Merge tag 'trace-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - simplify the Kconfig use of FTRACE and TRACE_IRQFLAGS_SUPPORT

 - bootconfig can now start histograms

 - bootconfig supports group/all enabling

 - histograms now can put values in linear size buckets

 - execnames can be passed to synthetic events

 - introduce "event probes" that attach to other events and can retrieve
   data from pointers of fields, or record fields as different types (a
   pointer to a string as a string instead of just a hex number)

 - various fixes and clean ups

* tag 'trace-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (35 commits)
  tracing/doc: Fix table format in histogram code
  selftests/ftrace: Add selftest for testing duplicate eprobes and kprobes
  selftests/ftrace: Add selftest for testing eprobe events on synthetic events
  selftests/ftrace: Add test case to test adding and removing of event probe
  selftests/ftrace: Fix requirement check of README file
  selftests/ftrace: Add clear_dynamic_events() to test cases
  tracing: Add a probe that attaches to trace events
  tracing/probes: Reject events which have the same name of existing one
  tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs
  tracing/probe: Change traceprobe_set_print_fmt() to take a type
  tracing/probes: Use struct_size() instead of defining custom macros
  tracing/probes: Allow for dot delimiter as well as slash for system names
  tracing/probe: Have traceprobe_parse_probe_arg() take a const arg
  tracing: Have dynamic events have a ref counter
  tracing: Add DYNAMIC flag for dynamic events
  tracing: Replace deprecated CPU-hotplug functions.
  MAINTAINERS: Add an entry for os noise/latency
  tracepoint: Fix kerneldoc comments
  bootconfig/tracing/ktest: Update ktest example for boot-time tracing
  tools/bootconfig: Use per-group/all enable option in ftrace2bconf script
  ...

1 files changed, 51 insertions, 1 deletions

diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 8e0631a4b046..3e475eeb5a99 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -310,8 +310,10 @@ enum {
 	TRACE_EVENT_FL_NO_SET_FILTER_BIT,
 	TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
 	TRACE_EVENT_FL_TRACEPOINT_BIT,
+	TRACE_EVENT_FL_DYNAMIC_BIT,
 	TRACE_EVENT_FL_KPROBE_BIT,
 	TRACE_EVENT_FL_UPROBE_BIT,
+	TRACE_EVENT_FL_EPROBE_BIT,
 };
 
 /*
@@ -321,8 +323,10 @@ enum {
  *  NO_SET_FILTER - Set when filter has error and is to be ignored
  *  IGNORE_ENABLE - For trace internal events, do not enable with debugfs file
  *  TRACEPOINT    - Event is a tracepoint
+ *  DYNAMIC       - Event is a dynamic event (created at run time)
  *  KPROBE        - Event is a kprobe
  *  UPROBE        - Event is a uprobe
+ *  EPROBE        - Event is an event probe
  */
 enum {
 	TRACE_EVENT_FL_FILTERED		= (1 << TRACE_EVENT_FL_FILTERED_BIT),
@@ -330,8 +334,10 @@ enum {
 	TRACE_EVENT_FL_NO_SET_FILTER	= (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
 	TRACE_EVENT_FL_IGNORE_ENABLE	= (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
 	TRACE_EVENT_FL_TRACEPOINT	= (1 << TRACE_EVENT_FL_TRACEPOINT_BIT),
+	TRACE_EVENT_FL_DYNAMIC		= (1 << TRACE_EVENT_FL_DYNAMIC_BIT),
 	TRACE_EVENT_FL_KPROBE		= (1 << TRACE_EVENT_FL_KPROBE_BIT),
 	TRACE_EVENT_FL_UPROBE		= (1 << TRACE_EVENT_FL_UPROBE_BIT),
+	TRACE_EVENT_FL_EPROBE		= (1 << TRACE_EVENT_FL_EPROBE_BIT),
 };
 
 #define TRACE_EVENT_FL_UKPROBE (TRACE_EVENT_FL_KPROBE | TRACE_EVENT_FL_UPROBE)
@@ -347,7 +353,14 @@ struct trace_event_call {
 	struct trace_event	event;
 	char			*print_fmt;
 	struct event_filter	*filter;
-	void			*mod;
+	/*
+	 * Static events can disappear with modules,
+	 * where as dynamic ones need their own ref count.
+	 */
+	union {
+		void				*module;
+		atomic_t			refcnt;
+	};
 	void			*data;
 
 	/* See the TRACE_EVENT_FL_* flags above */
@@ -363,6 +376,42 @@ struct trace_event_call {
 #endif
 };
 
+#ifdef CONFIG_DYNAMIC_EVENTS
+bool trace_event_dyn_try_get_ref(struct trace_event_call *call);
+void trace_event_dyn_put_ref(struct trace_event_call *call);
+bool trace_event_dyn_busy(struct trace_event_call *call);
+#else
+static inline bool trace_event_dyn_try_get_ref(struct trace_event_call *call)
+{
+	/* Without DYNAMIC_EVENTS configured, nothing should be calling this */
+	return false;
+}
+static inline void trace_event_dyn_put_ref(struct trace_event_call *call)
+{
+}
+static inline bool trace_event_dyn_busy(struct trace_event_call *call)
+{
+	/* Nothing should call this without DYNAIMIC_EVENTS configured. */
+	return true;
+}
+#endif
+
+static inline bool trace_event_try_get_ref(struct trace_event_call *call)
+{
+	if (call->flags & TRACE_EVENT_FL_DYNAMIC)
+		return trace_event_dyn_try_get_ref(call);
+	else
+		return try_module_get(call->module);
+}
+
+static inline void trace_event_put_ref(struct trace_event_call *call)
+{
+	if (call->flags & TRACE_EVENT_FL_DYNAMIC)
+		trace_event_dyn_put_ref(call);
+	else
+		module_put(call->module);
+}
+
 #ifdef CONFIG_PERF_EVENTS
 static inline bool bpf_prog_array_valid(struct trace_event_call *call)
 {
@@ -634,6 +683,7 @@ enum event_trigger_type {
 	ETT_EVENT_ENABLE	= (1 << 3),
 	ETT_EVENT_HIST		= (1 << 4),
 	ETT_HIST_ENABLE		= (1 << 5),
+	ETT_EVENT_EPROBE	= (1 << 6),
 };
 
 extern int filter_match_preds(struct event_filter *filter, void *rec);