<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/tty/serial, branch v4.4.166</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>sc16is7xx: Fix for multi-channel stall</title>
<updated>2018-11-21T08:27:39+00:00</updated>
<author>
<name>Phil Elwell</name>
<email>phil@raspberrypi.org</email>
</author>
<published>2018-09-12T14:31:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=06bbe23870049ca0bc1541d005efb0b2bdfd9486'/>
<id>06bbe23870049ca0bc1541d005efb0b2bdfd9486</id>
<content type='text'>
[ Upstream commit 8344498721059754e09d30fe255a12dab8fb03ef ]

The SC16IS752 is a dual-channel device. The two channels are largely
independent, but the IRQ signals are wired together as an open-drain,
active low signal which will be driven low while either of the
channels requires attention, which can be for significant periods of
time until operations complete and the interrupt can be acknowledged.
In that respect it is should be treated as a true level-sensitive IRQ.

The kernel, however, needs to be able to exit interrupt context in
order to use I2C or SPI to access the device registers (which may
involve sleeping).  Therefore the interrupt needs to be masked out or
paused in some way.

The usual way to manage sleeping from within an interrupt handler
is to use a threaded interrupt handler - a regular interrupt routine
does the minimum amount of work needed to triage the interrupt before
waking the interrupt service thread. If the threaded IRQ is marked as
IRQF_ONESHOT the kernel will automatically mask out the interrupt
until the thread runs to completion. The sc16is7xx driver used to
use a threaded IRQ, but a patch switched to using a kthread_worker
in order to set realtime priorities on the handler thread and for
other optimisations. The end result is non-threaded IRQ that
schedules some work then returns IRQ_HANDLED, making the kernel
think that all IRQ processing has completed.

The work-around to prevent a constant stream of interrupts is to
mark the interrupt as edge-sensitive rather than level-sensitive,
but interpreting an active-low source as a falling-edge source
requires care to prevent a total cessation of interrupts. Whereas
an edge-triggering source will generate a new edge for every interrupt
condition a level-triggering source will keep the signal at the
interrupting level until it no longer requires attention; in other
words, the host won't see another edge until all interrupt conditions
are cleared. It is therefore vital that the interrupt handler does not
exit with an outstanding interrupt condition, otherwise the kernel
will not receive another interrupt unless some other operation causes
the interrupt state on the device to be cleared.

The existing sc16is7xx driver has a very simple interrupt "thread"
(kthread_work job) that processes interrupts on each channel in turn
until there are no more. If both channels are active and the first
channel starts interrupting while the handler for the second channel
is running then it will not be detected and an IRQ stall ensues. This
could be handled easily if there was a shared IRQ status register, or
a convenient way to determine if the IRQ had been deasserted for any
length of time, but both appear to be lacking.

Avoid this problem (or at least make it much less likely to happen)
by reducing the granularity of per-channel interrupt processing
to one condition per iteration, only exiting the overall loop when
both channels are no longer interrupting.

Signed-off-by: Phil Elwell &lt;phil@raspberrypi.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 8344498721059754e09d30fe255a12dab8fb03ef ]

The SC16IS752 is a dual-channel device. The two channels are largely
independent, but the IRQ signals are wired together as an open-drain,
active low signal which will be driven low while either of the
channels requires attention, which can be for significant periods of
time until operations complete and the interrupt can be acknowledged.
In that respect it is should be treated as a true level-sensitive IRQ.

The kernel, however, needs to be able to exit interrupt context in
order to use I2C or SPI to access the device registers (which may
involve sleeping).  Therefore the interrupt needs to be masked out or
paused in some way.

The usual way to manage sleeping from within an interrupt handler
is to use a threaded interrupt handler - a regular interrupt routine
does the minimum amount of work needed to triage the interrupt before
waking the interrupt service thread. If the threaded IRQ is marked as
IRQF_ONESHOT the kernel will automatically mask out the interrupt
until the thread runs to completion. The sc16is7xx driver used to
use a threaded IRQ, but a patch switched to using a kthread_worker
in order to set realtime priorities on the handler thread and for
other optimisations. The end result is non-threaded IRQ that
schedules some work then returns IRQ_HANDLED, making the kernel
think that all IRQ processing has completed.

