<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/kernel/irq, branch v5.4.239</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>irqdomain: Fix domain registration race</title>
<updated>2023-03-17T07:32:49+00:00</updated>
<author>
<name>Marc Zyngier</name>
<email>maz@kernel.org</email>
</author>
<published>2023-02-13T10:42:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=985d9fa06b4b90f67e18e4ae3573421406ef253e'/>
<id>985d9fa06b4b90f67e18e4ae3573421406ef253e</id>
<content type='text'>
[ Upstream commit 8932c32c3053accd50702b36e944ac2016cd103c ]

Hierarchical domains created using irq_domain_create_hierarchy() are
currently added to the domain list before having been fully initialised.

This specifically means that a racing allocation request might fail to
allocate irq data for the inner domains of a hierarchy in case the
parent domain pointer has not yet been set up.

Note that this is not really any issue for irqchip drivers that are
registered early (e.g. via IRQCHIP_DECLARE() or IRQCHIP_ACPI_DECLARE())
but could potentially cause trouble with drivers that are registered
later (e.g. modular drivers using IRQCHIP_PLATFORM_DRIVER_BEGIN(),
gpiochip drivers, etc.).

Fixes: afb7da83b9f4 ("irqdomain: Introduce helper function irq_domain_add_hierarchy()")
Cc: stable@vger.kernel.org      # 3.19
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
[ johan: add commit message ]
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20230213104302.17307-8-johan+linaro@kernel.org
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 8932c32c3053accd50702b36e944ac2016cd103c ]

Hierarchical domains created using irq_domain_create_hierarchy() are
currently added to the domain list before having been fully initialised.

This specifically means that a racing allocation request might fail to
allocate irq data for the inner domains of a hierarchy in case the
parent domain pointer has not yet been set up.

Note that this is not really any issue for irqchip drivers that are
registered early (e.g. via IRQCHIP_DECLARE() or IRQCHIP_ACPI_DECLARE())
but could potentially cause trouble with drivers that are registered
later (e.g. modular drivers using IRQCHIP_PLATFORM_DRIVER_BEGIN(),
gpiochip drivers, etc.).

Fixes: afb7da83b9f4 ("irqdomain: Introduce helper function irq_domain_add_hierarchy()")
Cc: stable@vger.kernel.org      # 3.19
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
[ johan: add commit message ]
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20230213104302.17307-8-johan+linaro@kernel.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>irqdomain: Change the type of 'size' in __irq_domain_add() to be consistent</title>
<updated>2023-03-17T07:32:49+00:00</updated>
<author>
<name>Bixuan Cui</name>
<email>cuibixuan@huawei.com</email>
</author>
<published>2021-09-16T02:52:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=01ed8ff22a5b03aae57aef39e6d880a8ced3cda6'/>
<id>01ed8ff22a5b03aae57aef39e6d880a8ced3cda6</id>
<content type='text'>
[ Upstream commit 20c36ce2164f1774b487d443ece99b754bc6ad43 ]

The 'size' is used in struct_size(domain, revmap, size) and its input
parameter type is 'size_t'(unsigned int).
Changing the size to 'unsigned int' to make the type consistent.

Signed-off-by: Bixuan Cui &lt;cuibixuan@huawei.com&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20210916025203.44841-1-cuibixuan@huawei.com
Stable-dep-of: 8932c32c3053 ("irqdomain: Fix domain registration race")
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 20c36ce2164f1774b487d443ece99b754bc6ad43 ]

The 'size' is used in struct_size(domain, revmap, size) and its input
parameter type is 'size_t'(unsigned int).
Changing the size to 'unsigned int' to make the type consistent.

Signed-off-by: Bixuan Cui &lt;cuibixuan@huawei.com&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20210916025203.44841-1-cuibixuan@huawei.com
Stable-dep-of: 8932c32c3053 ("irqdomain: Fix domain registration race")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>irqdomain: Drop bogus fwspec-mapping error handling</title>
<updated>2023-03-11T15:44:03+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan+linaro@kernel.org</email>
</author>
<published>2023-02-13T10:42:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=df129eaa2b8808d0196972671b869f03e2d6764e'/>
<id>df129eaa2b8808d0196972671b869f03e2d6764e</id>
<content type='text'>
commit e3b7ab025e931accdc2c12acf9b75c6197f1c062 upstream.

In case a newly allocated IRQ ever ends up not having any associated
struct irq_data it would not even be possible to dispose the mapping.

Replace the bogus disposal with a WARN_ON().

This will also be used to fix a shared-interrupt mapping race, hence the
CC-stable tag.

