<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/hwtracing, branch v5.19.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>intel_th: pci: Add Raptor Lake-S CPU support</title>
<updated>2022-08-17T13:16:07+00:00</updated>
<author>
<name>Alexander Shishkin</name>
<email>alexander.shishkin@linux.intel.com</email>
</author>
<published>2022-07-05T08:26:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cb604d1c53e6993ea766f44b7e830699fe6ae796'/>
<id>cb604d1c53e6993ea766f44b7e830699fe6ae796</id>
<content type='text'>
[ Upstream commit ff46a601afc5a66a81c3945b83d0a2caeb88e8bc ]

Add support for the Trace Hub in Raptor Lake-S CPU.

Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220705082637.59979-7-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit ff46a601afc5a66a81c3945b83d0a2caeb88e8bc ]

Add support for the Trace Hub in Raptor Lake-S CPU.

Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220705082637.59979-7-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>intel_th: pci: Add Raptor Lake-S PCH support</title>
<updated>2022-08-17T13:16:07+00:00</updated>
<author>
<name>Alexander Shishkin</name>
<email>alexander.shishkin@linux.intel.com</email>
</author>
<published>2022-07-05T08:26:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c0fd76f69b720b9038752bf180e0bb0825587238'/>
<id>c0fd76f69b720b9038752bf180e0bb0825587238</id>
<content type='text'>
[ Upstream commit 23e2de5826e2fc4dd43e08bab3a2ea1a5338b063 ]

Add support for the Trace Hub in Raptor Lake-S PCH.

Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220705082637.59979-6-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 23e2de5826e2fc4dd43e08bab3a2ea1a5338b063 ]

Add support for the Trace Hub in Raptor Lake-S PCH.

Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220705082637.59979-6-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>intel_th: pci: Add Meteor Lake-P support</title>
<updated>2022-08-17T13:16:07+00:00</updated>
<author>
<name>Alexander Shishkin</name>
<email>alexander.shishkin@linux.intel.com</email>
</author>
<published>2022-07-05T08:26:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=03c14650165d1a96da117485efb8c255570f078d'/>
<id>03c14650165d1a96da117485efb8c255570f078d</id>
<content type='text'>
[ Upstream commit 802a9a0b1d91274ef10d9fe429b4cc1e8c200aef ]

Add support for the Trace Hub in Meteor Lake-P.

Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220705082637.59979-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 802a9a0b1d91274ef10d9fe429b4cc1e8c200aef ]

Add support for the Trace Hub in Meteor Lake-P.

Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220705082637.59979-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>intel_th: msu: Fix vmalloced buffers</title>
<updated>2022-08-17T13:15:29+00:00</updated>
<author>
<name>Alexander Shishkin</name>
<email>alexander.shishkin@linux.intel.com</email>
</author>
<published>2022-07-05T08:26:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4914c50670b6a531e2cb17cd984cc565b4681312'/>
<id>4914c50670b6a531e2cb17cd984cc565b4681312</id>
<content type='text'>
[ Upstream commit ac12ad3ccf6d386e64a9d6a890595a2509d24edd ]

After commit f5ff79fddf0e ("dma-mapping: remove CONFIG_DMA_REMAP") there's
a chance of DMA buffer getting allocated via vmalloc(), which messes up
the mmapping code:

&gt; RIP: msc_mmap_fault [intel_th_msu]
&gt; Call Trace:
&gt;  &lt;TASK&gt;
&gt;  __do_fault
&gt;  do_fault
...

Fix this by accounting for vmalloc possibility.

Fixes: ba39bd830605 ("intel_th: msu: Switch over to scatterlist")
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220705082637.59979-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit ac12ad3ccf6d386e64a9d6a890595a2509d24edd ]

After commit f5ff79fddf0e ("dma-mapping: remove CONFIG_DMA_REMAP") there's
a chance of DMA buffer getting allocated via vmalloc(), which messes up
the mmapping code:

&gt; RIP: msc_mmap_fault [intel_th_msu]
&gt; Call Trace:
&gt;  &lt;TASK&gt;
&gt;  __do_fault
&gt;  do_fault
...

Fix this by accounting for vmalloc possibility.