The work-around to prevent a constant stream of interrupts is to
mark the interrupt as edge-sensitive rather than level-sensitive,
but interpreting an active-low source as a falling-edge source
requires care to prevent a total cessation of interrupts. Whereas
an edge-triggering source will generate a new edge for every interrupt
condition a level-triggering source will keep the signal at the
interrupting level until it no longer requires attention; in other
words, the host won't see another edge until all interrupt conditions
are cleared. It is therefore vital that the interrupt handler does not
exit with an outstanding interrupt condition, otherwise the kernel
will not receive another interrupt unless some other operation causes
the interrupt state on the device to be cleared.

The existing sc16is7xx driver has a very simple interrupt "thread"
(kthread_work job) that processes interrupts on each channel in turn
until there are no more. If both channels are active and the first
channel starts interrupting while the handler for the second channel
is running then it will not be detected and an IRQ stall ensues. This
could be handled easily if there was a shared IRQ status register, or
a convenient way to determine if the IRQ had been deasserted for any
length of time, but both appear to be lacking.

Avoid this problem (or at least make it much less likely to happen)
by reducing the granularity of per-channel interrupt processing
to one condition per iteration, only exiting the overall loop when
both channels are no longer interrupting.

Signed-off-by: Phil Elwell &lt;phil@raspberrypi.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kgdboc: Passing ekgdboc to command line causes panic</title>
<updated>2018-11-21T08:27:36+00:00</updated>
<author>
<name>He Zhe</name>
<email>zhe.he@windriver.com</email>
</author>
<published>2018-08-17T14:42:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=54e9c8cf659f3f8d07a610b2836025cde6556f46'/>
<id>54e9c8cf659f3f8d07a610b2836025cde6556f46</id>
<content type='text'>
commit 1bd54d851f50dea6af30c3e6ff4f3e9aab5558f9 upstream.

kgdboc_option_setup does not check input argument before passing it
to strlen. The argument would be a NULL pointer if "ekgdboc", without
its value, is set in command line and thus cause the following panic.

PANIC: early exception 0xe3 IP 10:ffffffff8fbbb620 error 0 cr2 0x0
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.18-rc8+ #1
[    0.000000] RIP: 0010:strlen+0x0/0x20
...
[    0.000000] Call Trace
[    0.000000]  ? kgdboc_option_setup+0x9/0xa0
[    0.000000]  ? kgdboc_early_init+0x6/0x1b
[    0.000000]  ? do_early_param+0x4d/0x82
[    0.000000]  ? parse_args+0x212/0x330
[    0.000000]  ? rdinit_setup+0x26/0x26
[    0.000000]  ? parse_early_options+0x20/0x23
[    0.000000]  ? rdinit_setup+0x26/0x26
[    0.000000]  ? parse_early_param+0x2d/0x39
[    0.000000]  ? setup_arch+0x2f7/0xbf4
[    0.000000]  ? start_kernel+0x5e/0x4c2
[    0.000000]  ? load_ucode_bsp+0x113/0x12f
[    0.000000]  ? secondary_startup_64+0xa5/0xb0

This patch adds a check to prevent the panic.

Cc: stable@vger.kernel.org
Cc: jason.wessel@windriver.com
Cc: gregkh@linuxfoundation.org
Cc: jslaby@suse.com
Signed-off-by: He Zhe &lt;zhe.he@windriver.com&gt;
Reviewed-by: Daniel Thompson &lt;daniel.thompson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1bd54d851f50dea6af30c3e6ff4f3e9aab5558f9 upstream.

kgdboc_option_setup does not check input argument before passing it
to strlen. The argument would be a NULL pointer if "ekgdboc", without
its value, is set in command line and thus cause the following panic.

PANIC: early exception 0xe3 IP 10:ffffffff8fbbb620 error 0 cr2 0x0
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.18-rc8+ #1
[    0.000000] RIP: 0010:strlen+0x0/0x20
...
[    0.000000] Call Trace
[    0.000000]  ? kgdboc_option_setup+0x9/0xa0
[    0.000000]  ? kgdboc_early_init+0x6/0x1b
[    0.000000]  ? do_early_param+0x4d/0x82
[    0.000000]  ? parse_args+0x212/0x330
[    0.000000]  ? rdinit_setup+0x26/0x26
[    0.000000]  ? parse_early_options+0x20/0x23
[    0.000000]  ? rdinit_setup+0x26/0x26
[    0.000000]  ? parse_early_param+0x2d/0x39
[    0.000000]  ? setup_arch+0x2f7/0xbf4
[    0.000000]  ? start_kernel+0x5e/0x4c2
[    0.000000]  ? load_ucode_bsp+0x113/0x12f
[    0.000000]  ? secondary_startup_64+0xa5/0xb0

This patch adds a check to prevent the panic.

