<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/include, branch v4.4.31</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>pwm: Unexport children before chip removal</title>
<updated>2016-11-10T15:36:37+00:00</updated>
<author>
<name>David Hsu</name>
<email>davidhsu@google.com</email>
</author>
<published>2016-08-09T21:57:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4b06152a4822ef10a2b695d6fc75303ad657096b'/>
<id>4b06152a4822ef10a2b695d6fc75303ad657096b</id>
<content type='text'>
commit 0733424c9ba9f42242409d1ece780777272f7ea1 upstream.

Exported pwm channels aren't removed before the pwmchip and are
leaked. This results in invalid sysfs files. This fix removes
all exported pwm channels before chip removal.

Signed-off-by: David Hsu &lt;davidhsu@google.com&gt;
Fixes: 76abbdde2d95 ("pwm: Add sysfs interface")
Signed-off-by: Thierry Reding &lt;thierry.reding@gmail.com&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>
commit 0733424c9ba9f42242409d1ece780777272f7ea1 upstream.

Exported pwm channels aren't removed before the pwmchip and are
leaked. This results in invalid sysfs files. This fix removes
all exported pwm channels before chip removal.

Signed-off-by: David Hsu &lt;davidhsu@google.com&gt;
Fixes: 76abbdde2d95 ("pwm: Add sysfs interface")
Signed-off-by: Thierry Reding &lt;thierry.reding@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>tunnels: Remove encapsulation offloads on decap.</title>
<updated>2016-10-31T10:13:59+00:00</updated>
<author>
<name>Jesse Gross</name>
<email>jesse@kernel.org</email>
</author>
<published>2016-03-19T16:32:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9f9818f8c1cf44055634297247620be4755e7af2'/>
<id>9f9818f8c1cf44055634297247620be4755e7af2</id>
<content type='text'>
commit a09a4c8dd1ec7f830e1fb9e59eb72bddc965d168 upstream.

If a packet is either locally encapsulated or processed through GRO
it is marked with the offloads that it requires. However, when it is
decapsulated these tunnel offload indications are not removed. This
means that if we receive an encapsulated TCP packet, aggregate it with
GRO, decapsulate, and retransmit the resulting frame on a NIC that does
not support encapsulation, we won't be able to take advantage of hardware
offloads even though it is just a simple TCP packet at this point.

This fixes the problem by stripping off encapsulation offload indications
when packets are decapsulated.

The performance impacts of this bug are significant. In a test where a
Geneve encapsulated TCP stream is sent to a hypervisor, GRO'ed, decapsulated,
and bridged to a VM performance is improved by 60% (5Gbps-&gt;8Gbps) as a
result of avoiding unnecessary segmentation at the VM tap interface.

Reported-by: Ramu Ramamurthy &lt;sramamur@linux.vnet.ibm.com&gt;
Fixes: 68c33163 ("v4 GRE: Add TCP segmentation offload for GRE")
Signed-off-by: Jesse Gross &lt;jesse@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
(backported from commit a09a4c8dd1ec7f830e1fb9e59eb72bddc965d168)
[adapt iptunnel_pull_header arguments, avoid 7f290c9]
Signed-off-by: Stefan Bader &lt;stefan.bader@canonical.com&gt;
Signed-off-by: Juerg Haefliger &lt;juerg.haefliger@hpe.com&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>
commit a09a4c8dd1ec7f830e1fb9e59eb72bddc965d168 upstream.

If a packet is either locally encapsulated or processed through GRO
it is marked with the offloads that it requires. However, when it is
decapsulated these tunnel offload indications are not removed. This
means that if we receive an encapsulated TCP packet, aggregate it with
GRO, decapsulate, and retransmit the resulting frame on a NIC that does
not support encapsulation, we won't be able to take advantage of hardware
offloads even though it is just a simple TCP packet at this point.

This fixes the problem by stripping off encapsulation offload indications
when packets are decapsulated.

