Merge tag 'trace-3.15-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull more tracing updates from Steven Rostedt:
 "This includes the final patch to clean up and fix the issue with the
  design of tracepoints and how a user could register a tracepoint and
  have that tracepoint not be activated but no error was shown.

  The design was for an out of tree module but broke in tree users.  The
  clean up was to remove the saving of the hash table of tracepoint
  names such that they can be enabled before they exist (enabling a
  module tracepoint before that module is loaded).  This added more
  complexity than needed.  The clean up was to remove that code and just
  enable tracepoints that exist or fail if they do not.

  This removed a lot of code as well as the complexity that it brought.
  As a side effect, instead of registering a tracepoint by its name, the
  tracepoint needs to be registered with the tracepoint descriptor.
  This removes having to duplicate the tracepoint names that are
  enabled.

  The second patch was added that simplified the way modules were
  searched for.

  This cleanup required changes that were in the 3.15 queue as well as
  some changes that were added late in the 3.14-rc cycle.  This final
  change waited till the two were merged in upstream and then the change
  was added and full tests were run.  Unfortunately, the test found some
  errors, but after it was already submitted to the for-next branch and
  not to be rebased.  Sparse errors were detected by Fengguang Wu's bot
  tests, and my internal tests discovered that the anonymous union
  initialization triggered a bug in older gcc compilers.  Luckily, there
  was a bugzilla for the gcc bug which gave a work around to the
  problem.  The third and fourth patch handled the sparse error and the
  gcc bug respectively.

  A final patch was tagged along to fix a missing documentation for the
  README file"

* tag 'trace-3.15-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Add missing function triggers dump and cpudump to README
  tracing: Fix anonymous unions in struct ftrace_event_call
  tracepoint: Fix sparse warnings in tracepoint.c
  tracepoint: Simplify tracepoint module search
  tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints

5 files changed, 69 insertions, 28 deletions

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index cdc30111d2f..d16da3e53bc 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -7,6 +7,7 @@
 #include <linux/percpu.h>
 #include <linux/hardirq.h>
 #include <linux/perf_event.h>
+#include <linux/tracepoint.h>
 
 struct trace_array;
 struct trace_buffer;
@@ -232,6 +233,7 @@ enum {
 	TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
 	TRACE_EVENT_FL_WAS_ENABLED_BIT,
 	TRACE_EVENT_FL_USE_CALL_FILTER_BIT,
+	TRACE_EVENT_FL_TRACEPOINT_BIT,
 };
 
 /*
@@ -244,6 +246,7 @@ enum {
  *                    (used for module unloading, if a module event is enabled,
  *                     it is best to clear the buffers that used it).
  *  USE_CALL_FILTER - For ftrace internal events, don't use file filter
+ *  TRACEPOINT    - Event is a tracepoint
  */
 enum {
 	TRACE_EVENT_FL_FILTERED		= (1 << TRACE_EVENT_FL_FILTERED_BIT),
@@ -252,12 +255,17 @@ enum {
 	TRACE_EVENT_FL_IGNORE_ENABLE	= (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
 	TRACE_EVENT_FL_WAS_ENABLED	= (1 << TRACE_EVENT_FL_WAS_ENABLED_BIT),
 	TRACE_EVENT_FL_USE_CALL_FILTER	= (1 << TRACE_EVENT_FL_USE_CALL_FILTER_BIT),
+	TRACE_EVENT_FL_TRACEPOINT	= (1 << TRACE_EVENT_FL_TRACEPOINT_BIT),
 };
 
 struct ftrace_event_call {
 	struct list_head	list;
 	struct ftrace_event_class *class;
-	char			*name;
+	union {
+		char			*name;
+		/* Set TRACE_EVENT_FL_TRACEPOINT flag when using "tp" */
+		struct tracepoint	*tp;
+	};
 	struct trace_event	event;
 	const char		*print_fmt;
 	struct event_filter	*filter;
@@ -271,6 +279,7 @@ struct ftrace_event_call {
 	 *   bit 3:		ftrace internal event (do not enable)
 	 *   bit 4:		Event was enabled by module
 	 *   bit 5:		use call filter rather than file filter
+	 *   bit 6:		Event is a tracepoint
 	 */
 	int			flags; /* static flags of different events */
 
@@ -283,6 +292,15 @@ struct ftrace_event_call {
 #endif
 };
 
+static inline const char *
+ftrace_event_name(struct ftrace_event_call *call)
+{
+	if (call->flags & TRACE_EVENT_FL_TRACEPOINT)
+		return call->tp ? call->tp->name : NULL;
+	else
+		return call->name;
+}
+
 struct trace_array;
 struct ftrace_subsystem_dir;
 
@@ -353,7 +371,7 @@ struct ftrace_event_file {
 #define __TRACE_EVENT_FLAGS(name, value)				\
 	static int __init trace_init_flags_##name(void)			\
 	{								\
-		event_##name.flags = value;				\
+		event_##name.flags |= value;				\
 		return 0;						\
 	}								\
 	early_initcall(trace_init_flags_##name);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 697ceb70a9a..a4a0588c539 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -119,8 +119,10 @@ extern struct trace_event_functions exit_syscall_print_funcs;
 	static struct syscall_metadata __syscall_meta_##sname;		\
 	static struct ftrace_event_call __used				\
 	  event_enter_##sname = {					\
-		.name                   = "sys_enter"#sname,		\
 		.class			= &event_class_syscall_enter,	\
+		{							\
+			.name                   = "sys_enter"#sname,	\
+		},							\
 		.event.funcs            = &enter_syscall_print_funcs,	\
 		.data			= (void *)&__syscall_meta_##sname,\
 		.flags                  = TRACE_EVENT_FL_CAP_ANY,	\
@@ -133,8 +135,10 @@ extern struct trace_event_functions exit_syscall_print_funcs;
 	static struct syscall_metadata __syscall_meta_##sname;		\
 	static struct ftrace_event_call __used				\
 	  event_exit_##sname = {					\
-		.name                   = "sys_exit"#sname,		\
 		.class			= &event_class_syscall_exit,	\
+		{							\
+			.name                   = "sys_exit"#sname,	\
+		},							\
 		.event.funcs		= &exit_syscall_print_funcs,	\
 		.data			= (void *)&__syscall_meta_##sname,\
 		.flags                  = TRACE_EVENT_FL_CAP_ANY,	\
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 812b2553dfd..9d30ee469c2 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -6,7 +6,7 @@
  *
  * See Documentation/trace/tracepoints.txt.
  *
- * (C) Copyright 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ * Copyright (C) 2008-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * Heavily inspired from the Linux Kernel Markers.
  *
@@ -21,6 +21,7 @@
 
 struct module;
 struct tracepoint;
+struct notifier_block;
 
 struct tracepoint_func {
 	void *func;
@@ -35,31 +36,38 @@ struct tracepoint {
 	struct tracepoint_func __rcu *funcs;
 };
 
-/*
- * Connect a probe to a tracepoint.
- * Internal API, should not be used directly.
- */
-extern int tracepoint_probe_register(const char *name, void *probe, void *data);
-
-/*
- * Disconnect a probe from a tracepoint.
- * Internal API, should not be used directly.
- */
 extern int
-tracepoint_probe_unregister(const char *name, void *probe, void *data);
+tracepoint_probe_register(struct tracepoint *tp, void *probe, void *data);
+extern int
+tracepoint_probe_unregister(struct tracepoint *tp, void *probe, void *data);
+extern void
+for_each_kernel_tracepoint(void (*fct)(struct tracepoint *tp, void *priv),
+		void *priv);
 
 #ifdef CONFIG_MODULES
 struct tp_module {
 	struct list_head list;
-	unsigned int num_tracepoints;
-	struct tracepoint * const *tracepoints_ptrs;
+	struct module *mod;
 };
+
 bool trace_module_has_bad_taint(struct module *mod);
+extern int register_tracepoint_module_notifier(struct notifier_block *nb);
+extern int unregister_tracepoint_module_notifier(struct notifier_block *nb);
 #else
 static inline bool trace_module_has_bad_taint(struct module *mod)
 {
 	return false;
 }
+static inline
+int register_tracepoint_module_notifier(struct notifier_block *nb)
+{
+	return 0;
+}
+static inline
+int unregister_tracepoint_module_notifier(struct notifier_block *nb)
+{
+	return 0;
+}
 #endif /* CONFIG_MODULES */
 
