Convert all open-coded instances of bitfields retrieval/setting
to FIELD_PREP/FIELD_GET where possible.
Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220922113347.144383-10-sergiu.moga@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Previously, the atmel serial driver did not take into account the
possibility of using the more customizable generic clock as its
baudrate generator. Unless there is a Fractional Part available to
increase accuracy, there is a high chance that we may be able to
generate a baudrate closer to the desired one by using the GCLK as the
clock source. Now, depending on the error rate between
the desired baudrate and the actual baudrate, the serial driver will
fallback on the generic clock. The generic clock must be provided
in the DT node of the serial that may need a more flexible clock source.
Furthermore, define the bit that represents the choice of having GCLK
as a baudrate source clock inside the USCLKS bitmask of the Mode Register
of USART IP's.
Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com>
Link: https://lore.kernel.org/r/20220922113347.144383-9-sergiu.moga@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure that the driver only divides the clock divisor if the
IP handled at that point is USART, since UART IP's do not support
implicit peripheral clock division. Instead, in the case of UART,
go with the highest possible clock divisor.
Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220922113347.144383-8-sergiu.moga@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When clearing the mode of the serial IP inside the atmel_set_termios()
method, make sure that the difference between the bitfields placement
of the UART IP's and USART IP's is taken into account, as some of
them overlap with each other. For example, ATMEL_UA_BRSRCCK overlaps
with ATMEL_US_NBSTOP and ATMEL_US_USCLKS overlaps with ATMEL_UA_FILTER.
Furthermore, add definitions for the Baud Rate Source Clock and the
Filter bitfields of the Mode Register of UART IP's, since they were
missing.
Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com>
Link: https://lore.kernel.org/r/20220922113347.144383-7-sergiu.moga@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Invoking TIOCVHANGUP on 8250_mid port on Ice Lake-D and then reopening
the port triggers these faults during serial8250_do_startup():
DMAR: DRHD: handling fault status reg 3
DMAR: [DMA Write NO_PASID] Request device [00:1a.0] fault addr 0x0 [fault reason 0x05] PTE Write access is not set
If the IRQ hasn't been set up yet, the UART will have zeroes in its MSI
address/data registers. Disabling the IRQ at the interrupt controller
won't stop the UART from performing a DMA write to the address programmed
in its MSI address register (zero) when it wants to signal an interrupt.
The UARTs (in Ice Lake-D) implement PCI 2.1 style MSI without masking
capability, so there is no way to mask the interrupt at the source PCI
function level, except disabling the MSI capability entirely, but that
would cause it to fall back to INTx# assertion, and the PCI specification
prohibits disabling the MSI capability as a way to mask a function's
interrupt service request.
The MSI address register is zeroed by the hangup as the irq is freed.
The interrupt is signalled during serial8250_do_startup() performing a
THRE test that temporarily toggles THRI in IER. The THRE test currently
occurs before UART's irq (and MSI address) is properly set up.
Refactor serial8250_do_startup() such that irq is set up before the
THRE test. The current irq setup code is intermixed with the timer
setup code. As THRE test must be performed prior to the timer setup,
extract it into own function and call it only after the THRE test.
The ->setup_timer() needs to be part of the struct uart_8250_ops in
order to not create circular dependency between 8250 and 8250_base
modules.
Fixes: 40b36daad0 ("[PATCH] 8250 UART backup timer")
Reported-by: Lennert Buytenhek <buytenh@arista.com>
Tested-by: Lennert Buytenhek <buytenh@arista.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220922070005.2965-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Oxford Semiconductor PCIe (Tornado) 950 serial port devices need to
operate in the enhanced mode via the EFR register for the Divide-by-M
N/8 baud rate generator prescaler to be used in their native UART mode.
Otherwise the prescaler is fixed at 1 causing grossly incorrect baud
rates to be programmed.
Accessing the EFR register requires 16550A features to have been probed
for, so request this to happen regardless of SERIAL_8250_16550A_VARIANTS
by setting UPF_FULL_PROBE in port flags.
Fixes: 366f6c955d ("serial: 8250: Add proper clock handling for OxSemi PCIe devices")
Cc: stable@vger.kernel.org # v5.19+
Reported-by: Anders Blomdell <anders.blomdell@control.lth.se>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2209210005040.41633@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A SERIAL_8250_16550A_VARIANTS configuration option has been recently
defined that lets one request the 8250 driver not to probe for 16550A
device features so as to reduce the driver's device startup time in
virtual machines.
Some actual hardware devices require these features to have been fully
determined however for their driver to work correctly, so define a flag
to let drivers request full 16550A feature probing on a device-by-device
basis if required regardless of the SERIAL_8250_16550A_VARIANTS option
setting chosen.
