summaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/bpf/prog_tests/ringbuf.c
blob: 48c5695b7abf12ede5624f83950f04aac93f4587 (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
// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <linux/compiler.h>
#include <asm/barrier.h>
#include <test_progs.h>
#include <sys/mman.h>
#include <sys/epoll.h>
#include <time.h>
#include <sched.h>
#include <signal.h>
#include <pthread.h>
#include <sys/sysinfo.h>
#include <linux/perf_event.h>
#include <linux/ring_buffer.h>
#include "test_ringbuf.lskel.h"
#include "test_ringbuf_map_key.lskel.h"

#define EDONE 7777

static int duration = 0;

struct sample {
	int pid;
	int seq;
	long value;
	char comm[16];
};

static int sample_cnt;

static void atomic_inc(int *cnt)
{
	__atomic_add_fetch(cnt, 1, __ATOMIC_SEQ_CST);
}

static int atomic_xchg(int *cnt, int val)
{
	return __atomic_exchange_n(cnt, val, __ATOMIC_SEQ_CST);
}

static int process_sample(void *ctx, void *data, size_t len)
{
	struct sample *s = data;

	atomic_inc(&sample_cnt);

	switch (s->seq) {
	case 0:
		CHECK(s->value != 333, "sample1_value", "exp %ld, got %ld\n",
		      333L, s->value);
		return 0;
	case 1:
		CHECK(s->value != 777, "sample2_value", "exp %ld, got %ld\n",
		      777L, s->value);
		return -EDONE;
	default:
		/* we don't care about the rest */
		return 0;
	}
}

static struct test_ringbuf_map_key_lskel *skel_map_key;
static struct test_ringbuf_lskel *skel;
static struct ring_buffer *ringbuf;

static void trigger_samples()
{
	skel->bss->dropped = 0;
	skel->bss->total = 0;
	skel->bss->discarded = 0;

	/* trigger exactly two samples */
	skel->bss->value = 333;
	syscall(__NR_getpgid);
	skel->bss->value = 777;
	syscall(__NR_getpgid);
}

static void *poll_thread(void *input)
{
	long timeout = (long)input;

	return (void *)(long)ring_buffer__poll(ringbuf, timeout);
}

static void ringbuf_subtest(void)
{
	const size_t rec_sz = BPF_RINGBUF_HDR_SZ + sizeof(struct sample);
	pthread_t thread;
	long bg_ret = -1;
	int err, cnt, rb_fd;
	int page_size = getpagesize();
	void *mmap_ptr, *tmp_ptr;
	struct ring *ring;
	int map_fd;
	unsigned long avail_data, ring_size, cons_pos, prod_pos;

	skel = test_ringbuf_lskel__open();
	if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
		return;

	skel->maps.ringbuf.max_entries = page_size;

	err = test_ringbuf_lskel__load(skel);
	if (CHECK(err != 0, "skel_load", "skeleton load failed\n"))
		goto cleanup;

	rb_fd = skel->maps.ringbuf.map_fd;
	/* good read/write cons_pos */
	mmap_ptr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, rb_fd, 0);
	ASSERT_OK_PTR(mmap_ptr, "rw_cons_pos");
	tmp_ptr = mremap(mmap_ptr, page_size, 2 * page_size, MREMAP_MAYMOVE);
	if (!ASSERT_ERR_PTR(tmp_ptr, "rw_extend"))
		goto cleanup;
	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_EXEC), "exec_cons_pos_protect");
	ASSERT_OK(munmap(mmap_ptr, page_size), "unmap_rw");

	/* bad writeable prod_pos */
	mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, page_size);
	err = -errno;
	ASSERT_ERR_PTR(mmap_ptr, "wr_prod_pos");
	ASSERT_EQ(err, -EPERM, "wr_prod_pos_err");

	/* bad writeable data pages */
	mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, 2 * page_size);
	err = -errno;
	ASSERT_ERR_PTR(mmap_ptr, "wr_data_page_one");
	ASSERT_EQ(err, -EPERM, "wr_data_page_one_err");
	mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, 3 * page_size);
	ASSERT_ERR_PTR(mmap_ptr, "wr_data_page_two");
	mmap_ptr = mmap(NULL, 2 * page_size, PROT_WRITE, MAP_SHARED, rb_fd, 2 * page_size);
	ASSERT_ERR_PTR(mmap_ptr, "wr_data_page_all");

	/* good read-only pages */
	mmap_ptr = mmap(NULL, 4 * page_size, PROT_READ, MAP_SHARED, rb_fd, 0);
	if (!ASSERT_OK_PTR(mmap_ptr, "ro_prod_pos"))
		goto cleanup;

