<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/uio, branch v6.1.151</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>uio_hv_generic: Align ring size to system page</title>
<updated>2025-07-06T08:57:58+00:00</updated>
<author>
<name>Long Li</name>
<email>longli@microsoft.com</email>
</author>
<published>2025-05-06T00:56:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=db169a93f49a75b3152446bb06576b65c032e4be'/>
<id>db169a93f49a75b3152446bb06576b65c032e4be</id>
<content type='text'>
[ Upstream commit 0315fef2aff9f251ddef8a4b53db9187429c3553 ]

Following the ring header, the ring data should align to system page
boundary. Adjust the size if necessary.

Cc: stable@vger.kernel.org
Fixes: 95096f2fbd10 ("uio-hv-generic: new userspace i/o driver for VMBus")
Signed-off-by: Long Li &lt;longli@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Link: https://lore.kernel.org/r/1746492997-4599-4-git-send-email-longli@linuxonhyperv.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;1746492997-4599-4-git-send-email-longli@linuxonhyperv.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 0315fef2aff9f251ddef8a4b53db9187429c3553 ]

Following the ring header, the ring data should align to system page
boundary. Adjust the size if necessary.

Cc: stable@vger.kernel.org
Fixes: 95096f2fbd10 ("uio-hv-generic: new userspace i/o driver for VMBus")
Signed-off-by: Long Li &lt;longli@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Link: https://lore.kernel.org/r/1746492997-4599-4-git-send-email-longli@linuxonhyperv.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;1746492997-4599-4-git-send-email-longli@linuxonhyperv.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>uio_hv_generic: Query the ringbuffer size for device</title>
<updated>2025-07-06T08:57:58+00:00</updated>
<author>
<name>Saurabh Sengar</name>
<email>ssengar@linux.microsoft.com</email>
</author>
<published>2024-03-30T08:51:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=00eee6a7d182cefc6e17237c2cebb6e3eb4ba5cc'/>
<id>00eee6a7d182cefc6e17237c2cebb6e3eb4ba5cc</id>
<content type='text'>
[ Upstream commit e566ed5b64177a0c07b677568f623ed31d23406d ]

Query the ring buffer size from pre defined table per device
and use that value for allocating the ring buffer for that
device. Keep the size as current default which is 2 MB if
the device doesn't have any preferred ring size.

Signed-off-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Reviewed-by: Long Li &lt;longli@microsoft.com&gt;
Link: https://lore.kernel.org/r/1711788723-8593-3-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Stable-dep-of: 0315fef2aff9 ("uio_hv_generic: Align ring size to system page")
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 e566ed5b64177a0c07b677568f623ed31d23406d ]

Query the ring buffer size from pre defined table per device
and use that value for allocating the ring buffer for that
device. Keep the size as current default which is 2 MB if
the device doesn't have any preferred ring size.

Signed-off-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Reviewed-by: Long Li &lt;longli@microsoft.com&gt;
Link: https://lore.kernel.org/r/1711788723-8593-3-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Stable-dep-of: 0315fef2aff9 ("uio_hv_generic: Align ring size to system page")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>uio_hv_generic: Use correct size for interrupt and monitor pages</title>
<updated>2025-06-27T10:07:31+00:00</updated>
<author>
<name>Long Li</name>
<email>longli@microsoft.com</email>
</author>
<published>2025-05-06T00:56:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5d819dbf59488bbe941d599d0185ffdc11405270'/>
<id>5d819dbf59488bbe941d599d0185ffdc11405270</id>
<content type='text'>
commit c951ab8fd3589cf6991ed4111d2130816f2e3ac2 upstream.

Interrupt and monitor pages should be in Hyper-V page size (4k bytes).
This can be different from the system page size.

This size is read and used by the user-mode program to determine the
mapped data region. An example of such user-mode program is the VMBus
driver in DPDK.

