summaryrefslogtreecommitdiffstats
path: root/collectors/ebpf.plugin/ebpf_sync.c
blob: f838b65af07245ed28bf7ef73fe9025bcc2c5d72 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
// SPDX-License-Identifier: GPL-3.0-or-later

#include "ebpf.h"
#include "ebpf_sync.h"

static char *sync_counter_dimension_name[NETDATA_SYNC_IDX_END] = { "sync", "syncfs",  "msync", "fsync", "fdatasync",
                                                                   "sync_file_range" };
static netdata_syscall_stat_t sync_counter_aggregated_data[NETDATA_SYNC_IDX_END];
static netdata_publish_syscall_t sync_counter_publish_aggregated[NETDATA_SYNC_IDX_END];

static netdata_idx_t sync_hash_values[NETDATA_SYNC_IDX_END];

static ebpf_local_maps_t sync_maps[] = {{.name = "tbl_sync", .internal_input = NETDATA_SYNC_END,
                                         .user_input = 0, .type = NETDATA_EBPF_MAP_STATIC,
                                         .map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED},
                                        {.name = "tbl_syncfs", .internal_input = NETDATA_SYNC_END,
                                         .user_input = 0, .type = NETDATA_EBPF_MAP_STATIC,
                                         .map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED},
                                        {.name = "tbl_msync", .internal_input = NETDATA_SYNC_END,
                                         .user_input = 0, .type = NETDATA_EBPF_MAP_STATIC,
                                         .map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED},
                                        {.name = "tbl_fsync", .internal_input = NETDATA_SYNC_END,
                                         .user_input = 0, .type = NETDATA_EBPF_MAP_STATIC,
                                         .map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED},
                                        {.name = "tbl_fdatasync", .internal_input = NETDATA_SYNC_END,
                                         .user_input = 0, .type = NETDATA_EBPF_MAP_STATIC,
                                         .map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED},
                                         {.name = "tbl_syncfr", .internal_input = NETDATA_SYNC_END,
                                          .user_input = 0, .type = NETDATA_EBPF_MAP_STATIC,
                                          .map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED},
                                        {.name = NULL, .internal_input = 0, .user_input = 0,
                                         .type = NETDATA_EBPF_MAP_CONTROLLER,
                                         .map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED}};

struct config sync_config = { .first_section = NULL,
    .last_section = NULL,
    .mutex = NETDATA_MUTEX_INITIALIZER,
    .index = { .avl_tree = { .root = NULL, .compar = appconfig_section_compare },
        .rwlock = AVL_LOCK_INITIALIZER } };

netdata_ebpf_targets_t sync_targets[] = { {.name = NETDATA_SYSCALLS_SYNC, .mode = EBPF_LOAD_TRAMPOLINE},
                                          {.name = NETDATA_SYSCALLS_SYNCFS, .mode = EBPF_LOAD_TRAMPOLINE},
                                          {.name = NETDATA_SYSCALLS_MSYNC, .mode = EBPF_LOAD_TRAMPOLINE},
                                          {.name = NETDATA_SYSCALLS_FSYNC, .mode = EBPF_LOAD_TRAMPOLINE},
                                          {.name = NETDATA_SYSCALLS_FDATASYNC, .mode = EBPF_LOAD_TRAMPOLINE},
                                          {.name = NETDATA_SYSCALLS_SYNC_FILE_RANGE, .mode = EBPF_LOAD_TRAMPOLINE},
                                          {.name = NULL, .mode = EBPF_LOAD_TRAMPOLINE}};

#ifdef LIBBPF_MAJOR_VERSION
/*****************************************************************
 *
 *  BTF FUNCTIONS
 *
 *****************************************************************/

/**
 * Disable probe
 *
 * Disable kprobe to use another method.
 *
 * @param obj is the main structure for bpf objects.
 */
static inline void ebpf_sync_disable_probe(struct sync_bpf *obj)
{
    bpf_program__set_autoload(obj->progs.netdata_sync_kprobe, false);
}

/**
 * Disable trampoline
 *
 * Disable trampoline to use another method.
 *
 * @param obj is the main structure for bpf objects.
 */
static inline void ebpf_sync_disable_trampoline(struct sync_bpf *obj)
{
    bpf_program__set_autoload(obj->progs.netdata_sync_fentry, false);
}

