This fixes a bug in which the upper 32-bits of a 64-bit value which is
read by get_user() was lost on a 32-bit kernel.
While touching this code, split out pre-loading of %sr2 space register
and clean up code indent.

Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: Helge Deller <deller@gmx.de>

Al Viro noticed that userspace accesses via get_user()/put_user() can be
simplified a lot with regard to usage of the exception handling.

This patch implements a fixup routine for get_user() and put_user() in such
that the exception handler will automatically load -EFAULT into the register
%r8 (the error value) in case on a fault on userspace.  Additionally the fixup
routine will zero the target register on fault in case of a get_user() call.
The target register is extracted out of the faulting assembly instruction.

This patch brings a few benefits over the old implementation:
1. Exception handling gets much cleaner, easier and smaller in size.
2. Helper functions like fixup_get_user_skip_1 (all of fixup.S) can be dropped.
3. No need to hardcode %r9 as target register for get_user() any longer. This
   helps the compiler register allocator and thus creates less assembler
   statements.
4. No dependency on the exception_data contents any longer.
5. Nested faults will be handled cleanly.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: Helge Deller <deller@gmx.de>

Commit 09b871ffd4d8 (parisc: Define access_ok() as macro) missed to mark uaddr
as used, which then gives compiler warnings about unused variables.

Fix it by comparing uaddr to uaddr which then gets optimized away by the
compiler.

Signed-off-by: Helge Deller <deller@gmx.de>
Fixes: 09b871ffd4d8 ("parisc: Define access_ok() as macro")

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

The previously submitted patch did not resolve the random segmentation
faults observed on the phantom buildd system.  There are still
unresolved problems with the Debian 4.8 and 4.9 kernels on C8000.

The attached patch removes the flush of the offset map pages and does a
whole data cache flush for large ranges.  No other arch flushes the
offset map in these routines as far as I can tell.

I have not observed any random segmentation faults on rp3440 in two
weeks of testing with 4.10.0 and 4.10.1.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org      # v4.8+
Signed-off-by: Helge Deller <deller@gmx.de>

Pull parisc fixes and cleanups from Helge Deller:
 "Nothing really important in this patchset: fix resource leaks in error
  paths, coding style cleanups and code removal"

* 'parisc-4.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Remove flush_user_dcache_range and flush_user_icache_range
  parisc: fix a printk
  parisc: ccio-dma: Handle return NULL error from ioremap_nocache
  parisc: Define access_ok() as macro
  parisc: eisa: Fix resource leaks in error paths
  parisc: eisa: Remove coding style errors

Often all is needed is these small helpers, instead of compiler.h or a
full kprobes.h.  This is important for asm helpers, in fact even some
asm/kprobes.h make use of these helpers...  instead just keep a generic
asm file with helpers useful for asm code with the least amount of
clutter as possible.

Likewise we need now to also address what to do about this file for both
when architectures have CONFIG_HAVE_KPROBES, and when they do not.  Then
for when architectures have CONFIG_HAVE_KPROBES but have disabled
CONFIG_KPROBES.

Right now most asm/kprobes.h do not have guards against CONFIG_KPROBES,
this means most architecture code cannot include asm/kprobes.h safely.
Correct this and add guards for architectures missing them.
Additionally provide architectures that not have kprobes support with
the default asm-generic solution.  This lets us force asm/kprobes.h on
the header include/linux/kprobes.h always, but most importantly we can
now safely include just asm/kprobes.h on architecture code without
bringing the full kitchen sink of header files.

Two architectures already provided a guard against CONFIG_KPROBES on its
kprobes.h: sh, arch.  The rest of the architectures needed gaurds added.
We avoid including any not-needed headers on asm/kprobes.h unless
kprobes have been enabled.

In a subsequent atomic change we can try now to remove compiler.h from
include/linux/kprobes.h.

During this sweep I've also identified a few architectures defining a
common macro needed for both kprobes and ftrace, that of the definition
of the breakput instruction up.  Some refer to this as
BREAKPOINT_INSTRUCTION.  This must be kept outside of the #ifdef
CONFIG_KPROBES guard.

[mcgrof@kernel.org: fix arm64 build]
  Link: http://lkml.kernel.org/r/CAB=NE6X1WMByuARS4mZ1g9+W=LuVBnMDnh_5zyN0CLADaVh=Jw@mail.gmail.com
[sfr@canb.auug.org.au: fixup for kprobes declarations moving]
  Link: http://lkml.kernel.org/r/20170214165933.13ebd4f4@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170203233139.32682-1-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull rdma DMA mapping updates from Doug Ledford:
 "Drop IB DMA mapping code and use core DMA code instead.

  Bart Van Assche noted that the ib DMA mapping code was significantly
  similar enough to the core DMA mapping code that with a few changes it
  was possible to remove the IB DMA mapping code entirely and switch the
  RDMA stack to use the core DMA mapping code.

  This resulted in a nice set of cleanups, but touched the entire tree
  and has been kept separate for that reason."

* tag 'for-next-dma_ops' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (37 commits)
  IB/rxe, IB/rdmavt: Use dma_virt_ops instead of duplicating it
  IB/core: Remove ib_device.dma_device
  nvme-rdma: Switch from dma_device to dev.parent
  RDS: net: Switch from dma_device to dev.parent
  IB/srpt: Modify a debug statement
  IB/srp: Switch from dma_device to dev.parent
  IB/iser: Switch from dma_device to dev.parent
  IB/IPoIB: Switch from dma_device to dev.parent
  IB/rxe: Switch from dma_device to dev.parent
  IB/vmw_pvrdma: Switch from dma_device to dev.parent
  IB/usnic: Switch from dma_device to dev.parent
  IB/qib: Switch from dma_device to dev.parent
  IB/qedr: Switch from dma_device to dev.parent
  IB/ocrdma: Switch from dma_device to dev.parent
  IB/nes: Remove a superfluous assignment statement
  IB/mthca: Switch from dma_device to dev.parent
  IB/mlx5: Switch from dma_device to dev.parent
  IB/mlx4: Switch from dma_device to dev.parent
  IB/i40iw: Remove a superfluous assignment statement
  IB/hns: Switch from dma_device to dev.parent
  ...

The functions flush_user_dcache_range() and flush_user_icache_range()
are only used by the parisc signal handling code.  This code only needs
to flush a couple of lines, so the threshold check is unnecessary
overhead.

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

Define access_ok() as macro instead of static function. This fixes build
warnings in code where the second parameter is given as unsigned long.

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