<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/include, branch v3.0.101</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>random: run random_int_secret_init() run after all late_initcalls</title>
<updated>2013-10-22T07:41:44+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2013-09-10T14:52:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fa759b5d100c8b0d2ec2b83fcac990f2c3ac13b7'/>
<id>fa759b5d100c8b0d2ec2b83fcac990f2c3ac13b7</id>
<content type='text'>
commit 47d06e532e95b71c0db3839ebdef3fe8812fca2c upstream.

The some platforms (e.g., ARM) initializes their clocks as
late_initcalls for some unknown reason.  So make sure
random_int_secret_init() is run after all of the late_initcalls are
run.

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&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 47d06e532e95b71c0db3839ebdef3fe8812fca2c upstream.

The some platforms (e.g., ARM) initializes their clocks as
late_initcalls for some unknown reason.  So make sure
random_int_secret_init() is run after all of the late_initcalls are
run.

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ip: generate unique IP identificator if local fragmentation is allowed</title>
<updated>2013-10-13T21:51:07+00:00</updated>
<author>
<name>Ansis Atteka</name>
<email>aatteka@nicira.com</email>
</author>
<published>2013-09-18T22:29:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2a6a2791b1e6ebd7ad29f137a309471f92d71c55'/>
<id>2a6a2791b1e6ebd7ad29f137a309471f92d71c55</id>
<content type='text'>
[ Upstream commit 703133de331a7a7df47f31fb9de51dc6f68a9de8 ]

If local fragmentation is allowed, then ip_select_ident() and
ip_select_ident_more() need to generate unique IDs to ensure
correct defragmentation on the peer.

For example, if IPsec (tunnel mode) has to encrypt large skbs
that have local_df bit set, then all IP fragments that belonged
to different ESP datagrams would have used the same identificator.
If one of these IP fragments would get lost or reordered, then
peer could possibly stitch together wrong IP fragments that did
not belong to the same datagram. This would lead to a packet loss
or data corruption.

Signed-off-by: Ansis Atteka &lt;aatteka@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&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>
[ Upstream commit 703133de331a7a7df47f31fb9de51dc6f68a9de8 ]

If local fragmentation is allowed, then ip_select_ident() and
ip_select_ident_more() need to generate unique IDs to ensure
correct defragmentation on the peer.

For example, if IPsec (tunnel mode) has to encrypt large skbs
that have local_df bit set, then all IP fragments that belonged
to different ESP datagrams would have used the same identificator.
If one of these IP fragments would get lost or reordered, then
peer could possibly stitch together wrong IP fragments that did
not belong to the same datagram. This would lead to a packet loss
or data corruption.

Signed-off-by: Ansis Atteka &lt;aatteka@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>splice: fix racy pipe-&gt;buffers uses</title>
<updated>2013-10-05T14:00:40+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2012-06-12T13:24:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2e4e7cb96933d2c9794125b038bd9ea9cba9bcfc'/>
<id>2e4e7cb96933d2c9794125b038bd9ea9cba9bcfc</id>
<content type='text'>
commit 047fe3605235888f3ebcda0c728cb31937eadfe6 upstream.

Dave Jones reported a kernel BUG at mm/slub.c:3474! triggered
by splice_shrink_spd() called from vmsplice_to_pipe()

commit 35f3d14dbbc5 (pipe: add support for shrinking and growing pipes)
added capability to adjust pipe-&gt;buffers.

Problem is some paths don't hold pipe mutex and assume pipe-&gt;buffers
doesn't change for their duration.

Fix this by adding nr_pages_max field in struct splice_pipe_desc, and
use it in place of pipe-&gt;buffers where appropriate.

splice_shrink_spd() loses its struct pipe_inode_info argument.

Reported-by: Dave Jones &lt;davej@redhat.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Alexander Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Tom Herbert &lt;therbert@google.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt; # 2.6.35
Tested-by: Dave Jones &lt;davej@redhat.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&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 047fe3605235888f3ebcda0c728cb31937eadfe6 upstream.

