<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git, branch v3.10.55</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Linux 3.10.55</title>
<updated>2014-09-17T16:04:18+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2014-09-17T16:04:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=339f8f37f0203884332585e38c06536c8477d475'/>
<id>339f8f37f0203884332585e38c06536c8477d475</id>
<content type='text'>
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
</pre>
</div>
</content>
</entry>
<entry>
<title>libceph: gracefully handle large reply messages from the mon</title>
<updated>2014-09-17T16:04:02+00:00</updated>
<author>
<name>Sage Weil</name>
<email>sage@redhat.com</email>
</author>
<published>2014-08-04T14:01:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=12477ec830cb1bd188f23b80f6a0d976dd19090e'/>
<id>12477ec830cb1bd188f23b80f6a0d976dd19090e</id>
<content type='text'>
commit 73c3d4812b4c755efeca0140f606f83772a39ce4 upstream.

We preallocate a few of the message types we get back from the mon.  If we
get a larger message than we are expecting, fall back to trying to allocate
a new one instead of blindly using the one we have.

Signed-off-by: Sage Weil &lt;sage@redhat.com&gt;
Reviewed-by: Ilya Dryomov &lt;ilya.dryomov@inktank.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 73c3d4812b4c755efeca0140f606f83772a39ce4 upstream.

We preallocate a few of the message types we get back from the mon.  If we
get a larger message than we are expecting, fall back to trying to allocate
a new one instead of blindly using the one we have.

Signed-off-by: Sage Weil &lt;sage@redhat.com&gt;
Reviewed-by: Ilya Dryomov &lt;ilya.dryomov@inktank.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>libceph: rename ceph_msg::front_max to front_alloc_len</title>
<updated>2014-09-17T16:04:02+00:00</updated>
<author>
<name>Ilya Dryomov</name>
<email>ilya.dryomov@inktank.com</email>
</author>
<published>2014-01-09T18:08:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=842a5780d61743550cf319f1bb4aee6778088b1c'/>
<id>842a5780d61743550cf319f1bb4aee6778088b1c</id>
<content type='text'>
commit 3cea4c3071d4e55e9d7356efe9d0ebf92f0c2204 upstream.

Rename front_max field of struct ceph_msg to front_alloc_len to make
its purpose more clear.

Signed-off-by: Ilya Dryomov &lt;ilya.dryomov@inktank.com&gt;
Reviewed-by: Sage Weil &lt;sage@inktank.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 3cea4c3071d4e55e9d7356efe9d0ebf92f0c2204 upstream.

Rename front_max field of struct ceph_msg to front_alloc_len to make
its purpose more clear.

Signed-off-by: Ilya Dryomov &lt;ilya.dryomov@inktank.com&gt;
Reviewed-by: Sage Weil &lt;sage@inktank.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>tpm: Provide a generic means to override the chip returned timeouts</title>
<updated>2014-09-17T16:04:02+00:00</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgunthorpe@obsidianresearch.com</email>
</author>
<published>2014-05-22T00:26:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d64269e30131fbd8a2228323266c9e84ee6ab80d'/>
<id>d64269e30131fbd8a2228323266c9e84ee6ab80d</id>
<content type='text'>
commit 8e54caf407b98efa05409e1fee0e5381abd2b088 upstream.

Some Atmel TPMs provide completely wrong timeouts from their
TPM_CAP_PROP_TIS_TIMEOUT query. This patch detects that and returns
new correct values via a DID/VID table in the TIS driver.

Tested on ARM using an AT97SC3204T FW version 37.16

[PHuewe: without this fix these 'broken' Atmel TPMs won't function on
older kernels]
Signed-off-by: "Berg, Christopher" &lt;Christopher.Berg@atmel.com&gt;
Signed-off-by: Jason Gunthorpe &lt;jgunthorpe@obsidianresearch.com&gt;
Signed-off-by: Peter Huewe &lt;peterhuewe@gmx.de&gt;
[bwh: Backported to 3.10:
 - Adjust filename, context
 - s/chip-&gt;ops-&gt;/chip-&gt;vendor./]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&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 8e54caf407b98efa05409e1fee0e5381abd2b088 upstream.

Some Atmel TPMs provide completely wrong timeouts from their
TPM_CAP_PROP_TIS_TIMEOUT query. This patch detects that and returns
new correct values via a DID/VID table in the TIS driver.

Tested on ARM using an AT97SC3204T FW version 37.16

[PHuewe: without this fix these 'broken' Atmel TPMs won't function on
older kernels]
Signed-off-by: "Berg, Christopher" &lt;Christopher.Berg@atmel.com&gt;
Signed-off-by: Jason Gunthorpe &lt;jgunthorpe@obsidianresearch.com&gt;
Signed-off-by: Peter Huewe &lt;peterhuewe@gmx.de&gt;
[bwh: Backported to 3.10:
 - Adjust filename, context
 - s/chip-&gt;ops-&gt;/chip-&gt;vendor./]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vfs: fix bad hashing of dentries</title>
<updated>2014-09-17T16:04:02+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-09-13T18:30:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d4c96061fddd129778ce8b70fb093aa532f422d0'/>
<id>d4c96061fddd129778ce8b70fb093aa532f422d0</id>
<content type='text'>
commit 99d263d4c5b2f541dfacb5391e22e8c91ea982a6 upstream.

