This reverts commit 8b28626a.

Offset -8 is wrong because when it is applied then one instruction
before brki r14, 8 is called again when we return.
Offset -4 is correct and brki instruction is called again.

This change came from ancient MMU kernel.
Signed-off-by: NMichal Simek <monstr@monstr.eu>

Does block_sigmask() + tracehook_signal_handler();  called when
sigframe has been successfully built.  All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).

I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Only 3 out of 63 do not.  Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

replace boilerplate "should we use ->saved_sigmask or ->blocked?"
with calls of obvious inlined helper...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

first fruits of ..._restore_sigmask() helpers: now we can take
boilerplate "signal didn't have a handler, clear RESTORE_SIGMASK
and restore the blocked mask from ->saved_mask" into a common
helper.  Open-coded instances switched...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

never used...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check whether the signal we're about to block is
pending in the shared queue.

Also, use the new helper function introduced in commit 5e6292c0
("signal: add block_sigmask() for adding sigmask to current->blocked")
which centralises the code for updating current->blocked after
successfully delivering a signal and reduces the amount of duplicate code
across architectures.  In the past some architectures got this code wrong,
so using this helper function should stop that from happening again.
Acked-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NMichal Simek <monstr@monstr.eu>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

There are a couple of problems with the current signal code,

1. If we failed to setup the signal stack frame then we should not be
   masking any signals.

2. ka->sa.sa_mask is only added to the current blocked signals list if
   SA_NODEFER is set in ka->sa.sa_flags.  If we successfully setup the
   signal frame and are going to run the handler then we must honour
   sa_mask.
Acked-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NMichal Simek <monstr@monstr.eu>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

get_signal_to_deliver() already resets the signal handler if SA_ONESHOT is
set in ka->sa.sa_flags, there's no need to do it again in handle_signal().
 Furthermore, because we were modifying ka->sa.sa_handler (which is a copy
of sighand->action[]) instead of sighand->action[] the original code
actually had no effect on signal delivery.
Acked-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NMichal Simek <monstr@monstr.eu>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Instead of open coding the sequence from force_sigsegv() just call it.
This also fixes a bug because we were modifying ka->sa.sa_handler (which
is a copy of sighand->action[]), whereas the intention of the code was to
modify sighand->action[] directly.

As the original code was working with a copy it had no effect on signal
delivery.
Acked-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NMichal Simek <monstr@monstr.eu>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Warning log:
CHECK   arch/microblaze/kernel/signal.c
arch/microblaze/kernel/signal.c:200:9: warning: Using plain integer as NULL pointer
arch/microblaze/kernel/signal.c:201:9: warning: incorrect type in initializer (different address spaces)
arch/microblaze/kernel/signal.c:201:9:    expected void [noderef] *volatile __gu_val<asn:1>
arch/microblaze/kernel/signal.c:201:9:    got void *<noident>
Signed-off-by: NMichal Simek <monstr@monstr.eu>

r0_ram pool was used for saving/restoring register
content if hw exception happen. This poll was replaced by
pt_pool_space with PT_SIZE size.
Based on this change SAVE_STATE_ARG_SPACE was removed which
caused that PTO offset is zero that's why is also removed.

r0_ram space was used as scratchpad by v850. In early
Microblaze Linux developing phase was this part of code
blindly copied.
Signed-off-by: NMichal Simek <monstr@monstr.eu>

Generic rt_sigsuspend syscalls doesn't need any asm wrapper.
Signed-off-by: NMichal Simek <monstr@monstr.eu>

Microblaze version 7.20.d is the first MB version which can be run
on MMU linux. Please do not used previous version because they contain
HW bug.
Based on WB support was necessary to redesign whole cache design.
Microblaze versions from 7.20.a don't need to disable IRQ and cache
before working with them that's why there are special structures for it.
Signed-off-by: NMichal Simek <monstr@monstr.eu>

After the signal frame is set up on the userspace stack, ptrace() should
be given an opportunity to single-step into the signal handler

FRV, Blackfin, mn10300 and UM. Worth to look at that patches.
Signed-off-by: NMichal Simek <monstr@monstr.eu>

* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The prototypes in syscalls.h all make sense for
microblaze, but for some of them, the actual implementation
in sys_microblaze.c needs to be adapted.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMichal Simek <monstr@monstr.eu>

When legacy signal handling is disabled, the
arch/microblaze/kernel/signal.c implementation can
be much simpler, as most of it is handled generically
from kernel/signal.c.

This is also a prerequisite for using the generic
asm/unistd.h, which does not provide __NR_sigreturn,
because this macro is referenced by the current signal.c
implementation.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMichal Simek <monstr@monstr.eu>

Signed-off-by: NMichal Simek <monstr@monstr.eu>

We need to define set_restore_sigmask() in order to
get pselect and ppoll. Also, the setup_frame function
can not be used when __NR_sigreturn is not defined.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMichal Simek <monstr@monstr.eu>

The microblaze signal handling code gets some __user
pointers wrong, as shown by sparse.
This adds the annotations where appropriate and
change sys_rt_sigreturn to correctly pass a user
stack down to do_sigaltstack instead of a kernel
structure.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMichal Simek <monstr@monstr.eu>

For noMMU kernel this change nothing bring but this change
helps with MMU synchronization.
Signed-off-by: NMichal Simek <monstr@monstr.eu>

Remove duplicated #include's in
  arch/microblaze/include/asm/io.h
  arch/microblaze/kernel/prom.c
  arch/microblaze/kernel/ptrace.c
  arch/microblaze/kernel/signal.c
  arch/microblaze/kernel/sys_microblaze.c
Signed-off-by: NHuang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: NMichal Simek <monstr@monstr.eu>

Reviewed-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NStephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Acked-by: NJohn Linn <john.linn@xilinx.com>
Acked-by: NJohn Williams <john.williams@petalogix.com>
Signed-off-by: NMichal Simek <monstr@monstr.eu>