gt;num_tracepoints) actually
evaluates to something within the bounds of the array, but miss the
last tracepoint if the number of tracepoints is odd on 64-bit arch.

Fix this by introducing a new typedef: tracepoint_ptr_t, which
is either "const int" on architectures that have PREL32 relocations,
or "struct tracepoint * const" on architectures that does not have
this feature.

Also provide a new tracepoint_ptr_defer() static inline to
encapsulate deferencing this type rather than duplicate code and
ugly idefs within the for_each_tracepoint_range() implementation.

This issue appears in 4.19-rc kernels, and should ideally be fixed
before the end of the rc cycle.

Acked-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Acked-by: Jessica Yu &lt;jeyu@kernel.org&gt;
Link: http://lkml.kernel.org/r/20181013191050.22389-1-mathieu.desnoyers@efficios.com
Link: http://lkml.kernel.org/r/20180704083651.24360-7-ard.biesheuvel@linaro.org
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: James Morris &lt;james.morris@microsoft.com&gt;
Cc: James Morris &lt;jmorris@namei.org&gt;
Cc: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Nicolas Pitre &lt;nico@linaro.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Petr Mladek &lt;pmladek@suse.com&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: "Serge E. Hallyn" &lt;serge@hallyn.com&gt;
Cc: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Cc: Thomas Garnier &lt;thgarnie@google.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 46e0c9be206f ("kernel: tracepoints: add support for relative
references") changes the layout of the __tracepoint_ptrs section on
architectures supporting relative references. However, it does so
without turning struct tracepoint * const into const int elsewhere in
the tracepoint code, which has the following side-effect:

Setting mod-&gt;num_tracepoints is done in by module.c:

    mod-&gt;tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
                                         sizeof(*mod-&gt;tracepoints_ptrs),
                                         &amp;mod-&gt;num_tracepoints);

Basically, since sizeof(*mod-&gt;tracepoints_ptrs) is a pointer size
(rather than sizeof(int)), num_tracepoints is erroneously set to half the
size it should be on 64-bit arch. So a module with an odd number of
tracepoints misses the last tracepoint due to effect of integer
division.

So in the module going notifier:

        for_each_tracepoint_range(mod-&gt;tracepoints_ptrs,
                mod-&gt;tracepoints_ptrs + mod-&gt;num_tracepoints,
                tp_module_going_check_quiescent, NULL);

the expression (mod-&gt;tracepoints_ptrs + mod-&gt;num_tracepoints) actually
evaluates to something within the bounds of the array, but miss the
last tracepoint if the number of tracepoints is odd on 64-bit arch.

Fix this by introducing a new typedef: tracepoint_ptr_t, which
is either "const int" on architectures that have PREL32 relocations,
or "struct tracepoint * const" on architectures that does not have
this feature.

Also provide a new tracepoint_ptr_defer() static inline to
encapsulate deferencing this type rather than duplicate code and
ugly idefs within the for_each_tracepoint_range() implementation.

This issue appears in 4.19-rc kernels, and should ideally be fixed
before the end of the rc cycle.

Acked-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Acked-by: Jessica Yu &lt;jeyu@kernel.org&gt;
Link: http://lkml.kernel.org/r/20181013191050.22389-1-mathieu.desnoyers@efficios.com
Link: http://lkml.kernel.org/r/20180704083651.24360-7-ard.biesheuvel@linaro.org
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: James Morris &lt;james.morris@microsoft.com&gt;
Cc: James Morris &lt;jmorris@namei.org&gt;
Cc: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Nicolas Pitre &lt;nico@linaro.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Petr Mladek &lt;pmladek@suse.com&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: "Serge E. Hallyn" &lt;serge@hallyn.com&gt;
Cc: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Cc: Thomas Garnier &lt;thgarnie@google.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</pre>
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