<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/base, branch v5.15.97</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>driver core: Fix test_async_probe_init saves device in wrong array</title>
<updated>2023-02-01T07:27:14+00:00</updated>
<author>
<name>Chen Zhongjin</name>
<email>chenzhongjin@huawei.com</email>
</author>
<published>2022-11-25T06:35:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=caa28c7c83e362f83689356078826627819da220'/>
<id>caa28c7c83e362f83689356078826627819da220</id>
<content type='text'>
[ Upstream commit 9be182da0a7526f1b9a3777a336f83baa2e64d23 ]

In test_async_probe_init, second set of asynchronous devices are saved
in sync_dev[sync_id], which should be async_dev[async_id].
This makes these devices not unregistered when exit.

&gt; modprobe test_async_driver_probe &amp;&amp; \
&gt; modprobe -r test_async_driver_probe &amp;&amp; \
&gt; modprobe test_async_driver_probe
 ...
&gt; sysfs: cannot create duplicate filename '/devices/platform/test_async_driver.4'
&gt; kobject_add_internal failed for test_async_driver.4 with -EEXIST,
  don't try to register things with the same name in the same directory.

Fixes: 57ea974fb871 ("driver core: Rewrite test_async_driver_probe to cover serialization and NUMA affinity")
Signed-off-by: Chen Zhongjin &lt;chenzhongjin@huawei.com&gt;
Link: https://lore.kernel.org/r/20221125063541.241328-1-chenzhongjin@huawei.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 9be182da0a7526f1b9a3777a336f83baa2e64d23 ]

In test_async_probe_init, second set of asynchronous devices are saved
in sync_dev[sync_id], which should be async_dev[async_id].
This makes these devices not unregistered when exit.

&gt; modprobe test_async_driver_probe &amp;&amp; \
&gt; modprobe -r test_async_driver_probe &amp;&amp; \
&gt; modprobe test_async_driver_probe
 ...
&gt; sysfs: cannot create duplicate filename '/devices/platform/test_async_driver.4'
&gt; kobject_add_internal failed for test_async_driver.4 with -EEXIST,
  don't try to register things with the same name in the same directory.

Fixes: 57ea974fb871 ("driver core: Rewrite test_async_driver_probe to cover serialization and NUMA affinity")
Signed-off-by: Chen Zhongjin &lt;chenzhongjin@huawei.com&gt;
Link: https://lore.kernel.org/r/20221125063541.241328-1-chenzhongjin@huawei.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>device property: fix of node refcount leak in fwnode_graph_get_next_endpoint()</title>
<updated>2023-02-01T07:27:14+00:00</updated>
<author>
<name>Yang Yingliang</name>
<email>yangyingliang@huawei.com</email>
</author>
<published>2022-11-23T02:25:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7701a4bd45c11f9a289d8f262fad05705a012339'/>
<id>7701a4bd45c11f9a289d8f262fad05705a012339</id>
<content type='text'>
[ Upstream commit 39af728649b05e88a2b40e714feeee6451c3f18e ]

The 'parent' returned by fwnode_graph_get_port_parent()
with refcount incremented when 'prev' is not NULL, it
needs be put when finish using it.

Because the parent is const, introduce a new variable to
store the returned fwnode, then put it before returning
from fwnode_graph_get_next_endpoint().

Fixes: b5b41ab6b0c1 ("device property: Check fwnode-&gt;secondary in fwnode_graph_get_next_endpoint()")
Signed-off-by: Yang Yingliang &lt;yangyingliang@huawei.com&gt;
Reviewed-by: Sakari Ailus &lt;sakari.ailus@linux.intel.com&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Reviewed-and-tested-by: Daniel Scally &lt;djrscally@gmail.com&gt;
Link: https://lore.kernel.org/r/20221123022542.2999510-1-yangyingliang@huawei.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 39af728649b05e88a2b40e714feeee6451c3f18e ]

The 'parent' returned by fwnode_graph_get_port_parent()
with refcount incremented when 'prev' is not NULL, it
needs be put when finish using it.

Because the parent is const, introduce a new variable to
store the returned fwnode, then put it before returning
from fwnode_graph_get_next_endpoint().

