tests/probes/lttng-test.c

   1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   2  *
   3  * lttng-test.c
   4  *
   5  * Linux Trace Toolkit Next Generation Test Module
   6  *
   7  * Copyright 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  */
   9
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/proc_fs.h>
  13 #include <linux/byteorder/generic.h>
  14 #include <asm/byteorder.h>
  15
  16 #include <lttng-events.h>
  17 #include <lttng-tracer.h>
  18
  19 #define TP_MODULE_NOAUTOLOAD
  20 #define LTTNG_PACKAGE_BUILD
  21 #define CREATE_TRACE_POINTS
  22 #define TRACE_INCLUDE_PATH instrumentation/events/lttng-module
  23 #define TRACE_INCLUDE_FILE lttng-test
  24 #define LTTNG_INSTRUMENTATION
  25 #include <instrumentation/events/lttng-module/lttng-test.h>
  26
  27 DEFINE_TRACE(lttng_test_filter_event);
  28
  29 #define LTTNG_TEST_FILTER_EVENT_FILE    "lttng-test-filter-event"
  30
  31 #define LTTNG_WRITE_COUNT_MAX   64
  32
  33 static struct proc_dir_entry *lttng_test_filter_event_dentry;
  34
  35 static
  36 void trace_test_event(unsigned int nr_iter)
  37 {
  38         int i, netint;
  39         long values[] = { 1, 2, 3 };
  40         uint32_t net_values[] = { 1, 2, 3 };
  41         char text[10] = "test";
  42         char escape[10] = "\\*";
  43
  44         for (i = 0; i < 3; i++) {
  45                 net_values[i] = htonl(net_values[i]);
  46         }
  47         for (i = 0; i < nr_iter; i++) {
  48                 netint = htonl(i);
  49                 trace_lttng_test_filter_event(i, netint, values, text, strlen(text), escape, net_values);
  50         }
  51 }
  52
  53 /**
  54  * lttng_filter_event_write - trigger a lttng_test_filter_event
  55  * @file: file pointer
  56  * @user_buf: user string
  57  * @count: length to copy
  58  *
  59  * Return -1 on error, with EFAULT errno. Returns count on success.
  60  */
  61 static
  62 ssize_t lttng_test_filter_event_write(struct file *file, const char __user *user_buf,
  63                     size_t count, loff_t *ppos)
  64 {
  65         unsigned int nr_iter;
  66         ssize_t written;
  67         int ret;
  68
  69         /* Get the number of iterations */
  70         ret = kstrtouint_from_user(user_buf, count, 10, &nr_iter);
  71         if (ret) {
  72                 written = ret;
  73                 goto end;
  74         }
  75         /* Trace the event */
  76         trace_test_event(nr_iter);
  77         written = count;
  78         *ppos += written;
  79 end:
  80         return written;
  81 }
  82
  83 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0))
  84 static const struct proc_ops lttng_test_filter_event_proc_ops = {
  85         .proc_write = lttng_test_filter_event_write,
  86 };
  87 #else
  88 static const struct file_operations lttng_test_filter_event_proc_ops = {
  89         .write = lttng_test_filter_event_write,
  90 };
  91 #endif
  92
  93 static
  94 int __init lttng_test_init(void)
  95 {
  96         int ret = 0;
  97
  98         lttng_test_filter_event_dentry =
  99                         proc_create_data(LTTNG_TEST_FILTER_EVENT_FILE,
 100                                 S_IRUGO | S_IWUGO, NULL,
 101                                 &lttng_test_filter_event_proc_ops, NULL);
 102         if (!lttng_test_filter_event_dentry) {
 103                 printk(KERN_ERR "Error creating LTTng test filter file\n");
 104                 ret = -ENOMEM;
 105                 goto error;
 106         }
 107         ret = __lttng_events_init__lttng_test();
 108         if (ret)
 109                 goto error_events;
 110         return ret;
 111
 112 error_events:
 113         remove_proc_entry(LTTNG_TEST_FILTER_EVENT_FILE, NULL);
 114 error:
 115         return ret;
 116 }
 117
 118 module_init(lttng_test_init);
 119
 120 static
 121 void __exit lttng_test_exit(void)
 122 {
 123         __lttng_events_exit__lttng_test();
 124         if (lttng_test_filter_event_dentry)
 125                 remove_proc_entry(LTTNG_TEST_FILTER_EVENT_FILE, NULL);
 126 }
 127
 128 module_exit(lttng_test_exit);
 129
 130 MODULE_LICENSE("GPL and additional rights");
 131 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
 132 MODULE_DESCRIPTION("LTTng Test");
 133 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
 134         __stringify(LTTNG_MODULES_MINOR_VERSION) "."
 135         __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
 136         LTTNG_MODULES_EXTRAVERSION);