Currently N_HDLC line discipline uses a self-made singly linked list for
data buffers and has n_hdlc.tbuf pointer for buffer retransmitting after
an error.
The commit be10eb7589
("tty: n_hdlc add buffer flushing") introduced racy access to n_hdlc.tbuf.
After tx error concurrent flush_tx_queue() and n_hdlc_send_frames() can put
one data buffer to tx_free_buf_list twice. That causes double free in
n_hdlc_release().
Let's use standard kernel linked list and get rid of n_hdlc.tbuf:
in case of tx error put current data buffer after the head of tx_buf_list.
Change-Id: Ib34e9a2562765197e717492a1227aff565436e91
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The class of 4 n_hdls buf locks is the same because a single function
n_hdlc_buf_list_init is used to init all the locks. But since
flush_tx_queue takes n_hdlc->tx_buf_list.spinlock and then calls
n_hdlc_buf_put which takes n_hdlc->tx_free_buf_list.spinlock, lockdep
emits a warning:
=============================================
[ INFO: possible recursive locking detected ]
4.3.0-25.g91e30a7-default #1 Not tainted
---------------------------------------------
a.out/1248 is trying to acquire lock:
(&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fd020>] n_hdlc_buf_put+0x20/0x60 [n_hdlc]
but task is already holding lock:
(&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fdc07>] n_hdlc_tty_ioctl+0x127/0x1d0 [n_hdlc]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(&list->spinlock)->rlock);
lock(&(&list->spinlock)->rlock);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by a.out/1248:
#0: (&tty->ldisc_sem){++++++}, at: [<ffffffff814c9eb0>] tty_ldisc_ref_wait+0x20/0x50
#1: (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fdc07>] n_hdlc_tty_ioctl+0x127/0x1d0 [n_hdlc]
...
Call Trace:
...
[<ffffffff81738fd0>] _raw_spin_lock_irqsave+0x50/0x70
[<ffffffffa01fd020>] n_hdlc_buf_put+0x20/0x60 [n_hdlc]
[<ffffffffa01fdc24>] n_hdlc_tty_ioctl+0x144/0x1d0 [n_hdlc]
[<ffffffff814c25c1>] tty_ioctl+0x3f1/0xe40
...
Fix it by initializing the spin_locks separately. This removes also
reduntand memset of a freshly kzallocated space.
Change-Id: I32bc83c9e19953672857fe8182107772411d471a
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ioctl(TIOCGETD) retrieves the line discipline id directly from the
ldisc because the line discipline id (c_line) in termios is untrustworthy;
userspace may have set termios via ioctl(TCSETS*) without actually
changing the line discipline via ioctl(TIOCSETD).
However, directly accessing the current ldisc via tty->ldisc is
unsafe; the ldisc ptr dereferenced may be stale if the line discipline
is changing via ioctl(TIOCSETD) or hangup.
Wait for the line discipline reference (just like read() or write())
to retrieve the "current" line discipline id.
Bug: 28409131
Change-Id: I3f7a539ab31769f0e926d5c79d56bde652fbaf75
Cc: <stable@vger.kernel.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The tty atomic_write_lock does not provide an exclusion guarantee for
the tty driver if the termios settings are LECHO & !OPOST. And since
it is unexpected and not allowed to call TTY buffer helpers like
tty_insert_flip_string concurrently, this may lead to crashes when
concurrect writers call pty_write. In that case the following two
writers:
* the ECHOing from a workqueue and
* pty_write from the process
race and can overflow the corresponding TTY buffer like follows.
If we look into tty_insert_flip_string_fixed_flag, there is:
int space = __tty_buffer_request_room(port, goal, flags);
struct tty_buffer *tb = port->buf.tail;
...
memcpy(char_buf_ptr(tb, tb->used), chars, space);
...
tb->used += space;
so the race of the two can result in something like this:
A B
__tty_buffer_request_room
__tty_buffer_request_room
memcpy(buf(tb->used), ...)
tb->used += space;
memcpy(buf(tb->used), ...) ->BOOM
B's memcpy is past the tty_buffer due to the previous A's tb->used
increment.
Since the N_TTY line discipline input processing can output
concurrently with a tty write, obtain the N_TTY ldisc output_lock to
serialize echo output with normal tty writes. This ensures the tty
buffer helper tty_insert_flip_string is not called concurrently and
everything is fine.
