In 99.99% of the cases only root in a user namespace can mount /dev/pts
and in those cases the owner of /dev/pts/ptmx will remain root.root

In the oddball case where someone else has CAP_SYS_ADMIN this code
modifies the /dev/pts mount code to use current_fsuid and current_fsgid
as the values to use when creating the /dev/ptmx inode.  As is done
when any other file is created.

This is a code simplification, and it allows running without a root
user entirely.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

devpts does not and never will have anything to sync
so don't bother calling sync_filesystems on remount.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that all of the work of setting up a superblock has been moved to
devpts_fill_super simplify devpts_mount by calling mount_nodev instead
of rolling mount_nodev by hand.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The code makes more sense here and things are just clearer.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The patch makes changes not to enable parity error interrupt.
With the current implementation, each parity error results in
two distinct interrupts (almost always). The first one is normal
parity error interrupt with no data in the fifo and the second one
is a proper Rx interrupt with the received data in the fifo. By
disabling parity error interrupt we still ensure handling of
parity errors as for the Rx fifo interrupt the parity error still
shows up in the interrupt status register. Considering the fact
that the by default INPCK and IGNPAR are not set, this is the
optimal implementation for parity error handling.
Signed-off-by: NAnirudha Sarangi <anirudh@xilinx.com>
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
[stelford@cadence.com: cherry picked from
https://github.com/Xilinx/linux-xlnx commit
bf9f610b445e2c9ed33c41e1e0e30b43be4e1f97 with manual conflict
resolution]
Signed-off-by: NScott Telford <stelford@cadence.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds dma mode support for rx and tx
with pio mode as fallback in case of dma error.
Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Keep the clock enabled at the end of stm32_init_port
but disable it in stm32_serial_remove.
Note that stm32_pm function is there to manage the
clock at runtime.
Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

"st,hw-flow-ctrl" property is documented in device tree
binding whereas "auto-flow-control" was used in the code.
The driver is now aligned with the binding name
"st,hw-flow-ctrl".
Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds documentation of device tree bindings for the
STM32 USART
Signed-off-by: NMaxime Coquelin <mcoquelin.stm32@gmail.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Register offset management rework to support both
stm32f4 (default) and stm32f7. Driver rework to
ensure same functional level on both stm32f4 and
stm32f7: no new feature in this version yet.
Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

After issuing the reset, driver is not checking the rx and tx reset
done status. So, modified driver to wait for the reset done status.
Signed-off-by: NNava kishore Manne <navam@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds RXBS register access support for zynqmp.
To avoid the corner error conditions it will consider only
RXBS[2:0] bits while checking the error conditions
(Parity,Framing and BRAK).
Signed-off-by: NNava kishore Manne <navam@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

First loop in wait_for_xmitr could also trigger NMI
watchdog in case reading from the port is slow:

  PID: 0      TASK: ffffffff819c1460  CPU: 0   COMMAND: "swapper/0"
   #0 [ffff88019f405e58] crash_nmi_callback at ffffffff8104d382
   #1 [ffff88019f405e68] nmi_handle at ffffffff8168ead9
   #2 [ffff88019f405eb0] do_nmi at ffffffff8168ec53
   #3 [ffff88019f405ef0] end_repeat_nmi at ffffffff8168df13
      [exception RIP: delay_tsc+50]
      RIP: ffffffff81325642  RSP: ffff88019f403bb0  RFLAGS: 00000083
      RAX: 00000000000005c8  RBX: ffffffff81f83000  RCX: 0000024e4fb88a8b
      RDX: 0000024e4fb89053  RSI: 0000000000000000  RDI: 00000000000007d1
      RBP: ffff88019f403bb0   R8: 000000000000000a   R9: 0000000000000000
      R10: 0000000000000000  R11: ffff88019f403ad6  R12: 000000000000250f
      R13: 0000000000000020  R14: ffffffff81d360c7  R15: 0000000000000047
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
  --- <NMI exception stack> ---
   #4 [ffff88019f403bb0] delay_tsc at ffffffff81325642
   #5 [ffff88019f403bb8] __const_udelay at ffffffff813255a8
   #6 [ffff88019f403bc8] wait_for_xmitr at ffffffff81404390
   #7 [ffff88019f403bf0] serial8250_console_putchar at ffffffff8140455c
   #8 [ffff88019f403c10] uart_console_write at ffffffff813ff00a
   #9 [ffff88019f403c40] serial8250_console_write at ffffffff814044ae
  #10 [ffff88019f403c88] call_console_drivers.constprop.15 at ffffffff81086b01
  #11 [ffff88019f403cb0] console_unlock at ffffffff8108842f
  #12 [ffff88019f403ce8] vprintk_emit at ffffffff81088834
  #13 [ffff88019f403d58] vprintk_default at ffffffff81088ba9
  #14 [ffff88019f403d68] printk at ffffffff8167f034

Adding touch_nmi_watchdog call to the first loop as well.
Reported-by: NChunyu Hu <chuhu@redhat.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Less magic that only requires comments.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 0e125a5f ("tty: amba-pl011: define flag register bits for ZTE
device") changes earlycon function pl011_putc() to use a pointer to
uart_amba_port.  This causes a regression when earlycon is enabled,
because uart_amba_port is not available yet at earlycon time.  Let's
revert the change on pl011_putc() to fix the regression.

The earlycon support for ZTE device can probably be added later by
declaring a new earlycon setup function with a vendor specific
compatible.
Reported-by: NSudeep Holla <sudeep.holla@arm.com>
Fixes: 0e125a5f ("tty: amba-pl011: define flag register bits for ZTE device")
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Tested-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 5d7519df ("serial: mxs-auart: Disable clock on error path")
try to disable clock on error path, but still missing the clk_set_rate()
error handling path.
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For now, these fall back to regular (dark) colors.

