From 0340a6b7fb767f7f296b9bacc9a215920519a644 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Tue, 18 Aug 2020 15:57:37 +0200
Subject: module: Fix up module_notifier return values

While auditing all module notifiers I noticed a whole bunch of fail
wrt the return value. Notifiers have a 'special' return semantics.

As is; NOTIFY_DONE vs NOTIFY_OK is a bit vague; but
notifier_from_errno(0) results in NOTIFY_OK and NOTIFY_DONE has a
comment that says "Don't care".

From this I've used NOTIFY_DONE when the function completely ignores
the callback and notifier_to_error() isn't used.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Robert Richter <rric@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20200818135804.385360407@infradead.org
---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'kernel/trace/trace.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index f40d850ebabc..df499922b6a4 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9072,7 +9072,7 @@ static int trace_module_notify(struct notifier_block *self,
 		break;
 	}
 
-	return 0;
+	return NOTIFY_OK;
 }
 
 static struct notifier_block trace_module_nb = {
-- 
cgit 


From 22c36b18263426bdd97ef5e04c0e92224c612ee1 Mon Sep 17 00:00:00 2001
From: Wei Yang <richard.weiyang@linux.alibaba.com>
Date: Sun, 12 Jul 2020 09:10:36 +0800
Subject: tracing: make tracing_init_dentry() returns an integer instead of a
 d_entry pointer

Current tracing_init_dentry() return a d_entry pointer, while is not
necessary. This function returns NULL on success or error on failure,
which means there is no valid d_entry pointer return.

Let's return 0 on success and negative value for error.

Link: https://lkml.kernel.org/r/20200712011036.70948-5-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c                 | 36 ++++++++++++++++++------------------
 kernel/trace/trace.h                 |  2 +-
 kernel/trace/trace_dynevent.c        |  8 ++++----
 kernel/trace/trace_events_synth.c    |  9 +++------
 kernel/trace/trace_functions_graph.c |  8 ++++----
 kernel/trace/trace_hwlat.c           |  8 ++++----
 kernel/trace/trace_kprobe.c          | 10 +++++-----
 kernel/trace/trace_printk.c          |  8 ++++----
 kernel/trace/trace_stack.c           | 12 ++++++------
 kernel/trace/trace_stat.c            |  8 ++++----
 kernel/trace/trace_uprobe.c          |  9 ++++-----
 11 files changed, 57 insertions(+), 61 deletions(-)

(limited to 'kernel/trace/trace.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2a7c26345e83..29a9034b38d0 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -8971,21 +8971,21 @@ static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore)
  * directory. It is called via fs_initcall() by any of the boot up code
  * and expects to return the dentry of the top level tracing directory.
  */
-struct dentry *tracing_init_dentry(void)
+int tracing_init_dentry(void)
 {
 	struct trace_array *tr = &global_trace;
 
 	if (security_locked_down(LOCKDOWN_TRACEFS)) {
 		pr_warn("Tracing disabled due to lockdown\n");
-		return ERR_PTR(-EPERM);
+		return -EPERM;
 	}
 
 	/* The top level trace array uses  NULL as parent */
 	if (tr->dir)
-		return NULL;
+		return 0;
 
 	if (WARN_ON(!tracefs_initialized()))
-		return ERR_PTR(-ENODEV);
+		return -ENODEV;
 
 	/*
 	 * As there may still be users that expect the tracing
@@ -8996,7 +8996,7 @@ struct dentry *tracing_init_dentry(void)
 	tr->dir = debugfs_create_automount("tracing", NULL,
 					   trace_automount, NULL);
 
-	return NULL;
+	return 0;
 }
 
 extern struct trace_eval_map *__start_ftrace_eval_maps[];
@@ -9083,48 +9083,48 @@ static struct notifier_block trace_module_nb = {
 
 static __init int tracer_init_tracefs(void)
 {
-	struct dentry *d_tracer;
+	int ret;
 
 	trace_access_lock_init();
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
 	event_trace_init();
 
-	init_tracer_tracefs(&global_trace, d_tracer);
-	ftrace_init_tracefs_toplevel(&global_trace, d_tracer);
+	init_tracer_tracefs(&global_trace, NULL);
+	ftrace_init_tracefs_toplevel(&global_trace, NULL);
 
-	trace_create_file("tracing_thresh", 0644, d_tracer,
+	trace_create_file("tracing_thresh", 0644, NULL,
 			&global_trace, &tracing_thresh_fops);
 
-	trace_create_file("README", 0444, d_tracer,
+	trace_create_file("README", 0444, NULL,
 			NULL, &tracing_readme_fops);
 
-	trace_create_file("saved_cmdlines", 0444, d_tracer,
+	trace_create_file("saved_cmdlines", 0444, NULL,
 			NULL, &tracing_saved_cmdlines_fops);
 
-	trace_create_file("saved_cmdlines_size", 0644, d_tracer,
+	trace_create_file("saved_cmdlines_size", 0644, NULL,
 			  NULL, &tracing_saved_cmdlines_size_fops);
 
-	trace_create_file("saved_tgids", 0444, d_tracer,
+	trace_create_file("saved_tgids", 0444, NULL,
 			NULL, &tracing_saved_tgids_fops);
 
 	trace_eval_init();
 
-	trace_create_eval_file(d_tracer);
+	trace_create_eval_file(NULL);
 
 #ifdef CONFIG_MODULES
 	register_module_notifier(&trace_module_nb);
 #endif
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-	trace_create_file("dyn_ftrace_total_info", 0444, d_tracer,
+	trace_create_file("dyn_ftrace_total_info", 0444, NULL,
 			NULL, &tracing_dyn_info_fops);
 #endif
 
-	create_trace_instances(d_tracer);
+	create_trace_instances(NULL);
 
 	update_tracer_options(&global_trace);
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 610d21355526..0d3a405fe446 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -737,7 +737,7 @@ struct dentry *trace_create_file(const char *name,
 				 void *data,
 				 const struct file_operations *fops);
 
-struct dentry *tracing_init_dentry(void);
+int tracing_init_dentry(void);
 
 struct ring_buffer_event;
 
diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index 9f2e8520b748..9442a9bb080e 100644
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -206,14 +206,14 @@ static const struct file_operations dynamic_events_ops = {
 /* Make a tracefs interface for controlling dynamic events */
 static __init int init_dynamic_event(void)
 {
-	struct dentry *d_tracer;
 	struct dentry *entry;
+	int ret;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
-	entry = tracefs_create_file("dynamic_events", 0644, d_tracer,
+	entry = tracefs_create_file("dynamic_events", 0644, NULL,
 				    NULL, &dynamic_events_ops);
 
 	/* Event list interface */
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index c6cca0d1d584..f86a2aa0bccd 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -1757,7 +1757,6 @@ static const struct file_operations synth_events_fops = {
 static __init int trace_events_synth_init(void)
 {
 	struct dentry *entry = NULL;
-	struct dentry *d_tracer;
 	int err = 0;
 
 	err = dyn_event_register(&synth_event_ops);
@@ -1766,13 +1765,11 @@ static __init int trace_events_synth_init(void)
 		return err;
 	}
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer)) {
-		err = PTR_ERR(d_tracer);
+	err = tracing_init_dentry();
+	if (err)
 		goto err;
-	}
 