Josef Bacik found a performance regression between 3.2 and 3.10 and
narrowed it down to commit bfcfaa77bdf0 ("vfs: use 'unsigned long'
accesses for dcache name comparison and hashing"). He reports:

 "The test case is essentially

      for (i = 0; i &lt; 1000000; i++)
              mkdir("a$i");

  On xfs on a fio card this goes at about 20k dir/sec with 3.2, and 12k
  dir/sec with 3.10.  This is because we spend waaaaay more time in
  __d_lookup on 3.10 than in 3.2.

  The new hashing function for strings is suboptimal for &lt;
  sizeof(unsigned long) string names (and hell even &gt; sizeof(unsigned
  long) string names that I've tested).  I broke out the old hashing
  function and the new one into a userspace helper to get real numbers
  and this is what I'm getting:

      Old hash table had 1000000 entries, 0 dupes, 0 max dupes
      New hash table had 12628 entries, 987372 dupes, 900 max dupes
      We had 11400 buckets with a p50 of 30 dupes, p90 of 240 dupes, p99 of 567 dupes for the new hash

  My test does the hash, and then does the d_hash into a integer pointer
  array the same size as the dentry hash table on my system, and then
  just increments the value at the address we got to see how many
  entries we overlap with.

  As you can see the old hash function ended up with all 1 million
  entries in their own bucket, whereas the new one they are only
  distributed among ~12.5k buckets, which is why we're using so much
  more CPU in __d_lookup".

The reason for this hash regression is two-fold:

 - On 64-bit architectures the down-mixing of the original 64-bit
   word-at-a-time hash into the final 32-bit hash value is very
   simplistic and suboptimal, and just adds the two 32-bit parts
   together.

   In particular, because there is no bit shuffling and the mixing
   boundary is also a byte boundary, similar character patterns in the
   low and high word easily end up just canceling each other out.

 - the old byte-at-a-time hash mixed each byte into the final hash as it
   hashed the path component name, resulting in the low bits of the hash
   generally being a good source of hash data.  That is not true for the
   word-at-a-time case, and the hash data is distributed among all the
   bits.

The fix is the same in both cases: do a better job of mixing the bits up
and using as much of the hash data as possible.  We already have the
"hash_32|64()" functions to do that.

Reported-by: Josef Bacik &lt;jbacik@fb.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: Chris Mason &lt;clm@fb.com&gt;
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.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 99d263d4c5b2f541dfacb5391e22e8c91ea982a6 upstream.

Josef Bacik found a performance regression between 3.2 and 3.10 and
narrowed it down to commit bfcfaa77bdf0 ("vfs: use 'unsigned long'
accesses for dcache name comparison and hashing"). He reports:

 "The test case is essentially

      for (i = 0; i &lt; 1000000; i++)
              mkdir("a$i");

  On xfs on a fio card this goes at about 20k dir/sec with 3.2, and 12k
  dir/sec with 3.10.  This is because we spend waaaaay more time in
  __d_lookup on 3.10 than in 3.2.

  The new hashing function for strings is suboptimal for &lt;
  sizeof(unsigned long) string names (and hell even &gt; sizeof(unsigned
  long) string names that I've tested).  I broke out the old hashing
  function and the new one into a userspace helper to get real numbers
  and this is what I'm getting:

      Old hash table had 1000000 entries, 0 dupes, 0 max dupes
      New hash table had 12628 entries, 987372 dupes, 900 max dupes
      We had 11400 buckets with a p50 of 30 dupes, p90 of 240 dupes, p99 of 567 dupes for the new hash

  My test does the hash, and then does the d_hash into a integer pointer
  array the same size as the dentry hash table on my system, and then
  just increments the value at the address we got to see how many
  entries we overlap with.

  As you can see the old hash function ended up with all 1 million
  entries in their own bucket, whereas the new one they are only
  distributed among ~12.5k buckets, which is why we're using so much
  more CPU in __d_lookup".

The reason for this hash regression is two-fold:

 - On 64-bit architectures the down-mixing of the original 64-bit
   word-at-a-time hash into the final 32-bit hash value is very
   simplistic and suboptimal, and just adds the two 32-bit parts
   together.

   In particular, because there is no bit shuffling and the mixing
   boundary is also a byte boundary, similar character patterns in the
   low and high word easily end up just canceling each other out.

 - the old byte-at-a-time hash mixed each byte into the final hash as it
   hashed the path component name, resulting in the low bits of the hash
   generally being a good source of hash data.  That is not true for the
   word-at-a-time case, and the hash data is distributed among all the
   bits.

The fix is the same in both cases: do a better job of mixing the bits up
and using as much of the hash data as possible.  We already have the
"hash_32|64()" functions to do that.

Reported-by: Josef Bacik &lt;jbacik@fb.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: Chris Mason &lt;clm@fb.com&gt;
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>dcache.c: get rid of pointless macros</title>
<updated>2014-09-17T16:04:02+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2013-10-25T20:41:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a6c56468b3f3274896ee8da73608dc48ad4103e0'/>
<id>a6c56468b3f3274896ee8da73608dc48ad4103e0</id>
<content type='text'>
commit 482db9066199813d6b999b65a3171afdbec040b6 upstream.

D_HASH{MASK,BITS} are used once each, both in the same function (d_hash()).
At this point they are actively misguiding - they imply that values are
compiler constants, which is no longer true.

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&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 482db9066199813d6b999b65a3171afdbec040b6 upstream.

D_HASH{MASK,BITS} are used once each, both in the same function (d_hash()).
At this point they are actively misguiding - they imply that values are
compiler constants, which is no longer true.