Dave Jones reported a kernel BUG at mm/slub.c:3474! triggered
by splice_shrink_spd() called from vmsplice_to_pipe()

commit 35f3d14dbbc5 (pipe: add support for shrinking and growing pipes)
added capability to adjust pipe-&gt;buffers.

Problem is some paths don't hold pipe mutex and assume pipe-&gt;buffers
doesn't change for their duration.

Fix this by adding nr_pages_max field in struct splice_pipe_desc, and
use it in place of pipe-&gt;buffers where appropriate.

splice_shrink_spd() loses its struct pipe_inode_info argument.

Reported-by: Dave Jones &lt;davej@redhat.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Alexander Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Tom Herbert &lt;therbert@google.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt; # 2.6.35
Tested-by: Dave Jones &lt;davej@redhat.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: Clarify perf_cpu_context::active_pmu usage by renaming it to ::unique_pmu</title>
<updated>2013-10-01T15:55:47+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>a.p.zijlstra@chello.nl</email>
</author>
<published>2012-10-02T13:38:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=38770b82bdd3523d92596a0807d3751bb7d25224'/>
<id>38770b82bdd3523d92596a0807d3751bb7d25224</id>
<content type='text'>
commit 3f1f33206c16c7b3839d71372bc2ac3f305aa802 upstream.

Stephane thought the perf_cpu_context::active_pmu name confusing and
suggested using 'unique_pmu' instead.

This pointer is a pointer to a 'random' pmu sharing the cpuctx
instance, therefore limiting a for_each_pmu loop to those where
cpuctx-&gt;unique_pmu matches the pmu we get a loop over unique cpuctx
instances.

Suggested-by: Stephane Eranian &lt;eranian@google.com&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/n/tip-kxyjqpfj2fn9gt7kwu5ag9ks@git.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Li Zefan &lt;lizefan@huawei.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 3f1f33206c16c7b3839d71372bc2ac3f305aa802 upstream.

Stephane thought the perf_cpu_context::active_pmu name confusing and
suggested using 'unique_pmu' instead.

This pointer is a pointer to a 'random' pmu sharing the cpuctx
instance, therefore limiting a for_each_pmu loop to those where
cpuctx-&gt;unique_pmu matches the pmu we get a loop over unique cpuctx
instances.

Suggested-by: Stephane Eranian &lt;eranian@google.com&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/n/tip-kxyjqpfj2fn9gt7kwu5ag9ks@git.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Li Zefan &lt;lizefan@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>HID: provide a helper for validating hid reports</title>
<updated>2013-10-01T15:55:47+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2013-09-11T19:56:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7247e66f07168b28410549634ea5d29a84602f81'/>
<id>7247e66f07168b28410549634ea5d29a84602f81</id>
<content type='text'>
commit 331415ff16a12147d57d5c953f3a961b7ede348b upstream.

Many drivers need to validate the characteristics of their HID report
during initialization to avoid misusing the reports. This adds a common
helper to perform validation of the report exisitng, the field existing,
and the expected number of values within the field.

Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Reviewed-by: Benjamin Tissoires &lt;benjamin.tissoires@redhat.com&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&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 331415ff16a12147d57d5c953f3a961b7ede348b upstream.

Many drivers need to validate the characteristics of their HID report
during initialization to avoid misusing the reports. This adds a common
helper to perform validation of the report exisitng, the field existing,
and the expected number of values within the field.

Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Reviewed-by: Benjamin Tissoires &lt;benjamin.tissoires@redhat.com&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>HID: validate HID report id size</title>
<updated>2013-09-26T23:52:48+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2013-08-28T20:29:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=645c9dcabb2c234e6d4a546125830d04988a1f90'/>
<id>645c9dcabb2c234e6d4a546125830d04988a1f90</id>
<content type='text'>
commit 43622021d2e2b82ea03d883926605bdd0525e1d1 upstream.