Cc: stable@vger.kernel.org
Fixes: 95096f2fbd10 ("uio-hv-generic: new userspace i/o driver for VMBus")
Signed-off-by: Long Li &lt;longli@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Link: https://lore.kernel.org/r/1746492997-4599-3-git-send-email-longli@linuxonhyperv.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;1746492997-4599-3-git-send-email-longli@linuxonhyperv.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 c951ab8fd3589cf6991ed4111d2130816f2e3ac2 upstream.

Interrupt and monitor pages should be in Hyper-V page size (4k bytes).
This can be different from the system page size.

This size is read and used by the user-mode program to determine the
mapped data region. An example of such user-mode program is the VMBus
driver in DPDK.

Cc: stable@vger.kernel.org
Fixes: 95096f2fbd10 ("uio-hv-generic: new userspace i/o driver for VMBus")
Signed-off-by: Long Li &lt;longli@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Link: https://lore.kernel.org/r/1746492997-4599-3-git-send-email-longli@linuxonhyperv.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;1746492997-4599-3-git-send-email-longli@linuxonhyperv.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Drivers: hv: vmbus: Fix rescind handling in uio_hv_generic</title>
<updated>2024-09-12T09:10:26+00:00</updated>
<author>
<name>Naman Jain</name>
<email>namjain@linux.microsoft.com</email>
</author>
<published>2024-08-29T07:13:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=337c9ce376964378d84a7e9d04853788961dc16d'/>
<id>337c9ce376964378d84a7e9d04853788961dc16d</id>
<content type='text'>
commit 6fd28941447bf2c8ca0f26fda612a1cabc41663f upstream.

Rescind offer handling relies on rescind callbacks for some of the
resources cleanup, if they are registered. It does not unregister
vmbus device for the primary channel closure, when callback is
registered. Without it, next onoffer does not come, rescind flag
remains set and device goes to unusable state.

Add logic to unregister vmbus for the primary channel in rescind callback
to ensure channel removal and relid release, and to ensure that next
onoffer can be received and handled properly.

Cc: stable@vger.kernel.org
Fixes: ca3cda6fcf1e ("uio_hv_generic: add rescind support")
Signed-off-by: Naman Jain &lt;namjain@linux.microsoft.com&gt;
Reviewed-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Link: https://lore.kernel.org/r/20240829071312.1595-3-namjain@linux.microsoft.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 6fd28941447bf2c8ca0f26fda612a1cabc41663f upstream.

Rescind offer handling relies on rescind callbacks for some of the
resources cleanup, if they are registered. It does not unregister
vmbus device for the primary channel closure, when callback is
registered. Without it, next onoffer does not come, rescind flag
remains set and device goes to unusable state.

Add logic to unregister vmbus for the primary channel in rescind callback
to ensure channel removal and relid release, and to ensure that next
onoffer can be received and handled properly.

Cc: stable@vger.kernel.org
Fixes: ca3cda6fcf1e ("uio_hv_generic: add rescind support")
Signed-off-by: Naman Jain &lt;namjain@linux.microsoft.com&gt;
Reviewed-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Link: https://lore.kernel.org/r/20240829071312.1595-3-namjain@linux.microsoft.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>uio_hv_generic: Fix kernel NULL pointer dereference in hv_uio_rescind</title>
<updated>2024-09-12T09:10:26+00:00</updated>
<author>
<name>Saurabh Sengar</name>
<email>ssengar@linux.microsoft.com</email>
</author>
<published>2024-08-29T07:13:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2be373469be1774bbe03b0fa7e2854e65005b1cc'/>
<id>2be373469be1774bbe03b0fa7e2854e65005b1cc</id>
<content type='text'>
commit fb1adbd7e50f3d2de56d0a2bb0700e2e819a329e upstream.

For primary VM Bus channels, primary_channel pointer is always NULL. This
pointer is valid only for the secondary channels. Also, rescind callback
is meant for primary channels only.

Fix NULL pointer dereference by retrieving the device_obj from the parent
for the primary channel.

Cc: stable@vger.kernel.org
Fixes: ca3cda6fcf1e ("uio_hv_generic: add rescind support")
Signed-off-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Signed-off-by: Naman Jain &lt;namjain@linux.microsoft.com&gt;
Link: https://lore.kernel.org/r/20240829071312.1595-2-namjain@linux.microsoft.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 fb1adbd7e50f3d2de56d0a2bb0700e2e819a329e upstream.