Fixes: 1e2a7d78499e ("irqdomain: Don't set type when mapping an IRQ")
Cc: stable@vger.kernel.org      # 4.8
Tested-by: Hsin-Yi Wang &lt;hsinyi@chromium.org&gt;
Tested-by: Mark-PK Tsai &lt;mark-pk.tsai@mediatek.com&gt;
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20230213104302.17307-4-johan+linaro@kernel.org
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 e3b7ab025e931accdc2c12acf9b75c6197f1c062 upstream.

In case a newly allocated IRQ ever ends up not having any associated
struct irq_data it would not even be possible to dispose the mapping.

Replace the bogus disposal with a WARN_ON().

This will also be used to fix a shared-interrupt mapping race, hence the
CC-stable tag.

Fixes: 1e2a7d78499e ("irqdomain: Don't set type when mapping an IRQ")
Cc: stable@vger.kernel.org      # 4.8
Tested-by: Hsin-Yi Wang &lt;hsinyi@chromium.org&gt;
Tested-by: Mark-PK Tsai &lt;mark-pk.tsai@mediatek.com&gt;
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20230213104302.17307-4-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>irqdomain: Fix disassociation race</title>
<updated>2023-03-11T15:44:03+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan+linaro@kernel.org</email>
</author>
<published>2023-02-13T10:42:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=72232dbe14f9397fba188c3b6242b8b2230d9073'/>
<id>72232dbe14f9397fba188c3b6242b8b2230d9073</id>
<content type='text'>
commit 3f883c38f5628f46b30bccf090faec054088e262 upstream.

The global irq_domain_mutex is held when mapping interrupts from
non-hierarchical domains but currently not when disposing them.

This specifically means that updates of the domain mapcount is racy
(currently only used for statistics in debugfs).

Make sure to hold the global irq_domain_mutex also when disposing
mappings from non-hierarchical domains.

Fixes: 9dc6be3d4193 ("genirq/irqdomain: Add map counter")
Cc: stable@vger.kernel.org      # 4.13
Tested-by: Hsin-Yi Wang &lt;hsinyi@chromium.org&gt;
Tested-by: Mark-PK Tsai &lt;mark-pk.tsai@mediatek.com&gt;
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20230213104302.17307-3-johan+linaro@kernel.org
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 3f883c38f5628f46b30bccf090faec054088e262 upstream.

The global irq_domain_mutex is held when mapping interrupts from
non-hierarchical domains but currently not when disposing them.

This specifically means that updates of the domain mapcount is racy
(currently only used for statistics in debugfs).

Make sure to hold the global irq_domain_mutex also when disposing
mappings from non-hierarchical domains.

Fixes: 9dc6be3d4193 ("genirq/irqdomain: Add map counter")
Cc: stable@vger.kernel.org      # 4.13
Tested-by: Hsin-Yi Wang &lt;hsinyi@chromium.org&gt;
Tested-by: Mark-PK Tsai &lt;mark-pk.tsai@mediatek.com&gt;
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20230213104302.17307-3-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>irqdomain: Fix association race</title>
<updated>2023-03-11T15:44:02+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan+linaro@kernel.org</email>
</author>
<published>2023-02-13T10:42:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2101663687e6b42ad54e8ab3f7cbb68907d7cfca'/>
<id>2101663687e6b42ad54e8ab3f7cbb68907d7cfca</id>
<content type='text'>
commit b06730a571a9ff1ba5bd6b20bf9e50e5a12f1ec6 upstream.

The sanity check for an already mapped virq is done outside of the
irq_domain_mutex-protected section which means that an (unlikely) racing
association may not be detected.

Fix this by factoring out the association implementation, which will
also be used in a follow-on change to fix a shared-interrupt mapping
race.

Fixes: ddaf144c61da ("irqdomain: Refactor irq_domain_associate_many()")
Cc: stable@vger.kernel.org      # 3.11
Tested-by: Hsin-Yi Wang &lt;hsinyi@chromium.org&gt;
Tested-by: Mark-PK Tsai &lt;mark-pk.tsai@mediatek.com&gt;
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20230213104302.17307-2-johan+linaro@kernel.org
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 b06730a571a9ff1ba5bd6b20bf9e50e5a12f1ec6 upstream.

The sanity check for an already mapped virq is done outside of the
irq_domain_mutex-protected section which means that an (unlikely) racing
association may not be detected.

Fix this by factoring out the association implementation, which will
also be used in a follow-on change to fix a shared-interrupt mapping
race.