The "Report ID" field of a HID report is used to build indexes of
reports. The kernel's index of these is limited to 256 entries, so any
malicious device that sets a Report ID greater than 255 will trigger
memory corruption on the host:

[ 1347.156239] BUG: unable to handle kernel paging request at ffff88094958a878
[ 1347.156261] IP: [&lt;ffffffff813e4da0&gt;] hid_register_report+0x2a/0x8b

CVE-2013-2888

Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&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 43622021d2e2b82ea03d883926605bdd0525e1d1 upstream.

The "Report ID" field of a HID report is used to build indexes of
reports. The kernel's index of these is limited to 256 entries, so any
malicious device that sets a Report ID greater than 255 will trigger
memory corruption on the host:

[ 1347.156239] BUG: unable to handle kernel paging request at ffff88094958a878
[ 1347.156261] IP: [&lt;ffffffff813e4da0&gt;] hid_register_report+0x2a/0x8b

CVE-2013-2888

Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>rculist: list_first_or_null_rcu() should use list_entry_rcu()</title>
<updated>2013-09-26T23:52:47+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2013-06-28T17:34:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c97081c634fdee51845ca8a30f394cf06125a509'/>
<id>c97081c634fdee51845ca8a30f394cf06125a509</id>
<content type='text'>
commit c34ac00caefbe49d40058ae7200bd58725cebb45 upstream.

list_first_or_null() should test whether the list is empty and return
pointer to the first entry if not in a RCU safe manner.  It's broken
in several ways.

* It compares __kernel @__ptr with __rcu @__next triggering the
  following sparse warning.

  net/core/dev.c:4331:17: error: incompatible types in comparison expression (different address spaces)

* It doesn't perform rcu_dereference*() and computes the entry address
  using container_of() directly from the __rcu pointer which is
  inconsitent with other rculist interface.  As a result, all three
  in-kernel users - net/core/dev.c, macvlan, cgroup - are buggy.  They
  dereference the pointer w/o going through read barrier.

* While -&gt;next dereference passes through list_next_rcu(), the
  compiler is still free to fetch -&gt;next more than once and thus
  nullify the "__ptr != __next" condition check.

Fix it by making list_first_or_null_rcu() dereference -&gt;next directly
using ACCESS_ONCE() and then use list_entry_rcu() on it like other
rculist accessors.

v2: Paul pointed out that the compiler may fetch the pointer more than
    once nullifying the condition check.  ACCESS_ONCE() added on
    -&gt;next dereference.

v3: Restored () around macro param which was accidentally removed.
    Spotted by Paul.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Cc: Dipankar Sarma &lt;dipankar@in.ibm.com&gt;
Cc: "Paul E. McKenney" &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Li Zefan &lt;lizefan@huawei.com&gt;
Cc: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.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 c34ac00caefbe49d40058ae7200bd58725cebb45 upstream.

list_first_or_null() should test whether the list is empty and return
pointer to the first entry if not in a RCU safe manner.  It's broken
in several ways.

* It compares __kernel @__ptr with __rcu @__next triggering the
  following sparse warning.

  net/core/dev.c:4331:17: error: incompatible types in comparison expression (different address spaces)

* It doesn't perform rcu_dereference*() and computes the entry address
  using container_of() directly from the __rcu pointer which is
  inconsitent with other rculist interface.  As a result, all three
  in-kernel users - net/core/dev.c, macvlan, cgroup - are buggy.  They
  dereference the pointer w/o going through read barrier.

* While -&gt;next dereference passes through list_next_rcu(), the
  compiler is still free to fetch -&gt;next more than once and thus
  nullify the "__ptr != __next" condition check.