The performance impacts of this bug are significant. In a test where a
Geneve encapsulated TCP stream is sent to a hypervisor, GRO'ed, decapsulated,
and bridged to a VM performance is improved by 60% (5Gbps-&gt;8Gbps) as a
result of avoiding unnecessary segmentation at the VM tap interface.

Reported-by: Ramu Ramamurthy &lt;sramamur@linux.vnet.ibm.com&gt;
Fixes: 68c33163 ("v4 GRE: Add TCP segmentation offload for GRE")
Signed-off-by: Jesse Gross &lt;jesse@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
(backported from commit a09a4c8dd1ec7f830e1fb9e59eb72bddc965d168)
[adapt iptunnel_pull_header arguments, avoid 7f290c9]
Signed-off-by: Stefan Bader &lt;stefan.bader@canonical.com&gt;
Signed-off-by: Juerg Haefliger &lt;juerg.haefliger@hpe.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tunnels: Don't apply GRO to multiple layers of encapsulation.</title>
<updated>2016-10-31T10:13:59+00:00</updated>
<author>
<name>Jesse Gross</name>
<email>jesse@kernel.org</email>
</author>
<published>2016-03-19T16:32:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5699b3431e0b14736867484b8669ead2d40f575e'/>
<id>5699b3431e0b14736867484b8669ead2d40f575e</id>
<content type='text'>
commit fac8e0f579695a3ecbc4d3cac369139d7f819971 upstream.

When drivers express support for TSO of encapsulated packets, they
only mean that they can do it for one layer of encapsulation.
Supporting additional levels would mean updating, at a minimum,
more IP length fields and they are unaware of this.

No encapsulation device expresses support for handling offloaded
encapsulated packets, so we won't generate these types of frames
in the transmit path. However, GRO doesn't have a check for
multiple levels of encapsulation and will attempt to build them.

UDP tunnel GRO actually does prevent this situation but it only
handles multiple UDP tunnels stacked on top of each other. This
generalizes that solution to prevent any kind of tunnel stacking
that would cause problems.

Fixes: bf5a755f ("net-gre-gro: Add GRE support to the GRO stack")
Signed-off-by: Jesse Gross &lt;jesse@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Juerg Haefliger &lt;juerg.haefliger@hpe.com&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>
commit fac8e0f579695a3ecbc4d3cac369139d7f819971 upstream.

When drivers express support for TSO of encapsulated packets, they
only mean that they can do it for one layer of encapsulation.
Supporting additional levels would mean updating, at a minimum,
more IP length fields and they are unaware of this.

No encapsulation device expresses support for handling offloaded
encapsulated packets, so we won't generate these types of frames
in the transmit path. However, GRO doesn't have a check for
multiple levels of encapsulation and will attempt to build them.

UDP tunnel GRO actually does prevent this situation but it only
handles multiple UDP tunnels stacked on top of each other. This
generalizes that solution to prevent any kind of tunnel stacking
that would cause problems.

Fixes: bf5a755f ("net-gre-gro: Add GRE support to the GRO stack")
Signed-off-by: Jesse Gross &lt;jesse@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Juerg Haefliger &lt;juerg.haefliger@hpe.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>posix_acl: Clear SGID bit when setting file permissions</title>
<updated>2016-10-31T10:13:58+00:00</updated>
<author>
<name>Jan Kara</name>
<email>jack@suse.cz</email>
</author>
<published>2016-09-19T15:39:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=57c9cfdb61ea270936fab76da99a742c6ef0b86f'/>
<id>57c9cfdb61ea270936fab76da99a742c6ef0b86f</id>
<content type='text'>
commit 073931017b49d9458aa351605b43a7e34598caef upstream.

When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok().  Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2).  Fix that.

References: CVE-2016-7097
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Jeff Layton &lt;jlayton@redhat.com&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Andreas Gruenbacher &lt;agruenba@redhat.com&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>
commit 073931017b49d9458aa351605b43a7e34598caef upstream.

When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok().  Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2).  Fix that.

