The root of problem is carelessly zeroing pointer(in function __tty_buffer_flush()),
when another thread can use it. It can be cause of "NULL pointer dereference".
Main idea of the patch, this is never free last (struct tty_buffer) in the active buffer.
Only flush the data for ldisc(buf->head->read = buf->head->commit).
At that moment driver can collect(write) data in buffer without conflict.
It is repeat behavior of flush_to_ldisc(), only without feeding data to ldisc.
Also revert:
commit c56a00a165
tty: hold lock across tty buffer finding and buffer filling
In order to delete the unneeded locks any more.
Signed-off-by: Ilya Zykov <ilya@ilyx.ru>
CC: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The fields must be null-terminated, or next printk for %s, will cause issue.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The option allows you to remove TTY and compile without errors. This
saves space on systems that won't support TTY interfaces anyway.
bloat-o-meter output is below.
The bulk of this patch consists of Kconfig changes adding "depends on
TTY" to various serial devices and similar drivers that require the TTY
layer. Ideally, these dependencies would occur on a common intermediate
symbol such as SERIO, but most drivers "select SERIO" rather than
"depends on SERIO", and "select" does not respect dependencies.
bloat-o-meter output comparing our previous minimal to new minimal by
removing TTY. The list is filtered to not show removed entries with awk
'$3 != "-"' as the list was very long.
add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350)
function old new delta
chr_dev_init 166 170 +4
allow_signal 80 82 +2
static.__warned 143 142 -1
disallow_signal 63 62 -1
__set_special_pids 95 94 -1
unregister_console 126 121 -5
start_kernel 546 541 -5
register_console 593 588 -5
copy_from_user 45 40 -5
sys_setsid 128 120 -8
sys_vhangup 32 19 -13
do_exit 1543 1526 -17
bitmap_zero 60 40 -20
arch_local_irq_save 137 117 -20
release_task 674 652 -22
static.spin_unlock_irqrestore 308 260 -48
Signed-off-by: Joe Millenbach <jmillenbach@gmail.com>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Regression 'tty: fix "IRQ45: nobody cared"'
Regression commit 7b292b4bf9
Function reset_buffer_flags() also invoked during the ioctl(...,TCFLSH,..).
At the time of request we can have full buffers and throttled driver too.
If we don't unthrottle driver, we can get forever throttled driver, because,
after request, we will have empty buffers and throttled driver and
there is no place to unthrottle driver.
It simple reproduce with "pty" pair then one side sleep on tty->write_wait,
and other side do ioctl(...,TCFLSH,..). Then there is no place to do writers wake up.
Signed-off-by: Ilya Zykov <ilya@ilyx.ru>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A duplicate definition of the port variable was introduced in the
interrupt handler, which causes the build to break. The fix is to
rename the variable to tport, which is already properly used in
subsequent code.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert the last memory allocation (vt8500_port) to use devm_kzalloc
and remove the fail path cleanup code from vt8500_serial_probe.
Reorder iomem mapping above clk_enable to simplify fail code. The
clock is only enabled if all other resources are available.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UART modules on Wondermedia SoCs are connected via a gated clock
source, rather than directly to the 24Mhz reference clock. While
uboot enables UART0 for debugging, other UART ports are unavailable
until the clock is enabled.
This patch checks that a valid clock is actually passed from devicetree,
enables the clock in probe. This change removes the fallback when a
clock was not specified as it doesn't apply any longer (and would only
work if the UART clock was already enabled).
DTSI files are updated for VT8500, WM8505 and WM8650.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Many of the tty functions were converted to use a struct tty_port
instead of a struct tty_struct. Update the Tegra driver accordingly to
avoid build breakage.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The write() function could be used by printk(), which is atomic and
tweaking clock there can cause "BUG: sleeping function called from
invalid context".
Signed-off-by: Bao Haojun <hjbao@marvell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fix possible kernel crash if no platform data supplied.
