Pull x86 MPX support from Thomas Gleixner:
 "This enables support for x86 MPX.

  MPX is a new debug feature for bound checking in user space.  It
  requires kernel support to handle the bound tables and decode the
  bound violating instruction in the trap handler"

* 'x86-mpx-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  asm-generic: Remove asm-generic arch_bprm_mm_init()
  mm: Make arch_unmap()/bprm_mm_init() available to all architectures
  x86: Cleanly separate use of asm-generic/mm_hooks.h
  x86 mpx: Change return type of get_reg_offset()
  fs: Do not include mpx.h in exec.c
  x86, mpx: Add documentation on Intel MPX
  x86, mpx: Cleanup unused bound tables
  x86, mpx: On-demand kernel allocation of bounds tables
  x86, mpx: Decode MPX instruction to get bound violation information
  x86, mpx: Add MPX-specific mmap interface
  x86, mpx: Introduce VM_MPX to indicate that a VMA is MPX specific
  x86, mpx: Add MPX to disabled features
  ia64: Sync struct siginfo with general version
  mips: Sync struct siginfo with general version
  mpx: Extend siginfo structure to include bound violation information
  x86, mpx: Rename cfg_reg_u and status_reg
  x86: mpx: Give bndX registers actual names
  x86: Remove arbitrary instruction size limit in instruction decoder

This patch adds new fields about bound violation into siginfo
structure. si_lower and si_upper are respectively lower bound
and upper bound when bound violation is caused.

Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-mm@kvack.org
Cc: linux-mips@linux-mips.org
Cc: Dave Hansen <dave@sr71.net>
Link: http://lkml.kernel.org/r/20141114151819.1908C900@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

__cleanup_sighand() frees sighand without RCU grace period. This is
correct but this looks "obviously buggy" and constantly confuses the
readers, add the comments to explain how this works.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>

The kill_pid_info() can potentially loop indefinitely if tasks are created
and deleted sufficiently quickly, and if this happens, this function
will remain in a single RCU read-side critical section indefinitely.
This commit therefore exits the RCU read-side critical section on each
pass through the loop.  Because a race must happen to retry the loop,
this should have no performance impact in the common case.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>

Pull arch signal handling cleanup from Richard Weinberger:
 "This patch series moves all remaining archs to the get_signal(),
  signal_setup_done() and sigsp() functions.

  Currently these archs use open coded variants of the said functions.
  Further, unused parameters get removed from get_signal_to_deliver(),
  tracehook_signal_handler() and signal_delivered().

  At the end of the day we save around 500 lines of code."

* 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (43 commits)
  powerpc: Use sigsp()
  openrisc: Use sigsp()
  mn10300: Use sigsp()
  mips: Use sigsp()
  microblaze: Use sigsp()
  metag: Use sigsp()
  m68k: Use sigsp()
  m32r: Use sigsp()
  hexagon: Use sigsp()
  frv: Use sigsp()
  cris: Use sigsp()
  c6x: Use sigsp()
  blackfin: Use sigsp()
  avr32: Use sigsp()
  arm64: Use sigsp()
  arc: Use sigsp()
  sas_ss_flags: Remove nested ternary if
  Rip out get_signal_to_deliver()
  Clean up signal_delivered()
  tracehook_signal_handler: Remove sig, info, ka and regs
  ...

Now we can turn get_signal() to the main function.

Signed-off-by: Richard Weinberger <richard@nod.at>

 - Pass a ksignal struct to it
 - Remove unused regs parameter
 - Make it private as it's nowhere outside of kernel/signal.c is used

Signed-off-by: Richard Weinberger <richard@nod.at>

These parameters are nowhere used, so we can remove them.

Signed-off-by: Richard Weinberger <richard@nod.at>

The explicit local_irq_save() in __lock_task_sighand() is needed to avoid
a potential deadlock condition, as noted in a841796f11c90d53 (signal:
align __lock_task_sighand() irq disabling and RCU).  However, someone
reading the code might be forgiven for concluding that this separate
local_irq_save() was completely unnecessary.  This commit therefore adds
a comment referencing the shiny new block comment on rcu_read_unlock().

Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Now that allow_signal() is really trivial we can unify it with
disallow_signal().  Add the new helper, kernel_sigaction(), and
reimplement allow_signal/disallow_signal as a trivial wrappers.

This saves one EXPORT_SYMBOL() and the new helper can have more users.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>