Fixes: ba39bd830605 ("intel_th: msu: Switch over to scatterlist")
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220705082637.59979-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>intel_th: msu-sink: Potential dereference of null pointer</title>
<updated>2022-08-17T13:15:29+00:00</updated>
<author>
<name>Jiasheng Jiang</name>
<email>jiasheng@iscas.ac.cn</email>
</author>
<published>2022-07-05T08:26:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e1d427d46269db0ac024905128bbb8aa34f565e3'/>
<id>e1d427d46269db0ac024905128bbb8aa34f565e3</id>
<content type='text'>
[ Upstream commit 82f76a4a720791d889de775b5f7541d601efc8bd ]

The return value of dma_alloc_coherent() needs to be checked.
To avoid use of null pointer in sg_set_buf() in case of the failure of
alloc.

Fixes: f220df66f676 ("intel_th: msu-sink: An example msu buffer "sink"")
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Jiasheng Jiang &lt;jiasheng@iscas.ac.cn&gt;
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220705082637.59979-3-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 82f76a4a720791d889de775b5f7541d601efc8bd ]

The return value of dma_alloc_coherent() needs to be checked.
To avoid use of null pointer in sg_set_buf() in case of the failure of
alloc.

Fixes: f220df66f676 ("intel_th: msu-sink: An example msu buffer "sink"")
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Jiasheng Jiang &lt;jiasheng@iscas.ac.cn&gt;
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220705082637.59979-3-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>intel_th: Fix a resource leak in an error handling path</title>
<updated>2022-08-17T13:15:29+00:00</updated>
<author>
<name>Christophe JAILLET</name>
<email>christophe.jaillet@wanadoo.fr</email>
</author>
<published>2022-07-05T08:26:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fae9da7d4c2ccad3792de03e3cac1fe2bfabb73d'/>
<id>fae9da7d4c2ccad3792de03e3cac1fe2bfabb73d</id>
<content type='text'>
[ Upstream commit 086c28ab7c5699256aced0049aae9c42f1410313 ]

If an error occurs after calling 'pci_alloc_irq_vectors()',
'pci_free_irq_vectors()' must be called as already done in the remove
function.

Fixes: 7b7036d47c35 ("intel_th: pci: Use MSI interrupt signalling")
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220705082637.59979-2-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 086c28ab7c5699256aced0049aae9c42f1410313 ]

If an error occurs after calling 'pci_alloc_irq_vectors()',
'pci_free_irq_vectors()' must be called as already done in the remove
function.

Fixes: 7b7036d47c35 ("intel_th: pci: Use MSI interrupt signalling")
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220705082637.59979-2-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>coresight: syscfg: Update load and unload operations</title>
<updated>2022-08-17T13:15:23+00:00</updated>
<author>
<name>Mike Leach</name>
<email>mike.leach@linaro.org</email>
</author>
<published>2022-06-28T17:30:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=517ce24958f06bbcaf4e32aa664187e3feb1a135'/>
<id>517ce24958f06bbcaf4e32aa664187e3feb1a135</id>
<content type='text'>
[ Upstream commit 8add26f7ef33bba7984cb6ff7911c6aa970fe55a ]

The configfs system is a source of access to the config information in the
configuration and feature lists.

This can result in additional LOCKDEP issues as a result of the mutex
ordering between the config list mutex (cscfg_mutex) and the configfs
system mutexes.

As such we need to adjust how load/unload operations work to ensure correct
operation.

1) Previously the cscfg_mutex was held throughout the load/unload
operation. This is now only held during configuration list manipulations,
resulting in a multi-stage load/unload process.

2) All operations that manipulate the configfs representation of the
configurations and features are now separated out and run without the
cscfg_mutex being held. This avoids circular lock_dep issue with the
built-in configfs mutexes and semaphores

3) As the load and unload is now multi-stage, some parts under the
cscfg_mutex and others not:
i) A flag indicating a load / unload operation in progress is used to
serialise load / unload operations.
ii) activating any configuration not possible when unload is in progress.
iii) Configurations have an "available" flag set only after the last load
stage for the configuration is complete. Activation of the configuration
not possible till flag is set.

4) Following load/unload rules remain:
i) Unload prevented while any configuration is active remains.
ii) Unload in strict reverse order of load.
iii) Existing configurations can be activated while a new load operation
is underway. (by definition there can be no dependencies between an
existing configuration and a new loading one due to ii) above.)

Fixes: eb2ec49606c2 ("coresight: syscfg: Update load API for config loadable modules")
Reported-by: Suzuki Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Mike Leach &lt;mike.leach@linaro.org&gt;
Reviewed-and-tested-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Link: https://lore.kernel.org/r/20220628173004.30002-3-mike.leach@linaro.org
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 8add26f7ef33bba7984cb6ff7911c6aa970fe55a ]

The configfs system is a source of access to the config information in the
configuration and feature lists.