References: CVE-2016-7097
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Jeff Layton &lt;jlayton@redhat.com&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Andreas Gruenbacher &lt;agruenba@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>drm/prime: Pass the right module owner through to dma_buf_export()</title>
<updated>2016-10-31T10:13:57+00:00</updated>
<author>
<name>Chris Wilson</name>
<email>chris@chris-wilson.co.uk</email>
</author>
<published>2016-10-05T12:21:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7a9ddd2f1f4ba34cffb6121a6c360d426310f08c'/>
<id>7a9ddd2f1f4ba34cffb6121a6c360d426310f08c</id>
<content type='text'>
commit 56a76c0123d6cb034975901c80fce2627338ef9e upstream.

dma_buf_export() adds a reference to the owning module to the dmabuf (to
prevent the driver from being unloaded whilst a third party still refers
to the dmabuf). However, drm_gem_prime_export() was passing its own
THIS_MODULE (i.e. drm.ko) rather than the driver. Extract the right
owner from the device-&gt;fops instead.

v2: Use C99 initializers to zero out unset elements of
dma_buf_export_info
v3: Extract the right module from dev-&gt;fops.

Testcase: igt/vgem_basic/unload
Reported-by: Petri Latvala &lt;petri.latvala@intel.com&gt;
Signed-off-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Petri Latvala &lt;petri.latvala@intel.com&gt;
Cc: Christian König &lt;christian.koenig@amd.com&gt;
Tested-by: Petri Latvala &lt;petri.latvala@intel.com&gt;
Reviewed-by: Petri Latvala &lt;petri.latvala@intel.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: http://patchwork.freedesktop.org/patch/msgid/20161005122145.1507-1-chris@chris-wilson.co.uk
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 56a76c0123d6cb034975901c80fce2627338ef9e upstream.

dma_buf_export() adds a reference to the owning module to the dmabuf (to
prevent the driver from being unloaded whilst a third party still refers
to the dmabuf). However, drm_gem_prime_export() was passing its own
THIS_MODULE (i.e. drm.ko) rather than the driver. Extract the right
owner from the device-&gt;fops instead.

v2: Use C99 initializers to zero out unset elements of
dma_buf_export_info
v3: Extract the right module from dev-&gt;fops.

Testcase: igt/vgem_basic/unload
Reported-by: Petri Latvala &lt;petri.latvala@intel.com&gt;
Signed-off-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Petri Latvala &lt;petri.latvala@intel.com&gt;
Cc: Christian König &lt;christian.koenig@amd.com&gt;
Tested-by: Petri Latvala &lt;petri.latvala@intel.com&gt;
Reviewed-by: Petri Latvala &lt;petri.latvala@intel.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: http://patchwork.freedesktop.org/patch/msgid/20161005122145.1507-1-chris@chris-wilson.co.uk
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>target: Make EXTENDED_COPY 0xe4 failure return COPY TARGET DEVICE NOT REACHABLE</title>
<updated>2016-10-28T07:01:36+00:00</updated>
<author>
<name>Nicholas Bellinger</name>
<email>nab@linux-iscsi.org</email>
</author>
<published>2016-10-09T00:26:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f4186e0b11819ae3ae689df68816b993ed89b985'/>
<id>f4186e0b11819ae3ae689df68816b993ed89b985</id>
<content type='text'>
commit 449a137846c84829a328757cd21fd9ca65c08519 upstream.

This patch addresses a bug where EXTENDED_COPY across multiple LUNs
results in a CHECK_CONDITION when the source + destination are not
located on the same physical node.

ESX Host environments expect sense COPY_ABORTED w/ COPY TARGET DEVICE
NOT REACHABLE to be returned when this occurs, in order to signal
fallback to local copy method.

As described in section 6.3.3 of spc4r22:

  "If it is not possible to complete processing of a segment because the
   copy manager is unable to establish communications with a copy target
   device, because the copy target device does not respond to INQUIRY,
   or because the data returned in response to INQUIRY indicates
   an unsupported logical unit, then the EXTENDED COPY command shall be
   terminated with CHECK CONDITION status, with the sense key set to
   COPY ABORTED, and the additional sense code set to COPY TARGET DEVICE
   NOT REACHABLE."