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>IB/srp: Fix deadlock between host removal and multipathd</title>
<updated>2014-09-17T16:04:02+00:00</updated>
<author>
<name>Bart Van Assche</name>
<email>bvanassche@acm.org</email>
</author>
<published>2014-07-09T13:57:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=70efec16cf060603b54ea71c9cb4499f052efd69'/>
<id>70efec16cf060603b54ea71c9cb4499f052efd69</id>
<content type='text'>
commit bcc05910359183b431da92713e98eed478edf83a upstream.

If scsi_remove_host() is invoked after a SCSI device has been blocked,
if the fast_io_fail_tmo or dev_loss_tmo work gets scheduled on the
workqueue executing srp_remove_work() and if an I/O request is
scheduled after the SCSI device had been blocked by e.g. multipathd
then the following deadlock can occur:

    kworker/6:1     D ffff880831f3c460     0   195      2 0x00000000
    Call Trace:
     [&lt;ffffffff814aafd9&gt;] schedule+0x29/0x70
     [&lt;ffffffff814aa0ef&gt;] schedule_timeout+0x10f/0x2a0
     [&lt;ffffffff8105af6f&gt;] msleep+0x2f/0x40
     [&lt;ffffffff8123b0ae&gt;] __blk_drain_queue+0x4e/0x180
     [&lt;ffffffff8123d2d5&gt;] blk_cleanup_queue+0x225/0x230
     [&lt;ffffffffa0010732&gt;] __scsi_remove_device+0x62/0xe0 [scsi_mod]
     [&lt;ffffffffa000ed2f&gt;] scsi_forget_host+0x6f/0x80 [scsi_mod]
     [&lt;ffffffffa0002eba&gt;] scsi_remove_host+0x7a/0x130 [scsi_mod]
     [&lt;ffffffffa07cf5c5&gt;] srp_remove_work+0x95/0x180 [ib_srp]
     [&lt;ffffffff8106d7aa&gt;] process_one_work+0x1ea/0x6c0
     [&lt;ffffffff8106dd9b&gt;] worker_thread+0x11b/0x3a0
     [&lt;ffffffff810758bd&gt;] kthread+0xed/0x110
     [&lt;ffffffff814b972c&gt;] ret_from_fork+0x7c/0xb0
    multipathd      D ffff880096acc460     0  5340      1 0x00000000
    Call Trace:
     [&lt;ffffffff814aafd9&gt;] schedule+0x29/0x70
     [&lt;ffffffff814aa0ef&gt;] schedule_timeout+0x10f/0x2a0
     [&lt;ffffffff814ab79b&gt;] io_schedule_timeout+0x9b/0xf0
     [&lt;ffffffff814abe1c&gt;] wait_for_completion_io_timeout+0xdc/0x110
     [&lt;ffffffff81244b9b&gt;] blk_execute_rq+0x9b/0x100
     [&lt;ffffffff8124f665&gt;] sg_io+0x1a5/0x450
     [&lt;ffffffff8124fd21&gt;] scsi_cmd_ioctl+0x2a1/0x430
     [&lt;ffffffff8124fef2&gt;] scsi_cmd_blk_ioctl+0x42/0x50
     [&lt;ffffffffa00ec97e&gt;] sd_ioctl+0xbe/0x140 [sd_mod]
     [&lt;ffffffff8124bd04&gt;] blkdev_ioctl+0x234/0x840
     [&lt;ffffffff811cb491&gt;] block_ioctl+0x41/0x50
     [&lt;ffffffff811a0df0&gt;] do_vfs_ioctl+0x300/0x520
     [&lt;ffffffff811a1051&gt;] SyS_ioctl+0x41/0x80
     [&lt;ffffffff814b9962&gt;] tracesys+0xd0/0xd5

Fix this by scheduling removal work on another workqueue than the
transport layer timers.

Signed-off-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Reviewed-by: Sagi Grimberg &lt;sagig@mellanox.com&gt;
Reviewed-by: David Dillow &lt;dave@thedillows.org&gt;
Cc: Sebastian Parschauer &lt;sebastian.riemer@profitbricks.com&gt;
Signed-off-by: Roland Dreier &lt;roland@purestorage.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 bcc05910359183b431da92713e98eed478edf83a upstream.

If scsi_remove_host() is invoked after a SCSI device has been blocked,
if the fast_io_fail_tmo or dev_loss_tmo work gets scheduled on the
workqueue executing srp_remove_work() and if an I/O request is
scheduled after the SCSI device had been blocked by e.g. multipathd
then the following deadlock can occur:

    kworker/6:1     D ffff880831f3c460     0   195      2 0x00000000
    Call Trace:
     [&lt;ffffffff814aafd9&gt;] schedule+0x29/0x70
     [&lt;ffffffff814aa0ef&gt;] schedule_timeout+0x10f/0x2a0
     [&lt;ffffffff8105af6f&gt;] msleep+0x2f/0x40
     [&lt;ffffffff8123b0ae&gt;] __blk_drain_queue+0x4e/0x180
     [&lt;ffffffff8123d2d5&gt;] blk_cleanup_queue+0x225/0x230
     [&lt;ffffffffa0010732&gt;] __scsi_remove_device+0x62/0xe0 [scsi_mod]
     [&lt;ffffffffa000ed2f&gt;] scsi_forget_host+0x6f/0x80 [scsi_mod]
     [&lt;ffffffffa0002eba&gt;] scsi_remove_host+0x7a/0x130 [scsi_mod]
     [&lt;ffffffffa07cf5c5&gt;] srp_remove_work+0x95/0x180 [ib_srp]
     [&lt;ffffffff8106d7aa&gt;] process_one_work+0x1ea/0x6c0
     [&lt;ffffffff8106dd9b&gt;] worker_thread+0x11b/0x3a0
     [&lt;ffffffff810758bd&gt;] kthread+0xed/0x110
     [&lt;ffffffff814b972c&gt;] ret_from_fork+0x7c/0xb0
    multipathd      D ffff880096acc460     0  5340      1 0x00000000
    Call Trace:
     [&lt;ffffffff814aafd9&gt;] schedule+0x29/0x70
     [&lt;ffffffff814aa0ef&gt;] schedule_timeout+0x10f/0x2a0
     [&lt;ffffffff814ab79b&gt;] io_schedule_timeout+0x9b/0xf0
     [&lt;ffffffff814abe1c&gt;] wait_for_completion_io_timeout+0xdc/0x110
     [&lt;ffffffff81244b9b&gt;] blk_execute_rq+0x9b/0x100
     [&lt;ffffffff8124f665&gt;] sg_io+0x1a5/0x450
     [&lt;ffffffff8124fd21&gt;] scsi_cmd_ioctl+0x2a1/0x430
     [&lt;ffffffff8124fef2&gt;] scsi_cmd_blk_ioctl+0x42/0x50
     [&lt;ffffffffa00ec97e&gt;] sd_ioctl+0xbe/0x140 [sd_mod]
     [&lt;ffffffff8124bd04&gt;] blkdev_ioctl+0x234/0x840
     [&lt;ffffffff811cb491&gt;] block_ioctl+0x41/0x50
     [&lt;ffffffff811a0df0&gt;] do_vfs_ioctl+0x300/0x520
     [&lt;ffffffff811a1051&gt;] SyS_ioctl+0x41/0x80
     [&lt;ffffffff814b9962&gt;] tracesys+0xd0/0xd5

Fix this by scheduling removal work on another workqueue than the
transport layer timers.

Signed-off-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Reviewed-by: Sagi Grimberg &lt;sagig@mellanox.com&gt;
Reviewed-by: David Dillow &lt;dave@thedillows.org&gt;
Cc: Sebastian Parschauer &lt;sebastian.riemer@profitbricks.com&gt;
Signed-off-by: Roland Dreier &lt;roland@purestorage.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>blkcg: don't call into policy draining if root_blkg is already gone</title>
<updated>2014-09-17T16:04:02+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2014-07-05T22:43:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f5b48b7a3d0d1ab761ba939b6cbb4a07d37a750b'/>
<id>f5b48b7a3d0d1ab761ba939b6cbb4a07d37a750b</id>
<content type='text'>
commit 2a1b4cf2331d92bc009bf94fa02a24604cdaf24c upstream.

While a queue is being destroyed, all the blkgs are destroyed and its
-&gt;root_blkg pointer is set to NULL.  If someone else starts to drain
while the queue is in this state, the following oops happens.

  NULL pointer dereference at 0000000000000028
  IP: [&lt;ffffffff8144e944&gt;] blk_throtl_drain+0x84/0x230
  PGD e4a1067 PUD b773067 PMD 0
  Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
  Modules linked in: cfq_iosched(-) [last unloaded: cfq_iosched]
  CPU: 1 PID: 537 Comm: bash Not tainted 3.16.0-rc3-work+ #2
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  task: ffff88000e222250 ti: ffff88000efd4000 task.ti: ffff88000efd4000
  RIP: 0010:[&lt;ffffffff8144e944&gt;]  [&lt;ffffffff8144e944&gt;] blk_throtl_drain+0x84/0x230
  RSP: 0018:ffff88000efd7bf0  EFLAGS: 00010046
  RAX: 0000000000000000 RBX: ffff880015091450 RCX: 0000000000000001
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
  RBP: ffff88000efd7c10 R08: 0000000000000000 R09: 0000000000000001
  R10: ffff88000e222250 R11: 0000000000000000 R12: ffff880015091450
  R13: ffff880015092e00 R14: ffff880015091d70 R15: ffff88001508fc28
  FS:  00007f1332650740(0000) GS:ffff88001fa80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 0000000000000028 CR3: 0000000009446000 CR4: 00000000000006e0
  Stack:
   ffffffff8144e8f6 ffff880015091450 0000000000000000 ffff880015091d80
   ffff88000efd7c28 ffffffff8144ae2f ffff880015091450 ffff88000efd7c58
   ffffffff81427641 ffff880015091450 ffffffff82401f00 ffff880015091450
  Call Trace:
   [&lt;ffffffff8144ae2f&gt;] blkcg_drain_queue+0x1f/0x60
   [&lt;ffffffff81427641&gt;] __blk_drain_queue+0x71/0x180
   [&lt;ffffffff81429b3e&gt;] blk_queue_bypass_start+0x6e/0xb0
   [&lt;ffffffff814498b8&gt;] blkcg_deactivate_policy+0x38/0x120
   [&lt;ffffffff8144ec44&gt;] blk_throtl_exit+0x34/0x50
   [&lt;ffffffff8144aea5&gt;] blkcg_exit_queue+0x35/0x40
   [&lt;ffffffff8142d476&gt;] blk_release_queue+0x26/0xd0
   [&lt;ffffffff81454968&gt;] kobject_cleanup+0x38/0x70
   [&lt;ffffffff81454848&gt;] kobject_put+0x28/0x60
   [&lt;ffffffff81427505&gt;] blk_put_queue+0x15/0x20
   [&lt;ffffffff817d07bb&gt;] scsi_device_dev_release_usercontext+0x16b/0x1c0
   [&lt;ffffffff810bc339&gt;] execute_in_process_context+0x89/0xa0
   [&lt;ffffffff817d064c&gt;] scsi_device_dev_release+0x1c/0x20
   [&lt;ffffffff817930e2&gt;] device_release+0x32/0xa0
   [&lt;ffffffff81454968&gt;] kobject_cleanup+0x38/0x70
   [&lt;ffffffff81454848&gt;] kobject_put+0x28/0x60
   [&lt;ffffffff817934d7&gt;] put_device+0x17/0x20
   [&lt;ffffffff817d11b9&gt;] __scsi_remove_device+0xa9/0xe0
   [&lt;ffffffff817d121b&gt;] scsi_remove_device+0x2b/0x40
   [&lt;ffffffff817d1257&gt;] sdev_store_delete+0x27/0x30
   [&lt;ffffffff81792ca8&gt;] dev_attr_store+0x18/0x30
   [&lt;ffffffff8126f75e&gt;] sysfs_kf_write+0x3e/0x50
   [&lt;ffffffff8126ea87&gt;] kernfs_fop_write+0xe7/0x170
   [&lt;ffffffff811f5e9f&gt;] vfs_write+0xaf/0x1d0
   [&lt;ffffffff811f69bd&gt;] SyS_write+0x4d/0xc0
   [&lt;ffffffff81d24692&gt;] system_call_fastpath+0x16/0x1b