Fixes: b5b41ab6b0c1 ("device property: Check fwnode-&gt;secondary in fwnode_graph_get_next_endpoint()")
Signed-off-by: Yang Yingliang &lt;yangyingliang@huawei.com&gt;
Reviewed-by: Sakari Ailus &lt;sakari.ailus@linux.intel.com&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Reviewed-and-tested-by: Daniel Scally &lt;djrscally@gmail.com&gt;
Link: https://lore.kernel.org/r/20221123022542.2999510-1-yangyingliang@huawei.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>driver core: Fix bus_type.match() error handling in __driver_attach()</title>
<updated>2023-01-12T10:58:58+00:00</updated>
<author>
<name>Isaac J. Manjarres</name>
<email>isaacmanjarres@google.com</email>
</author>
<published>2022-09-21T00:14:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dfd05a13355693dd55beea21a49eed0d9dff1217'/>
<id>dfd05a13355693dd55beea21a49eed0d9dff1217</id>
<content type='text'>
commit 27c0d217340e47ec995557f61423ef415afba987 upstream.

When a driver registers with a bus, it will attempt to match with every
device on the bus through the __driver_attach() function. Currently, if
the bus_type.match() function encounters an error that is not
-EPROBE_DEFER, __driver_attach() will return a negative error code, which
causes the driver registration logic to stop trying to match with the
remaining devices on the bus.

This behavior is not correct; a failure while matching a driver to a
device does not mean that the driver won't be able to match and bind
with other devices on the bus. Update the logic in __driver_attach()
to reflect this.

Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
Cc: stable@vger.kernel.org
Cc: Saravana Kannan &lt;saravanak@google.com&gt;
Signed-off-by: Isaac J. Manjarres &lt;isaacmanjarres@google.com&gt;
Link: https://lore.kernel.org/r/20220921001414.4046492-1-isaacmanjarres@google.com
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 27c0d217340e47ec995557f61423ef415afba987 upstream.

When a driver registers with a bus, it will attempt to match with every
device on the bus through the __driver_attach() function. Currently, if
the bus_type.match() function encounters an error that is not
-EPROBE_DEFER, __driver_attach() will return a negative error code, which
causes the driver registration logic to stop trying to match with the
remaining devices on the bus.

This behavior is not correct; a failure while matching a driver to a
device does not mean that the driver won't be able to match and bind
with other devices on the bus. Update the logic in __driver_attach()
to reflect this.

Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
Cc: stable@vger.kernel.org
Cc: Saravana Kannan &lt;saravanak@google.com&gt;
Signed-off-by: Isaac J. Manjarres &lt;isaacmanjarres@google.com&gt;
Link: https://lore.kernel.org/r/20220921001414.4046492-1-isaacmanjarres@google.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>class: fix possible memory leak in __class_register()</title>
<updated>2022-12-31T12:14:27+00:00</updated>
<author>
<name>Yang Yingliang</name>
<email>yangyingliang@huawei.com</email>
</author>
<published>2022-10-26T08:28:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=417ef049e3fd3b0d2593c1d5ffa3d0d5d0a018a7'/>
<id>417ef049e3fd3b0d2593c1d5ffa3d0d5d0a018a7</id>
<content type='text'>
[ Upstream commit 8c3e8a6bdb5253b97ad532570f8b5db5f7a06407 ]

If class_add_groups() returns error, the 'cp-&gt;subsys' need be
unregister, and the 'cp' need be freed.

We can not call kset_unregister() here, because the 'cls' will
be freed in callback function class_release() and it's also
freed in caller's error path, it will cause double free.

So fix this by calling kobject_del() and kfree_const(name) to
cleanup kobject. Besides, call kfree() to free the 'cp'.