This can result in additional LOCKDEP issues as a result of the mutex
ordering between the config list mutex (cscfg_mutex) and the configfs
system mutexes.

As such we need to adjust how load/unload operations work to ensure correct
operation.

1) Previously the cscfg_mutex was held throughout the load/unload
operation. This is now only held during configuration list manipulations,
resulting in a multi-stage load/unload process.

2) All operations that manipulate the configfs representation of the
configurations and features are now separated out and run without the
cscfg_mutex being held. This avoids circular lock_dep issue with the
built-in configfs mutexes and semaphores

3) As the load and unload is now multi-stage, some parts under the
cscfg_mutex and others not:
i) A flag indicating a load / unload operation in progress is used to
serialise load / unload operations.
ii) activating any configuration not possible when unload is in progress.
iii) Configurations have an "available" flag set only after the last load
stage for the configuration is complete. Activation of the configuration
not possible till flag is set.

4) Following load/unload rules remain:
i) Unload prevented while any configuration is active remains.
ii) Unload in strict reverse order of load.
iii) Existing configurations can be activated while a new load operation
is underway. (by definition there can be no dependencies between an
existing configuration and a new loading one due to ii) above.)

Fixes: eb2ec49606c2 ("coresight: syscfg: Update load API for config loadable modules")
Reported-by: Suzuki Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Mike Leach &lt;mike.leach@linaro.org&gt;
Reviewed-and-tested-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Link: https://lore.kernel.org/r/20220628173004.30002-3-mike.leach@linaro.org
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>coresight: configfs: Fix unload of configurations on module exit</title>
<updated>2022-08-17T13:15:23+00:00</updated>
<author>
<name>Mike Leach</name>
<email>mike.leach@linaro.org</email>
</author>
<published>2022-06-28T17:30:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=471a84356c357190484992254bd493f8f3eb491f'/>
<id>471a84356c357190484992254bd493f8f3eb491f</id>
<content type='text'>
[ Upstream commit 199380decc5f9188a9e65676031950f1734aaffe ]

Any loaded configurations must be correctly unloaded on coresight module
exit, or issues can arise with nested locking in the configfs directory
code if built with CONFIG_LOCKDEP.

Prior to this patch, the preloaded configuration configfs directory entries
were being unloaded by the recursive code in
configfs_unregister_subsystem().

However, when built with CONFIG_LOCKDEP, this caused a nested lock warning,
which was not mitigated by the LOCKDEP dependent code in fs/configfs/dir.c
designed to prevent this, due to the different directory levels for the
root of the directory being removed.

As the preloaded (and all other) configurations are registered after
configfs_register_subsystem(), we now explicitly unload them before the
call to configfs_unregister_subsystem().

The new routine cscfg_unload_cfgs_on_exit() iterates through the load
owner list to unload any remaining configurations that were not unloaded
by the user before the module exits. This covers both the
CSCFG_OWNER_PRELOAD and CSCFG_OWNER_MODULE owner types, and will be
extended to cover future load owner types for CoreSight configurations.

Fixes: eb2ec49606c2 ("coresight: syscfg: Update load API for config loadable modules")
Reported-by: Suzuki Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Mike Leach &lt;mike.leach@linaro.org&gt;
Reviewed-and-tested-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Link: https://lore.kernel.org/r/20220628173004.30002-2-mike.leach@linaro.org
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 199380decc5f9188a9e65676031950f1734aaffe ]

Any loaded configurations must be correctly unloaded on coresight module
exit, or issues can arise with nested locking in the configfs directory
code if built with CONFIG_LOCKDEP.

Prior to this patch, the preloaded configuration configfs directory entries
were being unloaded by the recursive code in
configfs_unregister_subsystem().

However, when built with CONFIG_LOCKDEP, this caused a nested lock warning,
which was not mitigated by the LOCKDEP dependent code in fs/configfs/dir.c
designed to prevent this, due to the different directory levels for the
root of the directory being removed.

As the preloaded (and all other) configurations are registered after
configfs_register_subsystem(), we now explicitly unload them before the
call to configfs_unregister_subsystem().

The new routine cscfg_unload_cfgs_on_exit() iterates through the load
owner list to unload any remaining configurations that were not unloaded
by the user before the module exits. This covers both the
CSCFG_OWNER_PRELOAD and CSCFG_OWNER_MODULE owner types, and will be
extended to cover future load owner types for CoreSight configurations.