Cc: stable@vger.kernel.org
Cc: jason.wessel@windriver.com
Cc: gregkh@linuxfoundation.org
Cc: jslaby@suse.com
Signed-off-by: He Zhe &lt;zhe.he@windriver.com&gt;
Reviewed-by: Daniel Thompson &lt;daniel.thompson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>tty: serial: sprd: fix error return code in sprd_probe()</title>
<updated>2018-11-10T15:41:39+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavo@embeddedor.com</email>
</author>
<published>2017-08-08T22:42:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=27e13827973eccb7fcbf3c70832305082aa082c2'/>
<id>27e13827973eccb7fcbf3c70832305082aa082c2</id>
<content type='text'>
[ Upstream commit ec085c5a51b768947ca481f90b66653e36b3c566 ]

platform_get_irq() returns an error code, but the sprd_serial driver
ignores it and always returns -ENODEV. This is not correct and,
prevents -EPROBE_DEFER from being propagated properly.

Also, notice that platform_get_irq() no longer returns 0 on error:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e330b9a6bb35dc7097a4f02cb1ae7b6f96df92af

Print and propagate the return value of platform_get_irq on failure.

This issue was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva &lt;gustavo@embeddedor.com&gt;
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 ec085c5a51b768947ca481f90b66653e36b3c566 ]

platform_get_irq() returns an error code, but the sprd_serial driver
ignores it and always returns -ENODEV. This is not correct and,
prevents -EPROBE_DEFER from being propagated properly.

Also, notice that platform_get_irq() no longer returns 0 on error:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e330b9a6bb35dc7097a4f02cb1ae7b6f96df92af

Print and propagate the return value of platform_get_irq on failure.

This issue was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva &lt;gustavo@embeddedor.com&gt;
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>serial: imx: restore handshaking irq for imx1</title>
<updated>2018-10-10T06:52:08+00:00</updated>
<author>
<name>Uwe Kleine-König</name>
<email>u.kleine-koenig@pengutronix.de</email>
</author>
<published>2018-09-20T12:11:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9aeb6fd7e2d9b459df8cce696f51e5c7dba2d73a'/>
<id>9aeb6fd7e2d9b459df8cce696f51e5c7dba2d73a</id>
<content type='text'>
commit 7e620984b62532783912312e334f3c48cdacbd5d upstream.

Back in 2015 when irda was dropped from the driver imx1 was broken. This
change reintroduces the support for the third interrupt of the UART.

Fixes: afe9cbb1a6ad ("serial: imx: drop support for IRDA")
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Reviewed-by: Leonard Crestez &lt;leonard.crestez@nxp.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 7e620984b62532783912312e334f3c48cdacbd5d upstream.

Back in 2015 when irda was dropped from the driver imx1 was broken. This
change reintroduces the support for the third interrupt of the UART.

Fixes: afe9cbb1a6ad ("serial: imx: drop support for IRDA")
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Reviewed-by: Leonard Crestez &lt;leonard.crestez@nxp.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>serial: cpm_uart: return immediately from console poll</title>
<updated>2018-10-10T06:52:07+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@c-s.fr</email>
</author>
<published>2018-09-14T10:32:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=da9d7fd84db0b99bbc769a25e6ba44d8157054c5'/>
<id>da9d7fd84db0b99bbc769a25e6ba44d8157054c5</id>
<content type='text'>
commit be28c1e3ca29887e207f0cbcd294cefe5074bab6 upstream.

kgdb expects poll function to return immediately and
returning NO_POLL_CHAR when no character is available.

Fixes: f5316b4aea024 ("kgdb,8250,pl011: Return immediately from console poll")
Cc: Jason Wessel &lt;jason.wessel@windriver.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&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 be28c1e3ca29887e207f0cbcd294cefe5074bab6 upstream.

kgdb expects poll function to return immediately and
returning NO_POLL_CHAR when no character is available.

