mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-03 17:40:04 +00:00
![Kaixu Xia](/assets/img/avatar_default.png)
The value of variable ret is overwritten on the delete branch in the test_create_synth_event() and we care more about the above error than this delete portion. Remove it. Link: https://lkml.kernel.org/r/1605283360-6804-1-git-send-email-kaixuxia@tencent.com Reported-by: Tosk Robot <tencent_os_robot@tencent.com> Signed-off-by: Kaixu Xia <kaixuxia@tencent.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
529 lines
14 KiB
C
529 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Test module for in-kernel sythetic event creation and generation.
|
|
*
|
|
* Copyright (C) 2019 Tom Zanussi <zanussi@kernel.org>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/trace_events.h>
|
|
|
|
/*
|
|
* This module is a simple test of basic functionality for in-kernel
|
|
* synthetic event creation and generation, the first and second tests
|
|
* using synth_event_gen_cmd_start() and synth_event_add_field(), the
|
|
* third uses synth_event_create() to do it all at once with a static
|
|
* field array.
|
|
*
|
|
* Following that are a few examples using the created events to test
|
|
* various ways of tracing a synthetic event.
|
|
*
|
|
* To test, select CONFIG_SYNTH_EVENT_GEN_TEST and build the module.
|
|
* Then:
|
|
*
|
|
* # insmod kernel/trace/synth_event_gen_test.ko
|
|
* # cat /sys/kernel/debug/tracing/trace
|
|
*
|
|
* You should see several events in the trace buffer -
|
|
* "create_synth_test", "empty_synth_test", and several instances of
|
|
* "gen_synth_test".
|
|
*
|
|
* To remove the events, remove the module:
|
|
*
|
|
* # rmmod synth_event_gen_test
|
|
*
|
|
*/
|
|
|
|
static struct trace_event_file *create_synth_test;
|
|
static struct trace_event_file *empty_synth_test;
|
|
static struct trace_event_file *gen_synth_test;
|
|
|
|
/*
|
|
* Test to make sure we can create a synthetic event, then add more
|
|
* fields.
|
|
*/
|
|
static int __init test_gen_synth_cmd(void)
|
|
{
|
|
struct dynevent_cmd cmd;
|
|
u64 vals[7];
|
|
char *buf;
|
|
int ret;
|
|
|
|
/* Create a buffer to hold the generated command */
|
|
buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
|
|
/* Before generating the command, initialize the cmd object */
|
|
synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
|
|
|
|
/*
|
|
* Create the empty gen_synth_test synthetic event with the
|
|
* first 4 fields.
|
|
*/
|
|
ret = synth_event_gen_cmd_start(&cmd, "gen_synth_test", THIS_MODULE,
|
|
"pid_t", "next_pid_field",
|
|
"char[16]", "next_comm_field",
|
|
"u64", "ts_ns",
|
|
"u64", "ts_ms");
|
|
if (ret)
|
|
goto free;
|
|
|
|
/* Use synth_event_add_field to add the rest of the fields */
|
|
|
|
ret = synth_event_add_field(&cmd, "unsigned int", "cpu");
|
|
if (ret)
|
|
goto free;
|
|
|
|
ret = synth_event_add_field(&cmd, "char[64]", "my_string_field");
|
|
if (ret)
|
|
goto free;
|
|
|
|
ret = synth_event_add_field(&cmd, "int", "my_int_field");
|
|
if (ret)
|
|
goto free;
|
|
|
|
ret = synth_event_gen_cmd_end(&cmd);
|
|
if (ret)
|
|
goto free;
|
|
|
|
/*
|
|
* Now get the gen_synth_test event file. We need to prevent
|
|
* the instance and event from disappearing from underneath
|
|
* us, which trace_get_event_file() does (though in this case
|
|
* we're using the top-level instance which never goes away).
|
|
*/
|
|
gen_synth_test = trace_get_event_file(NULL, "synthetic",
|
|
"gen_synth_test");
|
|
if (IS_ERR(gen_synth_test)) {
|
|
ret = PTR_ERR(gen_synth_test);
|
|
goto delete;
|
|
}
|
|
|
|
/* Enable the event or you won't see anything */
|
|
ret = trace_array_set_clr_event(gen_synth_test->tr,
|
|
"synthetic", "gen_synth_test", true);
|
|
if (ret) {
|
|
trace_put_event_file(gen_synth_test);
|
|
goto delete;
|
|
}
|
|
|
|
/* Create some bogus values just for testing */
|
|
|
|
vals[0] = 777; /* next_pid_field */
|
|
vals[1] = (u64)(long)"hula hoops"; /* next_comm_field */
|
|
vals[2] = 1000000; /* ts_ns */
|
|
vals[3] = 1000; /* ts_ms */
|
|
vals[4] = raw_smp_processor_id(); /* cpu */
|
|
vals[5] = (u64)(long)"thneed"; /* my_string_field */
|
|
vals[6] = 598; /* my_int_field */
|
|
|
|
/* Now generate a gen_synth_test event */
|
|
ret = synth_event_trace_array(gen_synth_test, vals, ARRAY_SIZE(vals));
|
|
out:
|
|
return ret;
|
|
delete:
|
|
/* We got an error after creating the event, delete it */
|
|
synth_event_delete("gen_synth_test");
|
|
free:
|
|
kfree(buf);
|
|
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Test to make sure we can create an initially empty synthetic event,
|
|
* then add all the fields.
