We have seen NULL-pointer dereference crashes in tty->disc_data when the
N_TTY fallback driver failed to open during hangup.  The immediate cause
of this open to fail has been addressed in the preceding patch to
vmalloc(), but this code could be more robust.

As Alan pointed out in commit 8a8dabf2dd68 ("tty: handle the case where
we cannot restore a line discipline"), the N_TTY driver, historically
the safe fallback that could never fail, can indeed fail, but the
surrounding code is not prepared to handle this.  To avoid crashes he
added a new N_NULL driver to take N_TTY's place as the last resort.

Hook that fallback up to the hangup path.  Update tty_ldisc_reinit() to
reflect the reality that n_tty_open can indeed fail.

Link: http://lkml.kernel.org/r/20171004185959.GC2136@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alan Cox <alan@llwyncelyn.cymru>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sccnxp_probe() returns result of regulator_disable() that may lead
to returning zero, while device is not properly initialized.
Also the driver enables clocks, but it does not disable it.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The current driver register irq in .startup() and free the irq in
.shutdown(), then user will see the NULL interrupt output from
'cat /proc/interrupts' after the uart port test completed:
...
 41:        515          0          0          0     GICv3 257 Level     fsl-lpuart
 42:          2          0          0          0     GICv3 258 Level
...

It is better to register all the irqs during probe function via devm_request_irq()
to avoid to call free_irq().

Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Issue where unprintable characters can occur or output is cut off over
the serial uart / linux console depending on timing.

Problem occurs when changing the serial baud rate when setting up the
new console.The bcm63xx driver does a disable and flush of the uart tx
fifo while there is data still in the tx fifo.

If the tx fifo still has data it is trying to send out, we need to wait
until it is empty before disabling and flushing the uart.

When we now go to change the uart parameters including speed we check
if there is data currently in the tx fifo.If there is was mdelay(10)
and check again.If it tries 3 times and still has data in it we just
continue and sacrifice the tx fifo buffer.

A cleaner and more preferred approach would be to remove :
- spin_lock_irqsave()
- bcm_uart_disable()
- bcm_uart_flush()

However it is not clear if the author put those in to fix another
underlying issue.As a result this solution is a safer approach.

Output before the fix:
[0.306000] 14e00520.serial: ttyS0 at MMIO 0x14e00520 (irq = 9, base_baud = 1687500) is a° 0.315000] console[ttyS0] enabled

Output verified after the fix:
[0.315000] 14e00520.serial: ttyS0 at MMIO 0x14e00520 (irq = 9, base_baud = 1687500) is a bcm63xx_uart [0.334000] console[ttyS0] enabled

Signed-off-by: Russell Enderby <rte@gdn.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Paul reported, that low rates like B300 make the driver to hang in
mxser_wait_until_sent. His debugging tackled the issue down to the
info->timeout computation in mxser_set_baud. Obviously, ints are used
there and they easily overflow with these low rates: B300 makes
info->timeout to be -373.

So switch all these types to unsigned as it ought to be. And use the u64
domain to perform the computation as in the worst case, we need 35 bits
to store the computed value (before division).

And use do_div not to break 32 bit kernels.

[v2] make it actually build

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Paul <Paul@abelian.netcom.co.uk>
Tested-by: <Paul@abelian.netcom.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

... and __initconst if applicable.

Based on similar work for an older kernel in the Grsecurity patch.

[JD: fix toshiba-wmi build]
[JD: add htcpen]
[JD: move __initconst where checkscript wants it]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jean Delvare <jdelvare@suse.de>

Pull sparc updates from David Miller:

 1) Use register window state adjustment instructions when available,
    from Anthony Yznaga.

 2) Add VCC console concentrator driver, from Jag Raman.

 3) Add 16GB hugepage support, from Nitin Gupta.

 4) Support cpu 'poke' hypercall, from Vijay Kumar.

