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Commit d8275c45 authored by Steven Rostedt's avatar Steven Rostedt
Browse files

tracing: Move filtered_pid helper functions into trace.c 



As the filtered_pid functions are going to be used by function tracer as
well as trace_events, move the code into the generic trace.c file.

The functions moved are:

 trace_find_filtered_pid()
 trace_ignore_this_task()
 trace_filter_add_remove_task()

Kernel Doc text was also added.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 4e267db1

kernel/trace/trace.c

+78 −0
Original line number Diff line number Diff line
@@ -319,6 +319,84 @@ int call_filter_check_discard(struct trace_event_call *call, void *rec, 
	return 0;

}



/**

 * trace_find_filtered_pid - check if a pid exists in a filtered_pid list

 * @filtered_pids: The list of pids to check

 * @search_pid: The PID to find in @filtered_pids

 *

 * Returns true if @search_pid is fonud in @filtered_pids, and false otherwis.

 */

bool

trace_find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid)

{

	/*

	 * If pid_max changed after filtered_pids was created, we

	 * by default ignore all pids greater than the previous pid_max.

	 */

	if (search_pid >= filtered_pids->pid_max)

		return false;



	return test_bit(search_pid, filtered_pids->pids);

}



/**

 * trace_ignore_this_task - should a task be ignored for tracing

 * @filtered_pids: The list of pids to check

 * @task: The task that should be ignored if not filtered

 *

 * Checks if @task should be traced or not from @filtered_pids.

 * Returns true if @task should *NOT* be traced.

 * Returns false if @task should be traced.

 */

bool

trace_ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task)

{

	/*

	 * Return false, because if filtered_pids does not exist,

	 * all pids are good to trace.

	 */

	if (!filtered_pids)

		return false;



	return !trace_find_filtered_pid(filtered_pids, task->pid);

}



/**

 * trace_pid_filter_add_remove - Add or remove a task from a pid_list

 * @pid_list: The list to modify

 * @self: The current task for fork or NULL for exit

 * @task: The task to add or remove

 *

 * If adding a task, if @self is defined, the task is only added if @self

 * is also included in @pid_list. This happens on fork and tasks should

 * only be added when the parent is listed. If @self is NULL, then the

 * @task pid will be removed from the list, which would happen on exit

 * of a task.

 */

void trace_filter_add_remove_task(struct trace_pid_list *pid_list,

				  struct task_struct *self,

				  struct task_struct *task)

{

	if (!pid_list)

		return;



	/* For forks, we only add if the forking task is listed */

	if (self) {

		if (!trace_find_filtered_pid(pid_list, self->pid))

			return;

	}



	/* Sorry, but we don't support pid_max changing after setting */

	if (task->pid >= pid_list->pid_max)

		return;



	/* "self" is set for forks, and NULL for exits */

	if (self)

		set_bit(task->pid, pid_list->pids);

	else

		clear_bit(task->pid, pid_list->pids);

}



static cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu)

{

	u64 ts;

kernel/trace/trace_events.c

+0 −51
Original line number Diff line number Diff line
@@ -502,57 +502,6 @@ static void ftrace_clear_events(struct trace_array *tr) 
/* Shouldn't this be in a header? */

extern int pid_max;



/* Returns true if found in filter */

bool

trace_find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid)

{

	/*

	 * If pid_max changed after filtered_pids was created, we

	 * by default ignore all pids greater than the previous pid_max.

	 */

	if (search_pid >= filtered_pids->pid_max)

		return false;



	return test_bit(search_pid, filtered_pids->pids);

}



bool

trace_ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task)

{

	/*

	 * Return false, because if filtered_pids does not exist,

	 * all pids are good to trace.

	 */

	if (!filtered_pids)

		return false;



	return !trace_find_filtered_pid(filtered_pids, task->pid);

}



void trace_filter_add_remove_task(struct trace_pid_list *pid_list,

				  struct task_struct *self,

				  struct task_struct *task)

{

	if (!pid_list)

		return;



	/* For forks, we only add if the forking task is listed */

	if (self) {

		if (!trace_find_filtered_pid(pid_list, self->pid))

			return;

	}



	/* Sorry, but we don't support pid_max changing after setting */

	if (task->pid >= pid_list->pid_max)

		return;



	/* "self" is set for forks, and NULL for exits */

	if (self)

		set_bit(task->pid, pid_list->pids);

	else

		clear_bit(task->pid, pid_list->pids);

}



static void

event_filter_pid_sched_process_exit(void *data, struct task_struct *task)

{