tracing: Consolidate event trigger code

The event trigger code that checks for callback triggers before and
after recording of an event has lots of flags checks. This code is
duplicated throughout the ftrace events, kprobes and system calls.
They all do the exact same checks against the event flags.

Added helper functions ftrace_trigger_soft_disabled(),
event_trigger_unlock_commit() and event_trigger_unlock_commit_regs()
that consolidated the code and these are used instead.

Link: http://lkml.kernel.org/r/20140106222703.5e7dbba2@gandalf.local.home

Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

2 files changed, 16 insertions, 80 deletions

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 3afa716d626..bdbae450c13 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -929,20 +929,12 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
 	struct ring_buffer *buffer;
 	int size, dsize, pc;
 	unsigned long irq_flags;
-	unsigned long eflags;
-	enum event_trigger_type tt = ETT_NONE;
 	struct ftrace_event_call *call = &tk->tp.call;
 
 	WARN_ON(call != ftrace_file->event_call);
 
-	eflags = ftrace_file->flags;
-
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
-			event_triggers_call(ftrace_file, NULL);
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
-			return;
-	}
+	if (ftrace_trigger_soft_disabled(ftrace_file))
+		return;
 
 	local_save_flags(irq_flags);
 	pc = preempt_count();
@@ -960,16 +952,8 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
 	entry->ip = (unsigned long)tk->rp.kp.addr;
 	store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
 
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		tt = event_triggers_call(ftrace_file, entry);
-
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		ring_buffer_discard_commit(buffer, event);
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
-		trace_buffer_unlock_commit_regs(buffer, event,
-						irq_flags, pc, regs);
-	if (tt)
-		event_triggers_post_call(ftrace_file, tt);
+	event_trigger_unlock_commit_regs(ftrace_file, buffer, event,
+					 entry, irq_flags, pc, regs);
 }
 
 static __kprobes void
@@ -992,20 +976,12 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
 	struct ring_buffer *buffer;
 	int size, pc, dsize;
 	unsigned long irq_flags;
-	unsigned long eflags;
-	enum event_trigger_type tt = ETT_NONE;
 	struct ftrace_event_call *call = &tk->tp.call;
 
 	WARN_ON(call != ftrace_file->event_call);
 
-	eflags = ftrace_file->flags;
-
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
-			event_triggers_call(ftrace_file, NULL);
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
-			return;
-	}
+	if (ftrace_trigger_soft_disabled(ftrace_file))
+		return;
 
 	local_save_flags(irq_flags);
 	pc = preempt_count();
@@ -1024,16 +1000,8 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
 	entry->ret_ip = (unsigned long)ri->ret_addr;
 	store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
 
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		tt = event_triggers_call(ftrace_file, entry);
-
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		ring_buffer_discard_commit(buffer, event);
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
-		trace_buffer_unlock_commit_regs(buffer, event,
-						irq_flags, pc, regs);
-	if (tt)
-		event_triggers_post_call(ftrace_file, tt);
+	event_trigger_unlock_commit_regs(ftrace_file, buffer, event,
+					 entry, irq_flags, pc, regs);
 }
 
 static __kprobes void
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index a4acf9bbffa..759d5e00451 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -306,10 +306,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	struct syscall_trace_enter *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	enum event_trigger_type tt = ETT_NONE;
 	struct ring_buffer *buffer;
 	unsigned long irq_flags;
-	unsigned long eflags;
 	int pc;
 	int syscall_nr;
 	int size;
@@ -323,14 +321,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	if (!ftrace_file)
 		return;
 
-	eflags = ftrace_file->flags;
-
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
-			event_triggers_call(ftrace_file, NULL);
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
-			return;
-	}
+	if (ftrace_trigger_soft_disabled(ftrace_file))
+		return;
 
 	sys_data = syscall_nr_to_meta(syscall_nr);
 	if (!sys_data)
@@ -351,16 +343,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	entry->nr = syscall_nr;
 	syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
 
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		tt = event_triggers_call(ftrace_file, entry);
-
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		ring_buffer_discard_commit(buffer, event);
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
-		trace_current_buffer_unlock_commit(buffer, event,
-						   irq_flags, pc);
-	if (tt)
-		event_triggers_post_call(ftrace_file, tt);
+	event_trigger_unlock_commit(ftrace_file, buffer, event, entry,
+				    irq_flags, pc);
 }
 
 static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
@@ -370,10 +354,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	struct syscall_trace_exit *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	enum event_trigger_type tt = ETT_NONE;
 	struct ring_buffer *buffer;
 	unsigned long irq_flags;
-	unsigned long eflags;
 	int pc;
 	int syscall_nr;
 
@@ -386,14 +368,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	if (!ftrace_file)
 		return;
 
-	eflags = ftrace_file->flags;
-
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
-			event_triggers_call(ftrace_file, NULL);
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
-			return;
-	}
+	if (ftrace_trigger_soft_disabled(ftrace_file))
+		return;
 
 	sys_data = syscall_nr_to_meta(syscall_nr);
 	if (!sys_data)
@@ -413,16 +389,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	entry->nr = syscall_nr;
 	entry->ret = syscall_get_return_value(current, regs);
 
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		tt = event_triggers_call(ftrace_file, entry);
-
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		ring_buffer_discard_commit(buffer, event);
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
-		trace_current_buffer_unlock_commit(buffer, event,
-						   irq_flags, pc);
-	if (tt)
-		event_triggers_post_call(ftrace_file, tt);
+	event_trigger_unlock_commit(ftrace_file, buffer, event, entry,
+				    irq_flags, pc);
 }
 
 static int reg_event_syscall_enter(struct ftrace_event_file *file,