For primary VM Bus channels, primary_channel pointer is always NULL. This
pointer is valid only for the secondary channels. Also, rescind callback
is meant for primary channels only.

Fix NULL pointer dereference by retrieving the device_obj from the parent
for the primary channel.

Cc: stable@vger.kernel.org
Fixes: ca3cda6fcf1e ("uio_hv_generic: add rescind support")
Signed-off-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Signed-off-by: Naman Jain &lt;namjain@linux.microsoft.com&gt;
Link: https://lore.kernel.org/r/20240829071312.1595-2-namjain@linux.microsoft.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>uio_hv_generic: Don't free decrypted memory</title>
<updated>2024-05-17T09:56:08+00:00</updated>
<author>
<name>Rick Edgecombe</name>
<email>rick.p.edgecombe@intel.com</email>
</author>
<published>2024-03-11T16:15:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dabf12bf994318d939f70d47cfda30e47abb2c54'/>
<id>dabf12bf994318d939f70d47cfda30e47abb2c54</id>
<content type='text'>
[ Upstream commit 3d788b2fbe6a1a1a9e3db09742b90809d51638b7 ]

In CoCo VMs it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.

The VMBus device UIO driver could free decrypted/shared pages if
set_memory_decrypted() fails. Check the decrypted field in the gpadl
to decide whether to free the memory.

Signed-off-by: Rick Edgecombe &lt;rick.p.edgecombe@intel.com&gt;
Signed-off-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Reviewed-by: Kuppuswamy Sathyanarayanan &lt;sathyanarayanan.kuppuswamy@linux.intel.com&gt;
Acked-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20240311161558.1310-5-mhklinux@outlook.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;20240311161558.1310-5-mhklinux@outlook.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 3d788b2fbe6a1a1a9e3db09742b90809d51638b7 ]

In CoCo VMs it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.

The VMBus device UIO driver could free decrypted/shared pages if
set_memory_decrypted() fails. Check the decrypted field in the gpadl
to decide whether to free the memory.

Signed-off-by: Rick Edgecombe &lt;rick.p.edgecombe@intel.com&gt;
Signed-off-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Reviewed-by: Kuppuswamy Sathyanarayanan &lt;sathyanarayanan.kuppuswamy@linux.intel.com&gt;
Acked-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20240311161558.1310-5-mhklinux@outlook.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;20240311161558.1310-5-mhklinux@outlook.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>uio: Fix use-after-free in uio_open</title>
<updated>2024-01-20T10:50:10+00:00</updated>
<author>
<name>Guanghui Feng</name>
<email>guanghuifeng@linux.alibaba.com</email>
</author>
<published>2023-12-21T09:57:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=17a8519cb359c3b483fb5c7367efa9a8a508bdea'/>
<id>17a8519cb359c3b483fb5c7367efa9a8a508bdea</id>
<content type='text'>
commit 0c9ae0b8605078eafc3bea053cc78791e97ba2e2 upstream.

core-1				core-2
-------------------------------------------------------
uio_unregister_device		uio_open
				idev = idr_find()
device_unregister(&amp;idev-&gt;dev)
put_device(&amp;idev-&gt;dev)
uio_device_release
				get_device(&amp;idev-&gt;dev)
kfree(idev)
uio_free_minor(minor)
				uio_release
				put_device(&amp;idev-&gt;dev)
				kfree(idev)
-------------------------------------------------------

In the core-1 uio_unregister_device(), the device_unregister will kfree
idev when the idev-&gt;dev kobject ref is 1. But after core-1
device_unregister, put_device and before doing kfree, the core-2 may
get_device. Then:
1. After core-1 kfree idev, the core-2 will do use-after-free for idev.
2. When core-2 do uio_release and put_device, the idev will be double
   freed.

To address this issue, we can get idev atomic &amp; inc idev reference with
minor_lock.