Fixes: f5316b4aea024 ("kgdb,8250,pl011: Return immediately from console poll")
Cc: Jason Wessel &lt;jason.wessel@windriver.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/tty: add error handling for pcmcia_loop_config</title>
<updated>2018-10-10T06:52:06+00:00</updated>
<author>
<name>Zhouyang Jia</name>
<email>jiazhouyang09@gmail.com</email>
</author>
<published>2018-06-12T04:36:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4e9cf990bf43e290d5fca4d08a6dde7f68521fc0'/>
<id>4e9cf990bf43e290d5fca4d08a6dde7f68521fc0</id>
<content type='text'>
[ Upstream commit 85c634e919bd6ef17427f26a52920aeba12e16ee ]

When pcmcia_loop_config fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling pcmcia_loop_config.

Signed-off-by: Zhouyang Jia &lt;jiazhouyang09@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.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>
[ Upstream commit 85c634e919bd6ef17427f26a52920aeba12e16ee ]

When pcmcia_loop_config fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling pcmcia_loop_config.

Signed-off-by: Zhouyang Jia &lt;jiazhouyang09@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>serial: 8250_dw: always set baud rate in dw8250_set_termios</title>
<updated>2018-08-22T05:48:37+00:00</updated>
<author>
<name>Chen Hu</name>
<email>hu1.chen@intel.com</email>
</author>
<published>2018-07-27T10:32:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b4d2c57717fd0c905a4b8ebd5c534e770aeb93a2'/>
<id>b4d2c57717fd0c905a4b8ebd5c534e770aeb93a2</id>
<content type='text'>
commit dfcab6ba573445c703235ab6c83758eec12d7f28 upstream.

dw8250_set_termios() doesn't set baud rate if the arg "old ktermios" is
NULL. This happens during resume.
Call Trace:
...
[   54.928108] dw8250_set_termios+0x162/0x170
[   54.928114] serial8250_set_termios+0x17/0x20
[   54.928117] uart_change_speed+0x64/0x160
[   54.928119] uart_resume_port
...

So the baud rate is not restored after S3 and breaks the apps who use
UART, for example, console and bluetooth etc.

We address this issue by setting the baud rate irrespective of arg
"old", just like the drivers for other 8250 IPs. This is tested with
Intel Broxton platform.

Signed-off-by: Chen Hu &lt;hu1.chen@intel.com&gt;
Fixes: 4e26b134bd17 ("serial: 8250_dw: clock rate handling for all ACPI platforms")
Cc: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.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 dfcab6ba573445c703235ab6c83758eec12d7f28 upstream.

dw8250_set_termios() doesn't set baud rate if the arg "old ktermios" is
NULL. This happens during resume.
Call Trace:
...
[   54.928108] dw8250_set_termios+0x162/0x170
[   54.928114] serial8250_set_termios+0x17/0x20
[   54.928117] uart_change_speed+0x64/0x160
[   54.928119] uart_resume_port
...

So the baud rate is not restored after S3 and breaks the apps who use
UART, for example, console and bluetooth etc.

We address this issue by setting the baud rate irrespective of arg
"old", just like the drivers for other 8250 IPs. This is tested with
Intel Broxton platform.

Signed-off-by: Chen Hu &lt;hu1.chen@intel.com&gt;
Fixes: 4e26b134bd17 ("serial: 8250_dw: clock rate handling for all ACPI platforms")
Cc: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>serial: sh-sci: Use spin_{try}lock_irqsave instead of open coding version</title>
<updated>2018-07-03T09:21:26+00:00</updated>
<author>
<name>Daniel Wagner</name>
<email>daniel.wagner@siemens.com</email>
</author>
<published>2018-05-08T08:55:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=62b192d70864d9efb665b124aa0d00777cdd3de7'/>
<id>62b192d70864d9efb665b124aa0d00777cdd3de7</id>
<content type='text'>
commit 8afb1d2c12163f77777f84616a8e9444d0050ebe upstream.

Commit 40f70c03e33a ("serial: sh-sci: add locking to console write
function to avoid SMP lockup") copied the strategy to avoid locking
problems in conjuncture with the console from the UART8250
driver. Instead using directly spin_{try}lock_irqsave(),
local_irq_save() followed by spin_{try}lock() was used. While this is
correct on mainline, for -rt it is a problem. spin_{try}lock() will
check if it is running in a valid context. Since the local_irq_save()
has already been executed, the context has changed and
spin_{try}lock() will complain. The reason why spin_{try}lock()
complains is that on -rt the spin locks are turned into mutexes and
therefore can sleep. Sleeping with interrupts disabled is not valid.

