[for-next][PATCH 02/12] tracing: Move filtered_pid helper functions into trace.c
From: Steven Rostedt
Date: Sun Jul 03 2016 - 16:36:58 EST
From: Steven Rostedt <rostedt@xxxxxxxxxxx>
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: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace.c | 78 +++++++++++++++++++++++++++++++++++++++++++++
kernel/trace/trace_events.c | 51 -----------------------------
2 files changed, 78 insertions(+), 51 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8a4bd6b68a0b..0b87fe8e6d0b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -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;
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index b5e514c4dada..a11e6d9a3841 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -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)
{
--
2.8.1