linux-toradex.git/drivers/tty, branch v4.9.60

sparc64: Migrate hvcons irq to panicked cpu

2017-10-21T15:21:35+00:00

[ Upstream commit 7dd4fcf5b70694dc961eb6b954673e4fc9730dbd ]

On panic, all other CPUs are stopped except the one which had
hit panic. To keep console alive, we need to migrate hvcons irq
to panicked CPU.

Signed-off-by: Vijay Kumar 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

serial: 8250_port: Remove dangerous pr_debug()

2017-10-08T08:26:05+00:00

[ Upstream commit 699a11ba7ec869b006623182881f2f1f5b4aea53 ]

With CONFIG_DYNAMIC_DEBUG if dyndbg enables debug output in
8250_port.c deadlock happens inevitably on UART IRQ handling.

That's the problematic execution path:
---------------------------->8------------------------
UART IRQ:
  serial8250_interrupt() ->
    serial8250_handle_irq(): lock "port->lock" ->
      pr_debug() ->
        serial8250_console_write(): bump in locked "port->lock".

      OR (if above pr_debug() gets removed):
      serial8250_tx_chars() ->
        pr_debug() ->
          serial8250_console_write(): bump in locked "port->lock".
---------------------------->8------------------------

So let's get rid of those not that much useful debug entries.

Discussed problem could be easily reproduced with QEMU for x86_64.
As well as this fix could be mimicked with muting of dynamic debug for
the problematic lines as simple as:
---------------------------->8------------------------
dyndbg="+p; file 8250_port.c line 1756 -p; file 8250_port.c line 1822 -p"
---------------------------->8------------------------

Signed-off-by: Alexey Brodkin 
Cc: Jiri Slaby 
Cc: Peter Hurley 
Cc: Phillip Raffeck 
Cc: Anton Wuerfel 
Cc: "Matwey V. Kornilov" 
Cc: Yegor Yefremov 
Cc: Thor Thayer 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

tty: goldfish: Fix a parameter of a call to free_irq

2017-10-08T08:26:05+00:00

[ Upstream commit 1a5c2d1de7d35f5eb9793266237903348989502b ]

'request_irq()' and 'free_irq()' should be called with the same dev_id.

Signed-off-by: Christophe JAILLET 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

serial: 8250: moxa: Store num_ports in brd

2017-10-08T08:26:05+00:00

[ Upstream commit 9c4b60fe5313c125b1bf68ef04b0010512c27f2d ]

When struct moxa8250_board is allocated, then num_ports should
be initialized in order to use it later in moxa8250_remove.

Signed-off-by: Matwey V. Kornilov 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

tty: fix __tty_insert_flip_char regression

2017-09-27T12:39:19+00:00

commit 8a5a90a2a477b86a3dc2eaa5a706db9bfdd647ca upstream.

Sergey noticed a small but fatal mistake in __tty_insert_flip_char,
leading to an oops in an interrupt handler when using any serial
port.

The problem is that I accidentally took the tty_buffer pointer
before calling __tty_buffer_request_room(), which replaces the
buffer. This moves the pointer lookup to the right place after
allocating the new buffer space.

Fixes: 979990c62848 ("tty: improve tty_insert_flip_char() fast path")
Reported-by: Sergey Senozhatsky 
Tested-by: Sergey Senozhatsky 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

tty: improve tty_insert_flip_char() slow path

2017-09-27T12:39:19+00:00

commit 065ea0a7afd64d6cf3464bdd1d8cd227527e2045 upstream.

While working on improving the fast path of tty_insert_flip_char(),
I noticed that by calling tty_buffer_request_room(), we needlessly
move to the separate flag buffer mode for the tty, even when all
characters use TTY_NORMAL as the flag.

This changes the code to call __tty_buffer_request_room() with the
correct flag, which will then allocate a regular buffer when it rounds
out of space but no special flags have been used. I'm guessing that
this is the behavior that Peter Hurley intended when he introduced
the compacted flip buffers.

Fixes: acc0f67f307f ("tty: Halve flip buffer GFP_ATOMIC memory consumption")
Cc: Peter Hurley 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

tty: improve tty_insert_flip_char() fast path

2017-09-27T12:39:19+00:00

commit 979990c6284814617d8f2179d197f72ff62b5d85 upstream.

kernelci.org reports a crazy stack usage for the VT code when CONFIG_KASAN
is enabled:

drivers/tty/vt/keyboard.c: In function 'kbd_keycode':
drivers/tty/vt/keyboard.c:1452:1: error: the frame size of 2240 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]

The problem is that tty_insert_flip_char() gets inlined many times into
kbd_keycode(), and also into other functions, and each copy requires 128
bytes for stack redzone to check for a possible out-of-bounds access on
the 'ch' and 'flags' arguments that are passed into
tty_insert_flip_string_flags as a variable-length string.

This introduces a new __tty_insert_flip_char() function for the slow
path, which receives the two arguments by value. This completely avoids
the problem and the stack usage goes back down to around 100 bytes.

Without KASAN, this is also slightly better, as we don't have to
spill the arguments to the stack but can simply pass 'ch' and 'flag'
in registers, saving a few bytes in .text for each call site.

This should be backported to linux-4.0 or later, which first introduced
the stack sanitizer in the kernel.

Fixes: c420f167db8c ("kasan: enable stack instrumentation")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

vt: fix unchecked __put_user() in tioclinux ioctls

2017-07-21T05:42:22+00:00

commit 6987dc8a70976561d22450b5858fc9767788cc1c upstream.

Only read access is checked before this call.

Actually, at the moment this is not an issue, as every in-tree arch does
the same manual checks for VERIFY_READ vs VERIFY_WRITE, relying on the MMU
to tell them apart, but this wasn't the case in the past and may happen
again on some odd arch in the future.

If anyone cares about 3.7 and earlier, this is a security hole (untested)
on real 80386 CPUs.

Signed-off-by: Adam Borowski 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix late enablement of AUTORTS

2017-06-24T05:11:14+00:00

commit 5f76895e4c712b1b5af450cf344389b8c53ac2c2 upstream.

When changing hardware control flow for a UART with dedicated RTS/CTS
pins, the new AUTORTS state is not immediately reflected in the
hardware, but only when RTS is raised.  However, the serial core does
not call .set_mctrl() after .set_termios(), hence AUTORTS may only
become effective when the port is closed, and reopened later.
Note that this problem does not happen when manually using stty to
change CRTSCTS, as AUTORTS will work fine on next open.

To fix this, call .set_mctrl() from .set_termios() when dedicated
RTS/CTS pins are present, to refresh the AUTORTS or RTS state.
This is similar to what other drivers supporting AUTORTS do (e.g.
omap-serial).

Reported-by: Baumann, Christoph (C.) 
Fixes: 33f50ffc253854cf ("serial: sh-sci: Fix support for hardware-assisted RTS/CTS")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Greg Kroah-Hartman

serial: efm32: Fix parity management in 'efm32_uart_console_get_options()'

2017-06-24T05:11:14+00:00

commit be40597a1bc173bf9dadccdf5388b956f620ae8f upstream.

UARTn_FRAME_PARITY_ODD is 0x0300
UARTn_FRAME_PARITY_EVEN is 0x0200
So if the UART is configured for EVEN parity, it would be reported as ODD.
Fix it by correctly testing if the 2 bits are set.

Fixes: 3afbd89c9639 ("serial/efm32: add new driver")
Signed-off-by: Christophe JAILLET 
Acked-by: Uwe Kleine-König 
Signed-off-by: Greg Kroah-Hartman