/**
 * Disable tracepoint
 *
 * Disable tracepoints according information given.
 *
 * @param obj  object loaded
 * @param idx  Which syscall will not be disabled
 */
void ebpf_sync_disable_tracepoints(struct sync_bpf *obj, sync_syscalls_index_t idx)
{
    if (idx != NETDATA_SYNC_SYNC_IDX)
        bpf_program__set_autoload(obj->progs.netdata_sync_entry, false);

    if (idx != NETDATA_SYNC_SYNCFS_IDX)
        bpf_program__set_autoload(obj->progs.netdata_syncfs_entry, false);

    if (idx != NETDATA_SYNC_MSYNC_IDX)
        bpf_program__set_autoload(obj->progs.netdata_msync_entry, false);

    if (idx != NETDATA_SYNC_FSYNC_IDX)
        bpf_program__set_autoload(obj->progs.netdata_fsync_entry, false);

    if (idx != NETDATA_SYNC_FDATASYNC_IDX)
        bpf_program__set_autoload(obj->progs.netdata_fdatasync_entry, false);

    if (idx != NETDATA_SYNC_SYNC_FILE_RANGE_IDX)
        bpf_program__set_autoload(obj->progs.netdata_sync_file_range_entry, false);
}

/**
 * Set hash tables
 *
 * Set the values for maps according the value given by kernel.
 *
 * @param obj is the main structure for bpf objects.
 * @param idx    the index for the main structure
 */
static void ebpf_sync_set_hash_tables(struct sync_bpf *obj, sync_syscalls_index_t idx)
{
    sync_maps[idx].map_fd = bpf_map__fd(obj->maps.tbl_sync);
}

/**
 * Load and attach
 *
 * Load and attach the eBPF code in kernel.
 *
 * @param obj    is the main structure for bpf objects.
 * @param em     the structure with configuration
 * @param target the syscall that we are attaching a tracer.
 * @param idx    the index for the main structure
 *
 * @return it returns 0 on success and -1 otherwise
 */
static inline int ebpf_sync_load_and_attach(struct sync_bpf *obj, ebpf_module_t *em, char *target,
                                            sync_syscalls_index_t idx)
{
    netdata_ebpf_targets_t *synct = em->targets;
    netdata_ebpf_program_loaded_t test = synct[NETDATA_SYNC_SYNC_IDX].mode;

    if (test == EBPF_LOAD_TRAMPOLINE) {
        ebpf_sync_disable_probe(obj);
        ebpf_sync_disable_tracepoints(obj, NETDATA_SYNC_IDX_END);

        bpf_program__set_attach_target(obj->progs.netdata_sync_fentry, 0,
                                       target);
    } else if (test == EBPF_LOAD_PROBE ||
    test == EBPF_LOAD_RETPROBE) {
        ebpf_sync_disable_tracepoints(obj, NETDATA_SYNC_IDX_END);
        ebpf_sync_disable_trampoline(obj);
    } else {
        ebpf_sync_disable_probe(obj);
        ebpf_sync_disable_trampoline(obj);

        ebpf_sync_disable_tracepoints(obj, idx);
    }

    int ret = sync_bpf__load(obj);
    if (!ret) {
        if (test != EBPF_LOAD_PROBE && test != EBPF_LOAD_RETPROBE) {
            ret = sync_bpf__attach(obj);
        } else {
            obj->links.netdata_sync_kprobe = bpf_program__attach_kprobe(obj->progs.netdata_sync_kprobe,
                                                                        false, target);
            ret = (int)libbpf_get_error(obj->links.netdata_sync_kprobe);
        }

        if (!ret)
            ebpf_sync_set_hash_tables(obj, idx);
    }

    return ret;
}
#endif

/*****************************************************************
 *
 *  CLEANUP THREAD
 *
 *****************************************************************/

#ifdef LIBBPF_MAJOR_VERSION
/**
 * Cleanup Objects
 *
 * Cleanup loaded objects when thread was initialized.
 */
void ebpf_sync_cleanup_objects()
{
    int i;
    for (i = 0; local_syscalls[i].syscall; i++) {
        ebpf_sync_syscalls_t *w = &local_syscalls[i];
        if (w->sync_obj)
            sync_bpf__destroy(w->sync_obj);
    }
}
#endif

