1// SPDX-License-Identifier: GPL-2.0
2#define _GNU_SOURCE
3#include <linux/compiler.h>
4#include <asm/barrier.h>
5#include <test_progs.h>
6#include <sys/mman.h>
7#include <sys/epoll.h>
8#include <time.h>
9#include <sched.h>
10#include <signal.h>
11#include <pthread.h>
12#include <sys/sysinfo.h>
13#include <linux/perf_event.h>
14#include <linux/ring_buffer.h>
15#include "test_ringbuf.lskel.h"
16#include "test_ringbuf_map_key.lskel.h"
17
18#define EDONE 7777
19
20static int duration = 0;
21
22struct sample {
23	int pid;
24	int seq;
25	long value;
26	char comm[16];
27};
28
29static int sample_cnt;
30
31static void atomic_inc(int *cnt)
32{
33	__atomic_add_fetch(cnt, 1, __ATOMIC_SEQ_CST);
34}
35
36static int atomic_xchg(int *cnt, int val)
37{
38	return __atomic_exchange_n(cnt, val, __ATOMIC_SEQ_CST);
39}
40
41static int process_sample(void *ctx, void *data, size_t len)
42{
43	struct sample *s = data;
44
45	atomic_inc(&sample_cnt);
46
47	switch (s->seq) {
48	case 0:
49		CHECK(s->value != 333, "sample1_value", "exp %ld, got %ld\n",
50		      333L, s->value);
51		return 0;
52	case 1:
53		CHECK(s->value != 777, "sample2_value", "exp %ld, got %ld\n",
54		      777L, s->value);
55		return -EDONE;
56	default:
57		/* we don't care about the rest */
58		return 0;
59	}
60}
61
62static struct test_ringbuf_map_key_lskel *skel_map_key;
63static struct test_ringbuf_lskel *skel;
64static struct ring_buffer *ringbuf;
65
66static void trigger_samples()
67{
68	skel->bss->dropped = 0;
69	skel->bss->total = 0;
70	skel->bss->discarded = 0;
71
72	/* trigger exactly two samples */
73	skel->bss->value = 333;
74	syscall(__NR_getpgid);
75	skel->bss->value = 777;
76	syscall(__NR_getpgid);
77}
78
79static void *poll_thread(void *input)
80{
81	long timeout = (long)input;
82
83	return (void *)(long)ring_buffer__poll(ringbuf, timeout);
84}
85
86static void ringbuf_subtest(void)
87{
88	const size_t rec_sz = BPF_RINGBUF_HDR_SZ + sizeof(struct sample);
89	pthread_t thread;
90	long bg_ret = -1;
91	int err, cnt, rb_fd;
92	int page_size = getpagesize();
93	void *mmap_ptr, *tmp_ptr;
94	struct ring *ring;
95	int map_fd;
96	unsigned long avail_data, ring_size, cons_pos, prod_pos;
97
98	skel = test_ringbuf_lskel__open();
99	if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
100		return;
101
102	skel->maps.ringbuf.max_entries = page_size;
103
104	err = test_ringbuf_lskel__load(skel);
105	if (CHECK(err != 0, "skel_load", "skeleton load failed\n"))
106		goto cleanup;
107
108	rb_fd = skel->maps.ringbuf.map_fd;
109	/* good read/write cons_pos */
110	mmap_ptr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, rb_fd, 0);
111	ASSERT_OK_PTR(mmap_ptr, "rw_cons_pos");
112	tmp_ptr = mremap(mmap_ptr, page_size, 2 * page_size, MREMAP_MAYMOVE);
113	if (!ASSERT_ERR_PTR(tmp_ptr, "rw_extend"))
114		goto cleanup;
115	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_EXEC), "exec_cons_pos_protect");
116	ASSERT_OK(munmap(mmap_ptr, page_size), "unmap_rw");
117
118	/* bad writeable prod_pos */
119	mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, page_size);
120	err = -errno;
121	ASSERT_ERR_PTR(mmap_ptr, "wr_prod_pos");
122	ASSERT_EQ(err, -EPERM, "wr_prod_pos_err");
123
124	/* bad writeable data pages */
125	mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, 2 * page_size);
126	err = -errno;
127	ASSERT_ERR_PTR(mmap_ptr, "wr_data_page_one");
128	ASSERT_EQ(err, -EPERM, "wr_data_page_one_err");
129	mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, 3 * page_size);
130	ASSERT_ERR_PTR(mmap_ptr, "wr_data_page_two");
131	mmap_ptr = mmap(NULL, 2 * page_size, PROT_WRITE, MAP_SHARED, rb_fd, 2 * page_size);
132	ASSERT_ERR_PTR(mmap_ptr, "wr_data_page_all");
133
134	/* good read-only pages */
135	mmap_ptr = mmap(NULL, 4 * page_size, PROT_READ, MAP_SHARED, rb_fd, 0);
136	if (!ASSERT_OK_PTR(mmap_ptr, "ro_prod_pos"))
137		goto cleanup;
138
139	ASSERT_ERR(mprotect(mmap_ptr, 4 * page_size, PROT_WRITE), "write_protect");