Fault injection test can trigger this:

unreferenced object 0xffff888102fa8190 (size 8):
  comm "modprobe", pid 502, jiffies 4294906074 (age 49.296s)
  hex dump (first 8 bytes):
    70 6b 74 63 64 76 64 00                          pktcdvd.
  backtrace:
    [&lt;00000000e7c7703d&gt;] __kmalloc_track_caller+0x1ae/0x320
    [&lt;000000005e4d70bc&gt;] kstrdup+0x3a/0x70
    [&lt;00000000c2e5e85a&gt;] kstrdup_const+0x68/0x80
    [&lt;000000000049a8c7&gt;] kvasprintf_const+0x10b/0x190
    [&lt;0000000029123163&gt;] kobject_set_name_vargs+0x56/0x150
    [&lt;00000000747219c9&gt;] kobject_set_name+0xab/0xe0
    [&lt;0000000005f1ea4e&gt;] __class_register+0x15c/0x49a

unreferenced object 0xffff888037274000 (size 1024):
  comm "modprobe", pid 502, jiffies 4294906074 (age 49.296s)
  hex dump (first 32 bytes):
    00 40 27 37 80 88 ff ff 00 40 27 37 80 88 ff ff  .@'7.....@'7....
    00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00  .....N..........
  backtrace:
    [&lt;00000000151f9600&gt;] kmem_cache_alloc_trace+0x17c/0x2f0
    [&lt;00000000ecf3dd95&gt;] __class_register+0x86/0x49a

Fixes: ced6473e7486 ("driver core: class: add class_groups support")
Signed-off-by: Yang Yingliang &lt;yangyingliang@huawei.com&gt;
Link: https://lore.kernel.org/r/20221026082803.3458760-1-yangyingliang@huawei.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 8c3e8a6bdb5253b97ad532570f8b5db5f7a06407 ]

If class_add_groups() returns error, the 'cp-&gt;subsys' need be
unregister, and the 'cp' need be freed.

We can not call kset_unregister() here, because the 'cls' will
be freed in callback function class_release() and it's also
freed in caller's error path, it will cause double free.

So fix this by calling kobject_del() and kfree_const(name) to
cleanup kobject. Besides, call kfree() to free the 'cp'.

Fault injection test can trigger this:

unreferenced object 0xffff888102fa8190 (size 8):
  comm "modprobe", pid 502, jiffies 4294906074 (age 49.296s)
  hex dump (first 8 bytes):
    70 6b 74 63 64 76 64 00                          pktcdvd.
  backtrace:
    [&lt;00000000e7c7703d&gt;] __kmalloc_track_caller+0x1ae/0x320
    [&lt;000000005e4d70bc&gt;] kstrdup+0x3a/0x70
    [&lt;00000000c2e5e85a&gt;] kstrdup_const+0x68/0x80
    [&lt;000000000049a8c7&gt;] kvasprintf_const+0x10b/0x190
    [&lt;0000000029123163&gt;] kobject_set_name_vargs+0x56/0x150
    [&lt;00000000747219c9&gt;] kobject_set_name+0xab/0xe0
    [&lt;0000000005f1ea4e&gt;] __class_register+0x15c/0x49a

unreferenced object 0xffff888037274000 (size 1024):
  comm "modprobe", pid 502, jiffies 4294906074 (age 49.296s)
  hex dump (first 32 bytes):
    00 40 27 37 80 88 ff ff 00 40 27 37 80 88 ff ff  .@'7.....@'7....
    00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00  .....N..........
  backtrace:
    [&lt;00000000151f9600&gt;] kmem_cache_alloc_trace+0x17c/0x2f0
    [&lt;00000000ecf3dd95&gt;] __class_register+0x86/0x49a

Fixes: ced6473e7486 ("driver core: class: add class_groups support")
Signed-off-by: Yang Yingliang &lt;yangyingliang@huawei.com&gt;
Link: https://lore.kernel.org/r/20221026082803.3458760-1-yangyingliang@huawei.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>PM: runtime: Do not call __rpm_callback() from rpm_idle()</title>
<updated>2022-12-31T12:14:04+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2022-12-02T14:30:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b55ef8508ac482703dc90d111664748dda2608c7'/>
<id>b55ef8508ac482703dc90d111664748dda2608c7</id>
<content type='text'>
[ Upstream commit bc80c2e438dcbfcf748452ec0f7ad5b79ff3ad88 ]

Calling __rpm_callback() from rpm_idle() after adding device links
support to the former is a clear mistake.

Not only it causes rpm_idle() to carry out unnecessary actions, but it
is also against the assumption regarding the stability of PM-runtime
status across __rpm_callback() invocations, because rpm_suspend() and
rpm_resume() may run in parallel with __rpm_callback() when it is called
by rpm_idle() and the device's PM-runtime status can be updated by any
of them.