Tested on v4.1.y with ESX v5.5u2+ with BlockCopy across multiple nodes.

Reported-by: Nixon Vincent &lt;nixon.vincent@calsoftinc.com&gt;
Tested-by: Nixon Vincent &lt;nixon.vincent@calsoftinc.com&gt;
Cc: Nixon Vincent &lt;nixon.vincent@calsoftinc.com&gt;
Tested-by: Dinesh Israni &lt;ddi@datera.io&gt;
Signed-off-by: Dinesh Israni &lt;ddi@datera.io&gt;
Cc: Dinesh Israni &lt;ddi@datera.io&gt;
Signed-off-by: Nicholas Bellinger &lt;nab@linux-iscsi.org&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>
commit 449a137846c84829a328757cd21fd9ca65c08519 upstream.

This patch addresses a bug where EXTENDED_COPY across multiple LUNs
results in a CHECK_CONDITION when the source + destination are not
located on the same physical node.

ESX Host environments expect sense COPY_ABORTED w/ COPY TARGET DEVICE
NOT REACHABLE to be returned when this occurs, in order to signal
fallback to local copy method.

As described in section 6.3.3 of spc4r22:

  "If it is not possible to complete processing of a segment because the
   copy manager is unable to establish communications with a copy target
   device, because the copy target device does not respond to INQUIRY,
   or because the data returned in response to INQUIRY indicates
   an unsupported logical unit, then the EXTENDED COPY command shall be
   terminated with CHECK CONDITION status, with the sense key set to
   COPY ABORTED, and the additional sense code set to COPY TARGET DEVICE
   NOT REACHABLE."

Tested on v4.1.y with ESX v5.5u2+ with BlockCopy across multiple nodes.

Reported-by: Nixon Vincent &lt;nixon.vincent@calsoftinc.com&gt;
Tested-by: Nixon Vincent &lt;nixon.vincent@calsoftinc.com&gt;
Cc: Nixon Vincent &lt;nixon.vincent@calsoftinc.com&gt;
Tested-by: Dinesh Israni &lt;ddi@datera.io&gt;
Signed-off-by: Dinesh Israni &lt;ddi@datera.io&gt;
Cc: Dinesh Israni &lt;ddi@datera.io&gt;
Signed-off-by: Nicholas Bellinger &lt;nab@linux-iscsi.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>irqchip/gic-v3-its: Fix entry size mask for GITS_BASER</title>
<updated>2016-10-28T07:01:34+00:00</updated>
<author>
<name>Vladimir Murzin</name>
<email>vladimir.murzin@arm.com</email>
</author>
<published>2016-10-17T15:00:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=76fd38eae33765b92aefa73aaf6cca3f22a3faa3'/>
<id>76fd38eae33765b92aefa73aaf6cca3f22a3faa3</id>
<content type='text'>
commit 9224eb77e63f70f16c0b6b7a20ca7d395f3bc077 upstream.

Entry Size in GITS_BASER&lt;n&gt; occupies 5 bits [52:48], but we mask out 8
bits.

Fixes: cc2d3216f53c ("irqchip: GICv3: ITS command queue")
Signed-off-by: Vladimir Murzin &lt;vladimir.murzin@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&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>
commit 9224eb77e63f70f16c0b6b7a20ca7d395f3bc077 upstream.

Entry Size in GITS_BASER&lt;n&gt; occupies 5 bits [52:48], but we mask out 8
bits.

Fixes: cc2d3216f53c ("irqchip: GICv3: ITS command queue")
Signed-off-by: Vladimir Murzin &lt;vladimir.murzin@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;


</pre>
</div>
</content>
</entry>
<entry>
<title>Using BUG_ON() as an assert() is _never_ acceptable</title>
<updated>2016-10-28T07:01:34+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-10-04T04:03:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e765b192093d3b7fc8899bd33b0867492a405ba0'/>
<id>e765b192093d3b7fc8899bd33b0867492a405ba0</id>
<content type='text'>
commit 21f54ddae449f4bdd9f1498124901d67202243d9 upstream.