/**
 * Sync Free
 *
 * Cleanup variables after child threads to stop
 *
 * @param ptr thread data.
 */
static void ebpf_sync_free(ebpf_module_t *em)
{
#ifdef LIBBPF_MAJOR_VERSION
    ebpf_sync_cleanup_objects();
#endif

    pthread_mutex_lock(&ebpf_exit_cleanup);
    em->enabled = NETDATA_THREAD_EBPF_STOPPED;
    pthread_mutex_unlock(&ebpf_exit_cleanup);
}

/**
 * Exit
 *
 * Clean up the main thread.
 *
 * @param ptr thread data.
 */
static void ebpf_sync_exit(void *ptr)
{
    ebpf_module_t *em = (ebpf_module_t *)ptr;
    ebpf_sync_free(em);
}

/*****************************************************************
 *
 *  INITIALIZE THREAD
 *
 *****************************************************************/

/**
 * Load Legacy
 *
 * Load legacy code.
 *
 * @param w   is the sync output structure with pointers to objects loaded.
 * @param em  is structure with configuration
 *
 * @return 0 on success and -1 otherwise.
 */
static int ebpf_sync_load_legacy(ebpf_sync_syscalls_t *w, ebpf_module_t *em)
{
    em->thread_name = w->syscall;
    if (!w->probe_links) {
        w->probe_links = ebpf_load_program(ebpf_plugin_dir, em, running_on_kernel, isrh, &w->objects);
        if (!w->probe_links) {
            return -1;
        }
    }

    return 0;
}

/*
 * Initialize Syscalls
 *
 * Load the eBPF programs to monitor syscalls
 *
 * @return 0 on success and -1 otherwise.
 */
static int ebpf_sync_initialize_syscall(ebpf_module_t *em)
{
    int i;
    const char *saved_name = em->thread_name;
    int errors = 0;
    for (i = 0; local_syscalls[i].syscall; i++) {
        ebpf_sync_syscalls_t *w = &local_syscalls[i];
        if (w->enabled) {
            if (em->load & EBPF_LOAD_LEGACY) {
                if (ebpf_sync_load_legacy(w, em))
                    errors++;

                em->thread_name = saved_name;
            }
#ifdef LIBBPF_MAJOR_VERSION
            else {
                char syscall[NETDATA_EBPF_MAX_SYSCALL_LENGTH];
                ebpf_select_host_prefix(syscall, NETDATA_EBPF_MAX_SYSCALL_LENGTH, w->syscall, running_on_kernel);
                w->sync_obj = sync_bpf__open();
                if (!w->sync_obj) {
                    errors++;
                } else {
                    if (ebpf_is_function_inside_btf(default_btf, syscall)) {
                        if (ebpf_sync_load_and_attach(w->sync_obj, em, syscall, i)) {
                            errors++;
                        }
                    } else {
                        if (ebpf_sync_load_legacy(w, em))
                            errors++;
                    }
                    em->thread_name = saved_name;
                }
            }
#endif
        }
    }
    em->thread_name = saved_name;

    memset(sync_counter_aggregated_data, 0 , NETDATA_SYNC_IDX_END * sizeof(netdata_syscall_stat_t));
    memset(sync_counter_publish_aggregated, 0 , NETDATA_SYNC_IDX_END * sizeof(netdata_publish_syscall_t));
    memset(sync_hash_values, 0 , NETDATA_SYNC_IDX_END * sizeof(netdata_idx_t));

    return (errors) ? -1 : 0;
}

/*****************************************************************
 *
 *  DATA THREAD
 *
 *****************************************************************/

/**
 * Read global table
 *
 * Read the table with number of calls for all functions
 */
static void ebpf_sync_read_global_table()
{
    netdata_idx_t stored;
    uint32_t idx = NETDATA_SYNC_CALL;
    int i;
    for (i = 0; local_syscalls[i].syscall; i++) {
        if (local_syscalls[i].enabled) {
            int fd = sync_maps[i].map_fd;
            if (!bpf_map_lookup_elem(fd, &idx, &stored)) {
                sync_hash_values[i] = stored;
            }
        }
    }
}