Fixes: 21d5c57b3726 ("PM / runtime: Use device links")
Link: https://lore.kernel.org/linux-pm/36aed941-a73e-d937-2721-4f0decd61ce0@quicinc.com
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Adrian Hunter &lt;adrian.hunter@intel.com&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 bc80c2e438dcbfcf748452ec0f7ad5b79ff3ad88 ]

Calling __rpm_callback() from rpm_idle() after adding device links
support to the former is a clear mistake.

Not only it causes rpm_idle() to carry out unnecessary actions, but it
is also against the assumption regarding the stability of PM-runtime
status across __rpm_callback() invocations, because rpm_suspend() and
rpm_resume() may run in parallel with __rpm_callback() when it is called
by rpm_idle() and the device's PM-runtime status can be updated by any
of them.

Fixes: 21d5c57b3726 ("PM / runtime: Use device links")
Link: https://lore.kernel.org/linux-pm/36aed941-a73e-d937-2721-4f0decd61ce0@quicinc.com
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: domains: Fix handling of unavailable/disabled idle states</title>
<updated>2022-11-03T14:59:18+00:00</updated>
<author>
<name>Sudeep Holla</name>
<email>sudeep.holla@arm.com</email>
</author>
<published>2022-10-25T12:34:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=eb59cb2fabd4df3efc40c912a9eeff2b9360d181'/>
<id>eb59cb2fabd4df3efc40c912a9eeff2b9360d181</id>
<content type='text'>
[ Upstream commit e0c57a5c70c13317238cb19a7ded0eab4a5f7de5 ]

Platforms can provide the information about the availability of each
idle states via status flag. Platforms may have to disable one or more
idle states for various reasons like broken firmware or other unmet
dependencies.

Fix handling of such unavailable/disabled idle states by ignoring them
while parsing the states.

Fixes: a3381e3a65cb ("PM / domains: Fix up domain-idle-states OF parsing")
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&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 e0c57a5c70c13317238cb19a7ded0eab4a5f7de5 ]

Platforms can provide the information about the availability of each
idle states via status flag. Platforms may have to disable one or more
idle states for various reasons like broken firmware or other unmet
dependencies.

Fix handling of such unavailable/disabled idle states by ignoring them
while parsing the states.

Fixes: a3381e3a65cb ("PM / domains: Fix up domain-idle-states OF parsing")
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: topology: move store_cpu_topology() to shared code</title>
<updated>2022-10-26T10:34:22+00:00</updated>
<author>
<name>Conor Dooley</name>
<email>conor.dooley@microchip.com</email>
</author>
<published>2022-07-15T17:51:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d46c24f307fbc491980d4170071dc6d79b8b9b3e'/>
<id>d46c24f307fbc491980d4170071dc6d79b8b9b3e</id>
<content type='text'>
commit 456797da792fa7cbf6698febf275fe9b36691f78 upstream.

arm64's method of defining a default cpu topology requires only minimal
changes to apply to RISC-V also. The current arm64 implementation exits
early in a uniprocessor configuration by reading MPIDR &amp; claiming that
uniprocessor can rely on the default values.

This is appears to be a hangover from prior to '3102bc0e6ac7 ("arm64:
topology: Stop using MPIDR for topology information")', because the
current code just assigns default values for multiprocessor systems.

With the MPIDR references removed, store_cpu_topolgy() can be moved to
the common arch_topology code.

Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Reviewed-by: Atish Patra &lt;atishp@rivosinc.com&gt;
Signed-off-by: Conor Dooley &lt;conor.dooley@microchip.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 456797da792fa7cbf6698febf275fe9b36691f78 upstream.

arm64's method of defining a default cpu topology requires only minimal
changes to apply to RISC-V also. The current arm64 implementation exits
early in a uniprocessor configuration by reading MPIDR &amp; claiming that
uniprocessor can rely on the default values.

This is appears to be a hangover from prior to '3102bc0e6ac7 ("arm64:
topology: Stop using MPIDR for topology information")', because the
current code just assigns default values for multiprocessor systems.

With the MPIDR references removed, store_cpu_topolgy() can be moved to
the common arch_topology code.

Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Reviewed-by: Atish Patra &lt;atishp@rivosinc.com&gt;
Signed-off-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>driver core: Don't probe devices after bus_type.match() probe deferral</title>
<updated>2022-09-08T10:28:07+00:00</updated>
<author>
<name>Isaac J. Manjarres</name>
<email>isaacmanjarres@google.com</email>
</author>
<published>2022-08-17T18:40:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=253ec5fb84057c681a30d20314b8662fe424e3df'/>
<id>253ec5fb84057c681a30d20314b8662fe424e3df</id>
<content type='text'>
commit 25e9fbf0fd38868a429feabc38abebfc6dbf6542 upstream.

Both __device_attach_driver() and __driver_attach() check the return
code of the bus_type.match() function to see if the device needs to be
added to the deferred probe list. After adding the device to the list,
the logic attempts to bind the device to the driver anyway, as if the
device had matched with the driver, which is not correct.

If __device_attach_driver() detects that the device in question is not
ready to match with a driver on the bus, then it doesn't make sense for
the device to attempt to bind with the current driver or continue
attempting to match with any of the other drivers on the bus. So, update
the logic in __device_attach_driver() to reflect this.

If __driver_attach() detects that a driver tried to match with a device
that is not ready to match yet, then the driver should not attempt to bind
with the device. However, the driver can still attempt to match and bind
with other devices on the bus, as drivers can be bound to multiple
devices. So, update the logic in __driver_attach() to reflect this.

Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
Cc: stable@vger.kernel.org
Cc: Saravana Kannan &lt;saravanak@google.com&gt;
Reported-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Tested-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Reviewed-by: Saravana Kannan &lt;saravanak@google.com&gt;
Signed-off-by: Isaac J. Manjarres &lt;isaacmanjarres@google.com&gt;
Link: https://lore.kernel.org/r/20220817184026.3468620-1-isaacmanjarres@google.com
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 25e9fbf0fd38868a429feabc38abebfc6dbf6542 upstream.

Both __device_attach_driver() and __driver_attach() check the return
code of the bus_type.match() function to see if the device needs to be
added to the deferred probe list. After adding the device to the list,
the logic attempts to bind the device to the driver anyway, as if the
device had matched with the driver, which is not correct.

If __device_attach_driver() detects that the device in question is not
ready to match with a driver on the bus, then it doesn't make sense for
the device to attempt to bind with the current driver or continue
attempting to match with any of the other drivers on the bus. So, update
the logic in __device_attach_driver() to reflect this.

If __driver_attach() detects that a driver tried to match with a device
that is not ready to match yet, then the driver should not attempt to bind
with the device. However, the driver can still attempt to match and bind
with other devices on the bus, as drivers can be bound to multiple
devices. So, update the logic in __driver_attach() to reflect this.

Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
Cc: stable@vger.kernel.org
Cc: Saravana Kannan &lt;saravanak@google.com&gt;
Reported-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Tested-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Reviewed-by: Saravana Kannan &lt;saravanak@google.com&gt;
Signed-off-by: Isaac J. Manjarres &lt;isaacmanjarres@google.com&gt;
Link: https://lore.kernel.org/r/20220817184026.3468620-1-isaacmanjarres@google.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist</title>
<updated>2022-08-31T15:16:35+00:00</updated>
<author>
<name>Phil Auld</name>
<email>pauld@redhat.com</email>
</author>
<published>2022-07-15T13:49:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=799e39edb0a8508bba68226f17412d6fe973b014'/>
<id>799e39edb0a8508bba68226f17412d6fe973b014</id>
<content type='text'>
[ Upstream commit 7ee951acd31a88f941fd6535fbdee3a1567f1d63 ]

Using bin_attributes with a 0 size causes fstat and friends to return that
0 size. This breaks userspace code that retrieves the size before reading
the file. Rather than reverting 75bd50fa841 ("drivers/base/node.c: use
bin_attribute to break the size limitation of cpumap ABI") let's put in a
size value at compile time.

For cpulist the maximum size is on the order of
	NR_CPUS * (ceil(log10(NR_CPUS)) + 1)/2

which for 8192 is 20480 (8192 * 5)/2. In order to get near that you'd need
a system with every other CPU on one node. For example: (0,2,4,8, ... ).
To simplify the math and support larger NR_CPUS in the future we are using
(NR_CPUS * 7)/2. We also set it to a min of PAGE_SIZE to retain the older
behavior for smaller NR_CPUS.