BUG: sleeping function called from invalid context at /home/wagi/work/rt/v4.4-cip-rt/kernel/locking/rtmutex.c:995
in_atomic(): 0, irqs_disabled(): 128, pid: 778, name: irq/76-eth0
CPU: 0 PID: 778 Comm: irq/76-eth0 Not tainted 4.4.126-test-cip22-rt14-00403-gcd03665c8318 #12
Hardware name: Generic RZ/G1 (Flattened Device Tree)
Backtrace:
[&lt;c00140a0&gt;] (dump_backtrace) from [&lt;c001424c&gt;] (show_stack+0x18/0x1c)
 r7:c06b01f0 r6:60010193 r5:00000000 r4:c06b01f0
[&lt;c0014234&gt;] (show_stack) from [&lt;c01d3c94&gt;] (dump_stack+0x78/0x94)
[&lt;c01d3c1c&gt;] (dump_stack) from [&lt;c004c134&gt;] (___might_sleep+0x134/0x194)
 r7:60010113 r6:c06d3559 r5:00000000 r4:ffffe000
[&lt;c004c000&gt;] (___might_sleep) from [&lt;c04ded60&gt;] (rt_spin_lock+0x20/0x74)
 r5:c06f4d60 r4:c06f4d60
[&lt;c04ded40&gt;] (rt_spin_lock) from [&lt;c02577e4&gt;] (serial_console_write+0x100/0x118)
 r5:c06f4d60 r4:c06f4d60
[&lt;c02576e4&gt;] (serial_console_write) from [&lt;c0061060&gt;] (call_console_drivers.constprop.15+0x10c/0x124)
 r10:c06d2894 r9:c04e18b0 r8:00000028 r7:00000000 r6:c06d3559 r5:c06d2798
 r4:c06b9914 r3:c02576e4
[&lt;c0060f54&gt;] (call_console_drivers.constprop.15) from [&lt;c0062984&gt;] (console_unlock+0x32c/0x430)
 r10:c06d30d8 r9:00000028 r8:c06dd518 r7:00000005 r6:00000000 r5:c06d2798
 r4:c06d2798 r3:00000028
[&lt;c0062658&gt;] (console_unlock) from [&lt;c0062e1c&gt;] (vprintk_emit+0x394/0x4f0)
 r10:c06d2798 r9:c06d30ee r8:00000006 r7:00000005 r6:c06a78fc r5:00000027
 r4:00000003
[&lt;c0062a88&gt;] (vprintk_emit) from [&lt;c0062fa0&gt;] (vprintk+0x28/0x30)
 r10:c060bd46 r9:00001000 r8:c06b9a90 r7:c06b9a90 r6:c06b994c r5:c06b9a3c
 r4:c0062fa8
[&lt;c0062f78&gt;] (vprintk) from [&lt;c0062fb8&gt;] (vprintk_default+0x10/0x14)
[&lt;c0062fa8&gt;] (vprintk_default) from [&lt;c009cd30&gt;] (printk+0x78/0x84)
[&lt;c009ccbc&gt;] (printk) from [&lt;c025afdc&gt;] (credit_entropy_bits+0x17c/0x2cc)
 r3:00000001 r2:decade60 r1:c061a5ee r0:c061a523
 r4:00000006
[&lt;c025ae60&gt;] (credit_entropy_bits) from [&lt;c025bf74&gt;] (add_interrupt_randomness+0x160/0x178)
 r10:466e7196 r9:1f536000 r8:fffeef74 r7:00000000 r6:c06b9a60 r5:c06b9a3c
 r4:dfbcf680
[&lt;c025be14&gt;] (add_interrupt_randomness) from [&lt;c006536c&gt;] (irq_thread+0x1e8/0x248)
 r10:c006537c r9:c06cdf21 r8:c0064fcc r7:df791c24 r6:df791c00 r5:ffffe000
 r4:df525180
[&lt;c0065184&gt;] (irq_thread) from [&lt;c003fba4&gt;] (kthread+0x108/0x11c)
 r10:00000000 r9:00000000 r8:c0065184 r7:df791c00 r6:00000000 r5:df791d00
 r4:decac000
[&lt;c003fa9c&gt;] (kthread) from [&lt;c00101b8&gt;] (ret_from_fork+0x14/0x3c)
 r8:00000000 r7:00000000 r6:00000000 r5:c003fa9c r4:df791d00

Cc: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Signed-off-by: Daniel Wagner &lt;daniel.wagner@siemens.com&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
[dw: Backported to 4.4.]
Signed-off-by: Daniel Wagner &lt;daniel.wagner@siemens.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 8afb1d2c12163f77777f84616a8e9444d0050ebe upstream.