Fixes: ddaf144c61da ("irqdomain: Refactor irq_domain_associate_many()")
Cc: stable@vger.kernel.org      # 3.11
Tested-by: Hsin-Yi Wang &lt;hsinyi@chromium.org&gt;
Tested-by: Mark-PK Tsai &lt;mark-pk.tsai@mediatek.com&gt;
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20230213104302.17307-2-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()</title>
<updated>2023-03-11T15:43:42+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2020-07-13T22:01:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5de7a4254eb2d501cbb59918a152665b29c02109'/>
<id>5de7a4254eb2d501cbb59918a152665b29c02109</id>
<content type='text'>
[ Upstream commit b13fecb1c3a603c4b8e99b306fecf4f668c11b32 ]

This converts all the existing DECLARE_TASKLET() (and ...DISABLED)
macros with DECLARE_TASKLET_OLD() in preparation for refactoring the
tasklet callback type. All existing DECLARE_TASKLET() users had a "0"
data argument, it has been removed here as well.

Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Stable-dep-of: 1fdeb8b9f29d ("wifi: iwl3945: Add missing check for create_singlethread_workqueue")
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 b13fecb1c3a603c4b8e99b306fecf4f668c11b32 ]

This converts all the existing DECLARE_TASKLET() (and ...DISABLED)
macros with DECLARE_TASKLET_OLD() in preparation for refactoring the
tasklet callback type. All existing DECLARE_TASKLET() users had a "0"
data argument, it has been removed here as well.

Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Stable-dep-of: 1fdeb8b9f29d ("wifi: iwl3945: Add missing check for create_singlethread_workqueue")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genirq/irqdesc: Don't try to remove non-existing sysfs files</title>
<updated>2023-01-18T10:40:55+00:00</updated>
<author>
<name>Yang Yingliang</name>
<email>yangyingliang@huawei.com</email>
</author>
<published>2022-11-28T15:16:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d25bf9af860e948df33fe43393f3879e90f0e320'/>
<id>d25bf9af860e948df33fe43393f3879e90f0e320</id>
<content type='text'>
[ Upstream commit 9049e1ca41983ab773d7ea244bee86d7835ec9f5 ]

Fault injection tests trigger warnings like this:

  kernfs: can not remove 'chip_name', no directory
  WARNING: CPU: 0 PID: 253 at fs/kernfs/dir.c:1616 kernfs_remove_by_name_ns+0xce/0xe0
  RIP: 0010:kernfs_remove_by_name_ns+0xce/0xe0
  Call Trace:
   &lt;TASK&gt;
   remove_files.isra.1+0x3f/0xb0
   sysfs_remove_group+0x68/0xe0
   sysfs_remove_groups+0x41/0x70
   __kobject_del+0x45/0xc0
   kobject_del+0x29/0x40
   free_desc+0x42/0x70
   irq_free_descs+0x5e/0x90

The reason is that the interrupt descriptor sysfs handling does not roll
back on a failing kobject_add() during allocation. If the descriptor is
freed later on, kobject_del() is invoked with a not added kobject resulting
in the above warnings.

A proper rollback in case of a kobject_add() failure would be the straight
forward solution. But this is not possible due to the way how interrupt
descriptor sysfs handling works.

Interrupt descriptors are allocated before sysfs becomes available. So the
sysfs files for the early allocated descriptors are added later in the boot
process. At this point there can be nothing useful done about a failing
kobject_add(). For consistency the interrupt descriptor allocation always
treats kobject_add() failures as non-critical and just emits a warning.

To solve this problem, keep track in the interrupt descriptor whether
kobject_add() was successful or not and make the invocation of
kobject_del() conditional on that.

[ tglx: Massage changelog, comments and use a state bit. ]

Fixes: ecb3f394c5db ("genirq: Expose interrupt information through sysfs")
Signed-off-by: Yang Yingliang &lt;yangyingliang@huawei.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Link: https://lore.kernel.org/r/20221128151612.1786122-1-yangyingliang@huawei.com
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 9049e1ca41983ab773d7ea244bee86d7835ec9f5 ]

Fault injection tests trigger warnings like this:

  kernfs: can not remove 'chip_name', no directory
  WARNING: CPU: 0 PID: 253 at fs/kernfs/dir.c:1616 kernfs_remove_by_name_ns+0xce/0xe0
  RIP: 0010:kernfs_remove_by_name_ns+0xce/0xe0
  Call Trace:
   &lt;TASK&gt;
   remove_files.isra.1+0x3f/0xb0
   sysfs_remove_group+0x68/0xe0
   sysfs_remove_groups+0x41/0x70
   __kobject_del+0x45/0xc0
   kobject_del+0x29/0x40
   free_desc+0x42/0x70
   irq_free_descs+0x5e/0x90

The reason is that the interrupt descriptor sysfs handling does not roll
back on a failing kobject_add() during allocation. If the descriptor is
freed later on, kobject_del() is invoked with a not added kobject resulting
in the above warnings.