Note that this is nicely reproducible by an ordinary user using
forkpty and some setup around that (raw termios + ECHO). And it is
present in kernels at least after commit
d945cb9cce (pty: Rework the pty layer to
use the normal buffering logic) in 2.6.31-rc3.
js: add more info to the commit log
js: switch to bool
js: lock unconditionally
js: lock only the tty->ops->write call
Bug: 28803396
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: I9e235db6ec2bb950f26bd8a23f6145dab5dc0a15
Git-commit: 4291086b1f
Git-repo:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Avijit Kanti Das <avijitnsec@codeaurora.org>
[rsiddoji@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Ravi Kumar S <rsiddoji@codeaurora.org>
commit 0c55627167870255158db1cde0d28366f91c8872 upstream.
This is mostly a hardening fix, given that write-only access to other
users' ttys is usually only given through setgid tty executables.
Signed-off-by: Jann Horn <jann@thejh.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit e81107d4c6bd098878af9796b24edc8d4a9524fd upstream.
My colleague ran into a program stall on a x86_64 server, where
n_tty_read() was waiting for data even if there was data in the buffer
in the pty. kernel stack for the stuck process looks like below.
#0 [ffff88303d107b58] __schedule at ffffffff815c4b20
#1 [ffff88303d107bd0] schedule at ffffffff815c513e
#2 [ffff88303d107bf0] schedule_timeout at ffffffff815c7818
#3 [ffff88303d107ca0] wait_woken at ffffffff81096bd2
#4 [ffff88303d107ce0] n_tty_read at ffffffff8136fa23
#5 [ffff88303d107dd0] tty_read at ffffffff81368013
#6 [ffff88303d107e20] __vfs_read at ffffffff811a3704
#7 [ffff88303d107ec0] vfs_read at ffffffff811a3a57
#8 [ffff88303d107f00] sys_read at ffffffff811a4306
#9 [ffff88303d107f50] entry_SYSCALL_64_fastpath at ffffffff815c86d7
There seems to be two problems causing this issue.
First, in drivers/tty/n_tty.c, __receive_buf() stores the data and
updates ldata->commit_head using smp_store_release() and then checks
the wait queue using waitqueue_active(). However, since there is no
memory barrier, __receive_buf() could return without calling
wake_up_interactive_poll(), and at the same time, n_tty_read() could
start to wait in wait_woken() as in the following chart.
__receive_buf() n_tty_read()
------------------------------------------------------------------------
if (waitqueue_active(&tty->read_wait))
/* Memory operations issued after the
RELEASE may be completed before the
RELEASE operation has completed */
add_wait_queue(&tty->read_wait, &wait);
...
if (!input_available_p(tty, 0)) {
smp_store_release(&ldata->commit_head,
ldata->read_head);
...
timeout = wait_woken(&wait,
TASK_INTERRUPTIBLE, timeout);
------------------------------------------------------------------------
The second problem is that n_tty_read() also lacks a memory barrier
call and could also cause __receive_buf() to return without calling
wake_up_interactive_poll(), and n_tty_read() to wait in wait_woken()
as in the chart below.
__receive_buf() n_tty_read()
------------------------------------------------------------------------
spin_lock_irqsave(&q->lock, flags);
/* from add_wait_queue() */
...
if (!input_available_p(tty, 0)) {
/* Memory operations issued after the
RELEASE may be completed before the
RELEASE operation has completed */
smp_store_release(&ldata->commit_head,
ldata->read_head);
if (waitqueue_active(&tty->read_wait))
__add_wait_queue(q, wait);
spin_unlock_irqrestore(&q->lock,flags);
/* from add_wait_queue() */
...
timeout = wait_woken(&wait,
TASK_INTERRUPTIBLE, timeout);
------------------------------------------------------------------------
There are also other places in drivers/tty/n_tty.c which have similar
calls to waitqueue_active(), so instead of adding many memory barrier
calls, this patch simply removes the call to waitqueue_active(),
leaving just wake_up*() behind.
This fixes both problems because, even though the memory access before
or after the spinlocks in both wake_up*() and add_wait_queue() can
sneak into the critical section, it cannot go past it and the critical
section assures that they will be serialized (please see "INTER-CPU
ACQUIRING BARRIER EFFECTS" in Documentation/memory-barriers.txt for a
better explanation). Moreover, the resulting code is much simpler.