Fixes: 57c5f4df0a5a ("uio: fix crash after the device is unregistered")
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Guanghui Feng &lt;guanghuifeng@linux.alibaba.com&gt;
Reviewed-by: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Link: https://lore.kernel.org/r/1703152663-59949-1-git-send-email-guanghuifeng@linux.alibaba.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 0c9ae0b8605078eafc3bea053cc78791e97ba2e2 upstream.

core-1				core-2
-------------------------------------------------------
uio_unregister_device		uio_open
				idev = idr_find()
device_unregister(&amp;idev-&gt;dev)
put_device(&amp;idev-&gt;dev)
uio_device_release
				get_device(&amp;idev-&gt;dev)
kfree(idev)
uio_free_minor(minor)
				uio_release
				put_device(&amp;idev-&gt;dev)
				kfree(idev)
-------------------------------------------------------

In the core-1 uio_unregister_device(), the device_unregister will kfree
idev when the idev-&gt;dev kobject ref is 1. But after core-1
device_unregister, put_device and before doing kfree, the core-2 may
get_device. Then:
1. After core-1 kfree idev, the core-2 will do use-after-free for idev.
2. When core-2 do uio_release and put_device, the idev will be double
   freed.

To address this issue, we can get idev atomic &amp; inc idev reference with
minor_lock.

Fixes: 57c5f4df0a5a ("uio: fix crash after the device is unregistered")
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Guanghui Feng &lt;guanghuifeng@linux.alibaba.com&gt;
Reviewed-by: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Link: https://lore.kernel.org/r/1703152663-59949-1-git-send-email-guanghuifeng@linux.alibaba.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>uio: uio_dmem_genirq: Fix deadlock between irq config and handling</title>
<updated>2022-12-31T12:32:38+00:00</updated>
<author>
<name>Rafael Mendonca</name>
<email>rafaelmendsr@gmail.com</email>
</author>
<published>2022-09-30T22:40:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b9dcd53356eae2850209e9c39d7a1edd9325031a'/>
<id>b9dcd53356eae2850209e9c39d7a1edd9325031a</id>
<content type='text'>
[ Upstream commit 118b918018175d9fcd8db667f905012e986cc2c9 ]

This fixes a concurrency issue addressed in commit 34cb27528398 ("UIO: Fix
concurrency issue"):

  "In a SMP case there was a race condition issue between
  Uio_pdrv_genirq_irqcontrol() running on one CPU and irq handler on
  another CPU. Fix it by spin_locking shared resources access inside irq
  handler."

The implementation of "uio_dmem_genirq" was based on "uio_pdrv_genirq" and
it is used in a similar manner to the "uio_pdrv_genirq" driver with respect
to interrupt configuration and handling. At the time "uio_dmem_genirq" was
merged, both had the same implementation of the 'uio_info' handlers
irqcontrol() and handler(), thus, both had the same concurrency issue
mentioned by the above commit. However, the above patch was only applied to
the "uio_pdrv_genirq" driver.

Split out from commit 34cb27528398 ("UIO: Fix concurrency issue").

Fixes: 0a0c3b5a24bd ("Add new uio device for dynamic memory allocation")
Signed-off-by: Rafael Mendonca &lt;rafaelmendsr@gmail.com&gt;
Link: https://lore.kernel.org/r/20220930224100.816175-3-rafaelmendsr@gmail.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 118b918018175d9fcd8db667f905012e986cc2c9 ]

This fixes a concurrency issue addressed in commit 34cb27528398 ("UIO: Fix
concurrency issue"):

  "In a SMP case there was a race condition issue between
  Uio_pdrv_genirq_irqcontrol() running on one CPU and irq handler on
  another CPU. Fix it by spin_locking shared resources access inside irq
  handler."

The implementation of "uio_dmem_genirq" was based on "uio_pdrv_genirq" and
it is used in a similar manner to the "uio_pdrv_genirq" driver with respect
to interrupt configuration and handling. At the time "uio_dmem_genirq" was
merged, both had the same implementation of the 'uio_info' handlers
irqcontrol() and handler(), thus, both had the same concurrency issue
mentioned by the above commit. However, the above patch was only applied to
the "uio_pdrv_genirq" driver.