-	entry = tracefs_create_file("synthetic_events", 0644, d_tracer,
+	entry = tracefs_create_file("synthetic_events", 0644, NULL,
 				    NULL, &synth_events_fops);
 	if (!entry) {
 		err = -ENODEV;
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 4a9c49c08ec9..60d66278aa0d 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -1336,13 +1336,13 @@ static const struct file_operations graph_depth_fops = {
 
 static __init int init_graph_tracefs(void)
 {
-	struct dentry *d_tracer;
+	int ret;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
-	trace_create_file("max_graph_depth", 0644, d_tracer,
+	trace_create_file("max_graph_depth", 0644, NULL,
 			  NULL, &graph_depth_fops);
 
 	return 0;
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index 17873e5d0353..c9ad5c6fbaad 100644
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -538,14 +538,14 @@ static const struct file_operations window_fops = {
  */
 static int init_tracefs(void)
 {
-	struct dentry *d_tracer;
+	int ret;
 	struct dentry *top_dir;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return -ENOMEM;
 
-	top_dir = tracefs_create_dir("hwlat_detector", d_tracer);
+	top_dir = tracefs_create_dir("hwlat_detector", NULL);
 	if (!top_dir)
 		return -ENOMEM;
 
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index aefb6065b508..feca9b19cd74 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1901,14 +1901,14 @@ subsys_initcall(init_kprobe_trace_early);
 /* Make a tracefs interface for controlling probe points */
 static __init int init_kprobe_trace(void)
 {
-	struct dentry *d_tracer;
+	int ret;
 	struct dentry *entry;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
-	entry = tracefs_create_file("kprobe_events", 0644, d_tracer,
+	entry = tracefs_create_file("kprobe_events", 0644, NULL,
 				    NULL, &kprobe_events_ops);
 
 	/* Event list interface */
@@ -1916,7 +1916,7 @@ static __init int init_kprobe_trace(void)
 		pr_warn("Could not create tracefs 'kprobe_events' entry\n");
 
 	/* Profile interface */
-	entry = tracefs_create_file("kprobe_profile", 0444, d_tracer,
+	entry = tracefs_create_file("kprobe_profile", 0444, NULL,
 				    NULL, &kprobe_profile_ops);
 
 	if (!entry)
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index d4e31e969206..71b2e0fdc3e0 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -367,13 +367,13 @@ static const struct file_operations ftrace_formats_fops = {
 
 static __init int init_trace_printk_function_export(void)
 {
-	struct dentry *d_tracer;
+	int ret;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
-	trace_create_file("printk_formats", 0444, d_tracer,
+	trace_create_file("printk_formats", 0444, NULL,
 				    NULL, &ftrace_formats_fops);
 
 	return 0;
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 98bba4764c52..c408423e5d65 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -554,20 +554,20 @@ __setup("stacktrace", enable_stacktrace);
 
 static __init int stack_trace_init(void)
 {
-	struct dentry *d_tracer;
+	int ret;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
-	trace_create_file("stack_max_size", 0644, d_tracer,
+	trace_create_file("stack_max_size", 0644, NULL,
 			&stack_trace_max_size, &stack_max_size_fops);
 
-	trace_create_file("stack_trace", 0444, d_tracer,
+	trace_create_file("stack_trace", 0444, NULL,
 			NULL, &stack_trace_fops);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-	trace_create_file("stack_trace_filter", 0644, d_tracer,
+	trace_create_file("stack_trace_filter", 0644, NULL,
 			  &trace_ops, &stack_trace_filter_fops);
 #endif
 
diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index d1fa19773cc8..8d141c3825a9 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -276,13 +276,13 @@ static const struct file_operations tracing_stat_fops = {
 
 static int tracing_stat_init(void)
 {
-	struct dentry *d_tracing;
+	int ret;
 
-	d_tracing = tracing_init_dentry();
-	if (IS_ERR(d_tracing))
+	ret = tracing_init_dentry();
+	if (ret)
 		return -ENODEV;
 
-	stat_dir = tracefs_create_dir("trace_stat", d_tracing);
+	stat_dir = tracefs_create_dir("trace_stat", NULL);
 	if (!stat_dir) {
 		pr_warn("Could not create tracefs 'trace_stat' entry\n");
 		return -ENOMEM;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index f4286c9bdeb4..56729c6b6614 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1625,21 +1625,20 @@ void destroy_local_trace_uprobe(struct trace_event_call *event_call)
 /* Make a trace interface for controling probe points */
 static __init int init_uprobe_trace(void)
 {
-	struct dentry *d_tracer;
 	int ret;
 
 	ret = dyn_event_register(&trace_uprobe_ops);
 	if (ret)
 		return ret;
 
-	d_tracer = tracing_init_dentry();
-	if (IS_ERR(d_tracer))
+	ret = tracing_init_dentry();
+	if (ret)
 		return 0;
 
-	trace_create_file("uprobe_events", 0644, d_tracer,
+	trace_create_file("uprobe_events", 0644, NULL,
 				    NULL, &uprobe_events_ops);
 	/* Profile interface */
-	trace_create_file("uprobe_profile", 0444, d_tracer,
+	trace_create_file("uprobe_profile", 0444, NULL,
 				    NULL, &uprobe_profile_ops);
 	return 0;
 }
-- 
cgit 


From 5c8c206e4308ee33dea7c60b0cfcbed48a6438b4 Mon Sep 17 00:00:00 2001
From: Randy Dunlap <rdunlap@infradead.org>
Date: Thu, 6 Aug 2020 20:32:59 -0700
Subject: tracing: Delete repeated words in comments

Drop repeated words in kernel/trace/.
{and, the, not}

Link: https://lkml.kernel.org/r/20200807033259.13778-1-rdunlap@infradead.org

Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c             | 2 +-
 kernel/trace/trace.c              | 2 +-
 kernel/trace/trace_dynevent.c     | 2 +-
 kernel/trace/trace_events_synth.c | 2 +-
 kernel/trace/tracing_map.c        | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

(limited to 'kernel/trace/trace.c')

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 603255f5f085..84f32dbc7be8 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2402,7 +2402,7 @@ struct ftrace_ops direct_ops = {
  *
  * If the record has the FTRACE_FL_REGS set, that means that it
  * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
- * is not not set, then it wants to convert to the normal callback.
+ * is not set, then it wants to convert to the normal callback.
  *
  * Returns the address of the trampoline to set to
  */
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 29a9034b38d0..8fac7d6db222 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9287,7 +9287,7 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 	}
 