That just generally kills the machine, and makes debugging only much
harder, since the traces may long be gone.

Debugging by assert() is a disease.  Don't do it.  If you can continue,
you're much better off doing so with a live machine where you have a
much higher chance that the report actually makes it to the system logs,
rather than result in a machine that is just completely dead.

The only valid situation for BUG_ON() is when continuing is not an
option, because there is massive corruption.  But if you are just
verifying that something is true, you warn about your broken assumptions
(preferably just once), and limp on.

Fixes: 22f2ac51b6d6 ("mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page()")
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Miklos Szeredi &lt;miklos@szeredi.hu&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&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>
commit 21f54ddae449f4bdd9f1498124901d67202243d9 upstream.

That just generally kills the machine, and makes debugging only much
harder, since the traces may long be gone.

Debugging by assert() is a disease.  Don't do it.  If you can continue,
you're much better off doing so with a live machine where you have a
much higher chance that the report actually makes it to the system logs,
rather than result in a machine that is just completely dead.

The only valid situation for BUG_ON() is when continuing is not an
option, because there is massive corruption.  But if you are just
verifying that something is true, you warn about your broken assumptions
(preferably just once), and limp on.

Fixes: 22f2ac51b6d6 ("mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page()")
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Miklos Szeredi &lt;miklos@szeredi.hu&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page()</title>
<updated>2016-10-28T07:01:34+00:00</updated>
<author>
<name>Johannes Weiner</name>
<email>hannes@cmpxchg.org</email>
</author>
<published>2016-09-30T22:11:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f84311d7cd04cb1da9f0192417a584543be879a3'/>
<id>f84311d7cd04cb1da9f0192417a584543be879a3</id>
<content type='text'>
commit 22f2ac51b6d643666f4db093f13144f773ff3f3a upstream.

Antonio reports the following crash when using fuse under memory pressure:

  kernel BUG at /build/linux-a2WvEb/linux-4.4.0/mm/workingset.c:346!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: all of them
  CPU: 2 PID: 63 Comm: kswapd0 Not tainted 4.4.0-36-generic #55-Ubuntu
  Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013
  task: ffff88040cae6040 ti: ffff880407488000 task.ti: ffff880407488000
  RIP: shadow_lru_isolate+0x181/0x190
  Call Trace:
    __list_lru_walk_one.isra.3+0x8f/0x130
    list_lru_walk_one+0x23/0x30
    scan_shadow_nodes+0x34/0x50
    shrink_slab.part.40+0x1ed/0x3d0
    shrink_zone+0x2ca/0x2e0
    kswapd+0x51e/0x990
    kthread+0xd8/0xf0
    ret_from_fork+0x3f/0x70

which corresponds to the following sanity check in the shadow node
tracking:

  BUG_ON(node-&gt;count &amp; RADIX_TREE_COUNT_MASK);

The workingset code tracks radix tree nodes that exclusively contain
shadow entries of evicted pages in them, and this (somewhat obscure)
line checks whether there are real pages left that would interfere with
reclaim of the radix tree node under memory pressure.

While discussing ways how fuse might sneak pages into the radix tree
past the workingset code, Miklos pointed to replace_page_cache_page(),
and indeed there is a problem there: it properly accounts for the old
page being removed - __delete_from_page_cache() does that - but then
does a raw raw radix_tree_insert(), not accounting for the replacement
page.  Eventually the page count bits in node-&gt;count underflow while
leaving the node incorrectly linked to the shadow node LRU.

To address this, make sure replace_page_cache_page() uses the tracked
page insertion code, page_cache_tree_insert().  This fixes the page
accounting and makes sure page-containing nodes are properly unlinked
from the shadow node LRU again.

Also, make the sanity checks a bit less obscure by using the helpers for
checking the number of pages and shadows in a radix tree node.