140	ASSERT_ERR(mprotect(mmap_ptr, 4 * page_size, PROT_EXEC), "exec_protect");
141	ASSERT_ERR_PTR(mremap(mmap_ptr, 0, 4 * page_size, MREMAP_MAYMOVE), "ro_remap");
142	ASSERT_OK(munmap(mmap_ptr, 4 * page_size), "unmap_ro");
143
144	/* good read-only pages with initial offset */
145	mmap_ptr = mmap(NULL, page_size, PROT_READ, MAP_SHARED, rb_fd, page_size);
146	if (!ASSERT_OK_PTR(mmap_ptr, "ro_prod_pos"))
147		goto cleanup;
148
149	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_WRITE), "write_protect");
150	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_EXEC), "exec_protect");
151	ASSERT_ERR_PTR(mremap(mmap_ptr, 0, 3 * page_size, MREMAP_MAYMOVE), "ro_remap");
152	ASSERT_OK(munmap(mmap_ptr, page_size), "unmap_ro");
153
154	/* only trigger BPF program for current process */
155	skel->bss->pid = getpid();
156
157	ringbuf = ring_buffer__new(skel->maps.ringbuf.map_fd,
158				   process_sample, NULL, NULL);
159	if (CHECK(!ringbuf, "ringbuf_create", "failed to create ringbuf\n"))
160		goto cleanup;
161
162	err = test_ringbuf_lskel__attach(skel);
163	if (CHECK(err, "skel_attach", "skeleton attachment failed: %d\n", err))
164		goto cleanup;
165
166	trigger_samples();
167
168	ring = ring_buffer__ring(ringbuf, 0);
169	if (!ASSERT_OK_PTR(ring, "ring_buffer__ring_idx_0"))
170		goto cleanup;
171
172	map_fd = ring__map_fd(ring);
173	ASSERT_EQ(map_fd, skel->maps.ringbuf.map_fd, "ring_map_fd");
174
175	/* 2 submitted + 1 discarded records */
176	CHECK(skel->bss->avail_data != 3 * rec_sz,
177	      "err_avail_size", "exp %ld, got %ld\n",
178	      3L * rec_sz, skel->bss->avail_data);
179	CHECK(skel->bss->ring_size != page_size,
180	      "err_ring_size", "exp %ld, got %ld\n",
181	      (long)page_size, skel->bss->ring_size);
182	CHECK(skel->bss->cons_pos != 0,
183	      "err_cons_pos", "exp %ld, got %ld\n",
184	      0L, skel->bss->cons_pos);
185	CHECK(skel->bss->prod_pos != 3 * rec_sz,
186	      "err_prod_pos", "exp %ld, got %ld\n",
187	      3L * rec_sz, skel->bss->prod_pos);
188
189	/* verify getting this data directly via the ring object yields the same
190	 * results
191	 */
192	avail_data = ring__avail_data_size(ring);
193	ASSERT_EQ(avail_data, 3 * rec_sz, "ring_avail_size");
194	ring_size = ring__size(ring);
195	ASSERT_EQ(ring_size, page_size, "ring_ring_size");
196	cons_pos = ring__consumer_pos(ring);
197	ASSERT_EQ(cons_pos, 0, "ring_cons_pos");
198	prod_pos = ring__producer_pos(ring);
199	ASSERT_EQ(prod_pos, 3 * rec_sz, "ring_prod_pos");
200
201	/* poll for samples */
202	err = ring_buffer__poll(ringbuf, -1);
203
204	/* -EDONE is used as an indicator that we are done */
205	if (CHECK(err != -EDONE, "err_done", "done err: %d\n", err))
206		goto cleanup;
207	cnt = atomic_xchg(&sample_cnt, 0);
208	CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt);
209
210	/* we expect extra polling to return nothing */
211	err = ring_buffer__poll(ringbuf, 0);
212	if (CHECK(err != 0, "extra_samples", "poll result: %d\n", err))
213		goto cleanup;
214	cnt = atomic_xchg(&sample_cnt, 0);
215	CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt);
216
217	CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n",
218	      0L, skel->bss->dropped);
219	CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n",
220	      2L, skel->bss->total);
221	CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n",
222	      1L, skel->bss->discarded);
223
224	/* now validate consumer position is updated and returned */
225	trigger_samples();
226	CHECK(skel->bss->cons_pos != 3 * rec_sz,
227	      "err_cons_pos", "exp %ld, got %ld\n",
228	      3L * rec_sz, skel->bss->cons_pos);
229	err = ring_buffer__poll(ringbuf, -1);
230	CHECK(err <= 0, "poll_err", "err %d\n", err);
231	cnt = atomic_xchg(&sample_cnt, 0);
232	CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt);
233
234	/* start poll in background w/ long timeout */
235	err = pthread_create(&thread, NULL, poll_thread, (void *)(long)10000);
236	if (CHECK(err, "bg_poll", "pthread_create failed: %d\n", err))