776687bce42b ("block, blk-mq: draining can't be skipped even if
bypass_depth was non-zero") made it easier to trigger this bug by
making blk_queue_bypass_start() drain even when it loses the first
bypass test to blk_cleanup_queue(); however, the bug has always been
there even before the commit as blk_queue_bypass_start() could race
against queue destruction, win the initial bypass test but perform the
actual draining after blk_cleanup_queue() already destroyed all blkgs.

Fix it by skippping calling into policy draining if all the blkgs are
already gone.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Shirish Pargaonkar &lt;spargaonkar@suse.com&gt;
Reported-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
Reported-by: Jet Chen &lt;jet.chen@intel.com&gt;
Tested-by: Shirish Pargaonkar &lt;spargaonkar@suse.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.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 2a1b4cf2331d92bc009bf94fa02a24604cdaf24c upstream.

While a queue is being destroyed, all the blkgs are destroyed and its
-&gt;root_blkg pointer is set to NULL.  If someone else starts to drain
while the queue is in this state, the following oops happens.

  NULL pointer dereference at 0000000000000028
  IP: [&lt;ffffffff8144e944&gt;] blk_throtl_drain+0x84/0x230
  PGD e4a1067 PUD b773067 PMD 0
  Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
  Modules linked in: cfq_iosched(-) [last unloaded: cfq_iosched]
  CPU: 1 PID: 537 Comm: bash Not tainted 3.16.0-rc3-work+ #2
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  task: ffff88000e222250 ti: ffff88000efd4000 task.ti: ffff88000efd4000
  RIP: 0010:[&lt;ffffffff8144e944&gt;]  [&lt;ffffffff8144e944&gt;] blk_throtl_drain+0x84/0x230
  RSP: 0018:ffff88000efd7bf0  EFLAGS: 00010046
  RAX: 0000000000000000 RBX: ffff880015091450 RCX: 0000000000000001
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
  RBP: ffff88000efd7c10 R08: 0000000000000000 R09: 0000000000000001
  R10: ffff88000e222250 R11: 0000000000000000 R12: ffff880015091450
  R13: ffff880015092e00 R14: ffff880015091d70 R15: ffff88001508fc28
  FS:  00007f1332650740(0000) GS:ffff88001fa80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 0000000000000028 CR3: 0000000009446000 CR4: 00000000000006e0
  Stack:
   ffffffff8144e8f6 ffff880015091450 0000000000000000 ffff880015091d80
   ffff88000efd7c28 ffffffff8144ae2f ffff880015091450 ffff88000efd7c58
   ffffffff81427641 ffff880015091450 ffffffff82401f00 ffff880015091450
  Call Trace:
   [&lt;ffffffff8144ae2f&gt;] blkcg_drain_queue+0x1f/0x60
   [&lt;ffffffff81427641&gt;] __blk_drain_queue+0x71/0x180
   [&lt;ffffffff81429b3e&gt;] blk_queue_bypass_start+0x6e/0xb0
   [&lt;ffffffff814498b8&gt;] blkcg_deactivate_policy+0x38/0x120
   [&lt;ffffffff8144ec44&gt;] blk_throtl_exit+0x34/0x50
   [&lt;ffffffff8144aea5&gt;] blkcg_exit_queue+0x35/0x40
   [&lt;ffffffff8142d476&gt;] blk_release_queue+0x26/0xd0
   [&lt;ffffffff81454968&gt;] kobject_cleanup+0x38/0x70
   [&lt;ffffffff81454848&gt;] kobject_put+0x28/0x60
   [&lt;ffffffff81427505&gt;] blk_put_queue+0x15/0x20
   [&lt;ffffffff817d07bb&gt;] scsi_device_dev_release_usercontext+0x16b/0x1c0
   [&lt;ffffffff810bc339&gt;] execute_in_process_context+0x89/0xa0
   [&lt;ffffffff817d064c&gt;] scsi_device_dev_release+0x1c/0x20
   [&lt;ffffffff817930e2&gt;] device_release+0x32/0xa0
   [&lt;ffffffff81454968&gt;] kobject_cleanup+0x38/0x70
   [&lt;ffffffff81454848&gt;] kobject_put+0x28/0x60
   [&lt;ffffffff817934d7&gt;] put_device+0x17/0x20
   [&lt;ffffffff817d11b9&gt;] __scsi_remove_device+0xa9/0xe0
   [&lt;ffffffff817d121b&gt;] scsi_remove_device+0x2b/0x40
   [&lt;ffffffff817d1257&gt;] sdev_store_delete+0x27/0x30
   [&lt;ffffffff81792ca8&gt;] dev_attr_store+0x18/0x30
   [&lt;ffffffff8126f75e&gt;] sysfs_kf_write+0x3e/0x50
   [&lt;ffffffff8126ea87&gt;] kernfs_fop_write+0xe7/0x170
   [&lt;ffffffff811f5e9f&gt;] vfs_write+0xaf/0x1d0
   [&lt;ffffffff811f69bd&gt;] SyS_write+0x4d/0xc0
   [&lt;ffffffff81d24692&gt;] system_call_fastpath+0x16/0x1b