A proper rollback in case of a kobject_add() failure would be the straight
forward solution. But this is not possible due to the way how interrupt
descriptor sysfs handling works.

Interrupt descriptors are allocated before sysfs becomes available. So the
sysfs files for the early allocated descriptors are added later in the boot
process. At this point there can be nothing useful done about a failing
kobject_add(). For consistency the interrupt descriptor allocation always
treats kobject_add() failures as non-critical and just emits a warning.

To solve this problem, keep track in the interrupt descriptor whether
kobject_add() was successful or not and make the invocation of
kobject_del() conditional on that.

[ tglx: Massage changelog, comments and use a state bit. ]

Fixes: ecb3f394c5db ("genirq: Expose interrupt information through sysfs")
Signed-off-by: Yang Yingliang &lt;yangyingliang@huawei.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Link: https://lore.kernel.org/r/20221128151612.1786122-1-yangyingliang@huawei.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genirq: Don't return error on missing optional irq_request_resources()</title>
<updated>2022-08-25T09:17:29+00:00</updated>
<author>
<name>Antonio Borneo</name>
<email>antonio.borneo@foss.st.com</email>
</author>
<published>2022-05-12T16:05:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3fb368c0ae39ed6075fe45bef3ba9783213192a6'/>
<id>3fb368c0ae39ed6075fe45bef3ba9783213192a6</id>
<content type='text'>
[ Upstream commit 95001b756467ecc9f5973eb5e74e97699d9bbdf1 ]

Function irq_chip::irq_request_resources() is reported as optional
in the declaration of struct irq_chip.
If the parent irq_chip does not implement it, we should ignore it
and return.

Don't return error if the functions is missing.

Signed-off-by: Antonio Borneo &lt;antonio.borneo@foss.st.com&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20220512160544.13561-1-antonio.borneo@foss.st.com
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 95001b756467ecc9f5973eb5e74e97699d9bbdf1 ]

Function irq_chip::irq_request_resources() is reported as optional
in the declaration of struct irq_chip.
If the parent irq_chip does not implement it, we should ignore it
and return.

Don't return error if the functions is missing.

Signed-off-by: Antonio Borneo &lt;antonio.borneo@foss.st.com&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20220512160544.13561-1-antonio.borneo@foss.st.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>random: remove unused irq_flags argument from add_interrupt_randomness()</title>
<updated>2022-06-22T12:11:06+00:00</updated>
<author>
<name>Sebastian Andrzej Siewior</name>
<email>bigeasy@linutronix.de</email>
</author>
<published>2021-12-07T12:17:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6e6ae70c1eac27d3f58726a8f1037269ab2e81ab'/>
<id>6e6ae70c1eac27d3f58726a8f1037269ab2e81ab</id>
<content type='text'>
commit 703f7066f40599c290babdb79dd61319264987e9 upstream.

Since commit
   ee3e00e9e7101 ("random: use registers from interrupted code for CPU's w/o a cycle counter")

the irq_flags argument is no longer used.

Remove unused irq_flags.

Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Dexuan Cui &lt;decui@microsoft.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Haiyang Zhang &lt;haiyangz@microsoft.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: K. Y. Srinivasan &lt;kys@microsoft.com&gt;
Cc: Stephen Hemminger &lt;sthemmin@microsoft.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Wei Liu &lt;wei.liu@kernel.org&gt;
Cc: linux-hyperv@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Acked-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.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 703f7066f40599c290babdb79dd61319264987e9 upstream.

Since commit
   ee3e00e9e7101 ("random: use registers from interrupted code for CPU's w/o a cycle counter")

the irq_flags argument is no longer used.

Remove unused irq_flags.

Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Dexuan Cui &lt;decui@microsoft.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Haiyang Zhang &lt;haiyangz@microsoft.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: K. Y. Srinivasan &lt;kys@microsoft.com&gt;
Cc: Stephen Hemminger &lt;sthemmin@microsoft.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Wei Liu &lt;wei.liu@kernel.org&gt;
Cc: linux-hyperv@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Acked-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genirq: Synchronize interrupt thread startup</title>
<updated>2022-05-12T10:23:41+00:00</updated>
<author>
<name>Thomas Pfaff</name>
<email>tpfaff@pcs.com</email>
</author>
<published>2022-05-02T11:28:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ac5894fb8626311eb852b8755aa735d5bdfd9976'/>
<id>ac5894fb8626311eb852b8755aa735d5bdfd9976</id>
<content type='text'>
commit 8707898e22fd665bc1d7b18b809be4b56ce25bdd upstream.