/**
 * Create Sync charts
 *
 * Create charts and dimensions according user input.
 *
 * @param id        chart id
 * @param idx       the first index with data.
 * @param end       the last index with data.
 */
static void ebpf_send_sync_chart(char *id,
                                   int idx,
                                   int end)
{
    write_begin_chart(NETDATA_EBPF_MEMORY_GROUP, id);

    netdata_publish_syscall_t *move = &sync_counter_publish_aggregated[idx];

    while (move && idx <= end) {
        if (local_syscalls[idx].enabled)
            write_chart_dimension(move->name, sync_hash_values[idx]);

        move = move->next;
        idx++;
    }

    write_end_chart();
}

/**
 * Send data
 *
 * Send global charts to Netdata
 */
static void sync_send_data()
{
    if (local_syscalls[NETDATA_SYNC_FSYNC_IDX].enabled || local_syscalls[NETDATA_SYNC_FDATASYNC_IDX].enabled) {
        ebpf_send_sync_chart(NETDATA_EBPF_FILE_SYNC_CHART, NETDATA_SYNC_FSYNC_IDX, NETDATA_SYNC_FDATASYNC_IDX);
    }

    if (local_syscalls[NETDATA_SYNC_MSYNC_IDX].enabled)
        ebpf_one_dimension_write_charts(NETDATA_EBPF_MEMORY_GROUP, NETDATA_EBPF_MSYNC_CHART,
                                        sync_counter_publish_aggregated[NETDATA_SYNC_MSYNC_IDX].dimension,
                                        sync_hash_values[NETDATA_SYNC_MSYNC_IDX]);

    if (local_syscalls[NETDATA_SYNC_SYNC_IDX].enabled || local_syscalls[NETDATA_SYNC_SYNCFS_IDX].enabled) {
        ebpf_send_sync_chart(NETDATA_EBPF_SYNC_CHART, NETDATA_SYNC_SYNC_IDX, NETDATA_SYNC_SYNCFS_IDX);
    }

    if (local_syscalls[NETDATA_SYNC_SYNC_FILE_RANGE_IDX].enabled)
        ebpf_one_dimension_write_charts(NETDATA_EBPF_MEMORY_GROUP, NETDATA_EBPF_FILE_SEGMENT_CHART,
                                        sync_counter_publish_aggregated[NETDATA_SYNC_SYNC_FILE_RANGE_IDX].dimension,
                                        sync_hash_values[NETDATA_SYNC_SYNC_FILE_RANGE_IDX]);
}

/**
* Main loop for this collector.
*/
static void sync_collector(ebpf_module_t *em)
{
    heartbeat_t hb;
    heartbeat_init(&hb);
    int update_every = em->update_every;
    int counter = update_every - 1;
    while (!ebpf_exit_plugin) {
        (void)heartbeat_next(&hb, USEC_PER_SEC);
        if (ebpf_exit_plugin || ++counter != update_every)
            continue;

        counter = 0;
        ebpf_sync_read_global_table();
        pthread_mutex_lock(&lock);

        sync_send_data();

        pthread_mutex_unlock(&lock);
    }
}


/*****************************************************************
 *
 *  MAIN THREAD
 *
 *****************************************************************/

/**
 * Create Sync charts
 *
 * Create charts and dimensions according user input.
 *
 * @param id        chart id
 * @param title     chart title
 * @param order     order number of the specified chart
 * @param idx       the first index with data.
 * @param end       the last index with data.
 * @param update_every value to overwrite the update frequency set by the server.
 */
static void ebpf_create_sync_chart(char *id,
                                   char *title,
                                   int order,
                                   int idx,
                                   int end,
                                   int update_every)
{
    ebpf_write_chart_cmd(NETDATA_EBPF_MEMORY_GROUP, id, title, EBPF_COMMON_DIMENSION_CALL,
                         NETDATA_EBPF_SYNC_SUBMENU, NETDATA_EBPF_CHART_TYPE_LINE, NULL, order,
                         update_every,
                         NETDATA_EBPF_MODULE_NAME_SYNC);

    netdata_publish_syscall_t *move = &sync_counter_publish_aggregated[idx];

    while (move && idx <= end) {
        if (local_syscalls[idx].enabled)
            ebpf_write_global_dimension(move->name, move->dimension, move->algorithm);