Fixes: dc56ecb81a ("serial: 8250: Support disabling mdelay-filled probes of 16550A variants")
Cc: stable@vger.kernel.org # v5.6+
Reported-by: Anders Blomdell <anders.blomdell@control.lth.se>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2209202357520.41633@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This non-trivial code is doubled in transmit_chars(), so it deserves its
own function. This will make next patches easier.
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220920052049.20507-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mpc52xx_uart_int_rx_chars() returns unsigned int.
mpc52xx_uart_int_tx_chars() returns int.
The both results are binary ORed to the "keepgoing" variable. Unify all
three to bool as the only interesting value is whether we should keep
looping (true/false).
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220920052049.20507-7-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The condition in __serial_lpc32xx_tx()'s loop is barely readable.
Extract it to a separate function. This will make the cleanup in the
next patches easier too.
Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220920052049.20507-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The condition in lqasc_tx_chars()'s loop is barely readable. Extract it
to a separate function. This will make the cleanup in the next patches
easier too.
(Put it before lqasc_start_tx(), so that we can use it there later.)
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220920052049.20507-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Both altera_uart_{r,t}x_chars() need only uart_port, not altera_uart. So
pass the former from altera_uart_interrupt() directly.
Apart it maybe saves a dereference, this makes the transition of
altera_uart_tx_chars() easier to follow in the next patch.
Cc: Tobias Klauser <tklauser@distanz.ch>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220920052049.20507-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The "stop TX" path in altera_uart_tx_chars() is open-coded, so:
* use uart_circ_empty() to check if the buffer is empty, and
* when true, call altera_uart_stop_tx().
Cc: Tobias Klauser <tklauser@distanz.ch>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220920052049.20507-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make vt8500_tx_empty() more readable by introducing a new local variable
and move the function before handle_tx(). That way we can reuse it in
there too.
Cc: <linux-arm-kernel@lists.infradead.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220920052049.20507-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This error path needs to unwind instead of just returning directly.
Fixes: 03a8482c17 ("drivers: serial: jsm: Enable support for Digi Classic adapters")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YyxFh1+lOeZ9WfKO@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The serial-omap driver requires an rts-gpio for RS-485 to work.
Historically it has allowed enabling RS-485 even if no rts-gpio was
specified in the device tree.
That doesn't make any sense, so disable RS-485 on probe if rts-gpio is
missing and disallow user space from enabling it.
Three NULL pointer checks for up->rts_gpiod can be dropped as a result,
simplifying the driver slightly.
Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/f191dcca0d8ea03598c463fc0d3fba8941ff2275.1662888075.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A debug bit to output a complete transmission dump exists. Sometimes only
the user frames are relevant. Add an additional bit which limits the
transmission dump output to user data frames if set.
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220831073800.7459-6-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce defines to name the various debug bits used within the code to
improve readability and to make its specific use clear.
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220831073800.7459-5-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move the content of gsm_control_transmit() to a new function
gsm_control_command() with a more generic signature and analog to
gsm_control_reply(). Use this within gsm_control_transmit().
This is needed to simplify upcoming functional additions.
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220831073800.7459-4-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a macro which defines the possible number of virtual devices for n_gsm
to improve code readability.
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220831073800.7459-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add an enumeration for the gsm mux encoding types to improve code
readability and to avoid invalid values. Only two values are defined by the
standard:
- basic option mode
- advanced option mode (uses ISO HDLC standard transparency mechanism)
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220831073800.7459-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* new header (linut/termios_internal.h), pulled by the users of those
suckers
* defaults for INIT_C_CC and externs for conversion helpers moved over
there
* remove termios-base.h (empty now)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/YxDmptU7dNGZ+/Hn@ZenIV
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
default go into drivers/tty/tty_ioctl.c, unusual - into
arch/*/kernel/termios.c (only alpha and sparc have those).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/YxDmeUBHo0s/Ew8b@ZenIV
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In suspend/resume routines, icc flags are hardcoded.
Replace the hardcodes with macros available from header.
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com>
Link: https://lore.kernel.org/r/1662564702-7253-1-git-send-email-quic_vnivarth@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The variable hwid is assigned a value but it is never read. The
assignment is redundant and can be removed.
Cleans up clang scan build warning:
drivers/tty/mxser.c:401:7: warning: Although the value stored to 'hwid'
is used in the enclosing expression, the value is never actually read
from 'hwid' [deadcode.DeadStores]
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20220730130925.150018-1-colin.i.king@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I'm scratching my head why we have this printing_lock. Digging through
historical git trees shows that:
- Added in 1.1.73, and I found absolutely no reason why.