The cpumap file the size works out to be NR_CPUS/4 + NR_CPUS/32 - 1
(or NR_CPUS * 9/32 - 1) including the ","s.

Add a set of macros for these values to cpumask.h so they can be used in
multiple places. Apply these to the handful of such files in
drivers/base/topology.c as well as node.c.

As an example, on an 80 cpu 4-node system (NR_CPUS == 8192):

before:

-r--r--r--. 1 root root 0 Jul 12 14:08 system/node/node0/cpulist
-r--r--r--. 1 root root 0 Jul 11 17:25 system/node/node0/cpumap

after:

-r--r--r--. 1 root root 28672 Jul 13 11:32 system/node/node0/cpulist
-r--r--r--. 1 root root  4096 Jul 13 11:31 system/node/node0/cpumap

CONFIG_NR_CPUS = 16384
-r--r--r--. 1 root root 57344 Jul 13 14:03 system/node/node0/cpulist
-r--r--r--. 1 root root  4607 Jul 13 14:02 system/node/node0/cpumap

The actual number of cpus doesn't matter for the reported size since they
are based on NR_CPUS.

Fixes: 75bd50fa841d ("drivers/base/node.c: use bin_attribute to break the size limitation of cpumap ABI")
Fixes: bb9ec13d156e ("topology: use bin_attribute to break the size limitation of cpumap ABI")
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Cc: Yury Norov &lt;yury.norov@gmail.com&gt;
Cc: stable@vger.kernel.org
Acked-by: Yury Norov &lt;yury.norov@gmail.com&gt; (for include/linux/cpumask.h)
Signed-off-by: Phil Auld &lt;pauld@redhat.com&gt;
Link: https://lore.kernel.org/r/20220715134924.3466194-1-pauld@redhat.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 7ee951acd31a88f941fd6535fbdee3a1567f1d63 ]

Using bin_attributes with a 0 size causes fstat and friends to return that
0 size. This breaks userspace code that retrieves the size before reading
the file. Rather than reverting 75bd50fa841 ("drivers/base/node.c: use
bin_attribute to break the size limitation of cpumap ABI") let's put in a
size value at compile time.

For cpulist the maximum size is on the order of
	NR_CPUS * (ceil(log10(NR_CPUS)) + 1)/2

which for 8192 is 20480 (8192 * 5)/2. In order to get near that you'd need
a system with every other CPU on one node. For example: (0,2,4,8, ... ).
To simplify the math and support larger NR_CPUS in the future we are using
(NR_CPUS * 7)/2. We also set it to a min of PAGE_SIZE to retain the older
behavior for smaller NR_CPUS.

The cpumap file the size works out to be NR_CPUS/4 + NR_CPUS/32 - 1
(or NR_CPUS * 9/32 - 1) including the ","s.

Add a set of macros for these values to cpumask.h so they can be used in
multiple places. Apply these to the handful of such files in
drivers/base/topology.c as well as node.c.

As an example, on an 80 cpu 4-node system (NR_CPUS == 8192):

before:

-r--r--r--. 1 root root 0 Jul 12 14:08 system/node/node0/cpulist
-r--r--r--. 1 root root 0 Jul 11 17:25 system/node/node0/cpumap

after:

-r--r--r--. 1 root root 28672 Jul 13 11:32 system/node/node0/cpulist
-r--r--r--. 1 root root  4096 Jul 13 11:31 system/node/node0/cpumap

CONFIG_NR_CPUS = 16384
-r--r--r--. 1 root root 57344 Jul 13 14:03 system/node/node0/cpulist
-r--r--r--. 1 root root  4607 Jul 13 14:02 system/node/node0/cpumap

The actual number of cpus doesn't matter for the reported size since they
are based on NR_CPUS.