Split out from commit 34cb27528398 ("UIO: Fix concurrency issue").

Fixes: 0a0c3b5a24bd ("Add new uio device for dynamic memory allocation")
Signed-off-by: Rafael Mendonca &lt;rafaelmendsr@gmail.com&gt;
Link: https://lore.kernel.org/r/20220930224100.816175-3-rafaelmendsr@gmail.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>uio: uio_dmem_genirq: Fix missing unlock in irq configuration</title>
<updated>2022-12-31T12:32:38+00:00</updated>
<author>
<name>Rafael Mendonca</name>
<email>rafaelmendsr@gmail.com</email>
</author>
<published>2022-09-30T22:40:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ee180e867ce4b2f744799247b81050b3e5dd62cd'/>
<id>ee180e867ce4b2f744799247b81050b3e5dd62cd</id>
<content type='text'>
[ Upstream commit 9de255c461d1b3f0242b3ad1450c3323a3e00b34 ]

Commit b74351287d4b ("uio: fix a sleep-in-atomic-context bug in
uio_dmem_genirq_irqcontrol()") started calling disable_irq() without
holding the spinlock because it can sleep. However, that fix introduced
another bug: if interrupt is already disabled and a new disable request
comes in, then the spinlock is not unlocked:

root@localhost:~# printf '\x00\x00\x00\x00' &gt; /dev/uio0
root@localhost:~# printf '\x00\x00\x00\x00' &gt; /dev/uio0
root@localhost:~# [   14.851538] BUG: scheduling while atomic: bash/223/0x00000002
[   14.851991] Modules linked in: uio_dmem_genirq uio myfpga(OE) bochs drm_vram_helper drm_ttm_helper ttm drm_kms_helper drm snd_pcm ppdev joydev psmouse snd_timer snd e1000fb_sys_fops syscopyarea parport sysfillrect soundcore sysimgblt input_leds pcspkr i2c_piix4 serio_raw floppy evbug qemu_fw_cfg mac_hid pata_acpi ip_tables x_tables autofs4 [last unloaded: parport_pc]
[   14.854206] CPU: 0 PID: 223 Comm: bash Tainted: G           OE      6.0.0-rc7 #21
[   14.854786] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[   14.855664] Call Trace:
[   14.855861]  &lt;TASK&gt;
[   14.856025]  dump_stack_lvl+0x4d/0x67
[   14.856325]  dump_stack+0x14/0x1a
[   14.856583]  __schedule_bug.cold+0x4b/0x5c
[   14.856915]  __schedule+0xe81/0x13d0
[   14.857199]  ? idr_find+0x13/0x20
[   14.857456]  ? get_work_pool+0x2d/0x50
[   14.857756]  ? __flush_work+0x233/0x280
[   14.858068]  ? __schedule+0xa95/0x13d0
[   14.858307]  ? idr_find+0x13/0x20
[   14.858519]  ? get_work_pool+0x2d/0x50
[   14.858798]  schedule+0x6c/0x100
[   14.859009]  schedule_hrtimeout_range_clock+0xff/0x110
[   14.859335]  ? tty_write_room+0x1f/0x30
[   14.859598]  ? n_tty_poll+0x1ec/0x220
[   14.859830]  ? tty_ldisc_deref+0x1a/0x20
[   14.860090]  schedule_hrtimeout_range+0x17/0x20
[   14.860373]  do_select+0x596/0x840
[   14.860627]  ? __kernel_text_address+0x16/0x50
[   14.860954]  ? poll_freewait+0xb0/0xb0
[   14.861235]  ? poll_freewait+0xb0/0xb0
[   14.861517]  ? rpm_resume+0x49d/0x780
[   14.861798]  ? common_interrupt+0x59/0xa0
[   14.862127]  ? asm_common_interrupt+0x2b/0x40
[   14.862511]  ? __uart_start.isra.0+0x61/0x70
[   14.862902]  ? __check_object_size+0x61/0x280
[   14.863255]  core_sys_select+0x1c6/0x400
[   14.863575]  ? vfs_write+0x1c9/0x3d0
[   14.863853]  ? vfs_write+0x1c9/0x3d0
[   14.864121]  ? _copy_from_user+0x45/0x70
[   14.864526]  do_pselect.constprop.0+0xb3/0xf0
[   14.864893]  ? do_syscall_64+0x6d/0x90
[   14.865228]  ? do_syscall_64+0x6d/0x90
[   14.865556]  __x64_sys_pselect6+0x76/0xa0
[   14.865906]  do_syscall_64+0x60/0x90
[   14.866214]  ? syscall_exit_to_user_mode+0x2a/0x50
[   14.866640]  ? do_syscall_64+0x6d/0x90
[   14.866972]  ? do_syscall_64+0x6d/0x90
[   14.867286]  ? do_syscall_64+0x6d/0x90
[   14.867626]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...] stripped
[   14.872959]  &lt;/TASK&gt;