 	/*
-	 * We need to stop all tracing on all CPUS to read the
+	 * We need to stop all tracing on all CPUS to read
 	 * the next buffer. This is a bit expensive, but is
 	 * not done often. We fill all what we can read,
 	 * and then release the locks again.
diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index 9442a9bb080e..5fa49cfd2bb6 100644
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -402,7 +402,7 @@ void dynevent_arg_init(struct dynevent_arg *arg,
  * whitespace, all followed by a separator, if applicable.  After the
  * first arg string is successfully appended to the command string,
  * the optional @operator is appended, followed by the second arg and
- * and optional @separator.  If no separator was specified when
+ * optional @separator.  If no separator was specified when
  * initializing the arg, a space will be appended.
  */
 void dynevent_arg_pair_init(struct dynevent_arg_pair *arg_pair,
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index f86a2aa0bccd..7c765e80e974 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -1211,7 +1211,7 @@ __synth_event_trace_start(struct trace_event_file *file,
 	 * ENABLED bit is set (which attaches the probe thus allowing
 	 * this code to be called, etc).  Because this is called
 	 * directly by the user, we don't have that but we still need
-	 * to honor not logging when disabled.  For the the iterated
+	 * to honor not logging when disabled.  For the iterated
 	 * trace case, we save the enabed state upon start and just
 	 * ignore the following data calls.
 	 */
diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c
index 74738c9856f1..4b50fc0cb12c 100644
--- a/kernel/trace/tracing_map.c
+++ b/kernel/trace/tracing_map.c
@@ -260,7 +260,7 @@ int tracing_map_add_var(struct tracing_map *map)
  * to use cmp_fn.
  *
  * A key can be a subset of a compound key; for that purpose, the
- * offset param is used to describe where within the the compound key
+ * offset param is used to describe where within the compound key
  * the key referenced by this key field resides.
  *
  * Return: The index identifying the field in the map and associated
-- 
cgit 


From b427e765bdffcc18911ace199a17b09332a47d55 Mon Sep 17 00:00:00 2001
From: Xianting Tian <tian.xianting@h3c.com>
Date: Thu, 13 Aug 2020 19:28:03 +0800
Subject: tracing: Use __this_cpu_read() in trace_buffered_event_enable()

The code is executed with preemption disabled, so it's
safe to use __this_cpu_read().

Link: https://lkml.kernel.org/r/20200813112803.12256-1-tian.xianting@h3c.com

Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'kernel/trace/trace.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8fac7d6db222..1c4ca25944ba 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2511,7 +2511,7 @@ void trace_buffered_event_enable(void)
 
 		preempt_disable();
 		if (cpu == smp_processor_id() &&
-		    this_cpu_read(trace_buffered_event) !=
+		    __this_cpu_read(trace_buffered_event) !=
 		    per_cpu(trace_buffered_event, cpu))
 			WARN_ON_ONCE(1);
 		preempt_enable();
-- 
cgit 


From eb8d8b4c9848b200586aa98e105b39f159656ba6 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Sat, 5 Sep 2020 15:50:20 +0300
Subject: tracing: remove a pointless assignment

The "tr" is a stack variable so setting it to NULL before a return is
a no-op.  Delete the assignment.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 1 -
 1 file changed, 1 deletion(-)

(limited to 'kernel/trace/trace.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1c4ca25944ba..55b829863127 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -8799,7 +8799,6 @@ static int __remove_instance(struct trace_array *tr)
 	free_cpumask_var(tr->tracing_cpumask);
 	kfree(tr->name);
 	kfree(tr);
-	tr = NULL;
 
 	return 0;
 }
-- 
cgit 


From 4725cd89978c26405a20414f3a0fa6cbd2bf9aad Mon Sep 17 00:00:00 2001
From: Masami Hiramatsu <mhiramat@kernel.org>
Date: Thu, 10 Sep 2020 17:55:35 +0900
Subject: tracing/kprobes: Support perf-style return probe

Support perf-style return probe ("SYMBOL%return") for kprobe events.
This will allow boot-time tracing user to define a return probe event.

Link: https://lkml.kernel.org/r/159972813535.428528.4437029657208468954.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c        |  2 +-
 kernel/trace/trace_kprobe.c | 18 +++++++++++++++++-
 kernel/trace/trace_probe.h  |  1 +
 3 files changed, 19 insertions(+), 2 deletions(-)

(limited to 'kernel/trace/trace.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 55b829863127..ca6da462326d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5122,7 +5122,7 @@ static const char readme_msg[] =
 	"\t           -:[<group>/]<event>\n"
 #ifdef CONFIG_KPROBE_EVENTS
 	"\t    place: [<module>:]<symbol>[+<offset>]|<memaddr>\n"
-  "place (kretprobe): [<module>:]<symbol>[+<offset>]|<memaddr>\n"
+  "place (kretprobe): [<module>:]<symbol>[+<offset>]%return|<memaddr>\n"
 #endif
 #ifdef CONFIG_UPROBE_EVENTS
   "   place (uprobe): <path>:<offset>[(ref_ctr_offset)]\n"
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index f8e46929ceba..9d46415296eb 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -718,6 +718,9 @@ static int trace_kprobe_create(int argc, const char *argv[])
 	 *      p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
 	 *  - Add kretprobe:
 	 *      r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
+	 *    Or
+	 *      p:[GRP/]EVENT] [MOD:]KSYM[+0]%return [FETCHARGS]
+	 *
 	 * Fetch args:
 	 *  $retval	: fetch return value
 	 *  $stack	: fetch stack address
@@ -747,7 +750,6 @@ static int trace_kprobe_create(int argc, const char *argv[])
 	switch (argv[0][0]) {
 	case 'r':
 		is_return = true;
-		flags |= TPARG_FL_RETURN;
 		break;
 	case 'p':
 		break;
@@ -805,12 +807,26 @@ static int trace_kprobe_create(int argc, const char *argv[])
 		symbol = kstrdup(argv[1], GFP_KERNEL);
 		if (!symbol)
 			return -ENOMEM;
+
+		tmp = strchr(symbol, '%');
+		if (tmp) {
+			if (!strcmp(tmp, "%return")) {
+				*tmp = '\0';
+				is_return = true;
+			} else {
+				trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
+				goto parse_error;
+			}
+		}
+
 		/* TODO: support .init module functions */
 		ret = traceprobe_split_symbol_offset(symbol, &offset);
 		if (ret || offset < 0 || offset > UINT_MAX) {
 			trace_probe_log_err(0, BAD_PROBE_ADDR);
 			goto parse_error;
 		}
+		if (is_return)
+			flags |= TPARG_FL_RETURN;
 		if (kprobe_on_func_entry(NULL, symbol, offset))
 			flags |= TPARG_FL_FENTRY;
 		if (offset && is_return && !(flags & TPARG_FL_FENTRY)) {
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index a22b62813f8c..04d00987da69 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -404,6 +404,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
 	C(MAXACT_TOO_BIG,	"Maxactive is too big"),		\
 	C(BAD_PROBE_ADDR,	"Invalid probed address or symbol"),	\
 	C(BAD_RETPROBE,		"Retprobe address must be an function entry"), \
+	C(BAD_ADDR_SUFFIX,	"Invalid probed address suffix"), \
 	C(NO_GROUP_NAME,	"Group name is not specified"),		\
 	C(GROUP_TOO_LONG,	"Group name is too long"),		\
 	C(BAD_GROUP_NAME,	"Group name must follow the same rules as C identifiers"), \
-- 
cgit 


From 3dd3aae32dc91efab916b28cf95986186c6e8d6b Mon Sep 17 00:00:00 2001
From: Masami Hiramatsu <mhiramat@kernel.org>
Date: Thu, 10 Sep 2020 17:55:46 +0900
Subject: tracing/uprobes: Support perf-style return probe

Support perf-style return probe ("SYMBOL%return") for uprobe events
as same as kprobe events does.