Latency measurement using a ping-pong test over a pty doesn't show any
visible performance drop.
Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lizf: Backported to 3.4:
- adjust context
- s/wake_up_interruptible_poll/wake_up_interruptible/
- drop changes to __receive_buf() and n_tty_set_termios()]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 8687634b7908c42eb700e0469e110e02833611d1 upstream.
In RS485 mode, we may want to set the delay_rts_after_send value to 0.
In the datasheet, the 0 value is said to "disable" the Transmitter Timeguard but
this is exactly the expected behavior if we want no delay...
Moreover, if the value was set to non-zero value by device-tree or earlier
ioctl command, it was impossible to change it back to zero.
Reported-by: Sami Pietikäinen <Sami.Pietikainen@wapice.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 77bb3dfdc0d554befad58fdefbc41be5bc3ed38a upstream.
A non-percpu VIRQ (e.g., VIRQ_CONSOLE) may be freed on a different
VCPU than it is bound to. This can result in a race between
handle_percpu_irq() and removing the action in __free_irq() because
handle_percpu_irq() does not take desc->lock. The interrupt handler
sees a NULL action and oopses.
Only use the percpu chip/handler for per-CPU VIRQs (like VIRQ_TIMER).
# cat /proc/interrupts | grep virq
40: 87246 0 xen-percpu-virq timer0
44: 0 0 xen-percpu-virq debug0
47: 0 20995 xen-percpu-virq timer1
51: 0 0 xen-percpu-virq debug1
69: 0 0 xen-dyn-virq xen-pcpu
74: 0 0 xen-dyn-virq mce
75: 29 0 xen-dyn-virq hvc_console
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
[lizf: Backported to 3.4: adjust filename]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit b9d934f27c91b878c4b2e64299d6e419a4022f8d upstream.
After a resume the hypervisor/tools may change console event
channel number. We should re-query it.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 6befa9d883385c580369a2cc9e53fbf329771f6d upstream.
Do not probe all serial drivers by of_serial.c which are using
device_type = "serial"; property. Only drivers which have valid
compatible strings listed in the driver should be probed.
When PORT_UNKNOWN is setup probe will fail anyway.
Arnd quotation about driver historical background:
"when I wrote that driver initially, the idea was that it would
get used as a stub to hook up all other serial drivers but after
that, the common code learned to create platform devices from DT"
This patch fix the problem with on the system with xilinx_uartps and
16550a where of_serial failed to register for xilinx_uartps and because
of irq_dispose_mapping() removed irq_desc. Then when xilinx_uartps was asking
for irq with request_irq() EINVAL is returned.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 5c90c07b98c02198d9777a7c4f3047b0a94bf7ed upstream.
For systems with CONFIG_SERIAL_OF_PLATFORM=y and device_type =
"serial"; property in DT of_serial.c driver maps and unmaps IRQ (because
driver probe fails). Then a driver is called but irq mapping is not
created that's why driver is failing again in again on request_irq().
Based on this use platform_get_irq() instead of platform_get_resource()
which is doing irq_desc allocation and driver itself can request IRQ.
Fix both xilinx serial drivers in the tree.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 79fbf4a550ed6a22e1ae1516113e6c7fa5d56a53 upstream.
Fix overflow bug in tty_wait_until_sent on 64-bit machines, where an
infinite timeout (0) would be passed to the underlying tty-driver's
wait_until_sent-operation as a negative timeout (-1), causing it to
return immediately.
This manifests itself for example as tcdrain() returning immediately,
drivers not honouring the drain flags when setting terminal attributes,
or even dropped data on close as a requested infinite closing-wait
timeout would be ignored.
The first symptom was reported by Asier LLANO who noted that tcdrain()
returned prematurely when using the ftdi_sio usb-serial driver.
Fix this by passing 0 rather than MAX_SCHEDULE_TIMEOUT (LONG_MAX) to the
underlying tty driver.
Note that the serial-core wait_until_sent-implementation is not affected
by this bug due to a lucky chance (comparison to an unsigned maximum
timeout), and neither is the cyclades one that had an explicit check for
negative timeouts, but all other tty drivers appear to be affected.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: ZIV-Asier Llano Palacios <asier.llano@cgglobal.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit f0bf0bd07943bfde8f5ac39a32664810a379c7d3 upstream.
