ARC: Signal handling

Includes following fixes courtesy review by Al-Viro

* Tracer poke to Callee-regs were lost

  Before going off into do_signal( ) we save the user-mode callee regs
  (as they are not saved by default as part of pt_regs). This is to make
  sure that that a Tracer (if tracing related signal) is able to do likes
  of PEEKUSR(callee-reg).

  However in return path we were simply discarding the user-mode callee
  regs, which would break a POKEUSR(callee-reg) from a tracer.

* Issue related to multiple syscall restarts are addressed in next patch

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Jonas Bonn <jonas@southpole.se>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index a4e9806ace23..756beffd20cb 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -20,6 +20,7 @@ config ARC
         select GENERIC_KERNEL_EXECVE
         select GENERIC_KERNEL_THREAD
         select GENERIC_PENDING_IRQ if SMP
+        select GENERIC_SIGALTSTACK
         select GENERIC_SMP_IDLE_THREAD
         select HAVE_GENERIC_HARDIRQS
         select MODULES_USE_ELF_RELA