tests/probes/lttng-test.c

   1 /*
   2  * lttng-test.c
   3  *
   4  * Linux Trace Toolkit Next Generation Test Module
   5  *
   6  * Copyright 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; only
  11  * version 2.1 of the License.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include <linux/init.h>
  24 #include <linux/module.h>
  25 #include <linux/proc_fs.h>
  26 #include <linux/byteorder/generic.h>
  27
  28 #include <lttng-events.h>
  29 #include <lttng-tracer.h>
  30 #include <wrapper/tracepoint.h>
  31 #include <wrapper/kstrtox.h>
  32
  33 #define TP_MODULE_NOAUTOLOAD
  34 #define LTTNG_PACKAGE_BUILD
  35 #define CREATE_TRACE_POINTS
  36 #define TRACE_INCLUDE_PATH instrumentation/events/lttng-module
  37 #define TRACE_INCLUDE_FILE lttng-test
  38 #define LTTNG_INSTRUMENTATION
  39 #include <instrumentation/events/lttng-module/lttng-test.h>
  40
  41 DEFINE_TRACE(lttng_test_filter_event);
  42
  43 #define LTTNG_TEST_FILTER_EVENT_FILE    "lttng-test-filter-event"
  44
  45 #define LTTNG_WRITE_COUNT_MAX   64
  46
  47 static struct proc_dir_entry *lttng_test_filter_event_dentry;
  48
  49 static
  50 void trace_test_event(unsigned int nr_iter)
  51 {
  52         int i, netint;
  53         long values[] = { 1, 2, 3 };
  54         char text[10] = "test";
  55         char escape[10] = "\\*";
  56
  57         for (i = 0; i < nr_iter; i++) {
  58                 netint = htonl(i);
  59                 trace_lttng_test_filter_event(i, netint, values, text, strlen(text), escape);
  60         }
  61 }
  62
  63 /**
  64  * lttng_filter_event_write - trigger a lttng_test_filter_event
  65  * @file: file pointer
  66  * @user_buf: user string
  67  * @count: length to copy
  68  *
  69  * Return -1 on error, with EFAULT errno. Returns count on success.
  70  */
  71 static
  72 ssize_t lttng_test_filter_event_write(struct file *file, const char __user *user_buf,
  73                     size_t count, loff_t *ppos)
  74 {
  75         unsigned int nr_iter;
  76         ssize_t written;
  77         int ret;
  78
  79         /* Get the number of iterations */
  80         ret = lttng_kstrtouint_from_user(user_buf, count, 10, &nr_iter);
  81         if (ret) {
  82                 written = ret;
  83                 goto end;
  84         }
  85         /* Trace the event */
  86         trace_test_event(nr_iter);
  87         written = count;
  88         *ppos += written;
  89 end:
  90         return written;
  91 }
  92
  93 static const struct file_operations lttng_test_filter_event_operations = {
  94         .write = lttng_test_filter_event_write,
  95 };
  96
  97 static
  98 int __init lttng_test_init(void)
  99 {
 100         int ret = 0;
 101
 102         (void) wrapper_lttng_fixup_sig(THIS_MODULE);
 103         wrapper_vmalloc_sync_all();
 104         lttng_test_filter_event_dentry =
 105                         proc_create_data(LTTNG_TEST_FILTER_EVENT_FILE,
 106                                 S_IRUGO | S_IWUGO, NULL,
 107                                 &lttng_test_filter_event_operations, NULL);
 108         if (!lttng_test_filter_event_dentry) {
 109                 printk(KERN_ERR "Error creating LTTng test filter file\n");
 110                 ret = -ENOMEM;
 111                 goto error;
 112         }
 113         ret = __lttng_events_init__lttng_test();
 114         if (ret)
 115                 goto error_events;
 116         return ret;
 117
 118 error_events:
 119         remove_proc_entry(LTTNG_TEST_FILTER_EVENT_FILE, NULL);
 120 error:
 121         return ret;
 122 }
 123
 124 module_init(lttng_test_init);
 125
 126 static
 127 void __exit lttng_test_exit(void)
 128 {
 129         __lttng_events_exit__lttng_test();
 130         if (lttng_test_filter_event_dentry)
 131                 remove_proc_entry(LTTNG_TEST_FILTER_EVENT_FILE, NULL);
 132 }
 133
 134 module_exit(lttng_test_exit);
 135
 136 MODULE_LICENSE("GPL and additional rights");
 137 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
 138 MODULE_DESCRIPTION("LTTng Test");
 139 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
 140         __stringify(LTTNG_MODULES_MINOR_VERSION) "."
 141         __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
 142         LTTNG_MODULES_EXTRAVERSION);