tracing: ftrace events for user faults and undefined instructions

New ftrace events (user_fault and undef_instr) for data, prefetch
or undefined instruction aborts. The new ftrace events are under
events/exception.

Change-Id: Iea328b71a1f623861cac9b45d858c3bbe09e1b82
Signed-off-by: Pushkar Joshi <pushkarj@codeaurora.org>
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index ff5d873..12e6fcb 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -37,6 +37,8 @@
 
 #include "signal.h"
 
+#include <trace/events/exception.h>
+
 static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" };
 
 #ifdef CONFIG_LGE_CRASH_HANDLER
@@ -437,6 +439,8 @@
 	if (call_undef_hook(regs, instr) == 0)
 		return;
 
+	trace_undef_instr(regs, (void *)pc);
+
 #ifdef CONFIG_DEBUG_USER
 	if (user_debug & UDBG_UNDEFINED) {
 		printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index ed03b33..19ef5a6 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -37,6 +37,9 @@
 
 #include "fault.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/exception.h>
+
 #ifdef CONFIG_MMU
 
 #ifdef CONFIG_KPROBES
@@ -173,6 +176,8 @@
 {
 	struct siginfo si;
 
+	trace_user_fault(tsk, addr, fsr);
+
 #ifdef CONFIG_DEBUG_USER
 	if (((user_debug & UDBG_SEGV) && (sig == SIGSEGV)) ||
 	    ((user_debug & UDBG_BUS)  && (sig == SIGBUS))) {
diff --git a/include/trace/events/exception.h b/include/trace/events/exception.h
new file mode 100644
index 0000000..110e920
--- /dev/null
+++ b/include/trace/events/exception.h
@@ -0,0 +1,68 @@
+/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM exception
+
+#if !defined(_TRACE_EXCEPTION_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_EXCEPTION_H
+
+#include <linux/tracepoint.h>
+
+struct task_struct;
+
+TRACE_EVENT(user_fault,
+
+	TP_PROTO(struct task_struct *tsk, unsigned long addr, unsigned int fsr),
+
+	TP_ARGS(tsk, addr, fsr),
+
+	TP_STRUCT__entry(
+		__string(task_name, tsk->comm)
+		__field(unsigned long, addr)
+		__field(unsigned int, fsr)
+	),
+
+	TP_fast_assign(
+	__assign_str(task_name, tsk->comm)
+		__entry->addr	= addr;
+		__entry->fsr	= fsr;
+	),
+
+	TP_printk("task_name:%s addr:%lu, fsr:%u", __get_str(task_name),\
+		__entry->addr, __entry->fsr)
+);
+
+struct pt_regs;
+
+TRACE_EVENT(undef_instr,
+
+	TP_PROTO(struct pt_regs *regs, void *prog_cnt),
+
+	TP_ARGS(regs, prog_cnt),
+
+	TP_STRUCT__entry(
+		__field(void *, prog_cnt)
+		__field(struct pt_regs *, regs)
+	),
+
+	TP_fast_assign(
+		__entry->regs		= regs;
+		__entry->prog_cnt	= prog_cnt;
+	),
+
+	TP_printk("pc:%p", __entry->prog_cnt)
+);
+
+#endif
+
+#include <trace/define_trace.h>