776687bce42b ("block, blk-mq: draining can't be skipped even if
bypass_depth was non-zero") made it easier to trigger this bug by
making blk_queue_bypass_start() drain even when it loses the first
bypass test to blk_cleanup_queue(); however, the bug has always been
there even before the commit as blk_queue_bypass_start() could race
against queue destruction, win the initial bypass test but perform the
actual draining after blk_cleanup_queue() already destroyed all blkgs.

Fix it by skippping calling into policy draining if all the blkgs are
already gone.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Shirish Pargaonkar &lt;spargaonkar@suse.com&gt;
Reported-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
Reported-by: Jet Chen &lt;jet.chen@intel.com&gt;
Tested-by: Shirish Pargaonkar &lt;spargaonkar@suse.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>mtd: nand: omap: Fix 1-bit Hamming code scheme, omap_calculate_ecc()</title>
<updated>2014-09-17T16:04:02+00:00</updated>
<author>
<name>Roger Quadros</name>
<email>rogerq@ti.com</email>
</author>
<published>2014-08-25T23:15:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6562c0cc805b391489e2f511983300e802864aea'/>
<id>6562c0cc805b391489e2f511983300e802864aea</id>
<content type='text'>
commit 40ddbf5069bd4e11447c0088fc75318e0aac53f0 upstream.

commit 65b97cf6b8de introduced in v3.7 caused a regression
by using a reversed CS_MASK thus causing omap_calculate_ecc to
always fail. As the NAND base driver never checks for .calculate()'s
return value, the zeroed ECC values are used as is without showing
any error to the user. However, this won't work and the NAND device
won't be guarded by any error code.

Fix the issue by using the correct mask.

Code was tested on omap3beagle using the following procedure
- flash the primary bootloader (MLO) from the kernel to the first
NAND partition using nandwrite.
- boot the board from NAND. This utilizes OMAP ROM loader that
relies on 1-bit Hamming code ECC.

Fixes: 65b97cf6b8de (mtd: nand: omap2: handle nand on gpmc)

Signed-off-by: Roger Quadros &lt;rogerq@ti.com&gt;
Signed-off-by: Tony Lindgren &lt;tony@atomide.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 40ddbf5069bd4e11447c0088fc75318e0aac53f0 upstream.

commit 65b97cf6b8de introduced in v3.7 caused a regression
by using a reversed CS_MASK thus causing omap_calculate_ecc to
always fail. As the NAND base driver never checks for .calculate()'s
return value, the zeroed ECC values are used as is without showing
any error to the user. However, this won't work and the NAND device
won't be guarded by any error code.

Fix the issue by using the correct mask.

Code was tested on omap3beagle using the following procedure
- flash the primary bootloader (MLO) from the kernel to the first
NAND partition using nandwrite.
- boot the board from NAND. This utilizes OMAP ROM loader that
relies on 1-bit Hamming code ECC.

Fixes: 65b97cf6b8de (mtd: nand: omap2: handle nand on gpmc)

Signed-off-by: Roger Quadros &lt;rogerq@ti.com&gt;
Signed-off-by: Tony Lindgren &lt;tony@atomide.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>mtd/ftl: fix the double free of the buffers allocated in build_maps()</title>
<updated>2014-09-17T16:04:02+00:00</updated>
<author>
<name>Kevin Hao</name>
<email>haokexin@gmail.com</email>
</author>
<published>2014-07-03T02:35:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a9d28db622269c29825f13c28bae0f587f77aada'/>
<id>a9d28db622269c29825f13c28bae0f587f77aada</id>
<content type='text'>
commit a152056c912db82860a8b4c23d0bd3a5aa89e363 upstream.

I got the following panic on my fsl p5020ds board.