 5) Add M7/M8 optimized memcpy/memset/copy_{to,from}_user, from Babu
    Moger.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next: (33 commits)
  sparc64: Handle additional cases of no fault loads
  sparc64: speed up etrap/rtrap on NG2 and later processors
  sparc64: vcc: make ktermios const
  sparc: leon: grpci1: constify of_device_id
  sparc: leon: grpci2: constify of_device_id
  sparc64: vcc: Check for IS_ERR() instead of NULL
  sparc64: Cleanup hugepage table walk functions
  sparc64: Add 16GB hugepage support
  sparc64: Support huge PUD case in get_user_pages
  sparc64: vcc: Add install & cleanup TTY operations
  sparc64: vcc: Add break_ctl TTY operation
  sparc64: vcc: Add chars_in_buffer TTY operation
  sparc64: vcc: Add write & write_room TTY operations
  sparc64: vcc: Add hangup TTY operation
  sparc64: vcc: Add open & close TTY operations
  sparc64: vcc: Enable LDC event processing engine
  sparc64: vcc: Add RX & TX timer for delayed LDC operation
  sparc64: vcc: Create sysfs attribute group
  sparc64: vcc: Enable VCC port probe and removal
  sparc64: vcc: TTY driver initialization and cleanup
  ...

Pull powerpc updates from Michael Ellerman:
 "Nothing really major this release, despite quite a lot of activity.
  Just lots of things all over the place.

  Some things of note include:

   - Access via perf to a new type of PMU (IMC) on Power9, which can
     count both core events as well as nest unit events (Memory
     controller etc).

   - Optimisations to the radix MMU TLB flushing, mostly to avoid
     unnecessary Page Walk Cache (PWC) flushes when the structure of the
     tree is not changing.

   - Reworks/cleanups of do_page_fault() to modernise it and bring it
     closer to other architectures where possible.

   - Rework of our page table walking so that THP updates only need to
     send IPIs to CPUs where the affected mm has run, rather than all
     CPUs.

   - The size of our vmalloc area is increased to 56T on 64-bit hash MMU
     systems. This avoids problems with the percpu allocator on systems
     with very sparse NUMA layouts.

   - STRICT_KERNEL_RWX support on PPC32.

   - A new sched domain topology for Power9, to capture the fact that
     pairs of cores may share an L2 cache.

   - Power9 support for VAS, which is a new mechanism for accessing
     coprocessors, and initial support for using it with the NX
     compression accelerator.

   - Major work on the instruction emulation support, adding support for
     many new instructions, and reworking it so it can be used to
     implement the emulation needed to fixup alignment faults.

   - Support for guests under PowerVM to use the Power9 XIVE interrupt
     controller.

  And probably that many things again that are almost as interesting,
  but I had to keep the list short. Plus the usual fixes and cleanups as
  always.

  Thanks to: Alexey Kardashevskiy, Alistair Popple, Andreas Schwab,
  Aneesh Kumar K.V, Anju T Sudhakar, Arvind Yadav, Balbir Singh,
  Benjamin Herrenschmidt, Bhumika Goyal, Breno Leitao, Bryant G. Ly,
  Christophe Leroy, Cédric Le Goater, Dan Carpenter, Dou Liyang,
  Frederic Barrat, Gautham R. Shenoy, Geliang Tang, Geoff Levand, Hannes
  Reinecke, Haren Myneni, Ivan Mikhaylov, John Allen, Julia Lawall,
  LABBE Corentin, Laurentiu Tudor, Madhavan Srinivasan, Markus Elfring,
  Masahiro Yamada, Matt Brown, Michael Neuling, Murilo Opsfelder Araujo,
  Nathan Fontenot, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran,
  Paul Mackerras, Rashmica Gupta, Rob Herring, Rui Teng, Sam Bobroff,
  Santosh Sivaraj, Scott Wood, Shilpasri G Bhat, Sukadev Bhattiprolu,
  Suraj Jitindar Singh, Tobin C. Harding, Victor Aoqui"