This problem was taken care of three times already in
* b0de59b573 (TTY: do not update
atime/mtime on read/write),
* 37b7f3c765 (TTY: fix atime/mtime
regression), and
* b0b885657b (tty: fix up atime/mtime
mess, take three)
But it still misses one point. As John Paul correctly points out, we
do not care about setting date. If somebody ever changes wall
time backwards (by mistake for example), tty timestamps are never
updated until the original wall time passes.
So check the absolute difference of times and if it large than "8
seconds or so", always update the time. That means we will update
immediatelly when changing time. Ergo, CAP_SYS_TIME can foul the
check, but it was always that way.
Thanks John for serving me this so nicely debugged.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: John Paul Perry <john_paul.perry@alcatel-lucent.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit f2e0ea861117bda073d1d7ffbd3120c07c0d5d34 upstream.
I'm still receiving reports to my email address, so let's point this
at the linux-serial mailing list instead.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 37480a05685ed5b8e1b9bf5e5c53b5810258b149 upstream.
Commit 26df6d1340 ("tty: Add EXTPROC support for LINEMODE")
allows a process which has opened a pty master to send _any_ signal
to the process group of the pty slave. Although potentially
exploitable by a malicious program running a setuid program on
a pty slave, it's unknown if this exploit currently exists.
Limit to signals actually used.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Howard Chu <hyc@symas.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 19e3ae6b4f07a87822c1c9e7ed99d31860e701af upstream.
The vcs device's poll/fasync support relies on the vt notifier to signal
changes to the screen content. Notifier invocations were missing for
changes that comes through the selection interface though. Fix that.
Tested with BRLTTY 5.2.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: Dave Mielke <dave@mielke.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 1ff383a4c3eda8893ec61b02831826e1b1f46b41 upstream.
This patch adds waiting until transmit buffer and shifter will be empty
before clock disabling.
Without this fix it's possible to have clock disabled while data was
not transmited yet, which causes unproper state of TX line and problems
in following data transfers.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 9e326f7871 upstream.
We can call this function for a dummy console that doesn't support
setting the font mapping, which will result in a null ptr BUG. So check
for this case and return error for consoles w/o font mapping support.
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=59321
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lizf: Backported to 3.4: just return -EINVAL as we don't need to unlock]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 494c1eac7e upstream.
Only print one warning when a task is on the read_wait or write_wait
wait queue at final tty release.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 37b1645788 upstream.
Kernel oops can cause the tty to be unreleaseable (for example, if
n_tty_read() crashes while on the read_wait queue). This will cause
tty_release() to endlessly loop without sleeping.
Use a killable sleep timeout which grows by 2n+1 jiffies over the interval
[0, 120 secs.) and then jumps to forever (but still killable).
NB: killable just allows for the task to be rewoken manually, not
to be terminated.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 547039ec50 upstream.
uart_get_baud_rate() will return baud == 0 if the max rate is set
to the "magic" 38400 rate and the SPD_* flags are also specified.
On the first iteration, if the current baud rate is higher than the
max, the baud rate is clamped at the max (which in the degenerate
case is 38400). On the second iteration, the now-"magic" 38400 baud
rate selects the possibly higher alternate baud rate indicated by
the SPD_* flag. Since only two loop iterations are performed, the
loop is exited, a kernel WARNING is generated and a baud rate of
0 is returned.
Reproducible with:
setserial /dev/ttyS0 spd_hi base_baud 38400
Only perform the "magic" 38400 -> SPD_* baud transform on the first
loop iteration, which prevents the degenerate case from recognizing
the clamped baud rate as the "magic" 38400 value.
Reported-by: Robert Święcki <robert@swiecki.net>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 1ede7dcca3 upstream.
Quark X1000 contains two designware derived 8250 serial ports.
Each port has a unique PCI configuration space consisting of
BAR0:UART BAR1:DMA respectively.
Unlike the standard 8250 the register width is 32 bits for RHR,IER etc
The Quark UART has a fundamental clock @ 44.2368 MHz allowing for a
bitrate of up to about 2.76 megabits per second.