  Unable to handle kernel paging request for data at address 0x7375627379737465
  Faulting instruction address: 0xc000000000100778
  Oops: Kernel access of bad area, sig: 11 [#1]
  SMP NR_CPUS=24 CoreNet Generic
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.15.0-next-20140613 #145
  task: c0000000fe080000 ti: c0000000fe088000 task.ti: c0000000fe088000
  NIP: c000000000100778 LR: c00000000010073c CTR: 0000000000000000
  REGS: c0000000fe08aa00 TRAP: 0300   Not tainted  (3.15.0-next-20140613)
  MSR: 0000000080029000 &lt;CE,EE,ME&gt;  CR: 24ad2e24  XER: 00000000
  DEAR: 7375627379737465 ESR: 0000000000000000 SOFTE: 1
  GPR00: c0000000000c99b0 c0000000fe08ac80 c0000000009598e0 c0000000fe001d80
  GPR04: 00000000000000d0 0000000000000913 c000000007902b20 0000000000000000
  GPR08: c0000000feaae888 0000000000000000 0000000007091000 0000000000200200
  GPR12: 0000000028ad2e28 c00000000fff4000 c0000000007abe08 0000000000000000
  GPR16: c0000000007ab160 c0000000007aaf98 c00000000060ba68 c0000000007abda8
  GPR20: c0000000007abde8 c0000000feaea6f8 c0000000feaea708 c0000000007abd10
  GPR24: c000000000989370 c0000000008c6228 00000000000041ed c0000000fe00a400
  GPR28: c00000000017c1cc 00000000000000d0 7375627379737465 c0000000fe001d80
  NIP [c000000000100778] .__kmalloc_track_caller+0x70/0x168
  LR [c00000000010073c] .__kmalloc_track_caller+0x34/0x168
  Call Trace:
  [c0000000fe08ac80] [c00000000087e6b8] uevent_sock_list+0x0/0x10 (unreliable)
  [c0000000fe08ad20] [c0000000000c99b0] .kstrdup+0x44/0x90
  [c0000000fe08adc0] [c00000000017c1cc] .__kernfs_new_node+0x4c/0x130
  [c0000000fe08ae70] [c00000000017d7e4] .kernfs_new_node+0x2c/0x64
  [c0000000fe08aef0] [c00000000017db00] .kernfs_create_dir_ns+0x34/0xc8
  [c0000000fe08af80] [c00000000018067c] .sysfs_create_dir_ns+0x58/0xcc
  [c0000000fe08b010] [c0000000002c711c] .kobject_add_internal+0xc8/0x384
  [c0000000fe08b0b0] [c0000000002c7644] .kobject_add+0x64/0xc8
  [c0000000fe08b140] [c000000000355ebc] .device_add+0x11c/0x654
  [c0000000fe08b200] [c0000000002b5988] .add_disk+0x20c/0x4b4
  [c0000000fe08b2c0] [c0000000003a21d4] .add_mtd_blktrans_dev+0x340/0x514
  [c0000000fe08b350] [c0000000003a3410] .mtdblock_add_mtd+0x74/0xb4
  [c0000000fe08b3e0] [c0000000003a32cc] .blktrans_notify_add+0x64/0x94
  [c0000000fe08b470] [c00000000039b5b4] .add_mtd_device+0x1d4/0x368
  [c0000000fe08b520] [c00000000039b830] .mtd_device_parse_register+0xe8/0x104
  [c0000000fe08b5c0] [c0000000003b8408] .of_flash_probe+0x72c/0x734
  [c0000000fe08b750] [c00000000035ba40] .platform_drv_probe+0x38/0x84
  [c0000000fe08b7d0] [c0000000003599a4] .really_probe+0xa4/0x29c
  [c0000000fe08b870] [c000000000359d3c] .__driver_attach+0x100/0x104
  [c0000000fe08b900] [c00000000035746c] .bus_for_each_dev+0x84/0xe4
  [c0000000fe08b9a0] [c0000000003593c0] .driver_attach+0x24/0x38
  [c0000000fe08ba10] [c000000000358f24] .bus_add_driver+0x1c8/0x2ac
  [c0000000fe08bab0] [c00000000035a3a4] .driver_register+0x8c/0x158
  [c0000000fe08bb30] [c00000000035b9f4] .__platform_driver_register+0x6c/0x80
  [c0000000fe08bba0] [c00000000084e080] .of_flash_driver_init+0x1c/0x30
  [c0000000fe08bc10] [c000000000001864] .do_one_initcall+0xbc/0x238
  [c0000000fe08bd00] [c00000000082cdc0] .kernel_init_freeable+0x188/0x268
  [c0000000fe08bdb0] [c0000000000020a0] .kernel_init+0x1c/0xf7c
  [c0000000fe08be30] [c000000000000884] .ret_from_kernel_thread+0x58/0xd4
  Instruction dump:
  41bd0010 480000c8 4bf04eb5 60000000 e94d0028 e93f0000 7cc95214 e8a60008
  7fc9502a 2fbe0000 419e00c8 e93f0022 &lt;7f7e482a&gt; 39200000 88ed06b2 992d06b2
  ---[ end trace b4c9a94804a42d40 ]---

It seems that the corrupted partition header on my mtd device triggers
a bug in the ftl. In function build_maps() it will allocate the buffers
needed by the mtd partition, but if something goes wrong such as kmalloc
failure, mtd read error or invalid partition header parameter, it will
free all allocated buffers and then return non-zero. In my case, it
seems that partition header parameter 'NumTransferUnits' is invalid.

And the ftl_freepart() is a function which free all the partition
buffers allocated by build_maps(). Given the build_maps() is a self
cleaning function, so there is no need to invoke this function even
if build_maps() return with error. Otherwise it will causes the
buffers to be freed twice and then weird things would happen.

Signed-off-by: Kevin Hao &lt;haokexin@gmail.com&gt;
Signed-off-by: Brian Norris &lt;computersforpeace@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 a152056c912db82860a8b4c23d0bd3a5aa89e363 upstream.

I got the following panic on my fsl p5020ds board.

