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