signals: demultiplexing SIGTRAP signal

Currently a SIGTRAP can denote any one of below reasons.
	- Breakpoint hit
	- H/W debug register hit
	- Single step
	- Signal sent through kill() or rasie()

Architectures like powerpc/parisc provides infrastructure to demultiplex
SIGTRAP signal by passing down the information for receiving SIGTRAP through
si_code of siginfot_t structure. Here is an attempt is generalise this
infrastructure by extending it to x86 and x86_64 archs.

Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: akpm@linux-foundation.org
Cc: paulus@samba.org
Cc: linuxppc-dev@ozlabs.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c
index da5a596..0429c5d 100644
--- a/arch/x86/kernel/traps_32.c
+++ b/arch/x86/kernel/traps_32.c
@@ -891,6 +891,7 @@
 {
 	struct task_struct *tsk = current;
 	unsigned int condition;
+	int si_code;
 
 	trace_hardirqs_fixup();
 
@@ -935,8 +936,9 @@
 			goto clear_TF_reenable;
 	}
 
+	si_code = get_si_code((unsigned long)condition);
 	/* Ok, finally something we can handle */
-	send_sigtrap(tsk, regs, error_code);
+	send_sigtrap(tsk, regs, error_code, si_code);
 
 	/*
 	 * Disable additional traps. They'll be re-enabled when