 /*
@@ -72,6 +80,11 @@ static inline void tracepoint_synchronize_unregister(void)
 	synchronize_sched();
 }
 
+#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
+extern void syscall_regfunc(void);
+extern void syscall_unregfunc(void);
+#endif /* CONFIG_HAVE_SYSCALL_TRACEPOINTS */
+
 #define PARAMS(args...) args
 
 #endif /* _LINUX_TRACEPOINT_H */
@@ -160,14 +173,14 @@ static inline void tracepoint_synchronize_unregister(void)
 	static inline int						\
 	register_trace_##name(void (*probe)(data_proto), void *data)	\
 	{								\
-		return tracepoint_probe_register(#name, (void *)probe,	\
-						 data);			\
+		return tracepoint_probe_register(&__tracepoint_##name,	\
+						(void *)probe, data);	\
 	}								\
 	static inline int						\
 	unregister_trace_##name(void (*probe)(data_proto), void *data)	\
 	{								\
-		return tracepoint_probe_unregister(#name, (void *)probe, \
-						   data);		\
+		return tracepoint_probe_unregister(&__tracepoint_##name,\
+						(void *)probe, data);	\
 	}								\
 	static inline void						\
 	check_trace_callback_type_##name(void (*cb)(data_proto))	\
diff --git a/include/trace/events/syscalls.h b/include/trace/events/syscalls.h
index 5a4c04a75b3..14e49c79813 100644
--- a/include/trace/events/syscalls.h
+++ b/include/trace/events/syscalls.h
@@ -13,9 +13,6 @@
 
 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 
-extern void syscall_regfunc(void);
-extern void syscall_unregfunc(void);
-
 TRACE_EVENT_FN(sys_enter,
 
 	TP_PROTO(struct pt_regs *regs, long id),
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 8765126b328..0a1a4f7caf0 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -470,10 +470,13 @@ static inline notrace int ftrace_get_offsets_##call(			\
  * };
  *
  * static struct ftrace_event_call event_<call> = {
- *	.name			= "<call>",
  *	.class			= event_class_<template>,
+ *	{
+ *		.tp			= &__tracepoint_<call>,
+ *	},
  *	.event			= &ftrace_event_type_<call>,
  *	.print_fmt		= print_fmt_<call>,
+ *	.flags			= TRACE_EVENT_FL_TRACEPOINT,
  * };
  * // its only safe to use pointers when doing linker tricks to
  * // create an array.
@@ -605,10 +608,13 @@ static struct ftrace_event_class __used __refdata event_class_##call = { \
 #define DEFINE_EVENT(template, call, proto, args)			\
 									\
 static struct ftrace_event_call __used event_##call = {			\
-	.name			= #call,				\
 	.class			= &event_class_##template,		\
+	{								\
+		.tp			= &__tracepoint_##call,		\
+	},								\
 	.event.funcs		= &ftrace_event_type_funcs_##template,	\
 	.print_fmt		= print_fmt_##template,			\
+	.flags			= TRACE_EVENT_FL_TRACEPOINT,		\
 };									\
 static struct ftrace_event_call __used					\
 __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
@@ -619,10 +625,13 @@ __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
 static const char print_fmt_##call[] = print;				\
 									\
 static struct ftrace_event_call __used event_##call = {			\
-	.name			= #call,				\
 	.class			= &event_class_##template,		\
+	{								\
+		.tp			= &__tracepoint_##call,		\
+	},								\
 	.event.funcs		= &ftrace_event_type_funcs_##call,	\
 	.print_fmt		= print_fmt_##call,			\
+	.flags			= TRACE_EVENT_FL_TRACEPOINT,		\
 };									\
 static struct ftrace_event_call __used					\
 __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call