('myfpga' is a simple 'uio_dmem_genirq' driver I wrote to test this)

The implementation of "uio_dmem_genirq" was based on "uio_pdrv_genirq" and
it is used in a similar manner to the "uio_pdrv_genirq" driver with respect
to interrupt configuration and handling. At the time "uio_dmem_genirq" was
introduced, both had the same implementation of the 'uio_info' handlers
irqcontrol() and handler(). Then commit 34cb27528398 ("UIO: Fix concurrency
issue"), which was only applied to "uio_pdrv_genirq", ended up making them
a little different. That commit, among other things, changed disable_irq()
to disable_irq_nosync() in the implementation of irqcontrol(). The
motivation there was to avoid a deadlock between irqcontrol() and
handler(), since it added a spinlock in the irq handler, and disable_irq()
waits for the completion of the irq handler.

By changing disable_irq() to disable_irq_nosync() in irqcontrol(), we also
avoid the sleeping-while-atomic bug that commit b74351287d4b ("uio: fix a
sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") was trying to
fix. Thus, this fixes the missing unlock in irqcontrol() by importing the
implementation of irqcontrol() handler from the "uio_pdrv_genirq" driver.
In the end, it reverts commit b74351287d4b ("uio: fix a
sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") and change
disable_irq() to disable_irq_nosync().

It is worth noting that this still does not address the concurrency issue
fixed by commit 34cb27528398 ("UIO: Fix concurrency issue"). It will be
addressed separately in the next commits.

Split out from commit 34cb27528398 ("UIO: Fix concurrency issue").

Fixes: b74351287d4b ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()")
Signed-off-by: Rafael Mendonca &lt;rafaelmendsr@gmail.com&gt;
Link: https://lore.kernel.org/r/20220930224100.816175-2-rafaelmendsr@gmail.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 9de255c461d1b3f0242b3ad1450c3323a3e00b34 ]

Commit b74351287d4b ("uio: fix a sleep-in-atomic-context bug in
uio_dmem_genirq_irqcontrol()") started calling disable_irq() without
holding the spinlock because it can sleep. However, that fix introduced
another bug: if interrupt is already disabled and a new disable request
comes in, then the spinlock is not unlocked:

root@localhost:~# printf '\x00\x00\x00\x00' &gt; /dev/uio0
root@localhost:~# printf '\x00\x00\x00\x00' &gt; /dev/uio0
root@localhost:~# [   14.851538] BUG: scheduling while atomic: bash/223/0x00000002
[   14.851991] Modules linked in: uio_dmem_genirq uio myfpga(OE) bochs drm_vram_helper drm_ttm_helper ttm drm_kms_helper drm snd_pcm ppdev joydev psmouse snd_timer snd e1000fb_sys_fops syscopyarea parport sysfillrect soundcore sysimgblt input_leds pcspkr i2c_piix4 serio_raw floppy evbug qemu_fw_cfg mac_hid pata_acpi ip_tables x_tables autofs4 [last unloaded: parport_pc]
[   14.854206] CPU: 0 PID: 223 Comm: bash Tainted: G           OE      6.0.0-rc7 #21
[   14.854786] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[   14.855664] Call Trace:
[   14.855861]  &lt;TASK&gt;
[   14.856025]  dump_stack_lvl+0x4d/0x67
[   14.856325]  dump_stack+0x14/0x1a
[   14.856583]  __schedule_bug.cold+0x4b/0x5c
[   14.856915]  __schedule+0xe81/0x13d0
[   14.857199]  ? idr_find+0x13/0x20
[   14.857456]  ? get_work_pool+0x2d/0x50
[   14.857756]  ? __flush_work+0x233/0x280
[   14.858068]  ? __schedule+0xa95/0x13d0
[   14.858307]  ? idr_find+0x13/0x20
[   14.858519]  ? get_work_pool+0x2d/0x50
[   14.858798]  schedule+0x6c/0x100
[   14.859009]  schedule_hrtimeout_range_clock+0xff/0x110
[   14.859335]  ? tty_write_room+0x1f/0x30
[   14.859598]  ? n_tty_poll+0x1ec/0x220
[   14.859830]  ? tty_ldisc_deref+0x1a/0x20
[   14.860090]  schedule_hrtimeout_range+0x17/0x20
[   14.860373]  do_select+0x596/0x840
[   14.860627]  ? __kernel_text_address+0x16/0x50
[   14.860954]  ? poll_freewait+0xb0/0xb0
[   14.861235]  ? poll_freewait+0xb0/0xb0
[   14.861517]  ? rpm_resume+0x49d/0x780
[   14.861798]  ? common_interrupt+0x59/0xa0
[   14.862127]  ? asm_common_interrupt+0x2b/0x40
[   14.862511]  ? __uart_start.isra.0+0x61/0x70
[   14.862902]  ? __check_object_size+0x61/0x280
[   14.863255]  core_sys_select+0x1c6/0x400
[   14.863575]  ? vfs_write+0x1c9/0x3d0
[   14.863853]  ? vfs_write+0x1c9/0x3d0
[   14.864121]  ? _copy_from_user+0x45/0x70
[   14.864526]  do_pselect.constprop.0+0xb3/0xf0
[   14.864893]  ? do_syscall_64+0x6d/0x90
[   14.865228]  ? do_syscall_64+0x6d/0x90
[   14.865556]  __x64_sys_pselect6+0x76/0xa0
[   14.865906]  do_syscall_64+0x60/0x90
[   14.866214]  ? syscall_exit_to_user_mode+0x2a/0x50
[   14.866640]  ? do_syscall_64+0x6d/0x90
[   14.866972]  ? do_syscall_64+0x6d/0x90
[   14.867286]  ? do_syscall_64+0x6d/0x90
[   14.867626]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...] stripped
[   14.872959]  &lt;/TASK&gt;

('myfpga' is a simple 'uio_dmem_genirq' driver I wrote to test this)

The implementation of "uio_dmem_genirq" was based on "uio_pdrv_genirq" and
it is used in a similar manner to the "uio_pdrv_genirq" driver with respect
to interrupt configuration and handling. At the time "uio_dmem_genirq" was
introduced, both had the same implementation of the 'uio_info' handlers
irqcontrol() and handler(). Then commit 34cb27528398 ("UIO: Fix concurrency
issue"), which was only applied to "uio_pdrv_genirq", ended up making them
a little different. That commit, among other things, changed disable_irq()
to disable_irq_nosync() in the implementation of irqcontrol(). The
motivation there was to avoid a deadlock between irqcontrol() and
handler(), since it added a spinlock in the irq handler, and disable_irq()
waits for the completion of the irq handler.

By changing disable_irq() to disable_irq_nosync() in irqcontrol(), we also
avoid the sleeping-while-atomic bug that commit b74351287d4b ("uio: fix a
sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") was trying to
fix. Thus, this fixes the missing unlock in irqcontrol() by importing the
implementation of irqcontrol() handler from the "uio_pdrv_genirq" driver.
In the end, it reverts commit b74351287d4b ("uio: fix a
sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") and change
disable_irq() to disable_irq_nosync().