We should not use platform data in this case, instead we will use
default values from private driver structure.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This driver supports the RocketPort EXPRESS and RocketPort INFINITY
families of PCI/PCIe multiport serial adapters. These adapters use a
"RocketPort 2" ASIC that is not compatible with the original RocketPort
driver (CONFIG_ROCKETPORT).
Tested with the RocketPort EXPRESS Octa DB9 and Quad DB9. Also added an
old RocketPort 8J PCI card to the same system to verify that rocket.c and
rp2.c coexist peacefully.
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Matching PCI_ANY_ID causes conflicts with RocketPort 2 adapters, which
are supported by a different driver.
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Memory mapped via ioremap call is never released. Rather than add an
iounmap call, change allocation function to devm_request_and_ioremap.
Also, change the error on failure for this call to -EADDRNOTAVAIL rather than
-ENOMEM.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix two instances where the index to vt8500_uart_ports is tested
against > VT8500_MAX_PORTS. Correct usage should be >= VT8500_MAX_PORTS.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The pointer tty is dereferened in line 3135, so it is not necessary to check
null again in line 3140.
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The pointer info is dereferened in line 1009, so it is not necessary to check
null again in line 1012.
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Original table in OMAP TRM named "UART Mode Baud Rates, Divisor
Values, and Error Rates" determines modes not for all common baud
rates. E.g. for 1000000 baud rate mode should be 16x, but according to
that table it's determined as 13x. According to current implementation
of mode divisor selection, after requesting 1000000 baudrate from
driver, later one will configure chip to use MODE13 divisor. Assuming
48Mhz as common UART clock speed, MODE13 divisor will effectively give
1230769 baudrate, what is quite far from desired 1000000 baudrate.
While with MODE16 divisor, chip will produce exact 1000000 baudrate.
In old driver that served UART devices (8250.c and serial_core.c) this
divisor could have been configured by user-space program, but in
omap_serial.c driver implementation this ability was not implemented
(afaik, by design) thus disallowing proper usage of MODE16-compatible
baudrates.
Signed-off-by: Alexey Pelykh <alexey.pelykh@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit "serial/arc-uart: split probe from probe_earlyprintk" introduced
a build time warning:
"WARNING: vmlinux.o(.data+0x5baa0): Section mismatch in reference from
the variable early_arc_platform_driver to the function
.init.text:arc_serial_probe_earlyprintk()"
While at it - fixed another incorrectly placed initdata annotation.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: fengguang.wu@intel.com
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The fast lookup table to set baudrate is only right when ioclk
is 150MHz. for most platforms, ioclk is 150MHz, but some boards
might set ioclk to other frequency.
so re-calc the clk_div_reg when ioclk is not 150MHz. this patch
also gets clk in probe and puts it in remove.
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This one was omitted by the "TTY: switch tty_flip_buffer_push" patch
because I did not compile-test mips driver. Now I do.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The default burst is often 1 byte which is not very optimal.
The ideal burst size when using 16550A type port would be
1/2 of fifosize, but this does not work with all Designware
implementations. Setting it to 1/4 fifosize.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are no stubs for ACPI functions so the driver needs to
have this ifdef or it will not compile without ACPI.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove one useless wakeup, and do not use DMA with zero byte
transfers.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The tty buffer functions are converted to using tty_port
structure instead of struct tty, so we must do the same.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 89c8d91e31 ("tty: localise the lock") I see a dead lock
in one of my dummy_hcd + g_nokia test cases. The first run was usually
okay, the second often resulted in a splat by lockdep and the third was
usually a dead lock.