A kernel hang can be observed when running setserial in a loop on a kernel
with force threaded interrupts. The sequence of events is:

   setserial
     open("/dev/ttyXXX")
       request_irq()
     do_stuff()
      -&gt; serial interrupt
         -&gt; wake(irq_thread)
	      desc-&gt;threads_active++;
     close()
       free_irq()
         kthread_stop(irq_thread)
     synchronize_irq() &lt;- hangs because desc-&gt;threads_active != 0

The thread is created in request_irq() and woken up, but does not get on a
CPU to reach the actual thread function, which would handle the pending
wake-up. kthread_stop() sets the should stop condition which makes the
thread immediately exit, which in turn leaves the stale threads_active
count around.

This problem was introduced with commit 519cc8652b3a, which addressed a
interrupt sharing issue in the PCIe code.

Before that commit free_irq() invoked synchronize_irq(), which waits for
the hard interrupt handler and also for associated threads to complete.

To address the PCIe issue synchronize_irq() was replaced with
__synchronize_hardirq(), which only waits for the hard interrupt handler to
complete, but not for threaded handlers.

This was done under the assumption, that the interrupt thread already
reached the thread function and waits for a wake-up, which is guaranteed to
be handled before acting on the stop condition. The problematic case, that
the thread would not reach the thread function, was obviously overlooked.

Make sure that the interrupt thread is really started and reaches
thread_fn() before returning from __setup_irq().

This utilizes the existing wait queue in the interrupt descriptor. The
wait queue is unused for non-shared interrupts. For shared interrupts the
usage might cause a spurious wake-up of a waiter in synchronize_irq() or the
completion of a threaded handler might cause a spurious wake-up of the
waiter for the ready flag. Both are harmless and have no functional impact.

[ tglx: Amended changelog ]

Fixes: 519cc8652b3a ("genirq: Synchronize only with single thread on free_irq()")
Signed-off-by: Thomas Pfaff &lt;tpfaff@pcs.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Marc Zyngier &lt;maz@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/552fe7b4-9224-b183-bb87-a8f36d335690@pcs.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 8707898e22fd665bc1d7b18b809be4b56ce25bdd upstream.

A kernel hang can be observed when running setserial in a loop on a kernel
with force threaded interrupts. The sequence of events is:

   setserial
     open("/dev/ttyXXX")
       request_irq()
     do_stuff()
      -&gt; serial interrupt
         -&gt; wake(irq_thread)
	      desc-&gt;threads_active++;
     close()
       free_irq()
         kthread_stop(irq_thread)
     synchronize_irq() &lt;- hangs because desc-&gt;threads_active != 0

The thread is created in request_irq() and woken up, but does not get on a
CPU to reach the actual thread function, which would handle the pending
wake-up. kthread_stop() sets the should stop condition which makes the
thread immediately exit, which in turn leaves the stale threads_active
count around.

This problem was introduced with commit 519cc8652b3a, which addressed a
interrupt sharing issue in the PCIe code.

Before that commit free_irq() invoked synchronize_irq(), which waits for
the hard interrupt handler and also for associated threads to complete.

To address the PCIe issue synchronize_irq() was replaced with
__synchronize_hardirq(), which only waits for the hard interrupt handler to
complete, but not for threaded handlers.

This was done under the assumption, that the interrupt thread already
reached the thread function and waits for a wake-up, which is guaranteed to
be handled before acting on the stop condition. The problematic case, that
the thread would not reach the thread function, was obviously overlooked.

Make sure that the interrupt thread is really started and reaches
thread_fn() before returning from __setup_irq().

This utilizes the existing wait queue in the interrupt descriptor. The
wait queue is unused for non-shared interrupts. For shared interrupts the
usage might cause a spurious wake-up of a waiter in synchronize_irq() or the
completion of a threaded handler might cause a spurious wake-up of the
waiter for the ready flag. Both are harmless and have no functional impact.

[ tglx: Amended changelog ]

Fixes: 519cc8652b3a ("genirq: Synchronize only with single thread on free_irq()")
Signed-off-by: Thomas Pfaff &lt;tpfaff@pcs.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Marc Zyngier &lt;maz@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/552fe7b4-9224-b183-bb87-a8f36d335690@pcs.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