|
|
*/
|
|
static int __init test_empty_synth_event(void)
|
|
{
|
|
struct dynevent_cmd cmd;
|
|
u64 vals[7];
|
|
char *buf;
|
|
int ret;
|
|
|
|
/* Create a buffer to hold the generated command */
|
|
buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
|
|
/* Before generating the command, initialize the cmd object */
|
|
synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
|
|
|
|
/*
|
|
* Create the empty_synth_test synthetic event with no fields.
|
|
*/
|
|
ret = synth_event_gen_cmd_start(&cmd, "empty_synth_test", THIS_MODULE);
|
|
if (ret)
|
|
goto free;
|
|
|
|
/* Use synth_event_add_field to add all of the fields */
|
|
|
|
ret = synth_event_add_field(&cmd, "pid_t", "next_pid_field");
|
|
if (ret)
|
|
goto free;
|
|
|
|
ret = synth_event_add_field(&cmd, "char[16]", "next_comm_field");
|
|
if (ret)
|
|
goto free;
|
|
|
|
ret = synth_event_add_field(&cmd, "u64", "ts_ns");
|
|
if (ret)
|
|
goto free;
|
|
|
|
ret = synth_event_add_field(&cmd, "u64", "ts_ms");
|
|
if (ret)
|
|
goto free;
|
|
|
|
ret = synth_event_add_field(&cmd, "unsigned int", "cpu");
|
|
if (ret)
|
|
goto free;
|
|
|
|
ret = synth_event_add_field(&cmd, "char[64]", "my_string_field");
|
|
if (ret)
|
|
goto free;
|
|
|
|
ret = synth_event_add_field(&cmd, "int", "my_int_field");
|
|
if (ret)
|
|
goto free;
|
|
|
|
/* All fields have been added, close and register the synth event */
|
|
|
|
ret = synth_event_gen_cmd_end(&cmd);
|
|
if (ret)
|
|
goto free;
|
|
|
|
/*
|
|
* Now get the empty_synth_test event file. We need to
|
|
* prevent the instance and event from disappearing from
|
|
* underneath us, which trace_get_event_file() does (though in
|
|
* this case we're using the top-level instance which never
|
|
* goes away).
|
|
*/
|
|
empty_synth_test = trace_get_event_file(NULL, "synthetic",
|
|
"empty_synth_test");
|
|
if (IS_ERR(empty_synth_test)) {
|
|
ret = PTR_ERR(empty_synth_test);
|
|
goto delete;
|
|
}
|
|
|
|
/* Enable the event or you won't see anything */
|
|
ret = trace_array_set_clr_event(empty_synth_test->tr,
|
|
"synthetic", "empty_synth_test", true);
|
|
if (ret) {
|
|
trace_put_event_file(empty_synth_test);
|
|
goto delete;
|
|
}
|
|
|
|
/* Create some bogus values just for testing */
|
|
|
|
vals[0] = 777; /* next_pid_field */
|
|
vals[1] = (u64)(long)"tiddlywinks"; /* next_comm_field */
|
|
vals[2] = 1000000; /* ts_ns */
|
|
vals[3] = 1000; /* ts_ms */
|
|
vals[4] = raw_smp_processor_id(); /* cpu */
|
|
vals[5] = (u64)(long)"thneed_2.0"; /* my_string_field */
|
|
vals[6] = 399; /* my_int_field */
|
|
|
|
/* Now trace an empty_synth_test event */
|
|
ret = synth_event_trace_array(empty_synth_test, vals, ARRAY_SIZE(vals));
|
|
out:
|
|
return ret;
|
|
delete:
|
|
/* We got an error after creating the event, delete it */
|
|
synth_event_delete("empty_synth_test");
|
|
free:
|
|
kfree(buf);
|
|
|
|
goto out;
|
|
}
|
|
|
|
static struct synth_field_desc create_synth_test_fields[] = {
|
|
{ .type = "pid_t", .name = "next_pid_field" },
|
|
{ .type = "char[16]", .name = "next_comm_field" },
|
|
{ .type = "u64", .name = "ts_ns" },
|
|
{ .type = "char[]", .name = "dynstring_field_1" },
|
|
{ .type = "u64", .name = "ts_ms" },
|
|
{ .type = "unsigned int", .name = "cpu" },
|
|
{ .type = "char[64]", .name = "my_string_field" },
|
|
{ .type = "char[]", .name = "dynstring_field_2" },
|
|
{ .type = "int", .name = "my_int_field" },
|
|
};
|
|
|
|
/*
|
|
* Test synthetic event creation all at once from array of field
|
|
* descriptors.