Lockdep complained about tty->hangup_work and tty->legacy_mutex taken
both ways:
| ======================================================
| [ INFO: possible circular locking dependency detected ]
| 3.7.0-rc6+ #204 Not tainted
| -------------------------------------------------------
| kworker/2:1/35 is trying to acquire lock:
| (&tty->legacy_mutex){+.+.+.}, at: [<c14051e6>] tty_lock_nested+0x36/0x80
|
| but task is already holding lock:
| ((&tty->hangup_work)){+.+...}, at: [<c104f6e4>] process_one_work+0x124/0x5e0
|
| which lock already depends on the new lock.
|
| the existing dependency chain (in reverse order) is:
|
| -> #2 ((&tty->hangup_work)){+.+...}:
| [<c107fe74>] lock_acquire+0x84/0x190
| [<c104d82d>] flush_work+0x3d/0x240
| [<c12e6986>] tty_ldisc_flush_works+0x16/0x30
| [<c12e7861>] tty_ldisc_release+0x21/0x70
| [<c12e0dfc>] tty_release+0x35c/0x470
| [<c1105e28>] __fput+0xd8/0x270
| [<c1105fcd>] ____fput+0xd/0x10
| [<c1051dd9>] task_work_run+0xb9/0xf0
| [<c1002a51>] do_notify_resume+0x51/0x80
| [<c140550a>] work_notifysig+0x35/0x3b
|
| -> #1 (&tty->legacy_mutex/1){+.+...}:
| [<c107fe74>] lock_acquire+0x84/0x190
| [<c140276c>] mutex_lock_nested+0x6c/0x2f0
| [<c14051e6>] tty_lock_nested+0x36/0x80
| [<c1405279>] tty_lock_pair+0x29/0x70
| [<c12e0bb8>] tty_release+0x118/0x470
| [<c1105e28>] __fput+0xd8/0x270
| [<c1105fcd>] ____fput+0xd/0x10
| [<c1051dd9>] task_work_run+0xb9/0xf0
| [<c1002a51>] do_notify_resume+0x51/0x80
| [<c140550a>] work_notifysig+0x35/0x3b
|
| -> #0 (&tty->legacy_mutex){+.+.+.}:
| [<c107f3c9>] __lock_acquire+0x1189/0x16a0
| [<c107fe74>] lock_acquire+0x84/0x190
| [<c140276c>] mutex_lock_nested+0x6c/0x2f0
| [<c14051e6>] tty_lock_nested+0x36/0x80
| [<c140523f>] tty_lock+0xf/0x20
| [<c12df8e4>] __tty_hangup+0x54/0x410
| [<c12dfcb2>] do_tty_hangup+0x12/0x20
| [<c104f763>] process_one_work+0x1a3/0x5e0
| [<c104fec9>] worker_thread+0x119/0x3a0
| [<c1055084>] kthread+0x94/0xa0
| [<c140ca37>] ret_from_kernel_thread+0x1b/0x28
|
|other info that might help us debug this:
|
|Chain exists of:
| &tty->legacy_mutex --> &tty->legacy_mutex/1 --> (&tty->hangup_work)
|
| Possible unsafe locking scenario:
|
| CPU0 CPU1
| ---- ----
| lock((&tty->hangup_work));
| lock(&tty->legacy_mutex/1);
| lock((&tty->hangup_work));
| lock(&tty->legacy_mutex);
|
| *** DEADLOCK ***
Before the path mentioned tty_ldisc_release() look like this:
| tty_ldisc_halt(tty);
| tty_ldisc_flush_works(tty);
| tty_lock();
As it can be seen, it first flushes the workqueue and then grabs the
tty_lock. Now we grab the lock first:
| tty_lock_pair(tty, o_tty);
| tty_ldisc_halt(tty);
| tty_ldisc_flush_works(tty);
so lockdep's complaint seems valid.
The earlier version of this patch took the ldisc_mutex since the other
user of tty_ldisc_flush_works() (tty_set_ldisc()) did this.
Peter Hurley then said that it is should not be requried. Since it
wasn't done earlier, I dropped this part.
The code under tty_ldisc_kill() was executed earlier with the tty lock
taken so it is taken again.
I was able to reproduce the deadlock on v3.8-rc1, this patch fixes the
problem in my testcase. I didn't notice any problems so far.