This patch enables standard 8250 mode
Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 7400ce7ee9 (v3.4.92-76-g7400ce7ee959)
was a backport of commit ebebd49a8e upstream
("8250/16?50: Add support for Broadcom TruManage redirected serial port")
However, in the context of 3.4.x kernels, the pci setup code was
expecting a struct uart_port and not a struct uart_8250_port, leading to
the following concerning warnings:
drivers/tty/serial/8250/8250_pci.c: In function ‘pci_brcm_trumanage_setup’:
drivers/tty/serial/8250/8250_pci.c:1086:2: warning: passing argument 3 of ‘pci_default_setup’ from incompatible pointer type [enabled by default]
int ret = pci_default_setup(priv, board, port, idx);
^
drivers/tty/serial/8250/8250_pci.c:1036:1: note: expected ‘struct uart_port *’ but argument is of type ‘struct uart_8250_port *’
pci_default_setup(struct serial_private *priv,
^
drivers/tty/serial/8250/8250_pci.c: At top level:
drivers/tty/serial/8250/8250_pci.c:1746:3: warning: initialization from incompatible pointer type [enabled by default]
.setup = pci_brcm_trumanage_setup,
^
drivers/tty/serial/8250/8250_pci.c:1746:3: warning: (near initialization for ‘pci_serial_quirks[56].setup’) [enabled by default]
I'd also expect the initialization to not function correctly, and
perhaps dereference random garbage due to this. Since the uart_port
is a field within the uart_8250_port, the adaptation to fix these
warnings is a straightforward removal of a layer of indirection.
Cc: Stephen Hurd <shurd@broadcom.com>
Cc: Michael Chan <mchan@broadcom.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
[ Upstream commit fe418231b1 ]
Fix detection of BREAK on sunsab serial console: BREAK detection was only
performed when there were also serial characters received simultaneously.
To handle all BREAKs correctly, the check for BREAK and the corresponding
call to uart_handle_break() must also be done if count == 0, therefore
duplicate this code fragment and pull it out of the loop over the received
characters.
Patch applies to 3.16-rc6.
Signed-off-by: Christopher Alexander Tobias Schulze <cat.schulze@alice-dsl.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ebebd49a8e upstream.
Add support for the UART device present in Broadcom TruManage capable
NetXtreme chips (ie: 5761m 5762, and 5725).
This implementation has a hidden transmit FIFO, so running in single-byte
interrupt mode results in too many interrupts. The UART_CAP_HFIFO
capability was added to track this. It continues to reload the THR as long
as the THRE and TSRE bits are set in the LSR up to a specified limit (1024
is used here).
Signed-off-by: Stephen Hurd <shurd@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
[xr: Backported to 3.4:
- Adjust filenames
- Adjust context
- PORT_BRCM_TRUMANAGE is 22 not 24]
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d13402a4a9 upstream.
I've managed to find an 8 port version of the card 4 port card which was discussed here:
http://marc.info/?l=linux-serial&m=120760744205314&w=2
Looking back at that thread there were two issues in the original patch.
1) The I/O ports for the UARTs are within BAR2 not BAR0. This can been seen in the original post.
2) A serial quirk isn't needed as these cards have no memory in BAR0 which makes pci_plx9050_init just return.
This patch fixes the 4 port support to use BAR2, removes the bogus quirk and adds support for the 8 port card.