Link: https://lkml.kernel.org/r/159972814601.428528.7641183316212425445.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c        |  2 +-
 kernel/trace/trace_uprobe.c | 15 ++++++++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

(limited to 'kernel/trace/trace.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ca6da462326d..c35fcd2f2529 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5125,7 +5125,7 @@ static const char readme_msg[] =
   "place (kretprobe): [<module>:]<symbol>[+<offset>]%return|<memaddr>\n"
 #endif
 #ifdef CONFIG_UPROBE_EVENTS
-  "   place (uprobe): <path>:<offset>[(ref_ctr_offset)]\n"
+  "   place (uprobe): <path>:<offset>[%return][(ref_ctr_offset)]\n"
 #endif
 	"\t     args: <name>=fetcharg[:type]\n"
 	"\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n"
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 56729c6b6614..3cf7128e1ad3 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -528,7 +528,7 @@ end:
 
 /*
  * Argument syntax:
- *  - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
+ *  - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET[%return][(REF)] [FETCHARGS]
  */
 static int trace_uprobe_create(int argc, const char **argv)
 {
@@ -617,6 +617,19 @@ static int trace_uprobe_create(int argc, const char **argv)
 		}
 	}
 
+	/* Check if there is %return suffix */
+	tmp = strchr(arg, '%');
+	if (tmp) {
+		if (!strcmp(tmp, "%return")) {
+			*tmp = '\0';
+			is_return = true;
+		} else {
+			trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
+			ret = -EINVAL;
+			goto fail_address_parse;
+		}
+	}
+
 	/* Parse uprobe offset. */
 	ret = kstrtoul(arg, 0, &offset);
 	if (ret) {
-- 
cgit 


From 4114fbfd02f12d7a58cc4bd6fc36e0925266f9f7 Mon Sep 17 00:00:00 2001
From: Masami Hiramatsu <mhiramat@kernel.org>
Date: Thu, 10 Sep 2020 21:39:07 +0900
Subject: tracing: Enable creating new instance early boot

Enable creating new trace_array instance in early boot stage.
If the instances directory is not created, postpone it until
the tracefs is initialized.

Link: https://lkml.kernel.org/r/159974154763.478751.6289753509587233103.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c           | 53 +++++++++++++++++++++++++++++++++---------
 kernel/trace/trace.h           |  7 ++++++
 kernel/trace/trace_functions.c | 22 +++++++++++-------
 3 files changed, 63 insertions(+), 19 deletions(-)

(limited to 'kernel/trace/trace.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c35fcd2f2529..6211a13b3327 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -8636,6 +8636,24 @@ struct trace_array *trace_array_find_get(const char *instance)
 	return tr;
 }
 
+static int trace_array_create_dir(struct trace_array *tr)
+{
+	int ret;
+
+	tr->dir = tracefs_create_dir(tr->name, trace_instance_dir);
+	if (!tr->dir)
+		return -EINVAL;
+
+	ret = event_trace_add_tracer(tr->dir, tr);
+	if (ret)
+		tracefs_remove(tr->dir);
+
+	init_tracer_tracefs(tr, tr->dir);
+	__update_tracer_options(tr);
+
+	return ret;
+}
+
 static struct trace_array *trace_array_create(const char *name)
 {
 	struct trace_array *tr;
@@ -8671,30 +8689,27 @@ static struct trace_array *trace_array_create(const char *name)
 	if (allocate_trace_buffers(tr, trace_buf_size) < 0)
 		goto out_free_tr;
 
-	tr->dir = tracefs_create_dir(name, trace_instance_dir);
-	if (!tr->dir)
-		goto out_free_tr;
-
-	ret = event_trace_add_tracer(tr->dir, tr);
-	if (ret) {
-		tracefs_remove(tr->dir);
+	if (ftrace_allocate_ftrace_ops(tr) < 0)
 		goto out_free_tr;
-	}
 
 	ftrace_init_trace_array(tr);
 
-	init_tracer_tracefs(tr, tr->dir);
 	init_trace_flags_index(tr);
-	__update_tracer_options(tr);
+
+	if (trace_instance_dir) {
+		ret = trace_array_create_dir(tr);
+		if (ret)
+			goto out_free_tr;
+	}
 
 	list_add(&tr->list, &ftrace_trace_arrays);
 
 	tr->ref++;
 
-
 	return tr;
 
  out_free_tr:
+	ftrace_free_ftrace_ops(tr);
 	free_trace_buffers(tr);
 	free_cpumask_var(tr->tracing_cpumask);
 	kfree(tr->name);
@@ -8852,11 +8867,27 @@ static int instance_rmdir(const char *name)
 
 static __init void create_trace_instances(struct dentry *d_tracer)
 {
+	struct trace_array *tr;
+
 	trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer,
 							 instance_mkdir,
 							 instance_rmdir);
 	if (MEM_FAIL(!trace_instance_dir, "Failed to create instances directory\n"))
 		return;
+
+	mutex_lock(&event_mutex);
+	mutex_lock(&trace_types_lock);
+
+	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+		if (!tr->name)
+			continue;
+		if (MEM_FAIL(trace_array_create_dir(tr) < 0,
+			     "Failed to create instance directory\n"))
+			break;
+	}
+
+	mutex_unlock(&trace_types_lock);
+	mutex_unlock(&event_mutex);
 }
 
 static void
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 0d3a405fe446..525434145eea 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1125,6 +1125,8 @@ extern int ftrace_is_dead(void);
 int ftrace_create_function_files(struct trace_array *tr,
 				 struct dentry *parent);
 void ftrace_destroy_function_files(struct trace_array *tr);
+int ftrace_allocate_ftrace_ops(struct trace_array *tr);
+void ftrace_free_ftrace_ops(struct trace_array *tr);
 void ftrace_init_global_array_ops(struct trace_array *tr);
 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
 void ftrace_reset_array_ops(struct trace_array *tr);
@@ -1146,6 +1148,11 @@ ftrace_create_function_files(struct trace_array *tr,
 {
 	return 0;
 }
+static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
+{
+	return 0;
+}
+static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
 static inline __init void
 ftrace_init_global_array_ops(struct trace_array *tr) { }
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index dd4dff71d89a..2c2126e1871d 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -34,10 +34,14 @@ enum {
 	TRACE_FUNC_OPT_STACK	= 0x1,
 };
 