|
|
*/
|
|
static int __init test_create_synth_event(void)
|
|
{
|
|
u64 vals[9];
|
|
int ret;
|
|
|
|
/* Create the create_synth_test event with the fields above */
|
|
ret = synth_event_create("create_synth_test",
|
|
create_synth_test_fields,
|
|
ARRAY_SIZE(create_synth_test_fields),
|
|
THIS_MODULE);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/*
|
|
* Now get the create_synth_test event file. We need to
|
|
* prevent the instance and event from disappearing from
|
|
* underneath us, which trace_get_event_file() does (though in
|
|
* this case we're using the top-level instance which never
|
|
* goes away).
|
|
*/
|
|
create_synth_test = trace_get_event_file(NULL, "synthetic",
|
|
"create_synth_test");
|
|
if (IS_ERR(create_synth_test)) {
|
|
ret = PTR_ERR(create_synth_test);
|
|
goto delete;
|
|
}
|
|
|
|
/* Enable the event or you won't see anything */
|
|
ret = trace_array_set_clr_event(create_synth_test->tr,
|
|
"synthetic", "create_synth_test", true);
|
|
if (ret) {
|
|
trace_put_event_file(create_synth_test);
|
|
goto delete;
|
|
}
|
|
|
|
/* Create some bogus values just for testing */
|
|
|
|
vals[0] = 777; /* next_pid_field */
|
|
vals[1] = (u64)(long)"tiddlywinks"; /* next_comm_field */
|
|
vals[2] = 1000000; /* ts_ns */
|
|
vals[3] = (u64)(long)"xrayspecs"; /* dynstring_field_1 */
|
|
vals[4] = 1000; /* ts_ms */
|
|
vals[5] = raw_smp_processor_id(); /* cpu */
|
|
vals[6] = (u64)(long)"thneed"; /* my_string_field */
|
|
vals[7] = (u64)(long)"kerplunk"; /* dynstring_field_2 */
|
|
vals[8] = 398; /* my_int_field */
|
|
|
|
/* Now generate a create_synth_test event */
|
|
ret = synth_event_trace_array(create_synth_test, vals, ARRAY_SIZE(vals));
|
|
out:
|
|
return ret;
|
|
delete:
|
|
/* We got an error after creating the event, delete it */
|
|
synth_event_delete("create_synth_test");
|
|
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Test tracing a synthetic event by reserving trace buffer space,
|
|
* then filling in fields one after another.
|
|
*/
|
|
static int __init test_add_next_synth_val(void)
|
|
{
|
|
struct synth_event_trace_state trace_state;
|
|
int ret;
|
|
|
|
/* Start by reserving space in the trace buffer */
|
|
ret = synth_event_trace_start(gen_synth_test, &trace_state);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Write some bogus values into the trace buffer, one after another */
|
|
|
|
/* next_pid_field */
|
|
ret = synth_event_add_next_val(777, &trace_state);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/* next_comm_field */
|
|
ret = synth_event_add_next_val((u64)(long)"slinky", &trace_state);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/* ts_ns */
|
|
ret = synth_event_add_next_val(1000000, &trace_state);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/* ts_ms */
|
|
ret = synth_event_add_next_val(1000, &trace_state);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/* cpu */
|
|
ret = synth_event_add_next_val(raw_smp_processor_id(), &trace_state);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/* my_string_field */
|
|
ret = synth_event_add_next_val((u64)(long)"thneed_2.01", &trace_state);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/* my_int_field */
|
|
ret = synth_event_add_next_val(395, &trace_state);
|
|
out:
|
|
/* Finally, commit the event */
|
|
ret = synth_event_trace_end(&trace_state);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Test tracing a synthetic event by reserving trace buffer space,
|
|
* then filling in fields using field names, which can be done in any
|
|
* order.
