linux-toradex.git/drivers/tty, branch v3.19.2

serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is something in the FIFO"

2015-03-18T13:11:04+00:00

commit ca8bb4aefb932e3da105f28cbfba36d57a931081 upstream.

This reverts commit 0aa525d11859c1a4d5b78fdc704148e2ae03ae13.

The conditional RX-FIFO read seems to cause spurious interrupts and we
see just:
|serial8250: too much work for irq29

The previous behaviour was "default" for decades and Marvell's 88f6282 SoC
might not be the only that relies on it. Therefore the Omap fix is
reverted for now.

Fixes: 0aa525d11859 ("tty: serial: 8250_core: read only RX if there is
something in the FIFO")
Reported-By: Nicolas Schichan 
Debuged-By: Peter Hurley 
Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Greg Kroah-Hartman

tty: fix up atime/mtime mess, take four

2015-03-18T13:11:04+00:00

commit f0bf0bd07943bfde8f5ac39a32664810a379c7d3 upstream.

This problem was taken care of three times already in
* b0de59b5733d18b0d1974a060860a8b5c1b36a2e (TTY: do not update
  atime/mtime on read/write),
* 37b7f3c76595e23257f61bd80b223de8658617ee (TTY: fix atime/mtime
  regression), and
* b0b885657b6c8ef63a46bc9299b2a7715d19acde (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 
Reported-by: John Paul Perry 
Acked-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

TTY: fix tty_wait_until_sent on 64-bit machines

2015-03-18T13:11:02+00:00

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: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: ZIV-Asier Llano Palacios 
Signed-off-by: Johan Hovold 
Reviewed-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

serial: fsl_lpuart: avoid new transfer while DMA is running

2015-03-06T22:57:37+00:00

commit 5f1437f61a0b351d25b528c159360da3d5e8c77b upstream.

When the UART is in DMA receive mode (RDMAS set) and one character
just arrived while another interrupt is handled (e.g. TX), the RDRF
(receiver data register full flag) is set due to the water level of
1. But since the DMA will take care of this character, there is no
need to handle it by calling lpuart_prepare_rx. Handling it leads to
adding the RX timeout timer twice:

[   74.336698] Kernel BUG at 80053070 [verbose debug info unavailable]
[   74.342999] Internal error: Oops - BUG: 0 [#1] ARM0:00.00 khungtaskd
[   74.347817] Modules linked in:    0 S  0.0  0.0   0:00.00 writeback
[   74.350926] CPU: 0 PID: 0 Comm: swapper Not tainted 3.19.0-rc3-00001-g39d78e2 #1788
[   74.358617] Hardware name: Freescale Vybrid VF610 (Device Tree)t
[   74.364563] task: 807a7678 ti: 8079c000 task.ti: 8079c000 kblockd
[   74.370002] PC is at add_timer+0x24/0x28.0  0.0   0:00.09 kworker/u2:1
[   74.373960] LR is at lpuart_int+0x15c/0x3d8
[   74.378171] pc : [<80053070>]    lr : [<802e0d88>]    psr: a0010193
[   74.378171] sp : 8079de10  ip : 8079de20  fp : 8079de1c
[   74.389694] r10: 807d44c0  r9 : 8688c300  r8 : 00000013
[   74.394943] r7 : 20010193  r6 : 00000000  r5 : 000000a0  r4 : 86997210
[   74.401498] r3 : ffffa7da  r2 : 80817868  r1 : 86997210  r0 : 86997344
[   74.408052] Flags: NzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
[   74.415489] Control: 10c5387d  Table: 8611c059  DAC: 00000015
[   74.421265] Process swapper (pid: 0, stack limit = 0x8079c230)
...

Solve this by only execute the receiver path (lpuart_prepare_rx) if
the DMA receive mode (RDMAS) is not set. Also, make sure the flag is
cleared on initialization, in case it has been left set.

This can be best reproduced using UART as a serial console, then
running top while dd'ing data into the terminal.

Signed-off-by: Stefan Agner 
Signed-off-by: Greg Kroah-Hartman

serial: fsl_lpuart: delete timer on shutdown

2015-03-06T22:57:36+00:00

commit 4a8588a1cf867333187d9ff071e6fbdab587d194 upstream.