        move = move->next;
        idx++;
    }
}

/**
 * Create global charts
 *
 * Call ebpf_create_chart to create the charts for the collector.
 *
 * @param update_every value to overwrite the update frequency set by the server.
 */
static void ebpf_create_sync_charts(int update_every)
{
    if (local_syscalls[NETDATA_SYNC_FSYNC_IDX].enabled || local_syscalls[NETDATA_SYNC_FDATASYNC_IDX].enabled)
        ebpf_create_sync_chart(NETDATA_EBPF_FILE_SYNC_CHART,
                               "Monitor calls for <code>fsync(2)</code> and <code>fdatasync(2)</code>.", 21300,
                               NETDATA_SYNC_FSYNC_IDX, NETDATA_SYNC_FDATASYNC_IDX, update_every);

    if (local_syscalls[NETDATA_SYNC_MSYNC_IDX].enabled)
        ebpf_create_sync_chart(NETDATA_EBPF_MSYNC_CHART,
                               "Monitor calls for <code>msync(2)</code>.", 21301,
                               NETDATA_SYNC_MSYNC_IDX, NETDATA_SYNC_MSYNC_IDX, update_every);

    if (local_syscalls[NETDATA_SYNC_SYNC_IDX].enabled || local_syscalls[NETDATA_SYNC_SYNCFS_IDX].enabled)
        ebpf_create_sync_chart(NETDATA_EBPF_SYNC_CHART,
                               "Monitor calls for <code>sync(2)</code> and <code>syncfs(2)</code>.", 21302,
                               NETDATA_SYNC_SYNC_IDX, NETDATA_SYNC_SYNCFS_IDX, update_every);

    if (local_syscalls[NETDATA_SYNC_SYNC_FILE_RANGE_IDX].enabled)
        ebpf_create_sync_chart(NETDATA_EBPF_FILE_SEGMENT_CHART,
                               "Monitor calls for <code>sync_file_range(2)</code>.", 21303,
                               NETDATA_SYNC_SYNC_FILE_RANGE_IDX, NETDATA_SYNC_SYNC_FILE_RANGE_IDX, update_every);
}

/**
 * Parse Syscalls
 *
 * Parse syscall options available inside ebpf.d/sync.conf
 */
static void ebpf_sync_parse_syscalls()
{
    int i;
    for (i = 0; local_syscalls[i].syscall; i++) {
        local_syscalls[i].enabled = appconfig_get_boolean(&sync_config, NETDATA_SYNC_CONFIG_NAME,
                                                          local_syscalls[i].syscall, CONFIG_BOOLEAN_YES);
    }
}

/**
 * Sync thread
 *
 * Thread used to make sync thread
 *
 * @param ptr a pointer to `struct ebpf_module`
 *
 * @return It always return NULL
 */
void *ebpf_sync_thread(void *ptr)
{
    netdata_thread_cleanup_push(ebpf_sync_exit, ptr);

    ebpf_module_t *em = (ebpf_module_t *)ptr;
    em->maps = sync_maps;

    ebpf_sync_parse_syscalls();

#ifdef LIBBPF_MAJOR_VERSION
    ebpf_adjust_thread_load(em, default_btf);
#endif
    if (ebpf_sync_initialize_syscall(em)) {
        goto endsync;
    }

    int algorithms[NETDATA_SYNC_IDX_END] = { NETDATA_EBPF_INCREMENTAL_IDX, NETDATA_EBPF_INCREMENTAL_IDX,
                                             NETDATA_EBPF_INCREMENTAL_IDX, NETDATA_EBPF_INCREMENTAL_IDX,
                                             NETDATA_EBPF_INCREMENTAL_IDX, NETDATA_EBPF_INCREMENTAL_IDX };
    ebpf_global_labels(sync_counter_aggregated_data, sync_counter_publish_aggregated,
                       sync_counter_dimension_name, sync_counter_dimension_name,
                       algorithms, NETDATA_SYNC_IDX_END);

    pthread_mutex_lock(&lock);
    ebpf_create_sync_charts(em->update_every);
    ebpf_update_stats(&plugin_statistics, em);
    pthread_mutex_unlock(&lock);

    sync_collector(em);

endsync:
    ebpf_update_disabled_plugin_stats(em);

    netdata_thread_cleanup_pop(1);
    return NULL;
}