Fixes: 75bd50fa841d ("drivers/base/node.c: use bin_attribute to break the size limitation of cpumap ABI")
Fixes: bb9ec13d156e ("topology: use bin_attribute to break the size limitation of cpumap ABI")
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Cc: Yury Norov &lt;yury.norov@gmail.com&gt;
Cc: stable@vger.kernel.org
Acked-by: Yury Norov &lt;yury.norov@gmail.com&gt; (for include/linux/cpumask.h)
Signed-off-by: Phil Auld &lt;pauld@redhat.com&gt;
Link: https://lore.kernel.org/r/20220715134924.3466194-1-pauld@redhat.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>driver core: fix potential deadlock in __driver_attach</title>
<updated>2022-08-17T12:23:45+00:00</updated>
<author>
<name>Zhang Wensheng</name>
<email>zhangwensheng5@huawei.com</email>
</author>
<published>2022-06-22T07:43:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=733ab0c19bf17f6ad7c2b580ede006e369d5ab1b'/>
<id>733ab0c19bf17f6ad7c2b580ede006e369d5ab1b</id>
<content type='text'>
[ Upstream commit 70fe758352cafdee72a7b13bf9db065f9613ced8 ]

In __driver_attach function, There are also AA deadlock problem,
like the commit b232b02bf3c2 ("driver core: fix deadlock in
__device_attach").

stack like commit b232b02bf3c2 ("driver core: fix deadlock in
__device_attach").
list below:
    In __driver_attach function, The lock holding logic is as follows:
    ...
    __driver_attach
    if (driver_allows_async_probing(drv))
      device_lock(dev)      // get lock dev
        async_schedule_dev(__driver_attach_async_helper, dev); // func
          async_schedule_node
            async_schedule_node_domain(func)
              entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC);
              /* when fail or work limit, sync to execute func, but
                 __driver_attach_async_helper will get lock dev as
                 will, which will lead to A-A deadlock.  */
              if (!entry || atomic_read(&amp;entry_count) &gt; MAX_WORK) {
                func;
              else
                queue_work_node(node, system_unbound_wq, &amp;entry-&gt;work)
      device_unlock(dev)

    As above show, when it is allowed to do async probes, because of
    out of memory or work limit, async work is not be allowed, to do
    sync execute instead. it will lead to A-A deadlock because of
    __driver_attach_async_helper getting lock dev.

Reproduce:
and it can be reproduce by make the condition
(if (!entry || atomic_read(&amp;entry_count) &gt; MAX_WORK)) untenable, like
below:

[  370.785650] "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables
this message.
[  370.787154] task:swapper/0       state:D stack:    0 pid:    1 ppid:
0 flags:0x00004000
[  370.788865] Call Trace:
[  370.789374]  &lt;TASK&gt;
[  370.789841]  __schedule+0x482/0x1050
[  370.790613]  schedule+0x92/0x1a0
[  370.791290]  schedule_preempt_disabled+0x2c/0x50
[  370.792256]  __mutex_lock.isra.0+0x757/0xec0
[  370.793158]  __mutex_lock_slowpath+0x1f/0x30
[  370.794079]  mutex_lock+0x50/0x60
[  370.794795]  __device_driver_lock+0x2f/0x70
[  370.795677]  ? driver_probe_device+0xd0/0xd0
[  370.796576]  __driver_attach_async_helper+0x1d/0xd0
[  370.797318]  ? driver_probe_device+0xd0/0xd0
[  370.797957]  async_schedule_node_domain+0xa5/0xc0
[  370.798652]  async_schedule_node+0x19/0x30
[  370.799243]  __driver_attach+0x246/0x290
[  370.799828]  ? driver_allows_async_probing+0xa0/0xa0
[  370.800548]  bus_for_each_dev+0x9d/0x130
[  370.801132]  driver_attach+0x22/0x30
[  370.801666]  bus_add_driver+0x290/0x340
[  370.802246]  driver_register+0x88/0x140
[  370.802817]  ? virtio_scsi_init+0x116/0x116
[  370.803425]  scsi_register_driver+0x1a/0x30
[  370.804057]  init_sd+0x184/0x226
[  370.804533]  do_one_initcall+0x71/0x3a0
[  370.805107]  kernel_init_freeable+0x39a/0x43a
[  370.805759]  ? rest_init+0x150/0x150
[  370.806283]  kernel_init+0x26/0x230
[  370.806799]  ret_from_fork+0x1f/0x30

To fix the deadlock, move the async_schedule_dev outside device_lock,
as we can see, in async_schedule_node_domain, the parameter of
queue_work_node is system_unbound_wq, so it can accept concurrent
operations. which will also not change the code logic, and will
not lead to deadlock.