Fixes: eb2ec49606c2 ("coresight: syscfg: Update load API for config loadable modules")
Reported-by: Suzuki Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Mike Leach &lt;mike.leach@linaro.org&gt;
Reviewed-and-tested-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Link: https://lore.kernel.org/r/20220628173004.30002-2-mike.leach@linaro.org
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>coresight: Clear the connection field properly</title>
<updated>2022-08-17T13:13:57+00:00</updated>
<author>
<name>Suzuki K Poulose</name>
<email>suzuki.poulose@arm.com</email>
</author>
<published>2022-06-14T21:40:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bc57850fcb7e4cb91b6321d0ce83357cefd55c54'/>
<id>bc57850fcb7e4cb91b6321d0ce83357cefd55c54</id>
<content type='text'>
commit 2af89ebacf299b7fba5f3087d35e8a286ec33706 upstream.

coresight devices track their connections (output connections) and
hold a reference to the fwnode. When a device goes away, we walk through
the devices on the coresight bus and make sure that the references
are dropped. This happens both ways:
 a) For all output connections from the device, drop the reference to
    the target device via coresight_release_platform_data()

b) Iterate over all the devices on the coresight bus and drop the
   reference to fwnode if *this* device is the target of the output
   connection, via coresight_remove_conns()-&gt;coresight_remove_match().

However, the coresight_remove_match() doesn't clear the fwnode field,
after dropping the reference, this causes use-after-free and
additional refcount drops on the fwnode.

e.g., if we have two devices, A and B, with a connection, A -&gt; B.
If we remove B first, B would clear the reference on B, from A
via coresight_remove_match(). But when A is removed, it still has
a connection with fwnode still pointing to B. Thus it tries to  drops
the reference in coresight_release_platform_data(), raising the bells
like :

[   91.990153] ------------[ cut here ]------------
[   91.990163] refcount_t: addition on 0; use-after-free.
[   91.990212] WARNING: CPU: 0 PID: 461 at lib/refcount.c:25 refcount_warn_saturate+0xa0/0x144
[   91.990260] Modules linked in: coresight_funnel coresight_replicator coresight_etm4x(-)
 crct10dif_ce coresight ip_tables x_tables ipv6 [last unloaded: coresight_cpu_debug]
[   91.990398] CPU: 0 PID: 461 Comm: rmmod Tainted: G        W       T 5.19.0-rc2+ #53
[   91.990418] Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Feb  1 2019
[   91.990434] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   91.990454] pc : refcount_warn_saturate+0xa0/0x144
[   91.990476] lr : refcount_warn_saturate+0xa0/0x144
[   91.990496] sp : ffff80000c843640
[   91.990509] x29: ffff80000c843640 x28: ffff800009957c28 x27: ffff80000c8439a8
[   91.990560] x26: ffff00097eff1990 x25: ffff8000092b6ad8 x24: ffff00097eff19a8
[   91.990610] x23: ffff80000c8439a8 x22: 0000000000000000 x21: ffff80000c8439c2
[   91.990659] x20: 0000000000000000 x19: ffff00097eff1a10 x18: ffff80000ab99c40
[   91.990708] x17: 0000000000000000 x16: 0000000000000000 x15: ffff80000abf6fa0
[   91.990756] x14: 000000000000001d x13: 0a2e656572662d72 x12: 657466612d657375
[   91.990805] x11: 203b30206e6f206e x10: 6f69746964646120 x9 : ffff8000081aba28
[   91.990854] x8 : 206e6f206e6f6974 x7 : 69646461203a745f x6 : 746e756f63666572
[   91.990903] x5 : ffff00097648ec58 x4 : 0000000000000000 x3 : 0000000000000027
[   91.990952] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff00080260ba00
[   91.991000] Call trace:
[   91.991012]  refcount_warn_saturate+0xa0/0x144
[   91.991034]  kobject_get+0xac/0xb0
[   91.991055]  of_node_get+0x2c/0x40
[   91.991076]  of_fwnode_get+0x40/0x60
[   91.991094]  fwnode_handle_get+0x3c/0x60
[   91.991116]  fwnode_get_nth_parent+0xf4/0x110
[   91.991137]  fwnode_full_name_string+0x48/0xc0
[   91.991158]  device_node_string+0x41c/0x530
[   91.991178]  pointer+0x320/0x3ec
[   91.991198]  vsnprintf+0x23c/0x750
[   91.991217]  vprintk_store+0x104/0x4b0
[   91.991238]  vprintk_emit+0x8c/0x360
[   91.991257]  vprintk_default+0x44/0x50
[   91.991276]  vprintk+0xcc/0xf0
[   91.991295]  _printk+0x68/0x90
[   91.991315]  of_node_release+0x13c/0x14c
[   91.991334]  kobject_put+0x98/0x114
[   91.991354]  of_node_put+0x24/0x34
[   91.991372]  of_fwnode_put+0x40/0x5c
[   91.991390]  fwnode_handle_put+0x38/0x50
[   91.991411]  coresight_release_platform_data+0x74/0xb0 [coresight]
[   91.991472]  coresight_unregister+0x64/0xcc [coresight]
[   91.991525]  etm4_remove_dev+0x64/0x78 [coresight_etm4x]
[   91.991563]  etm4_remove_amba+0x1c/0x2c [coresight_etm4x]
[   91.991598]  amba_remove+0x3c/0x19c

