linux-stable.git/drivers/tty, branch linux-3.18.y

serial: uartps: console_setup() can't be placed to init section

2019-04-27T07:30:28+00:00

[ Upstream commit 4bb1ce2350a598502b23088b169e16b43d4bc639 ]

When console device is rebinded, console_setup() is called again.
But marking it as __init means that function will be clear after boot is
complete. If console device is binded again console_setup() is not found
and error "Unable to handle kernel paging request at virtual address"
is reported.

Signed-off-by: Michal Simek 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

tty: ldisc: add sysctl to prevent autoloading of ldiscs

2019-04-27T07:30:25+00:00

commit 7c0cca7c847e6e019d67b7d793efbbe3b947d004 upstream.

By default, the kernel will automatically load the module of any line
dicipline that is asked for.  As this sometimes isn't the safest thing
to do, provide a sysctl to disable this feature.

By default, we set this to 'y' as that is the historical way that Linux
has worked, and we do not want to break working systems.  But in the
future, perhaps this can default to 'n' to prevent this functionality.

Signed-off-by: Greg Kroah-Hartman 
Reviewed-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

tty: increase the default flip buffer limit to 2*640K

2019-04-27T07:30:24+00:00

[ Upstream commit 7ab57b76ebf632bf2231ccabe26bea33868118c6 ]

We increase the default limit for buffer memory allocation by a factor of
10 to 640K to prevent data loss when using fast serial interfaces.

For example when using RS485 without flow-control at speeds of 1Mbit/s
an upwards we've run into problems such as applications being too slow
to read out this buffer (on embedded devices based on imx53 or imx6).

If you want to write transmitted data to a slow SD card and thus have
realtime requirements, this limit can become a problem.

That shouldn't be the case and 640K buffers fix such problems for us.

This value is a maximum limit for allocation only. It has no effect
on systems that currently run fine. When transmission is slow enough
applications and hardware can keep up and increasing this limit
doesn't change anything.

It only _allows_ to allocate more than 2*64K in cases we currently fail to
allocate memory despite having some.

Signed-off-by: Manfred Schlaegl 
Signed-off-by: Martin Kepplinger 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

Disable kgdboc failed by echo space to /sys/module/kgdboc/parameters/kgdboc

2019-04-03T04:22:14+00:00

commit 3ec8002951ea173e24b466df1ea98c56b7920e63 upstream.

Echo "" to /sys/module/kgdboc/parameters/kgdboc will fail with "No such
device” error.

This is caused by function "configure_kgdboc" who init err to ENODEV
when the config is empty (legal input) the code go out with ENODEV
returned.

Fixes: 2dd453168643 ("kgdboc: Fix restrict error")
Signed-off-by: Wentao Wang 
Cc: stable 
Acked-by: Daniel Thompson 
Signed-off-by: Greg Kroah-Hartman

serial: max310x: Fix to avoid potential NULL pointer dereference

2019-04-03T04:22:14+00:00

commit 3a10e3dd52e80b9a97a3346020024d17b2c272d6 upstream.

of_match_device can return a NULL pointer when matching device is not
found. This patch avoids a scenario causing NULL pointer derefernce.

Signed-off-by: Aditya Pakki 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

serial: fsl_lpuart: fix maximum acceptable baud rate with over-sampling

2019-03-23T07:18:53+00:00

[ Upstream commit 815d835b7ba46685c316b000013367dacb2b461b ]

Using over-sampling ratio, lpuart can accept baud rate upto uartclk / 4.

Signed-off-by: Tomonori Sakita 
Signed-off-by: Atsushi Nemoto 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: fsl_lpuart: clear parity enable bit when disable parity

2019-02-20T09:08:56+00:00

[ Upstream commit 397bd9211fe014b347ca8f95a8f4e1017bac1aeb ]

Current driver only enable parity enable bit and never clear it
when user set the termios. The fix clear the parity enable bit when
PARENB flag is not set in termios->c_cflag.

Cc: Lukas Wunner 
Signed-off-by: Andy Duan 
Reviewed-by: Fabio Estevam 
Acked-by: Uwe Kleine-König 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

vt: invoke notifier on screen size change

2019-02-06T16:34:52+00:00

commit 0c9b1965faddad7534b6974b5b36c4ad37998f8e upstream.

User space using poll() on /dev/vcs devices are not awaken when a
screen size change occurs. Let's fix that.

Signed-off-by: Nicolas Pitre 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

tty/n_hdlc: fix __might_sleep warning

2019-02-06T16:34:51+00:00

commit fc01d8c61ce02c034e67378cd3e645734bc18c8c upstream.

Fix __might_sleep warning[1] in tty/n_hdlc.c read due to copy_to_user
call while current is TASK_INTERRUPTIBLE.  This is a false positive
since the code path does not depend on current state remaining
TASK_INTERRUPTIBLE.  The loop breaks out and sets TASK_RUNNING after
calling copy_to_user.

This patch supresses the warning by setting TASK_RUNNING before calling
copy_to_user.

[1] https://syzkaller.appspot.com/bug?id=17d5de7f1fcab794cb8c40032f893f52de899324

Signed-off-by: Paul Fulghum 
Reported-by: syzbot 
Cc: Tetsuo Handa 
Cc: Alan Cox 
Cc: stable 
Acked-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

tty: Handle problem if line discipline does not have receive_buf

2019-02-06T16:34:51+00:00

commit 27cfb3a53be46a54ec5e0bd04e51995b74c90343 upstream.

Some tty line disciplines do not have a receive buf callback, so
properly check for that before calling it.  If they do not have this
callback, just eat the character quietly, as we can't fail this call.

Reported-by: Jann Horn 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman