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, 22 insertions, 27 deletions

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index ea6178cb5e33..3a64ba4bbad6 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -80,10 +80,6 @@ static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev)
 	for_each_dyn_event(dpos)		\
 		if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos)))
 
-#define SIZEOF_TRACE_KPROBE(n)				\
-	(offsetof(struct trace_kprobe, tp.args) +	\
-	(sizeof(struct probe_arg) * (n)))
-
 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
 {
 	return tk->rp.handler != NULL;
@@ -265,7 +261,7 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
 	struct trace_kprobe *tk;
 	int ret = -ENOMEM;
 
-	tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
+	tk = kzalloc(struct_size(tk, tp.args, nargs), GFP_KERNEL);
 	if (!tk)
 		return ERR_PTR(ret);
 
@@ -543,6 +539,10 @@ static int unregister_trace_kprobe(struct trace_kprobe *tk)
 	if (trace_probe_is_enabled(&tk->tp))
 		return -EBUSY;
 
+	/* If there's a reference to the dynamic event */
+	if (trace_event_dyn_busy(trace_probe_event_call(&tk->tp)))
+		return -EBUSY;
+
 	/* Will fail if probe is being used by ftrace or perf */
 	if (unregister_kprobe_event(tk))
 		return -EBUSY;
@@ -618,7 +618,7 @@ static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to)
 	if (ret)
 		trace_probe_unlink(&tk->tp);
 	else
-		dyn_event_add(&tk->devent);
+		dyn_event_add(&tk->devent, trace_probe_event_call(&tk->tp));
 
 	return ret;
 }
@@ -647,7 +647,11 @@ static int register_trace_kprobe(struct trace_kprobe *tk)
 	/* Register new event */
 	ret = register_kprobe_event(tk);
 	if (ret) {
-		pr_warn("Failed to register probe event(%d)\n", ret);
+		if (ret == -EEXIST) {
+			trace_probe_log_set_index(0);
+			trace_probe_log_err(0, EVENT_EXIST);
+		} else
+			pr_warn("Failed to register probe event(%d)\n", ret);
 		goto end;
 	}
 
@@ -661,7 +665,7 @@ static int register_trace_kprobe(struct trace_kprobe *tk)
 	if (ret < 0)
 		unregister_kprobe_event(tk);
 	else
-		dyn_event_add(&tk->devent);
+		dyn_event_add(&tk->devent, trace_probe_event_call(&tk->tp));
 
 end:
 	mutex_unlock(&event_mutex);
@@ -703,14 +707,6 @@ static struct notifier_block trace_kprobe_module_nb = {
 	.priority = 1	/* Invoked after kprobe module callback */
 };
 
-/* Convert certain expected symbols into '_' when generating event names */
-static inline void sanitize_event_name(char *name)
-{
-	while (*name++ != '\0')
-		if (*name == ':' || *name == '.')
-			*name = '_';
-}
-
 static int __trace_kprobe_create(int argc, const char *argv[])
 {
 	/*
@@ -742,6 +738,7 @@ static int __trace_kprobe_create(int argc, const char *argv[])
 	bool is_return = false;
 	char *symbol = NULL, *tmp = NULL;
 	const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
+	enum probe_print_type ptype;
 	int maxactive = 0;
 	long offset = 0;
 	void *addr = NULL;
@@ -869,20 +866,14 @@ static int __trace_kprobe_create(int argc, const char *argv[])
 
 	/* parse arguments */
 	for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
-		tmp = kstrdup(argv[i], GFP_KERNEL);
-		if (!tmp) {
-			ret = -ENOMEM;
-			goto error;
-		}
-
 		trace_probe_log_set_index(i + 2);
-		ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags);
-		kfree(tmp);
+		ret = traceprobe_parse_probe_arg(&tk->tp, i, argv[i], flags);
 		if (ret)
 			goto error;	/* This can be -ENOMEM */
 	}
 
-	ret = traceprobe_set_print_fmt(&tk->tp, is_return);
+	ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
+	ret = traceprobe_set_print_fmt(&tk->tp, ptype);
 	if (ret < 0)
 		goto error;
 
@@ -1330,9 +1321,10 @@ probe_mem_read(void *dest, void *src, size_t size)
 
 /* Note that we don't verify it, since the code does not come from user space */
 static int
-process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
+process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 		   void *base)
 {
+	struct pt_regs *regs = rec;
 	unsigned long val;
 
 retry:
@@ -1806,6 +1798,7 @@ struct trace_event_call *
 create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
 			  bool is_return)
 {
+	enum probe_print_type ptype;
 	struct trace_kprobe *tk;
 	int ret;
 	char *event;
@@ -1829,7 +1822,9 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
 
 	init_trace_event_call(tk);
 
-	if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {
+	ptype = trace_kprobe_is_return(tk) ?
+		PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
+	if (traceprobe_set_print_fmt(&tk->tp, ptype) < 0) {
 		ret = -ENOMEM;
 		goto error;
 	}