- Converted to atomic bitops in 2.1.125pre2, I guess as part of SMP
enabling/bugfixes.
- Converted to a proper spinlock in b0940003f2 ("vt: bitlock fix")
because the hand-rolled atomic version lacked necessary memory
barriers.
Digging around in lore for that time period did also not shed further
light.
The only reason I think this might still be relevant today is that (to
my understanding at least, ymmv) during an oops we might be printing
without console_lock held. See console_flush_on_panic() and the
comments in there - we flush out the console buffers irrespective of
whether we managed to acquire the right locks.
The strange thing is that this reason is fairly recent, because the
console flushing was historically done without oops_in_progress set.
This only changed in c7c3f05e34 ("panic: avoid deadlocks in
re-entrant console drivers"), which removed the call to
bust_spinlocks(0) (which decrements oops_in_progress again) before
flushing out the console (which back then was open coded as a
console_trylock/unlock pair).
Note that this entire mess should be properly fixed in the
printk/console layer, and not inflicted on each implementation.
For now just document what's going on and check that in all other
cases callers obey the locking rules.
v2: WARN_CONSOLE_UNLOCKED already checks for oops_in_progress
(something else that should be fixed I guess), hence remove the
open-coded check I've had.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Xuezhi Zhang <zhangxuezhi1@coolpad.com>
Cc: Yangxi Xiang <xyangxi5@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: nick black <dankamongmen@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://lore.kernel.org/r/20220830144945.430528-1-daniel.vetter@ffwll.ch
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
console_unblank() does this too (called in both places right after),
and with a lot more confidence inspiring approach to locking.
Reconstructing this story is very strange:
In b61312d353 ("oops handling: ensure that any oops is flushed to
the mtdoops console") it is claimed that a printk(" "); flushed out
the console buffer, which was removed in e3e8a75d2a ("[PATCH]
Extract and use wake_up_klogd()"). In todays kernels this is done way
earlier in console_flush_on_panic with some really nasty tricks. I
didn't bother to fully reconstruct this all, least because the call to
bust_spinlock(0); gets moved every few years, depending upon how the
wind blows (or well, who screamed loudest about the various issue each
call site caused).
Before that commit the only calls to console_unblank() where in s390
arch code.
The other side here is the console->unblank callback, which was
introduced in 2.1.31 for the vt driver. Which predates the
console_unblank() function by a lot, which was added (without users)
in 2.4.14.3. So pretty much impossible to guess at any motivation
here. Also afaict the vt driver is the only (and always was the only)
console driver implementing the unblank callback, so no idea why a
call to console_unblank() was added for the mtdooops driver - the
action actually flushing out the console buffers is done from
console_unlock() only.
Note that as prep for the s390 users the locking was adjusted in
2.5.22 (I couldn't figure out how to properly reference the BK commit
from the historical git trees) from a normal semaphore to a trylock.
Note that a copy of the direct unblank_screen() call was added to
panic() in c7c3f05e34 ("panic: avoid deadlocks in re-entrant console
drivers"), which partially inlined the bust_spinlocks(0); call.
Long story short, I have no idea why the direct call to unblank_screen
survived for so long (the infrastructure to do it properly existed for
years), nor why it wasn't removed when the console_unblank() call was
finally added. But it makes a ton more sense to finally do that than
not - it's just better encapsulation to go through the console
functions instead of doing a direct call, so let's dare. Plus it
really does not make much sense to call the only unblank
implementation there is twice, once without, and once with appropriate
locking.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Xuezhi Zhang <zhangxuezhi1@coolpad.com>
Cc: Yangxi Xiang <xyangxi5@gmail.com>
Cc: nick black <dankamongmen@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Marco Elver <elver@google.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: David Gow <davidgow@google.com>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/r/20220830145004.430545-1-daniel.vetter@ffwll.ch
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The UAPI serial_core.h is guaranteed to be included by in-kernel
one (with the same name). Individual drivers do not need to include
it explicitly. Remove it from the driver.