Cc: Alan Cox <alan@linux.intel.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With ACPI 5.0 we can use the FixedDMA Resource Descriptor to
extract the needed information for DMA support.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for dmaengine API. The drivers can implement the
struct uart_8250_dma member in struct uart_8250_port and
8250.c can take care of the rest.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds support for ACPI 5.0 enumerated Designware UARTs.
ACPI does not deliver information about uart clk, so
delivering it with the driver_data.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Designware UART provides optional Component Parameter
Register that lists most of the capabilities of the UART,
including FIFO size. This uses that register to set FIFO
size for the port before registering it.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Trivial cleanup. This makes it easier to add different
methods to enumerate the device, for example ACPI 5.0
enumeration.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This needs to be done in order to later access the
Designware specific registers.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allow 8250.c to determine the port type for us. This allows
the driver take advantage of FIFO on Designware UARTs that
have it.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Modern UARTs are able to provide information about their
capabilities such as FIFO size. This allows the drivers to
deliver this information to 8250.c when they are registering
ports.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Before waking up the tty line discipline idle queue first check if the queue is
active (non empty). This prevents unnecessary entering the critical section in
the wake_up() function and therefore avoid needless scheduling overhead on a
PREEMPT_RT system caused by two processes being in the same critical section.
Signed-off-by: Ivo Sieben <meltedpianoman@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
for extern function uart_remove_one_port:
need check pointer whether be NULL, before the main work.
just like what the other extern function uart_add_one_port has done.
uart_add_one_port and uart_remove_one_port are pair
information:
for the callers (such as drivers/tty/serial/jsm: jsm_tty.c, jsm_driver.c)
they realy assume that:
they still can call uart_remove_one_port, after uart_add_one_port failed
we (as an extern function), have to understand it (just like kfree).
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use for_each_compatible_node() macro instead of open coding it.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds support for polling work mode, i.e. system is perform
periodical check chip status when IRQ-line is not connected to CPU.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that login from util-linux is forced to drop all references to a
TTY which it wants to hangup (to reach reference count 1) we are
seeing issues with telnet. When login closes its last reference to the
slave PTY, it also resets packet mode on the *master* side. And we
have a race here.
What telnet does is fork+exec of `login'. Then there are two
scenarios:
* `login' closes the slave TTY and resets thus master's packet mode,
but even now telnet properly sets the mode, or
* `telnetd' sets packet mode on the master, `login' closes the slave
TTY and resets master's packet mode.
The former case is OK. However the latter happens in much more cases,
by the order of magnitude to be precise. So when one tries to login to
such a messed telnet setup, they see the following:
inux login:
ogin incorrect
Note the missing first letters -- telnet thinks it is still in the
packet mode, so when it receives "linux login" from `login', it
considers "l" as the type of the packet and strips it.
SuS does not mention how the implementation should behave. Both BSDs I
checked (Free and Net) do not reset the flag upon the last close.
By this I am resurrecting an old bug, see References. We are hitting
it regularly now, i.e. with updated util-linux, ergo login.
Here, I am changing a behavior introduced back in 2.1 times. It would
better have a long time testing before goes upstream.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Bryan Mason <bmason@redhat.com>
References: https://lkml.org/lkml/2009/11/11/223
References: https://bugzilla.redhat.com/show_bug.cgi?id=504703
References: https://bugzilla.novell.com/show_bug.cgi?id=797042
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
spaces are used for indent in 3 places of tty/pty.c, we change it to tab.
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
the "\n" in panic message is excess, so we remove it in tty/pty.c as what it
is used in other places.
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit f96f7f7f39, at the
request of Jin.
Cc: xiaojin <jin.xiao@intel.com>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some __devexit markings came in from an older patch, this removes them.
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We test for !dc twice, remove the second test. Coverity found this.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
info in synclink bottom-halves cannot be NULL because it is taken from
work_struct using container_of. Remove the tests.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, the tty is not needed at all places in the ISR. So we can just
request in on demand when really needed.
This cleans TX and RX paths a bit as the indentation level can be
dropped by two now when we also invert the char_count if condition.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
This is the last one: tty_schedule_flip
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