Fixes: ef0ff68351be ("driver core: Probe devices asynchronously instead of the driver")
Signed-off-by: Zhang Wensheng &lt;zhangwensheng5@huawei.com&gt;
Link: https://lore.kernel.org/r/20220622074327.497102-1-zhangwensheng5@huawei.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 70fe758352cafdee72a7b13bf9db065f9613ced8 ]

In __driver_attach function, There are also AA deadlock problem,
like the commit b232b02bf3c2 ("driver core: fix deadlock in
__device_attach").

stack like commit b232b02bf3c2 ("driver core: fix deadlock in
__device_attach").
list below:
    In __driver_attach function, The lock holding logic is as follows:
    ...
    __driver_attach
    if (driver_allows_async_probing(drv))
      device_lock(dev)      // get lock dev
        async_schedule_dev(__driver_attach_async_helper, dev); // func
          async_schedule_node
            async_schedule_node_domain(func)
              entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC);
              /* when fail or work limit, sync to execute func, but
                 __driver_attach_async_helper will get lock dev as
                 will, which will lead to A-A deadlock.  */
              if (!entry || atomic_read(&amp;entry_count) &gt; MAX_WORK) {
                func;
              else
                queue_work_node(node, system_unbound_wq, &amp;entry-&gt;work)
      device_unlock(dev)

    As above show, when it is allowed to do async probes, because of
    out of memory or work limit, async work is not be allowed, to do
    sync execute instead. it will lead to A-A deadlock because of
    __driver_attach_async_helper getting lock dev.

Reproduce:
and it can be reproduce by make the condition
(if (!entry || atomic_read(&amp;entry_count) &gt; MAX_WORK)) untenable, like
below:

[  370.785650] "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables
this message.
[  370.787154] task:swapper/0       state:D stack:    0 pid:    1 ppid:
0 flags:0x00004000
[  370.788865] Call Trace:
[  370.789374]  &lt;TASK&gt;
[  370.789841]  __schedule+0x482/0x1050
[  370.790613]  schedule+0x92/0x1a0
[  370.791290]  schedule_preempt_disabled+0x2c/0x50
[  370.792256]  __mutex_lock.isra.0+0x757/0xec0
[  370.793158]  __mutex_lock_slowpath+0x1f/0x30
[  370.794079]  mutex_lock+0x50/0x60
[  370.794795]  __device_driver_lock+0x2f/0x70
[  370.795677]  ? driver_probe_device+0xd0/0xd0
[  370.796576]  __driver_attach_async_helper+0x1d/0xd0
[  370.797318]  ? driver_probe_device+0xd0/0xd0
[  370.797957]  async_schedule_node_domain+0xa5/0xc0
[  370.798652]  async_schedule_node+0x19/0x30
[  370.799243]  __driver_attach+0x246/0x290
[  370.799828]  ? driver_allows_async_probing+0xa0/0xa0
[  370.800548]  bus_for_each_dev+0x9d/0x130
[  370.801132]  driver_attach+0x22/0x30
[  370.801666]  bus_add_driver+0x290/0x340
[  370.802246]  driver_register+0x88/0x140
[  370.802817]  ? virtio_scsi_init+0x116/0x116
[  370.803425]  scsi_register_driver+0x1a/0x30
[  370.804057]  init_sd+0x184/0x226
[  370.804533]  do_one_initcall+0x71/0x3a0
[  370.805107]  kernel_init_freeable+0x39a/0x43a
[  370.805759]  ? rest_init+0x150/0x150
[  370.806283]  kernel_init+0x26/0x230
[  370.806799]  ret_from_fork+0x1f/0x30

To fix the deadlock, move the async_schedule_dev outside device_lock,
as we can see, in async_schedule_node_domain, the parameter of
queue_work_node is system_unbound_wq, so it can accept concurrent
operations. which will also not change the code logic, and will
not lead to deadlock.

Fixes: ef0ff68351be ("driver core: Probe devices asynchronously instead of the driver")
Signed-off-by: Zhang Wensheng &lt;zhangwensheng5@huawei.com&gt;
Link: https://lore.kernel.org/r/20220622074327.497102-1-zhangwensheng5@huawei.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>
</feed>
