mint: n_tty: Fix n_tty_write crash when echoing in raw mode

The tty atomic_write_lock does not provide an exclusion guarantee for
the tty driver if the termios settings are LECHO & !OPOST.  And since
it is unexpected and not allowed to call TTY buffer helpers like
tty_insert_flip_string concurrently, this may lead to crashes when
concurrect writers call pty_write. In that case the following two
writers:
* the ECHOing from a workqueue and
* pty_write from the process
race and can overflow the corresponding TTY buffer like follows.
If we look into tty_insert_flip_string_fixed_flag, there is:
  int space = __tty_buffer_request_room(port, goal, flags);
  struct tty_buffer *tb = port->buf.tail;
  ...
  memcpy(char_buf_ptr(tb, tb->used), chars, space);
  ...
  tb->used += space;
so the race of the two can result in something like this:
              A                                B
__tty_buffer_request_room
                                  __tty_buffer_request_room
memcpy(buf(tb->used), ...)
tb->used += space;
                                  memcpy(buf(tb->used), ...) ->BOOM
B's memcpy is past the tty_buffer due to the previous A's tb->used
increment.
Since the N_TTY line discipline input processing can output
concurrently with a tty write, obtain the N_TTY ldisc output_lock to
serialize echo output with normal tty writes.  This ensures the tty
buffer helper tty_insert_flip_string is not called concurrently and
everything is fine.
Note that this is nicely reproducible by an ordinary user using
forkpty and some setup around that (raw termios + ECHO). And it is
present in kernels at least after commit
d945cb9cce20ac7143c2de8d88b187f62db99bdc (pty: Rework the pty layer to
use the normal buffering logic) in 2.6.31-rc3.
js: add more info to the commit log
js: switch to bool
js: lock unconditionally
js: lock only the tty->ops->write call

References: CVE-2014-0196
Reported-and-tested-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Change-Id: I9d3d7b4a3bbd719ced5192c417b4338774447993
sony: msm8960: Add CPU hotplugging 

* thanks to thalamus and DooMLoRD and fixes from morfic, Shankar
* this is a squash of 5 commits

https://github.com/DooMLoRD/android_kernel_sony_msm8960/commit/32f767736b56b4bebda2052cb60ca9b5c5258184

https://github.com/DooMLoRD/android_kernel_sony_msm8960/commit/262112085876d95c45d7c31a53c42ff7df5b0832

https://github.com/DooMLoRD/android_kernel_sony_msm8960/commit/c642838f5e0c108540f12a0c707c016416219ad7

https://github.com/DooMLoRD/android_kernel_sony_msm8960/commit/547e5a4e48c60b3ff9e1a030491d8179ad4ed9ef

https://github.com/DooMLoRD/android_kernel_sony_msm8960/commit/591b939debde97c926b404e1f74f526d55d28431

Change-Id: I0c594d509622523c2cac093e1551f24a32f37fb3
Merge "sony: msm8960: Add CPU hotplugging " into android-4.4
Revert "sony: msm8960: Add CPU hotplugging "

This reverts commit 7be2b1764d3612d0a308d03bda447626b69e0222.

Change-Id: I6c0679a7bbab8498d945ed087b67ae7e77c3836e
Merge "Revert "sony: msm8960: Add CPU hotplugging "" into android-4.4
Merge pull request #1 from omnirom/android-4.4

merge latest omnirom source