Commit 591dffda authored by Steven Rostedt (Red Hat)'s avatar Steven Rostedt (Red Hat) Committed by Steven Rostedt

ftrace: Allow for function tracing instance to filter functions

Create a "set_ftrace_filter" and "set_ftrace_notrace" files in the instance
directories to let users filter of functions to trace for the given instance.
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent e3b3e2e8
......@@ -92,6 +92,7 @@ typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
* STUB - The ftrace_ops is just a place holder.
* INITIALIZED - The ftrace_ops has already been initialized (first use time
* register_ftrace_function() is called, it will initialized the ops)
* DELETED - The ops are being deleted, do not let them be registered again.
*/
enum {
FTRACE_OPS_FL_ENABLED = 1 << 0,
......@@ -103,6 +104,7 @@ enum {
FTRACE_OPS_FL_RECURSION_SAFE = 1 << 6,
FTRACE_OPS_FL_STUB = 1 << 7,
FTRACE_OPS_FL_INITIALIZED = 1 << 8,
FTRACE_OPS_FL_DELETED = 1 << 9,
};
/*
......
......@@ -436,6 +436,9 @@ static int remove_ftrace_list_ops(struct ftrace_ops **list,
static int __register_ftrace_function(struct ftrace_ops *ops)
{
if (ops->flags & FTRACE_OPS_FL_DELETED)
return -EINVAL;
if (FTRACE_WARN_ON(ops == &global_ops))
return -EINVAL;
......@@ -4112,6 +4115,36 @@ static const struct file_operations ftrace_graph_notrace_fops = {
};
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
void ftrace_create_filter_files(struct ftrace_ops *ops,
struct dentry *parent)
{
trace_create_file("set_ftrace_filter", 0644, parent,
ops, &ftrace_filter_fops);
trace_create_file("set_ftrace_notrace", 0644, parent,
ops, &ftrace_notrace_fops);
}
/*
* The name "destroy_filter_files" is really a misnomer. Although
* in the future, it may actualy delete the files, but this is
* really intended to make sure the ops passed in are disabled
* and that when this function returns, the caller is free to
* free the ops.
*
* The "destroy" name is only to match the "create" name that this
* should be paired with.
*/
void ftrace_destroy_filter_files(struct ftrace_ops *ops)
{
mutex_lock(&ftrace_lock);
if (ops->flags & FTRACE_OPS_FL_ENABLED)
ftrace_shutdown(ops, 0);
ops->flags |= FTRACE_OPS_FL_DELETED;
mutex_unlock(&ftrace_lock);
}
static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
{
......@@ -4121,11 +4154,7 @@ static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
trace_create_file("enabled_functions", 0444,
d_tracer, NULL, &ftrace_enabled_fops);
trace_create_file("set_ftrace_filter", 0644, d_tracer,
&global_ops, &ftrace_filter_fops);
trace_create_file("set_ftrace_notrace", 0644, d_tracer,
&global_ops, &ftrace_notrace_fops);
ftrace_create_filter_files(&global_ops, d_tracer);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
trace_create_file("set_graph_function", 0444, d_tracer,
......
......@@ -6161,6 +6161,7 @@ static int instance_delete(const char *name)
tracing_set_nop(tr);
event_trace_del_tracer(tr);
ftrace_destroy_function_files(tr);
debugfs_remove_recursive(tr->dir);
free_percpu(tr->trace_buffer.data);
ring_buffer_free(tr->trace_buffer.buffer);
......@@ -6291,6 +6292,9 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
trace_create_file("tracing_on", 0644, d_tracer,
tr, &rb_simple_fops);
if (ftrace_create_function_files(tr, d_tracer))
WARN(1, "Could not allocate function filter files");
#ifdef CONFIG_TRACER_SNAPSHOT
trace_create_file("snapshot", 0644, d_tracer,
tr, &snapshot_fops);
......
......@@ -819,13 +819,36 @@ static inline int ftrace_trace_task(struct task_struct *task)
return test_tsk_trace_trace(task);
}
extern int ftrace_is_dead(void);
int ftrace_create_function_files(struct trace_array *tr,
struct dentry *parent);
void ftrace_destroy_function_files(struct trace_array *tr);
#else
static inline int ftrace_trace_task(struct task_struct *task)
{
return 1;
}
static inline int ftrace_is_dead(void) { return 0; }
#endif
static inline int
ftrace_create_function_files(struct trace_array *tr,
struct dentry *parent)
{
return 0;
}
static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
#endif /* CONFIG_FUNCTION_TRACER */
#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
void ftrace_create_filter_files(struct ftrace_ops *ops,
struct dentry *parent);
void ftrace_destroy_filter_files(struct ftrace_ops *ops);
#else
/*
* The ops parameter passed in is usually undefined.
* This must be a macro.
*/
#define ftrace_create_filter_files(ops, parent) do { } while (0)
#define ftrace_destroy_filter_files(ops) do { } while (0)
#endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
int ftrace_event_is_function(struct ftrace_event_call *call);
......
......@@ -52,10 +52,34 @@ static int allocate_ftrace_ops(struct trace_array *tr)
return 0;
}
int ftrace_create_function_files(struct trace_array *tr,
struct dentry *parent)
{
int ret;
/* The top level array uses the "global_ops". */
if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL)) {
ret = allocate_ftrace_ops(tr);
if (ret)
return ret;
}
ftrace_create_filter_files(tr->ops, parent);
return 0;
}
void ftrace_destroy_function_files(struct trace_array *tr)
{
ftrace_destroy_filter_files(tr->ops);
kfree(tr->ops);
tr->ops = NULL;
}
static int function_trace_init(struct trace_array *tr)
{
struct ftrace_ops *ops;
int ret;
if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
/* There's only one global tr */
......@@ -69,10 +93,13 @@ static int function_trace_init(struct trace_array *tr)
else
ops = &trace_ops;
tr->ops = ops;
} else {
ret = allocate_ftrace_ops(tr);
if (ret)
return ret;
} else if (!tr->ops) {
/*
* Instance trace_arrays get their ops allocated
* at instance creation. Unless it failed
* the allocation.
*/
return -ENOMEM;
}
tr->trace_buffer.cpu = get_cpu();
......@@ -87,9 +114,6 @@ static void function_trace_reset(struct trace_array *tr)
{
tracing_stop_function_trace(tr);
tracing_stop_cmdline_record();
if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL))
kfree(tr->ops);
tr->ops = NULL;
}
static void function_trace_start(struct trace_array *tr)
......
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