Reproducible by: (Build all coresight components as modules):

  #!/bin/sh
  while true
  do
     for m in tmc stm cpu_debug etm4x replicator funnel
     do
     	modprobe coresight_${m}
     done

     for m in tmc stm cpu_debug etm4x replicator funnel
     do
     	rmmode coresight_${m}
     done
  done

Cc: stable@vger.kernel.org
Cc: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Cc: Mike Leach &lt;mike.leach@linaro.org&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Signed-off-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Fixes: 37ea1ffddffa ("coresight: Use fwnode handle instead of device names")
Link: https://lore.kernel.org/r/20220614214024.3005275-1-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.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 2af89ebacf299b7fba5f3087d35e8a286ec33706 upstream.

coresight devices track their connections (output connections) and
hold a reference to the fwnode. When a device goes away, we walk through
the devices on the coresight bus and make sure that the references
are dropped. This happens both ways:
 a) For all output connections from the device, drop the reference to
    the target device via coresight_release_platform_data()

b) Iterate over all the devices on the coresight bus and drop the
   reference to fwnode if *this* device is the target of the output
   connection, via coresight_remove_conns()-&gt;coresight_remove_match().

However, the coresight_remove_match() doesn't clear the fwnode field,
after dropping the reference, this causes use-after-free and
additional refcount drops on the fwnode.

e.g., if we have two devices, A and B, with a connection, A -&gt; B.
If we remove B first, B would clear the reference on B, from A
via coresight_remove_match(). But when A is removed, it still has
a connection with fwnode still pointing to B. Thus it tries to  drops
the reference in coresight_release_platform_data(), raising the bells
like :

[   91.990153] ------------[ cut here ]------------
[   91.990163] refcount_t: addition on 0; use-after-free.
[   91.990212] WARNING: CPU: 0 PID: 461 at lib/refcount.c:25 refcount_warn_saturate+0xa0/0x144
[   91.990260] Modules linked in: coresight_funnel coresight_replicator coresight_etm4x(-)
 crct10dif_ce coresight ip_tables x_tables ipv6 [last unloaded: coresight_cpu_debug]
[   91.990398] CPU: 0 PID: 461 Comm: rmmod Tainted: G        W       T 5.19.0-rc2+ #53
[   91.990418] Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Feb  1 2019
[   91.990434] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   91.990454] pc : refcount_warn_saturate+0xa0/0x144
[   91.990476] lr : refcount_warn_saturate+0xa0/0x144
[   91.990496] sp : ffff80000c843640
[   91.990509] x29: ffff80000c843640 x28: ffff800009957c28 x27: ffff80000c8439a8
[   91.990560] x26: ffff00097eff1990 x25: ffff8000092b6ad8 x24: ffff00097eff19a8
[   91.990610] x23: ffff80000c8439a8 x22: 0000000000000000 x21: ffff80000c8439c2
[   91.990659] x20: 0000000000000000 x19: ffff00097eff1a10 x18: ffff80000ab99c40
[   91.990708] x17: 0000000000000000 x16: 0000000000000000 x15: ffff80000abf6fa0
[   91.990756] x14: 000000000000001d x13: 0a2e656572662d72 x12: 657466612d657375
[   91.990805] x11: 203b30206e6f206e x10: 6f69746964646120 x9 : ffff8000081aba28
[   91.990854] x8 : 206e6f206e6f6974 x7 : 69646461203a745f x6 : 746e756f63666572
[   91.990903] x5 : ffff00097648ec58 x4 : 0000000000000000 x3 : 0000000000000027
[   91.990952] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff00080260ba00
[   91.991000] Call trace:
[   91.991012]  refcount_warn_saturate+0xa0/0x144
[   91.991034]  kobject_get+0xac/0xb0
[   91.991055]  of_node_get+0x2c/0x40
[   91.991076]  of_fwnode_get+0x40/0x60
[   91.991094]  fwnode_handle_get+0x3c/0x60
[   91.991116]  fwnode_get_nth_parent+0xf4/0x110
[   91.991137]  fwnode_full_name_string+0x48/0xc0
[   91.991158]  device_node_string+0x41c/0x530
[   91.991178]  pointer+0x320/0x3ec
[   91.991198]  vsnprintf+0x23c/0x750
[   91.991217]  vprintk_store+0x104/0x4b0
[   91.991238]  vprintk_emit+0x8c/0x360
[   91.991257]  vprintk_default+0x44/0x50
[   91.991276]  vprintk+0xcc/0xf0
[   91.991295]  _printk+0x68/0x90
[   91.991315]  of_node_release+0x13c/0x14c
[   91.991334]  kobject_put+0x98/0x114
[   91.991354]  of_node_put+0x24/0x34
[   91.991372]  of_fwnode_put+0x40/0x5c
[   91.991390]  fwnode_handle_put+0x38/0x50
[   91.991411]  coresight_release_platform_data+0x74/0xb0 [coresight]
[   91.991472]  coresight_unregister+0x64/0xcc [coresight]
[   91.991525]  etm4_remove_dev+0x64/0x78 [coresight_etm4x]
[   91.991563]  etm4_remove_amba+0x1c/0x2c [coresight_etm4x]
[   91.991598]  amba_remove+0x3c/0x19c