$ lspci -vvv -n -s 00:08.0
00:08.0 0780: 10b5:9050 (rev 01)
Subsystem: 10b5:1588
Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Interrupt: pin A routed to IRQ 17
Region 1: I/O ports at ff00 [size=128]
Region 2: I/O ports at fe00 [size=64]
Region 3: I/O ports at fd00 [size=8]
Capabilities: <access denied>
Kernel driver in use: serial
$ dmesg | grep 0000:00:08.0:
[ 0.083320] pci 0000:00:08.0: [10b5:9050] type 0 class 0x000780
[ 0.083355] pci 0000:00:08.0: reg 14: [io 0xff00-0xff7f]
[ 0.083369] pci 0000:00:08.0: reg 18: [io 0xfe00-0xfe3f]
[ 0.083382] pci 0000:00:08.0: reg 1c: [io 0xfd00-0xfd07]
[ 0.083460] pci 0000:00:08.0: PME# supported from D0 D3hot
[ 1.212867] 0000:00:08.0: ttyS4 at I/O 0xfe00 (irq = 17) is a 16550A
[ 1.233073] 0000:00:08.0: ttyS5 at I/O 0xfe08 (irq = 17) is a 16550A
[ 1.253270] 0000:00:08.0: ttyS6 at I/O 0xfe10 (irq = 17) is a 16550A
[ 1.273468] 0000:00:08.0: ttyS7 at I/O 0xfe18 (irq = 17) is a 16550A
[ 1.293666] 0000:00:08.0: ttyS8 at I/O 0xfe20 (irq = 17) is a 16550A
[ 1.313863] 0000:00:08.0: ttyS9 at I/O 0xfe28 (irq = 17) is a 16550A
[ 1.334061] 0000:00:08.0: ttyS10 at I/O 0xfe30 (irq = 17) is a 16550A
[ 1.354258] 0000:00:08.0: ttyS11 at I/O 0xfe38 (irq = 17) is a 16550A
Signed-off-by: Scott Ashcroft <scott.ashcroft@talk21.com>
[xr: Backported to 3.4: adjust context]
Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 64325a3be0 upstream.
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.
Signed-off-by: Ilya Zykov <ilya@ilyx.ru>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fc0919c68c upstream.
Fix tty-kref leak introduced by commit 384e301e ("pch_uart: fix a
deadlock when pch_uart as console") which never put its tty reference.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 19b85cfb19 upstream.
Fix tty_kref leak when tty_buffer_request room fails in dma-rx path.
Note that the tty ref isn't really needed anymore, but as the leak has
always been there, fixing it before removing should makes it easier to
backport the fix.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 329e56780e upstream.
Drivers are supposed to use the dev_* versions of the kfree_skb
interfaces. In a couple of cases we were called with IRQs
disabled as well which kfree_skb() does not expect.
Replaced kfree_skb calls w/ dev_kfree_skb and dev_kfree_skb_any
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Tested-by: Yin, Fengwei <fengwei.yin@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b4338e1efc upstream.
gsm_data_kick was recently modified to allow messages on the
tx queue bound for DLCI0 to flow even during FCOFF conditions.
Unfortunately we introduced a bug discovered by code inspection
where subsequent list traversers can access freed memory if
the DLCI0 messages were not all at the head of the list.
Replaced singly linked tx list w/ a list_head and used
provided interfaces for traversing and deleting members.
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Tested-by: Yin, Fengwei <fengwei.yin@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 10c6c383e4 upstream.
The design of uplink flow control in the mux driver is
that for constipated channels data will backup into the
per-channel fifos, and any messages that make it to the
outbound message queue will still go out.
Code was added to also stop messages that were in the outbound
queue but this requires filtering through all the messages on the
queue for stopped dlcis and changes some of the mux logic unneccessarily.
The message fiiltering was removed to be in line w/ the original design
as the message filtering does not provide any solution.
Extra debug messages used during investigation were also removed.
Signed-off-by: samix.lebsir <samix.lebsir@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c01af4fec2 upstream.
- Correcting handling of FCon/FCoff in order to respect 27.010 spec
- Consider FCon/off will overide all dlci flow control except for
dlci0 as we must be able to send control frames.
- Dlci constipated handling according to FC, RTC and RTR values.
- Modifying gsm_dlci_data_kick and gsm_dlci_data_sweep according
to dlci constipated value
Signed-off-by: Frederic Berat <fredericx.berat@intel.com>
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7be0670f7b upstream.
Remove the clock configuration from imx_setup_ufcr(). This
isn't needed here and will cause garbage output if done.
To be be sure that we only touch the bits we want (TXTL and RXTL)
we have to mask out all other bits of the UFCR register. Add
one non-existing bit macro for this, too (bit 6, DCEDTE on i.MX6).
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
CC: Shawn Guo <shawn.guo@linaro.org>
CC: Sascha Hauer <s.hauer@pengutronix.de>
CC: Troy Kisky <troy.kisky@boundarydevices.com>
CC: Xinyu Chen <xinyu.chen@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: deleted code in imx_setup_ufcr() refers to
sport->clk not sport->clk_per]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4291086b1f upstream.