Commit 40f70c03e33a ("serial: sh-sci: add locking to console write
function to avoid SMP lockup") copied the strategy to avoid locking
problems in conjuncture with the console from the UART8250
driver. Instead using directly spin_{try}lock_irqsave(),
local_irq_save() followed by spin_{try}lock() was used. While this is
correct on mainline, for -rt it is a problem. spin_{try}lock() will
check if it is running in a valid context. Since the local_irq_save()
has already been executed, the context has changed and
spin_{try}lock() will complain. The reason why spin_{try}lock()
complains is that on -rt the spin locks are turned into mutexes and
therefore can sleep. Sleeping with interrupts disabled is not valid.

BUG: sleeping function called from invalid context at /home/wagi/work/rt/v4.4-cip-rt/kernel/locking/rtmutex.c:995
in_atomic(): 0, irqs_disabled(): 128, pid: 778, name: irq/76-eth0
CPU: 0 PID: 778 Comm: irq/76-eth0 Not tainted 4.4.126-test-cip22-rt14-00403-gcd03665c8318 #12
Hardware name: Generic RZ/G1 (Flattened Device Tree)
Backtrace:
[&lt;c00140a0&gt;] (dump_backtrace) from [&lt;c001424c&gt;] (show_stack+0x18/0x1c)
 r7:c06b01f0 r6:60010193 r5:00000000 r4:c06b01f0
[&lt;c0014234&gt;] (show_stack) from [&lt;c01d3c94&gt;] (dump_stack+0x78/0x94)
[&lt;c01d3c1c&gt;] (dump_stack) from [&lt;c004c134&gt;] (___might_sleep+0x134/0x194)
 r7:60010113 r6:c06d3559 r5:00000000 r4:ffffe000
[&lt;c004c000&gt;] (___might_sleep) from [&lt;c04ded60&gt;] (rt_spin_lock+0x20/0x74)
 r5:c06f4d60 r4:c06f4d60
[&lt;c04ded40&gt;] (rt_spin_lock) from [&lt;c02577e4&gt;] (serial_console_write+0x100/0x118)
 r5:c06f4d60 r4:c06f4d60
[&lt;c02576e4&gt;] (serial_console_write) from [&lt;c0061060&gt;] (call_console_drivers.constprop.15+0x10c/0x124)
 r10:c06d2894 r9:c04e18b0 r8:00000028 r7:00000000 r6:c06d3559 r5:c06d2798
 r4:c06b9914 r3:c02576e4
[&lt;c0060f54&gt;] (call_console_drivers.constprop.15) from [&lt;c0062984&gt;] (console_unlock+0x32c/0x430)
 r10:c06d30d8 r9:00000028 r8:c06dd518 r7:00000005 r6:00000000 r5:c06d2798
 r4:c06d2798 r3:00000028
[&lt;c0062658&gt;] (console_unlock) from [&lt;c0062e1c&gt;] (vprintk_emit+0x394/0x4f0)
 r10:c06d2798 r9:c06d30ee r8:00000006 r7:00000005 r6:c06a78fc r5:00000027
 r4:00000003
[&lt;c0062a88&gt;] (vprintk_emit) from [&lt;c0062fa0&gt;] (vprintk+0x28/0x30)
 r10:c060bd46 r9:00001000 r8:c06b9a90 r7:c06b9a90 r6:c06b994c r5:c06b9a3c
 r4:c0062fa8
[&lt;c0062f78&gt;] (vprintk) from [&lt;c0062fb8&gt;] (vprintk_default+0x10/0x14)
[&lt;c0062fa8&gt;] (vprintk_default) from [&lt;c009cd30&gt;] (printk+0x78/0x84)
[&lt;c009ccbc&gt;] (printk) from [&lt;c025afdc&gt;] (credit_entropy_bits+0x17c/0x2cc)
 r3:00000001 r2:decade60 r1:c061a5ee r0:c061a523
 r4:00000006
[&lt;c025ae60&gt;] (credit_entropy_bits) from [&lt;c025bf74&gt;] (add_interrupt_randomness+0x160/0x178)
 r10:466e7196 r9:1f536000 r8:fffeef74 r7:00000000 r6:c06b9a60 r5:c06b9a3c
 r4:dfbcf680
[&lt;c025be14&gt;] (add_interrupt_randomness) from [&lt;c006536c&gt;] (irq_thread+0x1e8/0x248)
 r10:c006537c r9:c06cdf21 r8:c0064fcc r7:df791c24 r6:df791c00 r5:ffffe000
 r4:df525180
[&lt;c0065184&gt;] (irq_thread) from [&lt;c003fba4&gt;] (kthread+0x108/0x11c)
 r10:00000000 r9:00000000 r8:c0065184 r7:df791c00 r6:00000000 r5:df791d00
 r4:decac000
[&lt;c003fa9c&gt;] (kthread) from [&lt;c00101b8&gt;] (ret_from_fork+0x14/0x3c)
 r8:00000000 r7:00000000 r6:00000000 r5:c003fa9c r4:df791d00