Reproducible by: (Build all coresight components as modules):

  #!/bin/sh
  while true
  do
     for m in tmc stm cpu_debug etm4x replicator funnel
     do
     	modprobe coresight_${m}
     done

     for m in tmc stm cpu_debug etm4x replicator funnel
     do
     	rmmode coresight_${m}
     done
  done

Cc: stable@vger.kernel.org
Cc: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Cc: Mike Leach &lt;mike.leach@linaro.org&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Signed-off-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Fixes: 37ea1ffddffa ("coresight: Use fwnode handle instead of device names")
Link: https://lore.kernel.org/r/20220614214024.3005275-1-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>coresight: cpu-debug: Replace mutex with mutex_trylock on panic notifier</title>
<updated>2022-05-09T15:03:24+00:00</updated>
<author>
<name>Guilherme G. Piccoli</name>
<email>gpiccoli@igalia.com</email>
</author>
<published>2022-04-27T22:49:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1adff542d67a2ed1120955cb219bfff8a9c53f59'/>
<id>1adff542d67a2ed1120955cb219bfff8a9c53f59</id>
<content type='text'>
The panic notifier infrastructure executes registered callbacks when
a panic event happens - such callbacks are executed in atomic context,
with interrupts and preemption disabled in the running CPU and all other
CPUs disabled. That said, mutexes in such context are not a good idea.

This patch replaces a regular mutex with a mutex_trylock safer approach;
given the nature of the mutex used in the driver, it should be pretty
uncommon being unable to acquire such mutex in the panic path, hence
no functional change should be observed (and if it is, that would be
likely a deadlock with the regular mutex).

Fixes: 2227b7c74634 ("coresight: add support for CPU debug module")
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Cc: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Cc: Mike Leach &lt;mike.leach@linaro.org&gt;
Cc: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Guilherme G. Piccoli &lt;gpiccoli@igalia.com&gt;
Reviewed-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Link: https://lore.kernel.org/r/20220427224924.592546-10-gpiccoli@igalia.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The panic notifier infrastructure executes registered callbacks when
a panic event happens - such callbacks are executed in atomic context,
with interrupts and preemption disabled in the running CPU and all other
CPUs disabled. That said, mutexes in such context are not a good idea.

This patch replaces a regular mutex with a mutex_trylock safer approach;
given the nature of the mutex used in the driver, it should be pretty
uncommon being unable to acquire such mutex in the panic path, hence
no functional change should be observed (and if it is, that would be
likely a deadlock with the regular mutex).

Fixes: 2227b7c74634 ("coresight: add support for CPU debug module")
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Cc: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Cc: Mike Leach &lt;mike.leach@linaro.org&gt;
Cc: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Guilherme G. Piccoli &lt;gpiccoli@igalia.com&gt;
Reviewed-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Link: https://lore.kernel.org/r/20220427224924.592546-10-gpiccoli@igalia.com
</pre>
</div>
</content>
</entry>
</feed>