The tty atomic_write_lock does not provide an exclusion guarantee for
the tty driver if the termios settings are LECHO & !OPOST. And since
it is unexpected and not allowed to call TTY buffer helpers like
tty_insert_flip_string concurrently, this may lead to crashes when
concurrect writers call pty_write. In that case the following two
writers:
* the ECHOing from a workqueue and
* pty_write from the process
race and can overflow the corresponding TTY buffer like follows.
If we look into tty_insert_flip_string_fixed_flag, there is:
int space = __tty_buffer_request_room(port, goal, flags);
struct tty_buffer *tb = port->buf.tail;
...
memcpy(char_buf_ptr(tb, tb->used), chars, space);
...
tb->used += space;
so the race of the two can result in something like this:
A B
__tty_buffer_request_room
__tty_buffer_request_room
memcpy(buf(tb->used), ...)
tb->used += space;
memcpy(buf(tb->used), ...) ->BOOM
B's memcpy is past the tty_buffer due to the previous A's tb->used
increment.
Since the N_TTY line discipline input processing can output
concurrently with a tty write, obtain the N_TTY ldisc output_lock to
serialize echo output with normal tty writes. This ensures the tty
buffer helper tty_insert_flip_string is not called concurrently and
everything is fine.
Note that this is nicely reproducible by an ordinary user using
forkpty and some setup around that (raw termios + ECHO). And it is
present in kernels at least after commit
d945cb9cce (pty: Rework the pty layer to
use the normal buffering logic) in 2.6.31-rc3.
js: add more info to the commit log
js: switch to bool
js: lock unconditionally
js: lock only the tty->ops->write call
References: CVE-2014-0196
Reported-and-tested-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: output_lock is a member of struct tty_struct]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 501fed45b7 upstream.
When 'console=hvc0' is specified to the kernel parameter in x86 KVM guest,
hvc console is setup within a kthread. However, that will cause SEGV
and the boot will fail when the driver is builtin to the kernel,
because currently hvc_console_setup() is annotated with '__init'. This
patch removes '__init' to boot the guest successfully with 'console=hvc0'.
Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f76a1cbed1 upstream.
Commit 3e6c6f630a ("Delay creation of
khcvd thread") moved the call of hvc_init from being a device_initcall
into hvc_alloc, and used a non-null hvc_driver as indication of whether
hvc_init had already been called.
The problem with this is that hvc_driver is only assigned a value
at the bottom of hvc_init, and so there is a window where multiple
hvc_alloc calls can be in progress at the same time and hence try
and call hvc_init multiple times. Previously the use of device_init
guaranteed that hvc_init was only called once.
This manifests itself as sporadic instances of two hvc_init calls
racing each other, and with the loser of the race getting -EBUSY
from tty_register_driver() and hence that virtual console fails:
Couldn't register hvc console driver
virtio-ports vport0p1: error -16 allocating hvc for port
Here we add an atomic_t to guarantee we'll never run hvc_init twice.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: 3e6c6f630a ("Delay creation of khcvd thread")
Reported-by: Jim Somerville <Jim.Somerville@windriver.com>
Tested-by: Jim Somerville <Jim.Somerville@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3ac06b9056 upstream.
3GPP TS 07.10 states in section 5.4.6.3.7:
"The length byte contains the value 2 or 3 ... depending on the break
signal." The break byte is optional and if it is sent, the length is
3. In fact the driver was not able to work with modems that send this
break byte in their modem status control message. If the modem just
sends the break byte if it is really set, then weird things might
happen.
The code for deconding the modem status to the internal linux
presentation in gsm_process_modem has already a big comment about
this 2 or 3 byte length thing and it is already able to decode the
brk, but the code calling the gsm_process_modem function in
gsm_control_modem does not encode it and hand it over the right way.
This patch fixes this.
Without this fix if the modem sends the brk byte in it's modem status
control message the driver will hang when opening a muxed channel.
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0cc7c6c791 upstream.
