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