-static int allocate_ftrace_ops(struct trace_array *tr)
+int ftrace_allocate_ftrace_ops(struct trace_array *tr)
 {
 	struct ftrace_ops *ops;
 
+	/* The top level array uses the "global_ops" */
+	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
+		return 0;
+
 	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
 	if (!ops)
 		return -ENOMEM;
@@ -48,15 +52,19 @@ static int allocate_ftrace_ops(struct trace_array *tr)
 
 	tr->ops = ops;
 	ops->private = tr;
+
 	return 0;
 }
 
+void ftrace_free_ftrace_ops(struct trace_array *tr)
+{
+	kfree(tr->ops);
+	tr->ops = NULL;
+}
 
 int ftrace_create_function_files(struct trace_array *tr,
 				 struct dentry *parent)
 {
-	int ret;
-
 	/*
 	 * The top level array uses the "global_ops", and the files are
 	 * created on boot up.
@@ -64,9 +72,8 @@ int ftrace_create_function_files(struct trace_array *tr,
 	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
 		return 0;
 
-	ret = allocate_ftrace_ops(tr);
-	if (ret)
-		return ret;
+	if (!tr->ops)
+		return -EINVAL;
 
 	ftrace_create_filter_files(tr->ops, parent);
 
@@ -76,8 +83,7 @@ int ftrace_create_function_files(struct trace_array *tr,
 void ftrace_destroy_function_files(struct trace_array *tr)
 {
 	ftrace_destroy_filter_files(tr->ops);
-	kfree(tr->ops);
-	tr->ops = NULL;
+	ftrace_free_ftrace_ops(tr);
 }
 
 static int function_trace_init(struct trace_array *tr)
-- 
cgit 


From 720dee53ad8dfd528941fbbc264574601b04488a Mon Sep 17 00:00:00 2001
From: Masami Hiramatsu <mhiramat@kernel.org>
Date: Fri, 25 Sep 2020 01:40:08 +0900
Subject: tracing/boot: Initialize per-instance event list in early boot

Initialize per-instance event list in early boot time (before
initializing instance directory on tracefs). This fixes boot-time
tracing to correctly handle the boot-time per-instance settings.

Link: https://lkml.kernel.org/r/160096560826.182763.17110991546046128881.stgit@devnote2

Fixes: 4114fbfd02f1 ("tracing: Enable creating new instance early boot")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c        |  3 ++-
 kernel/trace/trace.h        |  1 +
 kernel/trace/trace_events.c | 30 ++++++++++++++++--------------
 3 files changed, 19 insertions(+), 15 deletions(-)

(limited to 'kernel/trace/trace.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 6211a13b3327..3f2533adae72 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -8700,7 +8700,8 @@ static struct trace_array *trace_array_create(const char *name)
 		ret = trace_array_create_dir(tr);
 		if (ret)
 			goto out_free_tr;
-	}
+	} else
+		__trace_early_add_events(tr);
 
 	list_add(&tr->list, &ftrace_trace_arrays);
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 525434145eea..5b0e797cacdd 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1658,6 +1658,7 @@ extern void trace_event_enable_tgid_record(bool enable);
 extern int event_trace_init(void);
 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
 extern int event_trace_del_tracer(struct trace_array *tr);
+extern void __trace_early_add_events(struct trace_array *tr);
 
 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
 						  const char *system,
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 42c0e7df6e70..851ab37058dd 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -3131,14 +3131,13 @@ static inline int register_event_cmds(void) { return 0; }
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 /*
- * The top level array has already had its trace_event_file
- * descriptors created in order to allow for early events to
- * be recorded. This function is called after the tracefs has been
- * initialized, and we now have to create the files associated
- * to the events.
+ * The top level array and trace arrays created by boot-time tracing
+ * have already had its trace_event_file descriptors created in order
+ * to allow for early events to be recorded.
+ * This function is called after the tracefs has been initialized,
+ * and we now have to create the files associated to the events.
  */
-static __init void
-__trace_early_add_event_dirs(struct trace_array *tr)
+static void __trace_early_add_event_dirs(struct trace_array *tr)
 {
 	struct trace_event_file *file;
 	int ret;
@@ -3153,13 +3152,12 @@ __trace_early_add_event_dirs(struct trace_array *tr)
 }
 
 /*
- * For early boot up, the top trace array requires to have
- * a list of events that can be enabled. This must be done before
- * the filesystem is set up in order to allow events to be traced
- * early.
+ * For early boot up, the top trace array and the trace arrays created
+ * by boot-time tracing require to have a list of events that can be
+ * enabled. This must be done before the filesystem is set up in order
+ * to allow events to be traced early.
  */
-static __init void
-__trace_early_add_events(struct trace_array *tr)
+void __trace_early_add_events(struct trace_array *tr)
 {
 	struct trace_event_call *call;
 	int ret;
@@ -3290,7 +3288,11 @@ int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
 		goto out;
 
 	down_write(&trace_event_sem);
-	__trace_add_event_dirs(tr);
+	/* If tr already has the event list, it is initialized in early boot. */
+	if (unlikely(!list_empty(&tr->events)))
+		__trace_early_add_event_dirs(tr);
+	else
+		__trace_add_event_dirs(tr);
 	up_write(&trace_event_sem);
 
  out:
-- 
cgit 


From 8438f5211479e4b8433f641634362264bc3bbd9e Mon Sep 17 00:00:00 2001
From: Tingwei Zhang <tingwei@codeaurora.org>
Date: Mon, 5 Oct 2020 10:13:13 +0300
Subject: tracing: Add flag to control different traces

More traces like event trace or trace marker will be supported.
Add flag for difference traces, so that they can be controlled
separately. Move current function trace to it's own flag
instead of global ftrace enable flag.

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20201005071319.78508-3-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/linux/trace.h |  5 +++++
 kernel/trace/trace.c  | 36 +++++++++++++++++++-----------------
 2 files changed, 24 insertions(+), 17 deletions(-)

(limited to 'kernel/trace/trace.c')

diff --git a/include/linux/trace.h b/include/linux/trace.h
index 36d255d66f88..c115a5d2269f 100644
--- a/include/linux/trace.h
+++ b/include/linux/trace.h
@@ -3,6 +3,9 @@
 #define _LINUX_TRACE_H
 
 #ifdef CONFIG_TRACING
+
+#define TRACE_EXPORT_FUNCTION	BIT(0)
+
 /*
  * The trace export - an export of Ftrace output. The trace_export
  * can process traces and export them to a registered destination as
@@ -15,10 +18,12 @@
  * next		- pointer to the next trace_export
  * write	- copy traces which have been delt with ->commit() to
  *		  the destination
+ * flags	- which ftrace to be exported
  */
 struct trace_export {
 	struct trace_export __rcu	*next;
 	void (*write)(struct trace_export *, const void *, unsigned int);
+	int flags;
 };
 
 int register_ftrace_export(struct trace_export *export);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index f40d850ebabc..3ca121ad8728 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2744,33 +2744,37 @@ trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
 
 static void
 trace_process_export(struct trace_export *export,
-	       struct ring_buffer_event *event)
+	       struct ring_buffer_event *event, int flag)
 {
 	struct trace_entry *entry;
 	unsigned int size = 0;
 