Interrupts were being cleaned up late in the shutdown handler, it is possible
that an interrupt can occur and schedule a tasklet that runs after the port is
cleaned up. There is a null dereference due to this race condition with the
following stacktrace:
[<c02092b0>] (atmel_tasklet_func+0x514/0x814) from [<c001fd34>] (tasklet_action+0x70/0xa8)
[<c001fd34>] (tasklet_action+0x70/0xa8) from [<c001f60c>] (__do_softirq+0x90/0x144)
[<c001f60c>] (__do_softirq+0x90/0x144) from [<c001fa18>] (irq_exit+0x40/0x4c)
[<c001fa18>] (irq_exit+0x40/0x4c) from [<c000e298>] (handle_IRQ+0x64/0x84)
[<c000e298>] (handle_IRQ+0x64/0x84) from [<c000d6c0>] (__irq_svc+0x40/0x50)
[<c000d6c0>] (__irq_svc+0x40/0x50) from [<c0208060>] (atmel_rx_dma_release+0x88/0xb8)
[<c0208060>] (atmel_rx_dma_release+0x88/0xb8) from [<c0209740>] (atmel_shutdown+0x104/0x160)
[<c0209740>] (atmel_shutdown+0x104/0x160) from [<c0205e8c>] (uart_port_shutdown+0x2c/0x38)
Signed-off-by: Marek Roszko <mark.roszko@gmail.com>
Acked-by: Leilei Zhao <leilei.zhao@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dc1dc2f8a5 upstream.
When booting a multi-platform m68k kernel on a non-Mac with "console=ttyS0"
on the kernel command line, it crashes with:
Unable to handle kernel NULL pointer dereference at virtual address (null)
Oops: 00000000
PC: [<0013ad28>] __pmz_startup+0x32/0x2a0
...
Call Trace: [<002c5d3e>] pmz_console_setup+0x64/0xe4
The normal tty driver doesn't crash, because init_pmz() checks
pmz_ports_count again after calling pmz_probe().
In the serial console initialization path, pmz_console_init() doesn't do
this, causing the driver to crash later.
Add a check for pmz_ports_count to fix this.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d220980b70 upstream.
This solves a problem observed in kexec'ed kernel where 200ms timeout is
too short and bootconsole fails to initialize. Console did eventually
become workable but much later into the boot process.
Observed timeout was around 260ms, but I decided to make it a little bigger
for more reliability.
This has been tested on Power7 machine with Petitboot as a primary
bootloader and PowerNV firmware.
Signed-off-by: Eugene Surovegin <surovegin@google.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 079a036f42 upstream.
Without this patch the driver waits ~1 ms for the UART to become idle. At
115200n8 this time is (theoretically) enough to transfer 11.5 characters
(= 115200 bits/s / (10 Bits/char) * 1ms). As the mxs-auart has a fifo size
of 16 characters the clock is gated too early. The problem is worse for
lower baud rates.
This only happens to really shut down the transmitter in the middle of a
transfer if /dev/ttyAPPx isn't opened in userspace (e.g. by a getty) but
was at least once (because the bootloader doesn't disable the transmitter).
So increase the timeout to 20 ms which should be enough for 9600n8, too.
Moreover skip gating the clock if the timeout is elapsed.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d970d7fe65 upstream.
The handler needs to ack the pending events before actually handling them.
Otherwise a new event might come in after it it considered non-pending or
handled and is acked then without being handled. So this event is only
noticed when the next interrupt happens.
Without this patch an i.MX28 based machine running an rt-patched kernel
regularly hangs during boot.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 828c6a102b upstream.
This reverts commit 8d2f8cd424.
As reported by Stefan, this device already works with the parport_serial
driver, so the 8250_pci driver should not also try to grab it as well.
Reported-by: Stefan Seyfried <stefan.seyfried@googlemail.com>
Cc: Wang YanQing <udknight@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 384e301e35 upstream.
When we use pch_uart as system console like 'console=ttyPCH0,115200',
then 'send break' to it. We'll encounter the deadlock on a cpu/core,
with interrupts disabled on the core. When we happen to have all irqs
affinity to cpu0 then the deadlock on cpu0 actually deadlock whole
system.
In pch_uart_interrupt, we have spin_lock_irqsave(&priv->lock, flags)
then call pch_uart_err_ir when break is received. Then the call to
dev_err would actually call to pch_console_write then we'll run into
another spin_lock(&priv->lock), with interrupts disabled.
So in the call sequence lead by pch_uart_interrupt, we should be
carefully to call functions that will 'print message to console' only
in case the uart port is not being used as serial console.
Signed-off-by: Liang Li <liang.li@windriver.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