It'd be tempting to replace blink with bright backgrounds, as permitted by
CGA/VGA -- we already muck with the other programmable bit (foreground
brightness vs 512 character font).  This would bring vgacon in line with
fbcon, which doesn't support blink anywhere but on some drivers renders
that bit as bright background.  If that is done, this commit should be
amended to be one of ways of setting that bit.
Signed-off-by: NAdam Borowski <kilobyte@angband.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

These codes are supported by all major terminals, thus they occasionally see
some use despite being redundant with \e[38;5;(x+8)m or (less exactly)
\e[1;3(x)m.
Signed-off-by: NAdam Borowski <kilobyte@angband.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some guy went on a patching spree, adding 24-bit colour support all around:
https://gist.github.com/XVilka/8346728Signed-off-by: NAdam Borowski <kilobyte@angband.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

All other uses of vc_npar are inclusive (save for < NPAR) which raises
eyebrows, so let's at least do so consistently.
Signed-off-by: NAdam Borowski <kilobyte@angband.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This makes it show up on UBSAN:
perl -e 'for (0..15) {my @x=("0")x$_;push @x,qw(38 2 64 128 192 4);printf
"\e[%smAfter %d zeroes.\e[0m\n", join(";",@x[0..($_+5<15?$_+5:15)]), $_}'

Seems harmless: if you can programmatically read attributes of a vt
character (/dev/vcsa*), multiple probes can obtain parts of vt_mode then
lowest byte (5th on 64-bit big-endian) of a pointer.
Signed-off-by: NAdam Borowski <kilobyte@angband.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The ptmx_fops structure is only changed during init, so mark it as such.
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 761ed4a9 ("tty: serial_core: convert uart_close to use
tty_port_close") created a case where a port used for a console does not
get shutdown on tty closing. Then a call to uart_tx_stopped() segfaults
because the tty is NULL. This could be fixed to restore old behavior,
but we also want to allow tty_ports to work without a tty attached. So
this change to allow a NULL tty_struct is needed either way.

Fixes: 761ed4a9 ("tty: serial_core: convert uart_close to use tty_port_close")
Reported-by: Nkernel test robot <xiaolong.ye@intel.com>
Signed-off-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

dmaengine_terminate_all() is deprecated and should be replaced by
dmaengine_terminate_sync() in non-atomic context or dmaengine_terminate_async()
with dmaengine_synchronize().

See commit b36f09c3 ("dmaengine: Add transfer termination synchronization support")
Signed-off-by: NFabien Lahoudere <fabien.lahoudere@collabora.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The commit 761ed4a9 ("tty: serial_core: convert uart_close to use
tty_port_close") refactored uart_close() to use tty_port_close().  At the same
time it introduced a potential NULL pointer dereference. Rearrange the code to
avoid kernel crash.

Fixes: 761ed4a9 ("tty: serial_core: convert uart_close to use tty_port_close")
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commit 18dfef9c ("serial: atmel: convert to irq handling
provided mctrl-gpio"), interrupts from GPIOs are not disabled any more
when the serial port is closed, leading to an oops when the one of the
input pin is toggled (CTS/DSR/DCD/RNG).

This is only the case if those pins are used as GPIOs, i.e. declared
like that:
usart1: serial@f8020000 {
        /* CTS and DTS will be handled by GPIO */
        status = "okay";
        rts-gpios = <&pioB 17 GPIO_ACTIVE_LOW>;
        cts-gpios = <&pioB 16 GPIO_ACTIVE_LOW>;
        dtr-gpios = <&pioB 14 GPIO_ACTIVE_LOW>;
        dsr-gpios = <&pioC 31 GPIO_ACTIVE_LOW>;
        rng-gpios = <&pioB 12 GPIO_ACTIVE_LOW>;
        dcd-gpios = <&pioB 15 GPIO_ACTIVE_LOW>;
};

That's because modem interrupts used to be freed in atmel_shutdown().
After commit 18dfef9c ("serial: atmel: convert to irq handling
provided mctrl-gpio"), this code was just removed.
Calling atmel_disable_ms() disables the interrupts and everything works
fine again.

Tested on at91sam9g35-cm

(This patch doesn't apply on -stable kernels, fixes for 4.4 and 4.7 will
be sent after this one is applied.)
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Fixes: 18dfef9c ("serial: atmel: convert to irq handling provided mctrl-gpio")
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The function lpuart_start_rx_dma() is called from several
places, in some of which, such as lpuart_startup(), a lock
be held here, so we should use GFP_ATOMIC when a lock is held.

Fixes: 5887ad43 ("tty: serial: fsl_lpuart: Use cyclic DMA for Rx")
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When dev.of_node is not NULL, we also need to set IRQF_TRIGGER_FALLING
flag, otherwise it may cause uncertain interrupts.
Signed-off-by: NLiu Xiang <liu.xiang6@zte.com.cn>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR.

Generated by: scripts/coccinelle/api/ptr_ret.cocci
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should disable the previously acquired clock when enabling s->clk
fails.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Guenter Roeck reported a regression caused by commit "serial: earlycon:
Extend earlycon command line option to support 64-bit addresses":

console= and earlycon= options have the following format:
...,<addr>,<options>

Historically used here simple_strtoul() had no problems with comma, but the
new and recommended kstrtoull() requires null-terminated string and returns
-EINVAL in case there are "options" at the end. There is no recommended to
use function currently that will support it, so stick to obsolete
simple_strtoull() variant.
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some functions called by serial_imx_probe emit an error message themself
(like kmalloc() and friends). clk_prepare_enable() and
devm_request_irq() however don't which might make the driver silently
fail to probe. So add an error message for these.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We want the fixes in here for merge issues.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>