commit ab8a261ba5e2dd9206da640de5870cc31d568a7c upstream.

On parisc we can not use the existing compat implementation for fanotify_mark()
because for the 64bit mask parameter the higher and lower 32bits are ordered
differently than what the compat function expects from big endian
architectures.

Specifically:
It finally turned out, that on hppa we end up with different assignments
of parameters to kernel arguments depending on if we call the glibc
wrapper function
 int fanotify_mark (int __fanotify_fd, unsigned int __flags,
                    uint64_t __mask, int __dfd, const char *__pathname);
or directly calling the syscall manually
 syscall(__NR_fanotify_mark, ...)

Reason is, that the syscall() function is implemented as C-function and
because we now have the sysno as first parameter in front of the other
parameters the compiler will unexpectedly add an empty paramenter in
front of the u64 value to ensure the correct calling alignment for 64bit
values.
This means, on hppa you can't simply use syscall() to call the kernel
fanotify_mark() function directly, but you have to use the glibc
function instead.

This patch fixes the kernel in the hppa-arch specifc coding to adjust
the parameters in a way as if userspace calls the glibc wrapper function
fanotify_mark().

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit eadcc7208a2237016be7bdff4551ba7614da85c8 upstream.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The 'renameat2()' system call was incorrectly added as a ENTRY_COMP() in
the parisc system call table by commit 18e480aa07f78 ("parisc: add
renameat2 syscall").  That causes a link-time error due to there not
being any compat version of that system call:

  arch/parisc/kernel/built-in.o: In function `sys_call_table':
  (.rodata+0xad0): undefined reference to `compat_sys_renameat2'
  make: *** [vmlinux] Error 1

Easily fixed by marking the system call as being the same for compat as
for native by using ENTRY_SAME() instead of ENTRY_COMP().

Reported-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Helge Deller <deller@gmx.de>

Pull parisc fixes from Helge Deller:
 "There are two patches in here:

  The first patch greatly improves latency and corrects the memory
  ordering in our light-weight atomic locking syscall.

  The second patch ratelimits printing of userspace segfaults in the
  same way as it's done on other platforms.  This fixes a possible DOS
  on parisc since it prevents the syslog to grow too fast.  For example,
  when the debian acl2 package was built on our debian buildd servers,
  this package produced lots of gigabytes in syslog in very short time
  and thus filled our harddisks, which then turned the server nearly
  completely unaccessible and unresponsive"

* 'parisc-3.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Improve LWS-CAS performance
  parisc: ratelimit userspace segfault printing

The attached change significantly improves the performance of the LWS-CAS code
in syscall.S.
This allows a number of packages to build (e.g., zeromq3, gtest and libxs)
that previously failed because slow LWS-CAS performance under contention. In
particular, interrupts taken while the lock was taken degraded performance
significantly.

The change does the following:

1) Disables interrupts around the CAS operation, and
2) Changes the loads and stores to use the ordered completer, "o", on
PA 2.0. "o" and "ma" with a zero offset are equivalent. The latter is
accepted on both PA 1.X and 2.0.

The use of ordered loads and stores probably makes no difference on all
existing hardware, but it seemed pedantically correct. In particular, the CAS
operation must complete before LDCW lock is released. As written before, a
processor could reorder the operations.

I don't believe the period interrupts are disabled is long enough to
significantly increase interrupt latency. For example, the TLB insert code is
longer. Worst case is a memory fault in the CAS operation.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 3.13+
Signed-off-by: Helge Deller <deller@gmx.de>

Ratelimit printing of userspace segfaults and make it runtime
configurable via the /proc/sys/debug/exception-trace variable. This
should resolve syslog from growing way too fast and thus prevents
possible system service attacks.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 3.13+

This patch affects only architectures where the stack grows upwards
(currently parisc and metag only). On those do not hardcode the maximum
initial stack size to 1GB for 32-bit processes, but make it configurable
via a config option.

The main problem with the hardcoded stack size is, that we have two
memory regions which grow upwards: stack and heap. To keep most of the
memory available for heap in a flexmap memory layout, it makes no sense
to hard allocate up to 1GB of the memory for stack which can't be used
as heap then.

This patch makes the stack size for 32-bit processes configurable and
uses 80MB as default value which has been in use during the last few
years on parisc and which hasn't showed any problems yet.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: linux-parisc@vger.kernel.org
Cc: linux-metag@vger.kernel.org
Cc: John David Anglin <dave.anglin@bell.net>

Pull parisc updates from Helge Deller:
 "There are two major changes in this patchset:

  The major fix is that the epoll_pwait() syscall for 32bit userspace
  was not using the compat wrapper on a 64bit kernel.

  Secondly we changed the value of SHMLBA from 4MB to PAGE_SIZE to
  reflect that we can actually mmap to any multiple of PAGE_SIZE.  The
  only thing which needs care is that shared mmaps need to be mapped at
  the same offset inside the 4MB cache window"

* 'parisc-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: fix epoll_pwait syscall on compat kernel
  parisc: change value of SHMLBA from 0x00400000 to PAGE_SIZE
  parisc: Replace __get_cpu_var uses for address calculation

This bug was detected with the libio-epoll-perl debian package where the
test case IO-Ppoll-compat.t failed.

Signed-off-by: Helge Deller <deller@gmx.de>
CC: stable@kernel.org   # 3.0+