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
  32 #define TP_MODULE_NOAUTOLOAD
  33 #define LTTNG_PACKAGE_BUILD
  34 #define CREATE_TRACE_POINTS
  35 #define TRACE_INCLUDE_PATH ../instrumentation/events/lttng-module
  36 #define TRACE_INCLUDE_FILE lttng-test
  37 #define LTTNG_INSTRUMENTATION
  38 #include "../instrumentation/events/lttng-module/lttng-test.h"
  39
  40 DEFINE_TRACE(lttng_test_filter_event);
  41
  42 #define LTTNG_TEST_FILTER_EVENT_FILE    "lttng-test-filter-event"
  43
  44 #define LTTNG_WRITE_COUNT_MAX   64
  45
  46 static struct proc_dir_entry *lttng_test_filter_event_dentry;
  47
  48 static
  49 void trace_test_event(unsigned int nr_iter)
  50 {
  51         int i, netint;
  52         long values[] = { 1, 2, 3 };
  53         char text[10] = "test";
  54         char escape[10] = "\\*";
  55
  56         for (i = 0; i < nr_iter; i++) {
  57                 netint = htonl(i);
  58                 trace_lttng_test_filter_event(i, netint, values, text, strlen(text), escape);
  59         }
  60 }
  61
  62 /**
  63  * lttng_filter_event_write - trigger a lttng_test_filter_event
  64  * @file: file pointer
  65  * @user_buf: user string
  66  * @count: length to copy
  67  *
  68  * Return -1 on error, with EFAULT errno. Returns count on success.
  69  */
  70 static
  71 ssize_t lttng_test_filter_event_write(struct file *file, const char __user *user_buf,
  72                     size_t count, loff_t *ppos)
  73 {
  74         unsigned int nr_iter;
  75         ssize_t written;
  76         int ret;
  77
  78         /* Get the number of iterations */
  79         ret = kstrtouint_from_user(user_buf, count, 10, &nr_iter);
  80         if (ret) {
  81                 written = ret;
  82                 goto end;
  83         }
  84         /* Trace the event */
  85         trace_test_event(nr_iter);
  86         written = count;
  87         *ppos += written;
  88 end:
  89         return written;
  90 }
  91
  92 static const struct file_operations lttng_test_filter_event_operations = {
  93         .write = lttng_test_filter_event_write,
  94 };
  95
  96 static
  97 int __init lttng_test_init(void)
  98 {
  99         int ret = 0;
 100
 101         (void) wrapper_lttng_fixup_sig(THIS_MODULE);
 102         wrapper_vmalloc_sync_all();
 103         lttng_test_filter_event_dentry =
 104                         proc_create_data(LTTNG_TEST_FILTER_EVENT_FILE,
 105                                 S_IRUGO | S_IWUGO, NULL,
 106                                 &lttng_test_filter_event_operations, NULL);
 107         if (!lttng_test_filter_event_dentry) {
 108                 printk(KERN_ERR "Error creating LTTng test filter file\n");
 109                 ret = -ENOMEM;
 110                 goto error;
 111         }
 112         ret = __lttng_events_init__lttng_test();
 113         if (ret)
 114                 goto error_events;
 115         return ret;
 116
 117 error_events:
 118         remove_proc_entry(LTTNG_TEST_FILTER_EVENT_FILE, NULL);
 119 error:
 120         return ret;
 121 }
 122
 123 module_init(lttng_test_init);
 124
 125 static
 126 void __exit lttng_test_exit(void)
 127 {
 128         __lttng_events_exit__lttng_test();
 129         if (lttng_test_filter_event_dentry)
 130                 remove_proc_entry(LTTNG_TEST_FILTER_EVENT_FILE, NULL);
 131 }
 132
 133 module_exit(lttng_test_exit);
 134
 135 MODULE_LICENSE("GPL and additional rights");
 136 MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
 137 MODULE_DESCRIPTION("LTTng Test");
 138 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
 139         __stringify(LTTNG_MODULES_MINOR_VERSION) "."
 140         __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
 141         LTTNG_MODULES_EXTRAVERSION);