Fix it by making list_first_or_null_rcu() dereference -&gt;next directly
using ACCESS_ONCE() and then use list_entry_rcu() on it like other
rculist accessors.

v2: Paul pointed out that the compiler may fetch the pointer more than
    once nullifying the condition check.  ACCESS_ONCE() added on
    -&gt;next dereference.

v3: Restored () around macro param which was accidentally removed.
    Spotted by Paul.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Cc: Dipankar Sarma &lt;dipankar@in.ibm.com&gt;
Cc: "Paul E. McKenney" &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Li Zefan &lt;lizefan@huawei.com&gt;
Cc: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ICMPv6: treat dest unreachable codes 5 and 6 as EACCES, not EPROTO</title>
<updated>2013-09-14T12:50:48+00:00</updated>
<author>
<name>Jiri Bohac</name>
<email>jbohac@suse.cz</email>
</author>
<published>2013-08-30T09:18:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2eeeacf627ab4bac67c3c1735b2c96fccbea6262'/>
<id>2eeeacf627ab4bac67c3c1735b2c96fccbea6262</id>
<content type='text'>
[ Upstream commit 61e76b178dbe7145e8d6afa84bb4ccea71918994 ]

RFC 4443 has defined two additional codes for ICMPv6 type 1 (destination
unreachable) messages:
        5 - Source address failed ingress/egress policy
	6 - Reject route to destination

Now they are treated as protocol error and icmpv6_err_convert() converts them
to EPROTO.

RFC 4443 says:
	"Codes 5 and 6 are more informative subsets of code 1."

Treat codes 5 and 6 as code 1 (EACCES)

Btw, connect() returning -EPROTO confuses firefox, so that fallback to
other/IPv4 addresses does not work:
https://bugzilla.mozilla.org/show_bug.cgi?id=910773

Signed-off-by: Jiri Bohac &lt;jbohac@suse.cz&gt;
Acked-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&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>
[ Upstream commit 61e76b178dbe7145e8d6afa84bb4ccea71918994 ]

RFC 4443 has defined two additional codes for ICMPv6 type 1 (destination
unreachable) messages:
        5 - Source address failed ingress/egress policy
	6 - Reject route to destination

Now they are treated as protocol error and icmpv6_err_convert() converts them
to EPROTO.

RFC 4443 says:
	"Codes 5 and 6 are more informative subsets of code 1."

Treat codes 5 and 6 as code 1 (EACCES)

Btw, connect() returning -EPROTO confuses firefox, so that fallback to
other/IPv4 addresses does not work:
https://bugzilla.mozilla.org/show_bug.cgi?id=910773

Signed-off-by: Jiri Bohac &lt;jbohac@suse.cz&gt;
Acked-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipv6: drop packets with multiple fragmentation headers</title>
<updated>2013-09-14T12:50:48+00:00</updated>
<author>
<name>Hannes Frederic Sowa</name>
<email>hannes@stressinduktion.org</email>
</author>
<published>2013-08-16T11:30:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1eeceae48fdc6e6fcb71403010ef5dd863b7ef2f'/>
<id>1eeceae48fdc6e6fcb71403010ef5dd863b7ef2f</id>
<content type='text'>
[ Upstream commit f46078cfcd77fa5165bf849f5e568a7ac5fa569c ]

It is not allowed for an ipv6 packet to contain multiple fragmentation
headers. So discard packets which were already reassembled by
fragmentation logic and send back a parameter problem icmp.

The updates for RFC 6980 will come in later, I have to do a bit more
research here.

Cc: YOSHIFUJI Hideaki &lt;yoshfuji@linux-ipv6.org&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&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>
[ Upstream commit f46078cfcd77fa5165bf849f5e568a7ac5fa569c ]

It is not allowed for an ipv6 packet to contain multiple fragmentation
headers. So discard packets which were already reassembled by
fragmentation logic and send back a parameter problem icmp.

The updates for RFC 6980 will come in later, I have to do a bit more
research here.

Cc: YOSHIFUJI Hideaki &lt;yoshfuji@linux-ipv6.org&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>SCSI: zfcp: fix lock imbalance by reworking request queue locking</title>
<updated>2013-08-29T16:42:13+00:00</updated>
<author>
<name>Martin Peschke</name>
<email>mpeschke@linux.vnet.ibm.com</email>
</author>
<published>2013-08-22T15:45:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=374172589a9c99e63c373b1c74588553237a74d3'/>
<id>374172589a9c99e63c373b1c74588553237a74d3</id>
<content type='text'>
commit d79ff142624e1be080ad8d09101f7004d79c36e1 upstream.