	ASSERT_ERR(mprotect(mmap_ptr, 4 * page_size, PROT_WRITE), "write_protect");
	ASSERT_ERR(mprotect(mmap_ptr, 4 * page_size, PROT_EXEC), "exec_protect");
	ASSERT_ERR_PTR(mremap(mmap_ptr, 0, 4 * page_size, MREMAP_MAYMOVE), "ro_remap");
	ASSERT_OK(munmap(mmap_ptr, 4 * page_size), "unmap_ro");

	/* good read-only pages with initial offset */
	mmap_ptr = mmap(NULL, page_size, PROT_READ, MAP_SHARED, rb_fd, page_size);
	if (!ASSERT_OK_PTR(mmap_ptr, "ro_prod_pos"))
		goto cleanup;

	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_WRITE), "write_protect");
	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_EXEC), "exec_protect");
	ASSERT_ERR_PTR(mremap(mmap_ptr, 0, 3 * page_size, MREMAP_MAYMOVE), "ro_remap");
	ASSERT_OK(munmap(mmap_ptr, page_size), "unmap_ro");

	/* only trigger BPF program for current process */
	skel->bss->pid = getpid();

	ringbuf = ring_buffer__new(skel->maps.ringbuf.map_fd,
				   process_sample, NULL, NULL);
	if (CHECK(!ringbuf, "ringbuf_create", "failed to create ringbuf\n"))
		goto cleanup;

	err = test_ringbuf_lskel__attach(skel);
	if (CHECK(err, "skel_attach", "skeleton attachment failed: %d\n", err))
		goto cleanup;

	trigger_samples();

	ring = ring_buffer__ring(ringbuf, 0);
	if (!ASSERT_OK_PTR(ring, "ring_buffer__ring_idx_0"))
		goto cleanup;

	map_fd = ring__map_fd(ring);
	ASSERT_EQ(map_fd, skel->maps.ringbuf.map_fd, "ring_map_fd");

	/* 2 submitted + 1 discarded records */
	CHECK(skel->bss->avail_data != 3 * rec_sz,
	      "err_avail_size", "exp %ld, got %ld\n",
	      3L * rec_sz, skel->bss->avail_data);
	CHECK(skel->bss->ring_size != page_size,
	      "err_ring_size", "exp %ld, got %ld\n",
	      (long)page_size, skel->bss->ring_size);
	CHECK(skel->bss->cons_pos != 0,
	      "err_cons_pos", "exp %ld, got %ld\n",
	      0L, skel->bss->cons_pos);
	CHECK(skel->bss->prod_pos != 3 * rec_sz,
	      "err_prod_pos", "exp %ld, got %ld\n",
	      3L * rec_sz, skel->bss->prod_pos);

	/* verify getting this data directly via the ring object yields the same
	 * results
	 */
	avail_data = ring__avail_data_size(ring);
	ASSERT_EQ(avail_data, 3 * rec_sz, "ring_avail_size");
	ring_size = ring__size(ring);
	ASSERT_EQ(ring_size, page_size, "ring_ring_size");
	cons_pos = ring__consumer_pos(ring);
	ASSERT_EQ(cons_pos, 0, "ring_cons_pos");
	prod_pos = ring__producer_pos(ring);
	ASSERT_EQ(prod_pos, 3 * rec_sz, "ring_prod_pos");

	/* poll for samples */
	err = ring_buffer__poll(ringbuf, -1);

	/* -EDONE is used as an indicator that we are done */
	if (CHECK(err != -EDONE, "err_done", "done err: %d\n", err))
		goto cleanup;
	cnt = atomic_xchg(&sample_cnt, 0);
	CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt);

	/* we expect extra polling to return nothing */
	err = ring_buffer__poll(ringbuf, 0);
	if (CHECK(err != 0, "extra_samples", "poll result: %d\n", err))
		goto cleanup;
	cnt = atomic_xchg(&sample_cnt, 0);
	CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt);

	CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n",
	      0L, skel->bss->dropped);
	CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n",
	      2L, skel->bss->total);
	CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n",
	      1L, skel->bss->discarded);

	/* now validate consumer position is updated and returned */
	trigger_samples();
	CHECK(skel->bss->cons_pos != 3 * rec_sz,
	      "err_cons_pos", "exp %ld, got %ld\n",
	      3L * rec_sz, skel->bss->cons_pos);
	err = ring_buffer__poll(ringbuf, -1);
	CHECK(err <= 0, "poll_err", "err %d\n", err);
	cnt = atomic_xchg(&sample_cnt, 0);
	CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt);

	/* start poll in background w/ long timeout */
	err = pthread_create(&thread, NULL, poll_thread, (void *)(long)10000);
	if (CHECK(err, "bg_poll", "pthread_create failed: %d\n", err))
		goto cleanup;

	/* turn off notifications now */
	skel->bss->flags = BPF_RB_NO_WAKEUP;

	/* give background thread a bit of a time */
	usleep(50000);
	trigger_samples();
	/* sleeping arbitrarily is bad, but no better way to know that
	 * epoll_wait() **DID NOT** unblock in background thread
	 */
	usleep(50000);
	/* background poll should still be blocked */
	err = pthread_tryjoin_np(thread, (void **)&bg_ret);
	if (CHECK(err != EBUSY, "try_join", "err %d\n", err))
		goto cleanup;