Note, it's a single driver in the entire kernel that does this.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220830152313.14650-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Syzkaller reports the following problem:
BUG: sleeping function called from invalid context at kernel/printk/printk.c:2347
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1105, name: syz-executor423
3 locks held by syz-executor423/1105:
#0: ffff8881468b9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x90 drivers/tty/tty_ldisc.c:266
#1: ffff8881468b9130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_write_lock drivers/tty/tty_io.c:952 [inline]
#1: ffff8881468b9130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: do_tty_write drivers/tty/tty_io.c:975 [inline]
#1: ffff8881468b9130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: file_tty_write.constprop.0+0x2a8/0x8e0 drivers/tty/tty_io.c:1118
#2: ffff88801b06c398 (&gsm->tx_lock){....}-{2:2}, at: gsmld_write+0x5e/0x150 drivers/tty/n_gsm.c:2717
irq event stamp: 3482
hardirqs last enabled at (3481): [<ffffffff81d13343>] __get_reqs_available+0x143/0x2f0 fs/aio.c:946
hardirqs last disabled at (3482): [<ffffffff87d39722>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
hardirqs last disabled at (3482): [<ffffffff87d39722>] _raw_spin_lock_irqsave+0x52/0x60 kernel/locking/spinlock.c:159
softirqs last enabled at (3408): [<ffffffff87e01002>] asm_call_irq_on_stack+0x12/0x20
softirqs last disabled at (3401): [<ffffffff87e01002>] asm_call_irq_on_stack+0x12/0x20
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 2 PID: 1105 Comm: syz-executor423 Not tainted 5.10.137-syzkaller #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x107/0x167 lib/dump_stack.c:118
___might_sleep.cold+0x1e8/0x22e kernel/sched/core.c:7304
console_lock+0x19/0x80 kernel/printk/printk.c:2347
do_con_write+0x113/0x1de0 drivers/tty/vt/vt.c:2909
con_write+0x22/0xc0 drivers/tty/vt/vt.c:3296
gsmld_write+0xd0/0x150 drivers/tty/n_gsm.c:2720
do_tty_write drivers/tty/tty_io.c:1028 [inline]
file_tty_write.constprop.0+0x502/0x8e0 drivers/tty/tty_io.c:1118
call_write_iter include/linux/fs.h:1903 [inline]
aio_write+0x355/0x7b0 fs/aio.c:1580
__io_submit_one fs/aio.c:1952 [inline]
io_submit_one+0xf45/0x1a90 fs/aio.c:1999
__do_sys_io_submit fs/aio.c:2058 [inline]
__se_sys_io_submit fs/aio.c:2028 [inline]
__x64_sys_io_submit+0x18c/0x2f0 fs/aio.c:2028
do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x61/0xc6
The problem happens in the following control flow:
gsmld_write(...)
spin_lock_irqsave(&gsm->tx_lock, flags) // taken a spinlock on TX data
con_write(...)
do_con_write(...)
console_lock()
might_sleep() // -> bug
As far as console_lock() might sleep it should not be called with
spinlock held.
The patch replaces tx_lock spinlock with mutex in order to avoid the
problem.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: 32dd59f969 ("tty: n_gsm: fix race condition in gsmld_write()")
Cc: stable <stable@kernel.org>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Link: https://lore.kernel.org/r/20220829131640.69254-3-pchelkin@ispras.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A kick_timer timer_list is replaced with kick_timeout delayed_work to be
able to synchronize with mutexes as a prerequisite for the introduction
of tx_mutex.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: c568f7086c ("tty: n_gsm: fix missing timer to handle stalled links")
Cc: stable <stable@kernel.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Suggested-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Link: https://lore.kernel.org/r/20220829131640.69254-2-pchelkin@ispras.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
syzbot is reporting use of uninitialized spinlock at gsmld_write() [1], for
commit 32dd59f969 ("tty: n_gsm: fix race condition in gsmld_write()")
allows accessing gsm->tx_lock before gsm_activate_mux() initializes it.
Since object initialization should be done right after allocation in order
to avoid accessing uninitialized memory, move initialization of
timer/work/waitqueue/spinlock from gsmld_open()/gsm_activate_mux() to
gsm_alloc_mux().
Link: https://syzkaller.appspot.com/bug?extid=cf155def4e717db68a12 [1]
Fixes: 32dd59f969 ("tty: n_gsm: fix race condition in gsmld_write()")
Reported-by: syzbot <syzbot+cf155def4e717db68a12@syzkaller.appspotmail.com>
Tested-by: syzbot <syzbot+cf155def4e717db68a12@syzkaller.appspotmail.com>
Cc: stable <stable@kernel.org>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/r/2110618e-57f0-c1ce-b2ad-b6cacef3f60e@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A null pointer dereference can happen when attempting to access the
"gsm->receive()" function in gsmld_receive_buf(). Currently, the code
assumes that gsm->recieve is only called after MUX activation.
Since the gsmld_receive_buf() function can be accessed without the need to
initialize the MUX, the gsm->receive() function will not be set and a
NULL pointer dereference will occur.
Fix this by avoiding the call to "gsm->receive()" in case the function is
not initialized by adding a sanity check.