-	entry = ring_buffer_event_data(event);
-	size = ring_buffer_event_length(event);
-	export->write(export, entry, size);
+	if (export->flags & flag) {
+		entry = ring_buffer_event_data(event);
+		size = ring_buffer_event_length(event);
+		export->write(export, entry, size);
+	}
 }
 
 static DEFINE_MUTEX(ftrace_export_lock);
 
 static struct trace_export __rcu *ftrace_exports_list __read_mostly;
 
-static DEFINE_STATIC_KEY_FALSE(ftrace_exports_enabled);
+static DEFINE_STATIC_KEY_FALSE(trace_function_exports_enabled);
 
-static inline void ftrace_exports_enable(void)
+static inline void ftrace_exports_enable(struct trace_export *export)
 {
-	static_branch_enable(&ftrace_exports_enabled);
+	if (export->flags & TRACE_EXPORT_FUNCTION)
+		static_branch_inc(&trace_function_exports_enabled);
 }
 
-static inline void ftrace_exports_disable(void)
+static inline void ftrace_exports_disable(struct trace_export *export)
 {
-	static_branch_disable(&ftrace_exports_enabled);
+	if (export->flags & TRACE_EXPORT_FUNCTION)
+		static_branch_dec(&trace_function_exports_enabled);
 }
 
-static void ftrace_exports(struct ring_buffer_event *event)
+static void ftrace_exports(struct ring_buffer_event *event, int flag)
 {
 	struct trace_export *export;
 
@@ -2778,7 +2782,7 @@ static void ftrace_exports(struct ring_buffer_event *event)
 
 	export = rcu_dereference_raw_check(ftrace_exports_list);
 	while (export) {
-		trace_process_export(export, event);
+		trace_process_export(export, event, flag);
 		export = rcu_dereference_raw_check(export->next);
 	}
 
@@ -2818,8 +2822,7 @@ rm_trace_export(struct trace_export **list, struct trace_export *export)
 static inline void
 add_ftrace_export(struct trace_export **list, struct trace_export *export)
 {
-	if (*list == NULL)
-		ftrace_exports_enable();
+	ftrace_exports_enable(export);
 
 	add_trace_export(list, export);
 }
@@ -2830,8 +2833,7 @@ rm_ftrace_export(struct trace_export **list, struct trace_export *export)
 	int ret;
 
 	ret = rm_trace_export(list, export);
-	if (*list == NULL)
-		ftrace_exports_disable();
+	ftrace_exports_disable(export);
 
 	return ret;
 }
@@ -2884,8 +2886,8 @@ trace_function(struct trace_array *tr,
 	entry->parent_ip		= parent_ip;
 
 	if (!call_filter_check_discard(call, entry, buffer, event)) {
-		if (static_branch_unlikely(&ftrace_exports_enabled))
-			ftrace_exports(event);
+		if (static_branch_unlikely(&trace_function_exports_enabled))
+			ftrace_exports(event, TRACE_EXPORT_FUNCTION);
 		__buffer_unlock_commit(buffer, event);
 	}
 }
-- 
cgit 


From 8ab7a2b7055c88c3da5e4684dfa015c6a8987c28 Mon Sep 17 00:00:00 2001
From: Tingwei Zhang <tingwei@codeaurora.org>
Date: Mon, 5 Oct 2020 10:13:14 +0300
Subject: tracing: Add trace_export support for event trace

Only function traces can be exported to other destinations currently.
This patch exports event trace as well. Move trace export related
function to the beginning of file so other trace can call
trace_process_export() to export.

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20201005071319.78508-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/linux/trace.h |   1 +
 kernel/trace/trace.c  | 259 ++++++++++++++++++++++++++------------------------
 2 files changed, 135 insertions(+), 125 deletions(-)

(limited to 'kernel/trace/trace.c')

diff --git a/include/linux/trace.h b/include/linux/trace.h
index c115a5d2269f..86033d214972 100644
--- a/include/linux/trace.h
+++ b/include/linux/trace.h
@@ -5,6 +5,7 @@
 #ifdef CONFIG_TRACING
 
 #define TRACE_EXPORT_FUNCTION	BIT(0)
+#define TRACE_EXPORT_EVENT	BIT(1)
 
 /*
  * The trace export - an export of Ftrace output. The trace_export
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 3ca121ad8728..a40ee413123c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -251,6 +251,138 @@ unsigned long long ns2usecs(u64 nsec)
 	return nsec;
 }
 
+static void
+trace_process_export(struct trace_export *export,
+	       struct ring_buffer_event *event, int flag)
+{
+	struct trace_entry *entry;
+	unsigned int size = 0;
+
+	if (export->flags & flag) {
+		entry = ring_buffer_event_data(event);
+		size = ring_buffer_event_length(event);
+		export->write(export, entry, size);
+	}
+}
+
+static DEFINE_MUTEX(ftrace_export_lock);
+
+static struct trace_export __rcu *ftrace_exports_list __read_mostly;
+
+static DEFINE_STATIC_KEY_FALSE(trace_function_exports_enabled);
+static DEFINE_STATIC_KEY_FALSE(trace_event_exports_enabled);
+
+static inline void ftrace_exports_enable(struct trace_export *export)
+{
+	if (export->flags & TRACE_EXPORT_FUNCTION)
+		static_branch_inc(&trace_function_exports_enabled);
+
+	if (export->flags & TRACE_EXPORT_EVENT)
+		static_branch_inc(&trace_event_exports_enabled);
+}
+
+static inline void ftrace_exports_disable(struct trace_export *export)
+{
+	if (export->flags & TRACE_EXPORT_FUNCTION)
+		static_branch_dec(&trace_function_exports_enabled);
+
+	if (export->flags & TRACE_EXPORT_EVENT)
+		static_branch_dec(&trace_event_exports_enabled);
+}
+
+static void ftrace_exports(struct ring_buffer_event *event, int flag)
+{
+	struct trace_export *export;
+
+	preempt_disable_notrace();
+
+	export = rcu_dereference_raw_check(ftrace_exports_list);
+	while (export) {
+		trace_process_export(export, event, flag);
+		export = rcu_dereference_raw_check(export->next);
+	}
+
+	preempt_enable_notrace();
+}
+
+static inline void
+add_trace_export(struct trace_export **list, struct trace_export *export)
+{
+	rcu_assign_pointer(export->next, *list);
+	/*
+	 * We are entering export into the list but another
+	 * CPU might be walking that list. We need to make sure
+	 * the export->next pointer is valid before another CPU sees
+	 * the export pointer included into the list.
+	 */
+	rcu_assign_pointer(*list, export);
+}
+
+static inline int
+rm_trace_export(struct trace_export **list, struct trace_export *export)
+{
+	struct trace_export **p;
+
+	for (p = list; *p != NULL; p = &(*p)->next)
+		if (*p == export)
+			break;
+
+	if (*p != export)
+		return -1;
+
+	rcu_assign_pointer(*p, (*p)->next);
+
+	return 0;
+}
+
+static inline void
+add_ftrace_export(struct trace_export **list, struct trace_export *export)
+{
+	ftrace_exports_enable(export);
+
+	add_trace_export(list, export);
+}
+
+static inline int
+rm_ftrace_export(struct trace_export **list, struct trace_export *export)
+{
+	int ret;
+
+	ret = rm_trace_export(list, export);
+	ftrace_exports_disable(export);
+
+	return ret;
+}
+
+int register_ftrace_export(struct trace_export *export)
+{
+	if (WARN_ON_ONCE(!export->write))
+		return -1;
+
+	mutex_lock(&ftrace_export_lock);
+
+	add_ftrace_export(&ftrace_exports_list, export);
+
+	mutex_unlock(&ftrace_export_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(register_ftrace_export);
+
+int unregister_ftrace_export(struct trace_export *export)
+{
+	int ret;
+
+	mutex_lock(&ftrace_export_lock);
+
+	ret = rm_ftrace_export(&ftrace_exports_list, export);
+
+	mutex_unlock(&ftrace_export_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(unregister_ftrace_export);
+
 /* trace_flags holds trace_options default values */
 #define TRACE_DEFAULT_FLAGS						\
 	(FUNCTION_DEFAULT_FLAGS |					\
@@ -2699,6 +2831,8 @@ void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
 	if (static_key_false(&tracepoint_printk_key.key))
 		output_printk(fbuffer);
 
