tracing/events: add support for modules to TRACE_EVENT
Impact: allow modules to add TRACE_EVENTS on load
This patch adds the final hooks to allow modules to use the TRACE_EVENT
macro. A notifier and a data structure are used to link the TRACE_EVENTs
defined in the module to connect them with the ftrace event tracing system.
It also adds the necessary automated clean ups to the trace events when a
module is removed.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 1781085..75f3ac0 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -7,6 +7,7 @@
struct trace_array;
struct tracer;
+struct dentry;
/*
* The trace entry - the most basic unit of tracing. This is what
@@ -87,6 +88,7 @@
char *name;
char *system;
struct dentry *dir;
+ struct trace_event *event;
int enabled;
int (*regfunc)(void);
void (*unregfunc)(void);
@@ -97,6 +99,7 @@
struct list_head fields;
int n_preds;
struct filter_pred **preds;
+ void *mod;
#ifdef CONFIG_EVENT_PROFILE
atomic_t profile_count;
diff --git a/include/linux/module.h b/include/linux/module.h
index 627ac08..6155fa4 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -337,6 +337,10 @@
const char **trace_bprintk_fmt_start;
unsigned int num_trace_bprintk_fmt;
#endif
+#ifdef CONFIG_EVENT_TRACING
+ struct ftrace_event_call *trace_events;
+ unsigned int num_trace_events;
+#endif
#ifdef CONFIG_MODULE_UNLOAD
/* What modules depend on me? */
diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h
index 28051da..15ca2c7 100644
--- a/include/linux/trace_seq.h
+++ b/include/linux/trace_seq.h
@@ -1,6 +1,8 @@
#ifndef _LINUX_TRACE_SEQ_H
#define _LINUX_TRACE_SEQ_H
+#include <linux/fs.h>
+
/*
* Trace sequences are used to allow a function to call several other functions
* to create a string of data to use (up to a max of PAGE_SIZE.