Cc: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Signed-off-by: Daniel Wagner &lt;daniel.wagner@siemens.com&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
[dw: Backported to 4.4.]
Signed-off-by: Daniel Wagner &lt;daniel.wagner@siemens.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>serial: samsung: fix maxburst parameter for DMA transactions</title>
<updated>2018-06-16T07:54:26+00:00</updated>
<author>
<name>Marek Szyprowski</name>
<email>m.szyprowski@samsung.com</email>
</author>
<published>2018-05-10T06:41:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6ffaa6e0f361e1bb20bd54c5f7df6daa381ecd7c'/>
<id>6ffaa6e0f361e1bb20bd54c5f7df6daa381ecd7c</id>
<content type='text'>
commit aa2f80e752c75e593b3820f42c416ed9458fa73e upstream.

The best granularity of residue that DMA engine can report is in the BURST
units, so the serial driver must use MAXBURST = 1 and DMA_SLAVE_BUSWIDTH_1_BYTE
if it relies on exact number of bytes transferred by DMA engine.

Fixes: 62c37eedb74c ("serial: samsung: add dma reqest/release functions")
Signed-off-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Acked-by: Krzysztof Kozlowski &lt;krzk@kernel.org&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit aa2f80e752c75e593b3820f42c416ed9458fa73e upstream.

The best granularity of residue that DMA engine can report is in the BURST
units, so the serial driver must use MAXBURST = 1 and DMA_SLAVE_BUSWIDTH_1_BYTE
if it relies on exact number of bytes transferred by DMA engine.

Fixes: 62c37eedb74c ("serial: samsung: add dma reqest/release functions")
Signed-off-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Acked-by: Krzysztof Kozlowski &lt;krzk@kernel.org&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>serial: arc_uart: Fix out-of-bounds access through DT alias</title>
<updated>2018-05-30T05:49:15+00:00</updated>
<author>
<name>Geert Uytterhoeven</name>
<email>geert+renesas@glider.be</email>
</author>
<published>2018-02-23T13:38:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f28308185eb38a2f973722a832c6ad134ba22cf2'/>
<id>f28308185eb38a2f973722a832c6ad134ba22cf2</id>
<content type='text'>
[ Upstream commit f9f5786987e81d166c60833edcb7d1836aa16944 ]

The arc_uart_ports[] array is indexed using a value derived from the
"serialN" alias in DT, which may lead to an out-of-bounds access.

Fix this by adding a range check.

Note that the array size is defined by a Kconfig symbol
(CONFIG_SERIAL_ARC_NR_PORTS), so this can even be triggered using a
legitimate DTB.

Fixes: ea28fd56fcde69af ("serial/arc-uart: switch to devicetree based probing")
Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.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>
[ Upstream commit f9f5786987e81d166c60833edcb7d1836aa16944 ]

The arc_uart_ports[] array is indexed using a value derived from the
"serialN" alias in DT, which may lead to an out-of-bounds access.

Fix this by adding a range check.

Note that the array size is defined by a Kconfig symbol
(CONFIG_SERIAL_ARC_NR_PORTS), so this can even be triggered using a
legitimate DTB.

Fixes: ea28fd56fcde69af ("serial/arc-uart: switch to devicetree based probing")
Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