|
|
*/
|
|
static int __init test_add_synth_val(void)
|
|
{
|
|
struct synth_event_trace_state trace_state;
|
|
int ret;
|
|
|
|
/* Start by reserving space in the trace buffer */
|
|
ret = synth_event_trace_start(gen_synth_test, &trace_state);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Write some bogus values into the trace buffer, using field names */
|
|
|
|
ret = synth_event_add_val("ts_ns", 1000000, &trace_state);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = synth_event_add_val("ts_ms", 1000, &trace_state);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = synth_event_add_val("cpu", raw_smp_processor_id(), &trace_state);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = synth_event_add_val("next_pid_field", 777, &trace_state);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = synth_event_add_val("next_comm_field", (u64)(long)"silly putty",
|
|
&trace_state);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = synth_event_add_val("my_string_field", (u64)(long)"thneed_9",
|
|
&trace_state);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = synth_event_add_val("my_int_field", 3999, &trace_state);
|
|
out:
|
|
/* Finally, commit the event */
|
|
ret = synth_event_trace_end(&trace_state);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Test tracing a synthetic event all at once from array of values.
|
|
*/
|
|
static int __init test_trace_synth_event(void)
|
|
{
|
|
int ret;
|
|
|
|
/* Trace some bogus values just for testing */
|
|
ret = synth_event_trace(create_synth_test, 9, /* number of values */
|
|
(u64)444, /* next_pid_field */
|
|
(u64)(long)"clackers", /* next_comm_field */
|
|
(u64)1000000, /* ts_ns */
|
|
(u64)(long)"viewmaster",/* dynstring_field_1 */
|
|
(u64)1000, /* ts_ms */
|
|
(u64)raw_smp_processor_id(), /* cpu */
|
|
(u64)(long)"Thneed", /* my_string_field */
|
|
(u64)(long)"yoyos", /* dynstring_field_2 */
|
|
(u64)999); /* my_int_field */
|
|
return ret;
|
|
}
|
|
|
|
static int __init synth_event_gen_test_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = test_gen_synth_cmd();
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = test_empty_synth_event();
|
|
if (ret) {
|
|
WARN_ON(trace_array_set_clr_event(gen_synth_test->tr,
|
|
"synthetic",
|
|
"gen_synth_test", false));
|
|
trace_put_event_file(gen_synth_test);
|
|
WARN_ON(synth_event_delete("gen_synth_test"));
|
|
goto out;
|
|
}
|
|
|
|
ret = test_create_synth_event();
|
|
if (ret) {
|
|
WARN_ON(trace_array_set_clr_event(gen_synth_test->tr,
|
|
"synthetic",
|
|
"gen_synth_test", false));
|
|
trace_put_event_file(gen_synth_test);
|
|
WARN_ON(synth_event_delete("gen_synth_test"));
|
|
|
|
WARN_ON(trace_array_set_clr_event(empty_synth_test->tr,
|
|
"synthetic",
|
|
"empty_synth_test", false));
|
|
trace_put_event_file(empty_synth_test);
|
|
WARN_ON(synth_event_delete("empty_synth_test"));
|
|
goto out;
|
|
}
|
|
|
|
ret = test_add_next_synth_val();
|
|
WARN_ON(ret);
|
|
|
|
ret = test_add_synth_val();
|
|
WARN_ON(ret);
|
|
|
|
ret = test_trace_synth_event();
|
|
WARN_ON(ret);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static void __exit synth_event_gen_test_exit(void)
|
|
{
|
|
/* Disable the event or you can't remove it */
|
|
WARN_ON(trace_array_set_clr_event(gen_synth_test->tr,
|
|
"synthetic",
|
|
"gen_synth_test", false));
|
|
|
|
/* Now give the file and instance back */
|
|
trace_put_event_file(gen_synth_test);
|
|
|
|
/* Now unregister and free the synthetic event */
|
|
WARN_ON(synth_event_delete("gen_synth_test"));
|
|
|
|
/* Disable the event or you can't remove it */
|
|
WARN_ON(trace_array_set_clr_event(empty_synth_test->tr,
|
|
"synthetic",
|
|
"empty_synth_test", false));
|
|
|
|
/* Now give the file and instance back */
|
|
trace_put_event_file(empty_synth_test);
|
|
|
|
/* Now unregister and free the synthetic event */
|
|
WARN_ON(synth_event_delete("empty_synth_test"));
|
|
|
|
/* Disable the event or you can't remove it */
|
|
WARN_ON(trace_array_set_clr_event(create_synth_test->tr,
|
|
"synthetic",
|
|
"create_synth_test", false));
|
|
|
|
/* Now give the file and instance back */
|
|
trace_put_event_file(create_synth_test);
|
|
|
|
/* Now unregister and free the synthetic event */
|
|
WARN_ON(synth_event_delete("create_synth_test"));
|
|
}
|
|
|
|
module_init(synth_event_gen_test_init)
|
|
module_exit(synth_event_gen_test_exit)
|
|
|
|
MODULE_AUTHOR("Tom Zanussi");
|
|
MODULE_DESCRIPTION("synthetic event generation test");
|
|
MODULE_LICENSE("GPL v2");
|