User applications running on SMP kernels have long suffered from instability
and random segmentation faults.  This patch improves the situation although
there is more work to be done.

One of the problems is the various routines in pgtable.h that update page table
entries use different locking mechanisms, or no lock at all (set_pte_at).  This
change modifies the routines to all use the same lock pa_dbit_lock.  This lock
is used for dirty bit updates in the interruption code. The patch also purges
the TLB entries associated with the PTE to ensure that inconsistent values are
not used after the page table entry is updated.  The UP and SMP code are now
identical.

The change also includes a minor update to the purge_tlb_entries function in
cache.c to improve its efficiency.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>

When targetting 32-bit processors, __put_user emits a pair of stw
instructions for the 8-byte case. If the type of __val is a pointer, the
marshalling code casts it to the wider integer type of u64, resulting
in the following compiler warnings:

  kernel/signal.c: In function 'copy_siginfo_to_user':
  kernel/signal.c:2752:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  kernel/signal.c:2752:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  [...]

This patch fixes the warnings by removing the marshalling code and using
the correct output modifiers in the __put_{user,kernel}_asm64 macros
so that GCC will allocate the right registers without the need to
extract the two words explicitly.

Cc: Helge Deller <deller@gmx.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Helge Deller <deller@gmx.de>

Change kunmap macro to static inline function to fix build error
compiling drivers/base/dma-buf.c.

Without the change, the following error can occur:

   CC      drivers/base/dma-buf.o
drivers/base/dma-buf.c: In function 'dma_buf_kunmap':
drivers/base/dma-buf.c:427:46:
error: macro "kunmap" passed 3 arguments, but takes just 1

I believe parisc is the only arch to implement kunmap using a macro.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>

This fixes compile warnings like this one:
net/ipv4/igmp.c: In function ‘ip_mc_leave_group’:
net/ipv4/igmp.c:1898:3: warning: overflow in implicit constant conversion [-Woverflow]

atomic_sub() is defined as __atomic_add_return(-(VAL),(v))))
and if VAL is of type unsigned int (as returned by sizeof()), negating
this value will overflow. Fix this by type-casting VAL to int type.

Signed-off-by: Helge Deller <deller@gmx.de>

Pull signal handling cleanups from Al Viro:
 "This is the first pile; another one will come a bit later and will
  contain SYSCALL_DEFINE-related patches.

   - a bunch of signal-related syscalls (both native and compat)
     unified.

   - a bunch of compat syscalls switched to COMPAT_SYSCALL_DEFINE
     (fixing several potential problems with missing argument
     validation, while we are at it)

   - a lot of now-pointless wrappers killed

   - a couple of architectures (cris and hexagon) forgot to save
     altstack settings into sigframe, even though they used the
     (uninitialized) values in sigreturn; fixed.

   - microblaze fixes for delivery of multiple signals arriving at once

   - saner set of helpers for signal delivery introduced, several
     architectures switched to using those."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (143 commits)
  x86: convert to ksignal
  sparc: convert to ksignal
  arm: switch to struct ksignal * passing
  alpha: pass k_sigaction and siginfo_t using ksignal pointer
  burying unused conditionals
  make do_sigaltstack() static
  arm64: switch to generic old sigaction() (compat-only)
  arm64: switch to generic compat rt_sigaction()
  arm64: switch compat to generic old sigsuspend
  arm64: switch to generic compat rt_sigqueueinfo()
  arm64: switch to generic compat rt_sigpending()
  arm64: switch to generic compat rt_sigprocmask()
  arm64: switch to generic sigaltstack
  sparc: switch to generic old sigsuspend
  sparc: COMPAT_SYSCALL_DEFINE does all sign-extension as well as SYSCALL_DEFINE
  sparc: kill sign-extending wrappers for native syscalls
  kill sparc32_open()
  sparc: switch to use of generic old sigaction
  sparc: switch sys_compat_rt_sigaction() to COMPAT_SYSCALL_DEFINE
  mips: switch to generic sys_fork() and sys_clone()
  ...

Pull parisc updates from Helge Deller.

The bulk of this is optimized page coping/clearing and cache flushing
(virtual caches are lovely) by John David Anglin.

* 'parisc-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: (31 commits)
  arch/parisc/include/asm: use ARRAY_SIZE macro in mmzone.h
  parisc: remove empty lines and unnecessary #ifdef coding in include/asm/signal.h
  parisc: sendfile and sendfile64 syscall cleanups
  parisc: switch to available compat_sched_rr_get_interval implementation
  parisc: fix fallocate syscall
  parisc: fix error return codes for rt_sigaction and rt_sigprocmask
  parisc: convert msgrcv and msgsnd syscalls to use compat layer
  parisc: correctly wire up mq_* functions for CONFIG_COMPAT case
  parisc: fix personality on 32bit kernel
  parisc: wire up process_vm_readv, process_vm_writev, kcmp and finit_module syscalls
  parisc: led driver requires CONFIG_VM_EVENT_COUNTERS
  parisc: remove unused compat_rt_sigframe.h header
  parisc/mm/fault.c: Port OOM changes to do_page_fault
  parisc: space register variables need to be in native length (unsigned long)
  parisc: fix ptrace breakage
  parisc: always detect multiple physical ranges
  parisc: ensure that mmapped shared pages are aligned at SHMLBA addresses
  parisc: disable preemption while flushing D- or I-caches through TMPALIAS region
  parisc: remove IRQF_DISABLED
  parisc: fixes and cleanups in page cache flushing (4/4)
  ...

Signed-off-by: Nikitas Angelinas <nikitasangelinas@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>

Signed-off-by: Helge Deller <deller@gmx.de>

Utilize the existing compat_sys_sendfile function for 64bit kernel and add
wrappers for sendfile and sendfile64 to correctly handle the 32/64 bit sign
extension.

Signed-off-by: Helge Deller <deller@gmx.de>

Signed-off-by: Helge Deller <deller@gmx.de>