+	if (static_branch_unlikely(&trace_event_exports_enabled))
+		ftrace_exports(fbuffer->event, TRACE_EXPORT_EVENT);
 	event_trigger_unlock_commit_regs(fbuffer->trace_file, fbuffer->buffer,
 				    fbuffer->event, fbuffer->entry,
 				    fbuffer->flags, fbuffer->pc, fbuffer->regs);
@@ -2742,131 +2876,6 @@ trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
 	__buffer_unlock_commit(buffer, event);
 }
 
-static void
-trace_process_export(struct trace_export *export,
-	       struct ring_buffer_event *event, int flag)
-{
-	struct trace_entry *entry;
-	unsigned int size = 0;
-
-	if (export->flags & flag) {
-		entry = ring_buffer_event_data(event);
-		size = ring_buffer_event_length(event);
-		export->write(export, entry, size);
-	}
-}
-
-static DEFINE_MUTEX(ftrace_export_lock);
-
-static struct trace_export __rcu *ftrace_exports_list __read_mostly;
-
-static DEFINE_STATIC_KEY_FALSE(trace_function_exports_enabled);
-
-static inline void ftrace_exports_enable(struct trace_export *export)
-{
-	if (export->flags & TRACE_EXPORT_FUNCTION)
-		static_branch_inc(&trace_function_exports_enabled);
-}
-
-static inline void ftrace_exports_disable(struct trace_export *export)
-{
-	if (export->flags & TRACE_EXPORT_FUNCTION)
-		static_branch_dec(&trace_function_exports_enabled);
-}
-
-static void ftrace_exports(struct ring_buffer_event *event, int flag)
-{
-	struct trace_export *export;
-
-	preempt_disable_notrace();
-
-	export = rcu_dereference_raw_check(ftrace_exports_list);
-	while (export) {
-		trace_process_export(export, event, flag);
-		export = rcu_dereference_raw_check(export->next);
-	}
-
-	preempt_enable_notrace();
-}
-
-static inline void
-add_trace_export(struct trace_export **list, struct trace_export *export)
-{
-	rcu_assign_pointer(export->next, *list);
-	/*
-	 * We are entering export into the list but another
-	 * CPU might be walking that list. We need to make sure
-	 * the export->next pointer is valid before another CPU sees
-	 * the export pointer included into the list.
-	 */
-	rcu_assign_pointer(*list, export);
-}
-
-static inline int
-rm_trace_export(struct trace_export **list, struct trace_export *export)
-{
-	struct trace_export **p;
-
-	for (p = list; *p != NULL; p = &(*p)->next)
-		if (*p == export)
-			break;
-
-	if (*p != export)
-		return -1;
-
-	rcu_assign_pointer(*p, (*p)->next);
-
-	return 0;
-}
-
-static inline void
-add_ftrace_export(struct trace_export **list, struct trace_export *export)
-{
-	ftrace_exports_enable(export);
-
-	add_trace_export(list, export);
-}
-
-static inline int
-rm_ftrace_export(struct trace_export **list, struct trace_export *export)
-{
-	int ret;
-
-	ret = rm_trace_export(list, export);
-	ftrace_exports_disable(export);
-
-	return ret;
-}
-
-int register_ftrace_export(struct trace_export *export)
-{
-	if (WARN_ON_ONCE(!export->write))
-		return -1;
-
-	mutex_lock(&ftrace_export_lock);
-
-	add_ftrace_export(&ftrace_exports_list, export);
-
-	mutex_unlock(&ftrace_export_lock);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(register_ftrace_export);
-
-int unregister_ftrace_export(struct trace_export *export)
-{
-	int ret;
-
-	mutex_lock(&ftrace_export_lock);
-
-	ret = rm_ftrace_export(&ftrace_exports_list, export);
-
-	mutex_unlock(&ftrace_export_lock);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(unregister_ftrace_export);
-
 void
 trace_function(struct trace_array *tr,
 	       unsigned long ip, unsigned long parent_ip, unsigned long flags,
-- 
cgit 


From 458999c6f67b0ffcc704a4892041dd700adf7d83 Mon Sep 17 00:00:00 2001
From: Tingwei Zhang <tingwei@codeaurora.org>
Date: Mon, 5 Oct 2020 10:13:15 +0300
Subject: tracing: Add trace_export support for trace_marker

Add the support to route trace_marker buffer to other destination
via trace_export.