[mhocko@suse.com: backport for 4.4]
Fixes: 449dd6984d0e ("mm: keep page cache radix tree nodes in check")
Link: http://lkml.kernel.org/r/20160919155822.29498-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Reported-by: Antonio SJ Musumeci &lt;trapexit@spawn.link&gt;
Debugged-by: Miklos Szeredi &lt;miklos@szeredi.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&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>
commit 22f2ac51b6d643666f4db093f13144f773ff3f3a upstream.

Antonio reports the following crash when using fuse under memory pressure:

  kernel BUG at /build/linux-a2WvEb/linux-4.4.0/mm/workingset.c:346!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: all of them
  CPU: 2 PID: 63 Comm: kswapd0 Not tainted 4.4.0-36-generic #55-Ubuntu
  Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013
  task: ffff88040cae6040 ti: ffff880407488000 task.ti: ffff880407488000
  RIP: shadow_lru_isolate+0x181/0x190
  Call Trace:
    __list_lru_walk_one.isra.3+0x8f/0x130
    list_lru_walk_one+0x23/0x30
    scan_shadow_nodes+0x34/0x50
    shrink_slab.part.40+0x1ed/0x3d0
    shrink_zone+0x2ca/0x2e0
    kswapd+0x51e/0x990
    kthread+0xd8/0xf0
    ret_from_fork+0x3f/0x70

which corresponds to the following sanity check in the shadow node
tracking:

  BUG_ON(node-&gt;count &amp; RADIX_TREE_COUNT_MASK);

The workingset code tracks radix tree nodes that exclusively contain
shadow entries of evicted pages in them, and this (somewhat obscure)
line checks whether there are real pages left that would interfere with
reclaim of the radix tree node under memory pressure.

While discussing ways how fuse might sneak pages into the radix tree
past the workingset code, Miklos pointed to replace_page_cache_page(),
and indeed there is a problem there: it properly accounts for the old
page being removed - __delete_from_page_cache() does that - but then
does a raw raw radix_tree_insert(), not accounting for the replacement
page.  Eventually the page count bits in node-&gt;count underflow while
leaving the node incorrectly linked to the shadow node LRU.

To address this, make sure replace_page_cache_page() uses the tracked
page insertion code, page_cache_tree_insert().  This fixes the page
accounting and makes sure page-containing nodes are properly unlinked
from the shadow node LRU again.

Also, make the sanity checks a bit less obscure by using the helpers for
checking the number of pages and shadows in a radix tree node.

[mhocko@suse.com: backport for 4.4]
Fixes: 449dd6984d0e ("mm: keep page cache radix tree nodes in check")
Link: http://lkml.kernel.org/r/20160919155822.29498-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Reported-by: Antonio SJ Musumeci &lt;trapexit@spawn.link&gt;
Debugged-by: Miklos Szeredi &lt;miklos@szeredi.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>lightnvm: ensure that nvm_dev_ops can be used without CONFIG_NVM</title>
<updated>2016-10-28T07:01:32+00:00</updated>
<author>
<name>Jens Axboe</name>
<email>axboe@fb.com</email>
</author>
<published>2016-01-13T20:04:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f2e81c026017222c18b178f175adf415c276b131'/>
<id>f2e81c026017222c18b178f175adf415c276b131</id>
<content type='text'>
commit a7fd9a4f3e8179bab31e4637236ebb0e0b7867c6 upstream.

null_blk defines an empty version of this ops structure if CONFIG_NVM
isn't set, but it doesn't know the type. Move those bits out of the
protection of CONFIG_NVM in the main lightnvm include.

Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
[pebolle: backport to v4.4]
Signed-off-by: Paul Bolle &lt;pebolle@tiscali.nl&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>
commit a7fd9a4f3e8179bab31e4637236ebb0e0b7867c6 upstream.

null_blk defines an empty version of this ops structure if CONFIG_NVM
isn't set, but it doesn't know the type. Move those bits out of the
protection of CONFIG_NVM in the main lightnvm include.

Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
[pebolle: backport to v4.4]
Signed-off-by: Paul Bolle &lt;pebolle@tiscali.nl&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;


</pre>
</div>
</content>
</entry>
</feed>