If the serial port gets closed while a RX transfer is in progress,
the timer might fire after the serial port shutdown finished. This
leads in a NULL pointer dereference:

[    7.508324] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[    7.516590] pgd = 86348000
[    7.519445] [00000000] *pgd=86179831, *pte=00000000, *ppte=00000000
[    7.526145] Internal error: Oops: 17 [#1] ARM
[    7.530611] Modules linked in:
[    7.533876] CPU: 0 PID: 123 Comm: systemd Not tainted 3.19.0-rc3-00004-g5b11ea7 #1778
[    7.541827] Hardware name: Freescale Vybrid VF610 (Device Tree)
[    7.547862] task: 861c3400 ti: 86ac8000 task.ti: 86ac8000
[    7.553392] PC is at lpuart_timer_func+0x24/0xf8
[    7.558127] LR is at lpuart_timer_func+0x20/0xf8
[    7.562857] pc : [<802df99c>]    lr : [<802df998>]    psr: 600b0113
[    7.562857] sp : 86ac9b90  ip : 86ac9b90  fp : 86ac9bbc
[    7.574467] r10: 80817180  r9 : 80817b98  r8 : 80817998
[    7.579803] r7 : 807acee0  r6 : 86989000  r5 : 00000100  r4 : 86997210
[    7.586444] r3 : 86ac8000  r2 : 86ac9bc0  r1 : 86997210  r0 : 00000000
[    7.593085] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[    7.600341] Control: 10c5387d  Table: 86348059  DAC: 00000015
[    7.606203] Process systemd (pid: 123, stack limit = 0x86ac8230)

Setup the timer on UART startup which allows to delete the timer
unconditionally on shutdown. This also saves the initialization
on each transfer.

Signed-off-by: Stefan Agner 
Signed-off-by: Greg Kroah-Hartman

vt: provide notifications on selection changes

2015-03-06T22:57:35+00:00

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 
Cc: Dave Mielke 
Signed-off-by: Greg Kroah-Hartman

tty/serial: at91: fix error handling in atmel_serial_probe()

2015-03-06T22:57:33+00:00

commit 6fbb9bdf0f3fbe23aeff806489791aa876adaffb upstream.

-EDEFER error wasn't handle properly by atmel_serial_probe().
As an example, when atmel_serial_probe() is called for the first time, we pass
the test_and_set_bit() test to check whether the port has already been
initalized. Then we call atmel_init_port(), which may return -EDEFER, possibly
returned before by clk_get(). Consequently atmel_serial_probe() used to return
this error code WITHOUT clearing the port bit in the "atmel_ports_in_use" mask.
When atmel_serial_probe() was called for the second time, it used to fail on
the test_and_set_bit() function then returning -EBUSY.

When atmel_serial_probe() fails, this patch make it clear the port bit in the
"atmel_ports_in_use" mask, if needed, before returning the error code.

Signed-off-by: Cyrille Pitchen 
Acked-by: Nicolas Ferre 
Signed-off-by: Greg Kroah-Hartman

tty/serial: at91: enable peripheral clock before accessing I/O registers

2015-03-06T22:57:33+00:00

commit d4f641876a68d1961e30c202709cc2d484f69f6f upstream.

atmel_serial_probe() calls atmel_init_port(). In turn, atmel_init_port() calls
clk_disable_unprepare() to disable the peripheral clock before returning.

Later atmel_serial_probe() accesses some I/O registers such as the Mode and
Control registers for RS485 support then the Name and Version registers, through a call to
atmel_get_ip_name(), but at that moment the peripheral clock was still
disabled.

Signed-off-by: Cyrille Pitchen 
Acked-by: Nicolas Ferre 
Signed-off-by: Greg Kroah-Hartman

tty/serial: at91: use correct type for dma_sync__for_cpu() and dma_sync__for_device()

2015-03-06T22:57:32+00:00

commit 485819b5b9ed82372dacae775998f3c33717f7fe upstream.

dma_sync_*_for_cpu() and dma_sync_*_for_device() use 'enum dma_data_direction',
not 'enum dma_transfer_direction'

Signed-off-by: Cyrille Pitchen 
Acked-by: Nicolas Ferre 
Signed-off-by: Greg Kroah-Hartman

tty: Prevent untrappable signals from malicious program

2015-03-06T22:57:32+00:00

commit 37480a05685ed5b8e1b9bf5e5c53b5810258b149 upstream.

Commit 26df6d13406d1a5 ("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 
Cc: Howard Chu 
Cc: One Thousand Gnomes 
Cc: Jiri Slaby 
Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

linux-toradex.git/drivers/tty, branch v3.19.2

serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is something in the FIFO"

tty: fix up atime/mtime mess, take four

TTY: fix tty_wait_until_sent on 64-bit machines

serial: fsl_lpuart: avoid new transfer while DMA is running

serial: fsl_lpuart: delete timer on shutdown

vt: provide notifications on selection changes

tty/serial: at91: fix error handling in atmel_serial_probe()

tty/serial: at91: enable peripheral clock before accessing I/O registers

tty/serial: at91: use correct type for dma_sync_*_for_cpu() and dma_sync_*_for_device()

tty: Prevent untrappable signals from malicious program

tty/serial: at91: use correct type for dma_sync__for_cpu() and dma_sync__for_device()