* tag 'powerpc-4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (321 commits)
  powerpc/xive: Fix section __init warning
  powerpc: Fix kernel crash in emulation of vector loads and stores
  powerpc/xive: improve debugging macros
  powerpc/xive: add XIVE Exploitation Mode to CAS
  powerpc/xive: introduce H_INT_ESB hcall
  powerpc/xive: add the HW IRQ number under xive_irq_data
  powerpc/xive: introduce xive_esb_write()
  powerpc/xive: rename xive_poke_esb() in xive_esb_read()
  powerpc/xive: guest exploitation of the XIVE interrupt controller
  powerpc/xive: introduce a common routine xive_queue_page_alloc()
  powerpc/sstep: Avoid used uninitialized error
  axonram: Return directly after a failed kzalloc() in axon_ram_probe()
  axonram: Improve a size determination in axon_ram_probe()
  axonram: Delete an error message for a failed memory allocation in axon_ram_probe()
  powerpc/powernv/npu: Move tlb flush before launching ATSD
  powerpc/macintosh: constify wf_sensor_ops structures
  powerpc/iommu: Use permission-specific DEVICE_ATTR variants
  powerpc/eeh: Delete an error out of memory message at init time
  powerpc/mm: Use seq_putc() in two functions
  macintosh: Convert to using %pOF instead of full_name
  ...

Pull staging/IIO driver updates from Greg KH:
 "Here is the big staging and IIO driver update for 4.14-rc1.

  Lots of staging driver fixes and cleanups, including some reorginizing
  of the lustre header files to try to impose some sanity on what is,
  and what is not, the uapi for that filesystem.

  There are some tty core changes in here as well, as the speakup
  drivers need them, and that's ok with me, they are sane and the
  speakup code is getting nicer because of it.

  There is also the addition of the obiligatory new wifi driver, just
  because it has been a release or two since we added our last one...

  Other than that, lots and lots of small coding style fixes, as usual.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (612 commits)
  staging:rtl8188eu:core Fix remove unneccessary else block
  staging: typec: fusb302: make structure fusb302_psy_desc static
  staging: unisys: visorbus: make two functions static
  staging: fsl-dpaa2/eth: fix off-by-one FD ctrl bitmaks
  staging: r8822be: Simplify deinit_priv()
  staging: r8822be: Remove some dead code
  staging: vboxvideo: Use CONFIG_DRM_KMS_FB_HELPER to check for fbdefio availability
  staging:rtl8188eu Fix comparison to NULL
  staging: rts5208: rename mmc_ddr_tunning_rx_cmd to mmc_ddr_tuning_rx_cmd
  Staging: Pi433: style fix - tabs and spaces
  staging: pi433: fix spelling mistake: "preample" -> "preamble"
  staging:rtl8188eu:core Fix Code Indent
  staging: typec: fusb302: Export current-limit through a power_supply class dev
  staging: typec: fusb302: Add support for USB2 charger detection through extcon
  staging: typec: fusb302: Use client->irq as irq if set
  staging: typec: fusb302: Get max snk mv/ma/mw from device-properties
  staging: typec: fusb302: Set max supply voltage to 5V
  staging: typec: tcpm: Add get_current_limit tcpc_dev callback
  staging:rtl8188eu Use __func__ instead of function name
  staging: lustre: coding style fixes found by checkpatch.pl
  ...

Pull tty/serial updates from Greg KH:
 "Here is the big tty/serial driver update for 4.14-rc1.

  Well, not all that big, just a number of small serial driver fixes,
  and a new serial driver. Also in here are some much needed goldfish
  tty driver (emulator) fixes to try to get that codebase under control.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (94 commits)
  tty: goldfish: Implement support for kernel 'earlycon' parameter
  tty: goldfish: Use streaming DMA for r/w operations on Ranchu platforms
  tty: goldfish: Refactor constants to better reflect their nature
  serial: 8250_port: Remove useless NULL checks
  earlycon: initialise baud field of earlycon device structure
  tty: hvcs: make ktermios const
  pty: show associative slave of ptmx in fdinfo
  tty: n_gsm: Add compat_ioctl
  tty: hvcs: constify vio_device_id
  tty: hvc_vio: constify vio_device_id
  tty: mips_ejtag_fdc: constify mips_cdmm_device_id
  Introduce 8250_men_mcb
  mcb: introduce mcb_get_resource()
  serial: imx: Avoid post-PIO cleanup if TX DMA is started
  tty: serial: imx: disable irq after suspend
  serial: 8250_uniphier: add suspend/resume support
  serial: 8250_uniphier: use CHAR register for canary to detect power-off
  serial: 8250_uniphier: fix serial port index in private data
  serial: 8250: of: Add new port type for MediaTek BTIF controller on MT7622/23 SoC
  dt-bindings: serial: 8250: Add MediaTek BTIF controller bindings
  ...