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Diffstat (limited to 'kernel/trace/trace_events.c')
-rw-r--r--kernel/trace/trace_events.c106
1 files changed, 96 insertions, 10 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index fcd3975a88d1..f38234ecea18 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -238,7 +238,7 @@ bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
if (!pid_list)
return false;
- data = this_cpu_ptr(tr->trace_buffer.data);
+ data = this_cpu_ptr(tr->array_buffer.data);
return data->ignore_pid;
}
@@ -273,6 +273,7 @@ void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
if (!fbuffer->event)
return NULL;
+ fbuffer->regs = NULL;
fbuffer->entry = ring_buffer_event_data(fbuffer->event);
return fbuffer->entry;
}
@@ -547,7 +548,7 @@ event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
pid_list = rcu_dereference_sched(tr->filtered_pids);
- this_cpu_write(tr->trace_buffer.data->ignore_pid,
+ this_cpu_write(tr->array_buffer.data->ignore_pid,
trace_ignore_this_task(pid_list, prev) &&
trace_ignore_this_task(pid_list, next));
}
@@ -561,7 +562,7 @@ event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
pid_list = rcu_dereference_sched(tr->filtered_pids);
- this_cpu_write(tr->trace_buffer.data->ignore_pid,
+ this_cpu_write(tr->array_buffer.data->ignore_pid,
trace_ignore_this_task(pid_list, next));
}
@@ -572,12 +573,12 @@ event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
struct trace_pid_list *pid_list;
/* Nothing to do if we are already tracing */
- if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
+ if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
return;
pid_list = rcu_dereference_sched(tr->filtered_pids);
- this_cpu_write(tr->trace_buffer.data->ignore_pid,
+ this_cpu_write(tr->array_buffer.data->ignore_pid,
trace_ignore_this_task(pid_list, task));
}
@@ -588,13 +589,13 @@ event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
struct trace_pid_list *pid_list;
/* Nothing to do if we are not tracing */
- if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
+ if (this_cpu_read(tr->array_buffer.data->ignore_pid))
return;
pid_list = rcu_dereference_sched(tr->filtered_pids);
/* Set tracing if current is enabled */
- this_cpu_write(tr->trace_buffer.data->ignore_pid,
+ this_cpu_write(tr->array_buffer.data->ignore_pid,
trace_ignore_this_task(pid_list, current));
}
@@ -626,7 +627,7 @@ static void __ftrace_clear_event_pids(struct trace_array *tr)
}
for_each_possible_cpu(cpu)
- per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
+ per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
rcu_assign_pointer(tr->filtered_pids, NULL);
@@ -1595,7 +1596,7 @@ static void ignore_task_cpu(void *data)
pid_list = rcu_dereference_protected(tr->filtered_pids,
mutex_is_locked(&event_mutex));
- this_cpu_write(tr->trace_buffer.data->ignore_pid,
+ this_cpu_write(tr->array_buffer.data->ignore_pid,
trace_ignore_this_task(pid_list, current));
}
@@ -2553,6 +2554,91 @@ find_event_file(struct trace_array *tr, const char *system, const char *event)
return file;
}
+/**
+ * trace_get_event_file - Find and return a trace event file
+ * @instance: The name of the trace instance containing the event
+ * @system: The name of the system containing the event
+ * @event: The name of the event
+ *
+ * Return a trace event file given the trace instance name, trace
+ * system, and trace event name. If the instance name is NULL, it
+ * refers to the top-level trace array.
+ *
+ * This function will look it up and return it if found, after calling
+ * trace_array_get() to prevent the instance from going away, and
+ * increment the event's module refcount to prevent it from being
+ * removed.
+ *
+ * To release the file, call trace_put_event_file(), which will call
+ * trace_array_put() and decrement the event's module refcount.
+ *
+ * Return: The trace event on success, ERR_PTR otherwise.
+ */
+struct trace_event_file *trace_get_event_file(const char *instance,
+ const char *system,
+ const char *event)
+{
+ struct trace_array *tr = top_trace_array();
+ struct trace_event_file *file = NULL;
+ int ret = -EINVAL;
+
+ if (instance) {
+ tr = trace_array_find_get(instance);
+ if (!tr)
+ return ERR_PTR(-ENOENT);
+ } else {
+ ret = trace_array_get(tr);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
+ mutex_lock(&event_mutex);
+
+ file = find_event_file(tr, system, event);
+ if (!file) {
+ trace_array_put(tr);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Don't let event modules unload while in use */
+ ret = try_module_get(file->event_call->mod);
+ if (!ret) {
+ trace_array_put(tr);
+ ret = -EBUSY;
+ goto out;
+ }
+
+ ret = 0;
+ out:
+ mutex_unlock(&event_mutex);
+
+ if (ret)
+ file = ERR_PTR(ret);
+
+ return file;
+}
+EXPORT_SYMBOL_GPL(trace_get_event_file);
+
+/**
+ * trace_put_event_file - Release a file from trace_get_event_file()
+ * @file: The trace event file
+ *
+ * If a file was retrieved using trace_get_event_file(), this should
+ * be called when it's no longer needed. It will cancel the previous
+ * trace_array_get() called by that function, and decrement the
+ * event's module refcount.
+ */
+void trace_put_event_file(struct trace_event_file *file)
+{
+ mutex_lock(&event_mutex);
+ module_put(file->event_call->mod);
+ mutex_unlock(&event_mutex);
+
+ trace_array_put(file->tr);
+}
+EXPORT_SYMBOL_GPL(trace_put_event_file);
+
#ifdef CONFIG_DYNAMIC_FTRACE
/* Avoid typos */
@@ -3409,8 +3495,8 @@ static void __init
function_test_events_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *pt_regs)
{
+ struct trace_buffer *buffer;
struct ring_buffer_event *event;
- struct ring_buffer *buffer;
struct ftrace_entry *entry;
unsigned long flags;
long disabled;