	/* BPF side did everything right */
	CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n",
	      0L, skel->bss->dropped);
	CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n",
	      2L, skel->bss->total);
	CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n",
	      1L, skel->bss->discarded);
	cnt = atomic_xchg(&sample_cnt, 0);
	CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt);

	/* clear flags to return to "adaptive" notification mode */
	skel->bss->flags = 0;

	/* produce new samples, no notification should be triggered, because
	 * consumer is now behind
	 */
	trigger_samples();

	/* background poll should still be blocked */
	err = pthread_tryjoin_np(thread, (void **)&bg_ret);
	if (CHECK(err != EBUSY, "try_join", "err %d\n", err))
		goto cleanup;

	/* still no samples, because consumer is behind */
	cnt = atomic_xchg(&sample_cnt, 0);
	CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt);

	skel->bss->dropped = 0;
	skel->bss->total = 0;
	skel->bss->discarded = 0;

	skel->bss->value = 333;
	syscall(__NR_getpgid);
	/* now force notifications */
	skel->bss->flags = BPF_RB_FORCE_WAKEUP;
	skel->bss->value = 777;
	syscall(__NR_getpgid);

	/* now we should get a pending notification */
	usleep(50000);
	err = pthread_tryjoin_np(thread, (void **)&bg_ret);
	if (CHECK(err, "join_bg", "err %d\n", err))
		goto cleanup;

	if (CHECK(bg_ret <= 0, "bg_ret", "epoll_wait result: %ld", bg_ret))
		goto cleanup;

	/* due to timing variations, there could still be non-notified
	 * samples, so consume them here to collect all the samples
	 */
	err = ring_buffer__consume(ringbuf);
	CHECK(err < 0, "rb_consume", "failed: %d\b", err);

	/* also consume using ring__consume to make sure it works the same */
	err = ring__consume(ring);
	ASSERT_GE(err, 0, "ring_consume");

	/* 3 rounds, 2 samples each */
	cnt = atomic_xchg(&sample_cnt, 0);
	CHECK(cnt != 6, "cnt", "exp %d samples, got %d\n", 6, cnt);

	/* BPF side did everything right */
	CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n",
	      0L, skel->bss->dropped);
	CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n",
	      2L, skel->bss->total);
	CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n",
	      1L, skel->bss->discarded);

	test_ringbuf_lskel__detach(skel);
cleanup:
	ring_buffer__free(ringbuf);
	test_ringbuf_lskel__destroy(skel);
}

static int process_map_key_sample(void *ctx, void *data, size_t len)
{
	struct sample *s;
	int err, val;

	s = data;
	switch (s->seq) {
	case 1:
		ASSERT_EQ(s->value, 42, "sample_value");
		err = bpf_map_lookup_elem(skel_map_key->maps.hash_map.map_fd,
					  s, &val);
		ASSERT_OK(err, "hash_map bpf_map_lookup_elem");
		ASSERT_EQ(val, 1, "hash_map val");
		return -EDONE;
	default:
		return 0;
	}
}

static void ringbuf_map_key_subtest(void)
{
	int err;

	skel_map_key = test_ringbuf_map_key_lskel__open();
	if (!ASSERT_OK_PTR(skel_map_key, "test_ringbuf_map_key_lskel__open"))
		return;

	skel_map_key->maps.ringbuf.max_entries = getpagesize();
	skel_map_key->bss->pid = getpid();

	err = test_ringbuf_map_key_lskel__load(skel_map_key);
	if (!ASSERT_OK(err, "test_ringbuf_map_key_lskel__load"))
		goto cleanup;

	ringbuf = ring_buffer__new(skel_map_key->maps.ringbuf.map_fd,
				   process_map_key_sample, NULL, NULL);
	if (!ASSERT_OK_PTR(ringbuf, "ring_buffer__new"))
		goto cleanup;

	err = test_ringbuf_map_key_lskel__attach(skel_map_key);
	if (!ASSERT_OK(err, "test_ringbuf_map_key_lskel__attach"))
		goto cleanup_ringbuf;

	syscall(__NR_getpgid);
	ASSERT_EQ(skel_map_key->bss->seq, 1, "skel_map_key->bss->seq");
	err = ring_buffer__poll(ringbuf, -1);
	ASSERT_EQ(err, -EDONE, "ring_buffer__poll");

cleanup_ringbuf:
	ring_buffer__free(ringbuf);
cleanup:
	test_ringbuf_map_key_lskel__destroy(skel_map_key);
}

void test_ringbuf(void)
{
	if (test__start_subtest("ringbuf"))
		ringbuf_subtest();
	if (test__start_subtest("ringbuf_map_key"))
		ringbuf_map_key_subtest();
}