It is worth noting that this still does not address the concurrency issue
fixed by commit 34cb27528398 ("UIO: Fix concurrency issue"). It will be
addressed separately in the next commits.

Split out from commit 34cb27528398 ("UIO: Fix concurrency issue").

Fixes: b74351287d4b ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()")
Signed-off-by: Rafael Mendonca &lt;rafaelmendsr@gmail.com&gt;
Link: https://lore.kernel.org/r/20220930224100.816175-2-rafaelmendsr@gmail.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>uio: dfl: add IOPLL user-clock feature id</title>
<updated>2022-09-01T15:00:33+00:00</updated>
<author>
<name>Peter Colberg</name>
<email>peter.colberg@intel.com</email>
</author>
<published>2022-08-31T20:48:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d82a7aed83bacaee08cf77503e3d0e6e667f8526'/>
<id>d82a7aed83bacaee08cf77503e3d0e6e667f8526</id>
<content type='text'>
Add a Device Feature List (DFL) feature id [1] for the configurable
IOPLL user clock source, which can be used to configure the clock
speeds that are used for RTL logic that is programmed into the
Partial Reconfiguration (PR) region of an FPGA.

The IOPLL user-space driver [2] contains frequency tables [3]
with the specific user clock frequencies for an implementation.

For each desired frequency, the table values are produced by calling
the quartus tool, the same tool that generates the IOPLL RTL logic.
The quartus tool allows the RTL designer to select different options
which can affect the table values. The table-driven, user-space
driver allows for supporting future, modified implementations and
provides users the ability to modify the IOPLL implementation.

[1] https://github.com/OPAE/dfl-feature-id
[2] https://github.com/OPAE/opae-sdk/blob/a494f54a9f0356d0425edbff228f0254a4c70303/libraries/plugins/xfpga/usrclk/fpga_user_clk.c
[3] https://github.com/OPAE/opae-sdk/blob/a494f54a9f0356d0425edbff228f0254a4c70303/libraries/plugins/xfpga/usrclk/fpga_user_clk_freq.h

Acked-by: Xu Yilun &lt;yilun.xu@intel.com&gt;
Signed-off-by: Russ Weight &lt;russell.h.weight@intel.com&gt;
Signed-off-by: Peter Colberg &lt;peter.colberg@intel.com&gt;
Link: https://lore.kernel.org/r/20220831204851.4683-1-peter.colberg@intel.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>
Add a Device Feature List (DFL) feature id [1] for the configurable
IOPLL user clock source, which can be used to configure the clock
speeds that are used for RTL logic that is programmed into the
Partial Reconfiguration (PR) region of an FPGA.

The IOPLL user-space driver [2] contains frequency tables [3]
with the specific user clock frequencies for an implementation.

For each desired frequency, the table values are produced by calling
the quartus tool, the same tool that generates the IOPLL RTL logic.
The quartus tool allows the RTL designer to select different options
which can affect the table values. The table-driven, user-space
driver allows for supporting future, modified implementations and
provides users the ability to modify the IOPLL implementation.

[1] https://github.com/OPAE/dfl-feature-id
[2] https://github.com/OPAE/opae-sdk/blob/a494f54a9f0356d0425edbff228f0254a4c70303/libraries/plugins/xfpga/usrclk/fpga_user_clk.c
[3] https://github.com/OPAE/opae-sdk/blob/a494f54a9f0356d0425edbff228f0254a4c70303/libraries/plugins/xfpga/usrclk/fpga_user_clk_freq.h

Acked-by: Xu Yilun &lt;yilun.xu@intel.com&gt;
Signed-off-by: Russ Weight &lt;russell.h.weight@intel.com&gt;
Signed-off-by: Peter Colberg &lt;peter.colberg@intel.com&gt;
Link: https://lore.kernel.org/r/20220831204851.4683-1-peter.colberg@intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