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20201005071319.78508-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/linux/trace.h | 1 +
 kernel/trace/trace.c  | 9 +++++++++
 2 files changed, 10 insertions(+)

(limited to 'kernel/trace/trace.c')

diff --git a/include/linux/trace.h b/include/linux/trace.h
index 86033d214972..886a4ffd9d45 100644
--- a/include/linux/trace.h
+++ b/include/linux/trace.h
@@ -6,6 +6,7 @@
 
 #define TRACE_EXPORT_FUNCTION	BIT(0)
 #define TRACE_EXPORT_EVENT	BIT(1)
+#define TRACE_EXPORT_MARKER	BIT(2)
 
 /*
  * The trace export - an export of Ftrace output. The trace_export
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a40ee413123c..6048fba2f590 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -271,6 +271,7 @@ static struct trace_export __rcu *ftrace_exports_list __read_mostly;
 
 static DEFINE_STATIC_KEY_FALSE(trace_function_exports_enabled);
 static DEFINE_STATIC_KEY_FALSE(trace_event_exports_enabled);
+static DEFINE_STATIC_KEY_FALSE(trace_marker_exports_enabled);
 
 static inline void ftrace_exports_enable(struct trace_export *export)
 {
@@ -279,6 +280,9 @@ static inline void ftrace_exports_enable(struct trace_export *export)
 
 	if (export->flags & TRACE_EXPORT_EVENT)
 		static_branch_inc(&trace_event_exports_enabled);
+
+	if (export->flags & TRACE_EXPORT_MARKER)
+		static_branch_inc(&trace_marker_exports_enabled);
 }
 
 static inline void ftrace_exports_disable(struct trace_export *export)
@@ -288,6 +292,9 @@ static inline void ftrace_exports_disable(struct trace_export *export)
 
 	if (export->flags & TRACE_EXPORT_EVENT)
 		static_branch_dec(&trace_event_exports_enabled);
+
+	if (export->flags & TRACE_EXPORT_MARKER)
+		static_branch_dec(&trace_marker_exports_enabled);
 }
 
 static void ftrace_exports(struct ring_buffer_event *event, int flag)
@@ -6687,6 +6694,8 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 	} else
 		entry->buf[cnt] = '\0';
 
+	if (static_branch_unlikely(&trace_marker_exports_enabled))
+		ftrace_exports(event, TRACE_EXPORT_MARKER);
 	__buffer_unlock_commit(buffer, event);
 
 	if (tt)
-- 
cgit 


From 1bc36bd4a8557285870b34cfec7910871049e93e Mon Sep 17 00:00:00 2001
From: Tom Zanussi <zanussi@kernel.org>
Date: Sun, 4 Oct 2020 17:14:07 -0500
Subject: tracing: Add README information for synthetic_events file

Add an entry with a basic description of events/synthetic_events along
with a simple example.

Link: https://lkml.kernel.org/r/3c7f178cf95aaeebc01eda7d95600dd937233eb7.1601848695.git.zanussi@kernel.org

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

(limited to 'kernel/trace/trace.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 3f2533adae72..73fd0e0c0f39 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5249,7 +5249,12 @@ static const char readme_msg[] =
 	"\t        trace(<synthetic_event>,param list)  - generate synthetic event\n"
 	"\t        save(field,...)                      - save current event fields\n"
 #ifdef CONFIG_TRACER_SNAPSHOT
-	"\t        snapshot()                           - snapshot the trace buffer\n"
+	"\t        snapshot()                           - snapshot the trace buffer\n\n"
+#endif
+#ifdef CONFIG_SYNTH_EVENTS
+	"  events/synthetic_events\t- Create/append/remove/show synthetic events\n"
+	"\t  Write into this file to define/undefine new synthetic events.\n"
+	"\t     example: echo 'myevent u64 lat; char name[]' >> synthetic_events\n"
 #endif
 #endif
 ;
-- 
cgit 


From 43aa422c0c07135236bd91cbb45b048fd85e73b5 Mon Sep 17 00:00:00 2001
From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Date: Wed, 30 Sep 2020 19:43:03 +0100
Subject: tracing: Remove a pointless assignment

The variable 'len' has been assigned a value but is not used after that.
So, remove the assignement.

Link: https://lkml.kernel.org/r/20200930184303.22896-1-sudipm.mukherjee@gmail.com

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 1 -
 1 file changed, 1 deletion(-)

(limited to 'kernel/trace/trace.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 73fd0e0c0f39..0806fa9f2815 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6667,7 +6667,6 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 		written = -EFAULT;
 	} else
 		written = cnt;
-	len = cnt;
 
 	if (tr->trace_marker_file && !list_empty(&tr->trace_marker_file->triggers)) {
 		/* do not add \n before testing triggers, but add \0 */
-- 
cgit 


From 499f7bb0853570c5d9cbf2a2ecbed517852cacfa Mon Sep 17 00:00:00 2001
From: Qiujun Huang <hqjagain@gmail.com>
Date: Sat, 10 Oct 2020 22:09:24 +0800
Subject: tracing: Fix some typos in comments

s/wihin/within/
s/retrieven/retrieved/
s/suppport/support/
s/wil/will/
s/accidently/accidentally/
s/if the if the/if the/

Link: https://lkml.kernel.org/r/20201010140924.3809-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 4 ++--
 kernel/trace/trace.h | 8 ++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

(limited to 'kernel/trace/trace.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0806fa9f2815..63c97012ed39 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9465,7 +9465,7 @@ __init static int tracer_alloc_buffers(void)
 	}
 
 	/*
-	 * Make sure we don't accidently add more trace options
+	 * Make sure we don't accidentally add more trace options
 	 * than we have bits for.
 	 */
 	BUILD_BUG_ON(TRACE_ITER_LAST_BIT > TRACE_FLAGS_MAX_SIZE);
@@ -9494,7 +9494,7 @@ __init static int tracer_alloc_buffers(void)
 
 	/*
 	 * The prepare callbacks allocates some memory for the ring buffer. We
-	 * don't free the buffer if the if the CPU goes down. If we were to free
+	 * don't free the buffer if the CPU goes down. If we were to free
 	 * the buffer, then the user would lose any trace that was in the
 	 * buffer. The memory will be removed once the "instance" is removed.
 	 */
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 5b0e797cacdd..f777bb68e660 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -246,7 +246,7 @@ typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
  * passed in turn to the cond_snapshot.update() function.  That data
  * can be compared by the update() implementation with the cond_data
- * contained wihin the struct cond_snapshot instance associated with
+ * contained within the struct cond_snapshot instance associated with
  * the trace_array.  Because the tr->max_lock is held throughout the
  * update() call, the update() function can directly retrieve the
  * cond_snapshot and cond_data associated with the per-instance
@@ -271,7 +271,7 @@ typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
  *	take the snapshot, by returning 'true' if so, 'false' if no
  *	snapshot should be taken.  Because the max_lock is held for
  *	the duration of update(), the implementation is safe to
- *	directly retrieven and save any implementation data it needs
+ *	directly retrieved and save any implementation data it needs
  *	to in association with the snapshot.
  */
 struct cond_snapshot {
@@ -573,7 +573,7 @@ struct tracer {
  *   The function callback, which can use the FTRACE bits to
  *    check for recursion.
  *
- * Now if the arch does not suppport a feature, and it calls
+ * Now if the arch does not support a feature, and it calls
  * the global list function which calls the ftrace callback
  * all three of these steps will do a recursion protection.
  * There's no reason to do one if the previous caller already
@@ -1479,7 +1479,7 @@ __trace_event_discard_commit(struct trace_buffer *buffer,
 /*
  * Helper function for event_trigger_unlock_commit{_regs}().
  * If there are event triggers attached to this event that requires
- * filtering against its fields, then they wil be called as the
+ * filtering against its fields, then they will be called as the
  * entry already holds the field information of the current event.
  *
  * It also checks if the event should be discarded or not.
-- 
cgit