Call Trace:
<TASK>
gsmld_receive_buf+0x1c2/0x2f0 drivers/tty/n_gsm.c:2861
tiocsti drivers/tty/tty_io.c:2293 [inline]
tty_ioctl+0xa75/0x15d0 drivers/tty/tty_io.c:2692
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Link: https://syzkaller.appspot.com/bug?id=bdf035c61447f8c6e0e6920315d577cb5cc35ac5
Fixes: 01aecd9171 ("tty: n_gsm: fix tty registration before control channel open")
Cc: stable <stable@kernel.org>
Reported-and-tested-by: syzbot+e3563f0c94e188366dbb@syzkaller.appspotmail.com
Signed-off-by: Mazin Al Haddad <mazinalhaddad05@gmail.com>
Link: https://lore.kernel.org/r/20220814015211.84180-1-mazinalhaddad05@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Whenever the atmel_rs485_config() driver method would be called,
the USART mode is reset to normal mode before even checking if
RS485 flag is set, thus resulting in losing the previous USART
mode in the case where the checking fails.
Some tools, such as `linux-serial-test`, lead to the driver calling
this method when doing the setup of the serial port: after setting the
port mode (Hardware Flow Control, Normal Mode, RS485 Mode, etc.),
`linux-serial-test` tries to enable/disable RS485 depending on
the commandline arguments that were passed.
Example of how this issue could reveal itself:
When doing a serial communication with Hardware Flow Control through
`linux-serial-test`, the tool would lead to the driver roughly doing
the following:
- set the corresponding bit to 1 (ATMEL_US_USMODE_HWHS bit in the
ATMEL_US_MR register) through the atmel_set_termios() to enable
Hardware Flow Control
- disable RS485 through the atmel_config_rs485() method
Thus, when the latter is called, the mode will be reset and the
previously set bit is unset, leaving USART in normal mode instead of
the expected Hardware Flow Control mode.
This fix ensures that this reset is only done if the checking for
RS485 succeeds and that the previous mode is preserved otherwise.
Fixes: e8faff7330 ("ARM: 6092/1: atmel_serial: support for RS485 communications")
Cc: stable <stable@kernel.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com>
Link: https://lore.kernel.org/r/20220824142902.502596-1-sergiu.moga@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the user initializes the uart port, and waits for the transmit
engine to complete in lpuart32_set_termios(), if the UART TX fifo has
dirty data and the UARTMODIR enable the flow control, the TX fifo may
never be empty. So here we should disable the flow control first to make
sure the transmit engin can complete.
Fixes: 380c966c09 ("tty: serial: fsl_lpuart: add 32-bit register interface support")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20220821101527.10066-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Do not follow a NULL pointer if the tty_port_client_operations does not
implement the ->lookahead_buf() callback, which is the case with
serdev's ttyport.
Reported-by: Hans de Goede <hdegoede@redhat.com>
Fixes: 6bb6fa6908 ("tty: Implement lookahead to process XON/XOFF timely")
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20220818115026.2237893-1-vincent.whitchurch@axis.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The setting of RS485 RTS polarity is inverse in the current driver.
When the property of 'rs485-rts-active-low' is enabled in the dts node,
the RTS signal should be LOW during sending. Otherwise, if there is no
such a property, the RTS should be HIGH during sending.
Fixes: 03895cf41d ("tty: serial: fsl_lpuart: Add support for RS-485")
Cc: stable <stable@kernel.org>
Signed-off-by: Nicolas Diaz <nicolas.diaz@nxp.com>
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Link: https://lore.kernel.org/r/20220805144529.604856-1-shenwei.wang@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When changing the console font with ioctl(KDFONTOP) the new font size
can be bigger than the previous font. A previous selection may thus now
be outside of the new screen size and thus trigger out-of-bounds
accesses to graphics memory if the selection is removed in
vc_do_resize().
Prevent such out-of-memory accesses by dropping the selection before the
various con_font_set() console handlers are called.
Reported-by: syzbot+14b0e8f3fd1612e35350@syzkaller.appspotmail.com
Cc: stable <stable@kernel.org>
Tested-by: Khalid Masum <khalid.masum.92@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Link: https://lore.kernel.org/r/YuV9apZGNmGfjcor@p100
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The number of bits can be calculated using tty_get_frame_size(), no
need for the driver to do it on its own.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220830084925.5608-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver features a custom frame length calculation but the result is
never used. Remove it.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220830084925.5608-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The number of bits can be calculated using tty_get_frame_size(), no
need for the driver to do it on its own. Change bits to unsigned and
baud too since we're touching the declarations line anyway (the
respective core functions are typed unsigned).
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220830084925.5608-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
