unicore32 builds fail with

  arch/unicore32/kernel/signal.c: In function ‘setup_frame’:
  arch/unicore32/kernel/signal.c:257: error: ‘usig’ undeclared (first use in this function)
  arch/unicore32/kernel/signal.c:279: error: ‘usig’ undeclared (first use in this function)
  arch/unicore32/kernel/signal.c: In function ‘handle_signal’:
  arch/unicore32/kernel/signal.c:306: warning: unused variable ‘tsk’
  arch/unicore32/kernel/signal.c: In function ‘do_signal’:
  arch/unicore32/kernel/signal.c:376: error: implicit declaration of function ‘get_signsl’
  make[1]: *** [arch/unicore32/kernel/signal.o] Error 1
  make: *** [arch/unicore32/kernel/signal.o] Error 2

Bisect points to commit 649671c9 ("unicore32: Use get_signal()
signal_setup_done()").

This code never even compiled.  Reverting the patch does not work, since
previously used functions no longer exist, so try to fix it up.  Compile
tested only.

Fixes: 649671c9 ("unicore32: Use get_signal() signal_setup_done()")
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the more generic functions get_signal() signal_setup_done()
for signal delivery.
Signed-off-by: NRichard Weinberger <richard@nod.at>

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

This include is no longer needed.
(seems to be a leftover from try_to_freeze())
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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>

get_signal_to_deliver() will handle it itself
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>

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

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: NGuan Xuetao <gxt@mprc.pku.edu.cn>
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>

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.

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: NGuan Xuetao <gxt@mprc.pku.edu.cn>

This patch implements signals.
Signed-off-by: NGuan Xuetao <gxt@mprc.pku.edu.cn>