This patch adds wait_event_interruptible_lock_irq_timeout(), which is a
straight-forward descendant of wait_event_interruptible_timeout() and
wait_event_interruptible_lock_irq().

The zfcp driver used to call wait_event_interruptible_timeout()
in combination with some intricate and error-prone locking. Using
wait_event_interruptible_lock_irq_timeout() as a replacement
nicely cleans up that locking.

This rework removes a situation that resulted in a locking imbalance
in zfcp_qdio_sbal_get():

BUG: workqueue leaked lock or atomic: events/1/0xffffff00/10
    last function: zfcp_fc_wka_port_offline+0x0/0xa0 [zfcp]

It was introduced by commit c2af7545aaff3495d9bf9a7608c52f0af86fb194
"[SCSI] zfcp: Do not wait for SBALs on stopped queue", which had a new
code path related to ZFCP_STATUS_ADAPTER_QDIOUP that took an early exit
without a required lock being held. The problem occured when a
special, non-SCSI I/O request was being submitted in process context,
when the adapter's queues had been torn down. In this case the bug
surfaced when the Fibre Channel port connection for a well-known address
was closed during a concurrent adapter shut-down procedure, which is a
rare constellation.

This patch also fixes these warnings from the sparse tool (make C=1):

drivers/s390/scsi/zfcp_qdio.c:224:12: warning: context imbalance in
 'zfcp_qdio_sbal_check' - wrong count at exit
drivers/s390/scsi/zfcp_qdio.c:244:5: warning: context imbalance in
 'zfcp_qdio_sbal_get' - unexpected unlock

Last but not least, we get rid of that crappy lock-unlock-lock
sequence at the beginning of the critical section.

It is okay to call zfcp_erp_adapter_reopen() with req_q_lock held.

Reported-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Reported-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Signed-off-by: Martin Peschke &lt;mpeschke@linux.vnet.ibm.com&gt;
Signed-off-by: Steffen Maier &lt;maier@linux.vnet.ibm.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.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 d79ff142624e1be080ad8d09101f7004d79c36e1 upstream.

This patch adds wait_event_interruptible_lock_irq_timeout(), which is a
straight-forward descendant of wait_event_interruptible_timeout() and
wait_event_interruptible_lock_irq().

The zfcp driver used to call wait_event_interruptible_timeout()
in combination with some intricate and error-prone locking. Using
wait_event_interruptible_lock_irq_timeout() as a replacement
nicely cleans up that locking.

This rework removes a situation that resulted in a locking imbalance
in zfcp_qdio_sbal_get():

BUG: workqueue leaked lock or atomic: events/1/0xffffff00/10
    last function: zfcp_fc_wka_port_offline+0x0/0xa0 [zfcp]

It was introduced by commit c2af7545aaff3495d9bf9a7608c52f0af86fb194
"[SCSI] zfcp: Do not wait for SBALs on stopped queue", which had a new
code path related to ZFCP_STATUS_ADAPTER_QDIOUP that took an early exit
without a required lock being held. The problem occured when a
special, non-SCSI I/O request was being submitted in process context,
when the adapter's queues had been torn down. In this case the bug
surfaced when the Fibre Channel port connection for a well-known address
was closed during a concurrent adapter shut-down procedure, which is a
rare constellation.

This patch also fixes these warnings from the sparse tool (make C=1):

drivers/s390/scsi/zfcp_qdio.c:224:12: warning: context imbalance in
 'zfcp_qdio_sbal_check' - wrong count at exit
drivers/s390/scsi/zfcp_qdio.c:244:5: warning: context imbalance in
 'zfcp_qdio_sbal_get' - unexpected unlock

Last but not least, we get rid of that crappy lock-unlock-lock
sequence at the beginning of the critical section.

It is okay to call zfcp_erp_adapter_reopen() with req_q_lock held.

Reported-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Reported-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Signed-off-by: Martin Peschke &lt;mpeschke@linux.vnet.ibm.com&gt;
Signed-off-by: Steffen Maier &lt;maier@linux.vnet.ibm.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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