  Unable to handle kernel paging request for data at address 0x7375627379737465
  Faulting instruction address: 0xc000000000100778
  Oops: Kernel access of bad area, sig: 11 [#1]
  SMP NR_CPUS=24 CoreNet Generic
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.15.0-next-20140613 #145
  task: c0000000fe080000 ti: c0000000fe088000 task.ti: c0000000fe088000
  NIP: c000000000100778 LR: c00000000010073c CTR: 0000000000000000
  REGS: c0000000fe08aa00 TRAP: 0300   Not tainted  (3.15.0-next-20140613)
  MSR: 0000000080029000 &lt;CE,EE,ME&gt;  CR: 24ad2e24  XER: 00000000
  DEAR: 7375627379737465 ESR: 0000000000000000 SOFTE: 1
  GPR00: c0000000000c99b0 c0000000fe08ac80 c0000000009598e0 c0000000fe001d80
  GPR04: 00000000000000d0 0000000000000913 c000000007902b20 0000000000000000
  GPR08: c0000000feaae888 0000000000000000 0000000007091000 0000000000200200
  GPR12: 0000000028ad2e28 c00000000fff4000 c0000000007abe08 0000000000000000
  GPR16: c0000000007ab160 c0000000007aaf98 c00000000060ba68 c0000000007abda8
  GPR20: c0000000007abde8 c0000000feaea6f8 c0000000feaea708 c0000000007abd10
  GPR24: c000000000989370 c0000000008c6228 00000000000041ed c0000000fe00a400
  GPR28: c00000000017c1cc 00000000000000d0 7375627379737465 c0000000fe001d80
  NIP [c000000000100778] .__kmalloc_track_caller+0x70/0x168
  LR [c00000000010073c] .__kmalloc_track_caller+0x34/0x168
  Call Trace:
  [c0000000fe08ac80] [c00000000087e6b8] uevent_sock_list+0x0/0x10 (unreliable)
  [c0000000fe08ad20] [c0000000000c99b0] .kstrdup+0x44/0x90
  [c0000000fe08adc0] [c00000000017c1cc] .__kernfs_new_node+0x4c/0x130
  [c0000000fe08ae70] [c00000000017d7e4] .kernfs_new_node+0x2c/0x64
  [c0000000fe08aef0] [c00000000017db00] .kernfs_create_dir_ns+0x34/0xc8
  [c0000000fe08af80] [c00000000018067c] .sysfs_create_dir_ns+0x58/0xcc
  [c0000000fe08b010] [c0000000002c711c] .kobject_add_internal+0xc8/0x384
  [c0000000fe08b0b0] [c0000000002c7644] .kobject_add+0x64/0xc8
  [c0000000fe08b140] [c000000000355ebc] .device_add+0x11c/0x654
  [c0000000fe08b200] [c0000000002b5988] .add_disk+0x20c/0x4b4
  [c0000000fe08b2c0] [c0000000003a21d4] .add_mtd_blktrans_dev+0x340/0x514
  [c0000000fe08b350] [c0000000003a3410] .mtdblock_add_mtd+0x74/0xb4
  [c0000000fe08b3e0] [c0000000003a32cc] .blktrans_notify_add+0x64/0x94
  [c0000000fe08b470] [c00000000039b5b4] .add_mtd_device+0x1d4/0x368
  [c0000000fe08b520] [c00000000039b830] .mtd_device_parse_register+0xe8/0x104
  [c0000000fe08b5c0] [c0000000003b8408] .of_flash_probe+0x72c/0x734
  [c0000000fe08b750] [c00000000035ba40] .platform_drv_probe+0x38/0x84
  [c0000000fe08b7d0] [c0000000003599a4] .really_probe+0xa4/0x29c
  [c0000000fe08b870] [c000000000359d3c] .__driver_attach+0x100/0x104
  [c0000000fe08b900] [c00000000035746c] .bus_for_each_dev+0x84/0xe4
  [c0000000fe08b9a0] [c0000000003593c0] .driver_attach+0x24/0x38
  [c0000000fe08ba10] [c000000000358f24] .bus_add_driver+0x1c8/0x2ac
  [c0000000fe08bab0] [c00000000035a3a4] .driver_register+0x8c/0x158
  [c0000000fe08bb30] [c00000000035b9f4] .__platform_driver_register+0x6c/0x80
  [c0000000fe08bba0] [c00000000084e080] .of_flash_driver_init+0x1c/0x30
  [c0000000fe08bc10] [c000000000001864] .do_one_initcall+0xbc/0x238
  [c0000000fe08bd00] [c00000000082cdc0] .kernel_init_freeable+0x188/0x268
  [c0000000fe08bdb0] [c0000000000020a0] .kernel_init+0x1c/0xf7c
  [c0000000fe08be30] [c000000000000884] .ret_from_kernel_thread+0x58/0xd4
  Instruction dump:
  41bd0010 480000c8 4bf04eb5 60000000 e94d0028 e93f0000 7cc95214 e8a60008
  7fc9502a 2fbe0000 419e00c8 e93f0022 &lt;7f7e482a&gt; 39200000 88ed06b2 992d06b2
  ---[ end trace b4c9a94804a42d40 ]---

It seems that the corrupted partition header on my mtd device triggers
a bug in the ftl. In function build_maps() it will allocate the buffers
needed by the mtd partition, but if something goes wrong such as kmalloc
failure, mtd read error or invalid partition header parameter, it will
free all allocated buffers and then return non-zero. In my case, it
seems that partition header parameter 'NumTransferUnits' is invalid.

And the ftl_freepart() is a function which free all the partition
buffers allocated by build_maps(). Given the build_maps() is a self
cleaning function, so there is no need to invoke this function even
if build_maps() return with error. Otherwise it will causes the
buffers to be freed twice and then weird things would happen.

Signed-off-by: Kevin Hao &lt;haokexin@gmail.com&gt;
Signed-off-by: Brian Norris &lt;computersforpeace@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
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