237		goto cleanup;
238
239	/* turn off notifications now */
240	skel->bss->flags = BPF_RB_NO_WAKEUP;
241
242	/* give background thread a bit of a time */
243	usleep(50000);
244	trigger_samples();
245	/* sleeping arbitrarily is bad, but no better way to know that
246	 * epoll_wait() **DID NOT** unblock in background thread
247	 */
248	usleep(50000);
249	/* background poll should still be blocked */
250	err = pthread_tryjoin_np(thread, (void **)&bg_ret);
251	if (CHECK(err != EBUSY, "try_join", "err %d\n", err))
252		goto cleanup;
253
254	/* BPF side did everything right */
255	CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n",
256	      0L, skel->bss->dropped);
257	CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n",
258	      2L, skel->bss->total);
259	CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n",
260	      1L, skel->bss->discarded);
261	cnt = atomic_xchg(&sample_cnt, 0);
262	CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt);
263
264	/* clear flags to return to "adaptive" notification mode */
265	skel->bss->flags = 0;
266
267	/* produce new samples, no notification should be triggered, because
268	 * consumer is now behind
269	 */
270	trigger_samples();
271
272	/* background poll should still be blocked */
273	err = pthread_tryjoin_np(thread, (void **)&bg_ret);
274	if (CHECK(err != EBUSY, "try_join", "err %d\n", err))
275		goto cleanup;
276
277	/* still no samples, because consumer is behind */
278	cnt = atomic_xchg(&sample_cnt, 0);
279	CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt);
280
281	skel->bss->dropped = 0;
282	skel->bss->total = 0;
283	skel->bss->discarded = 0;
284
285	skel->bss->value = 333;
286	syscall(__NR_getpgid);
287	/* now force notifications */
288	skel->bss->flags = BPF_RB_FORCE_WAKEUP;
289	skel->bss->value = 777;
290	syscall(__NR_getpgid);
291
292	/* now we should get a pending notification */
293	usleep(50000);
294	err = pthread_tryjoin_np(thread, (void **)&bg_ret);
295	if (CHECK(err, "join_bg", "err %d\n", err))
296		goto cleanup;
297
298	if (CHECK(bg_ret <= 0, "bg_ret", "epoll_wait result: %ld", bg_ret))
299		goto cleanup;
300
301	/* due to timing variations, there could still be non-notified
302	 * samples, so consume them here to collect all the samples
303	 */
304	err = ring_buffer__consume(ringbuf);
305	CHECK(err < 0, "rb_consume", "failed: %d\b", err);
306
307	/* also consume using ring__consume to make sure it works the same */
308	err = ring__consume(ring);
309	ASSERT_GE(err, 0, "ring_consume");
310
311	/* 3 rounds, 2 samples each */
312	cnt = atomic_xchg(&sample_cnt, 0);
313	CHECK(cnt != 6, "cnt", "exp %d samples, got %d\n", 6, cnt);
314
315	/* BPF side did everything right */
316	CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n",
317	      0L, skel->bss->dropped);
318	CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n",
319	      2L, skel->bss->total);
320	CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n",
321	      1L, skel->bss->discarded);
322
323	test_ringbuf_lskel__detach(skel);
324cleanup:
325	ring_buffer__free(ringbuf);
326	test_ringbuf_lskel__destroy(skel);
327}
328
329static int process_map_key_sample(void *ctx, void *data, size_t len)
330{
331	struct sample *s;
332	int err, val;
333
334	s = data;
335	switch (s->seq) {
336	case 1:
337		ASSERT_EQ(s->value, 42, "sample_value");
338		err = bpf_map_lookup_elem(skel_map_key->maps.hash_map.map_fd,
339					  s, &val);
340		ASSERT_OK(err, "hash_map bpf_map_lookup_elem");
341		ASSERT_EQ(val, 1, "hash_map val");
342		return -EDONE;
343	default:
344		return 0;
345	}
346}
347
348static void ringbuf_map_key_subtest(void)
349{
350	int err;
351
352	skel_map_key = test_ringbuf_map_key_lskel__open();
353	if (!ASSERT_OK_PTR(skel_map_key, "test_ringbuf_map_key_lskel__open"))
354		return;
355
356	skel_map_key->maps.ringbuf.max_entries = getpagesize();
357	skel_map_key->bss->pid = getpid();
358
359	err = test_ringbuf_map_key_lskel__load(skel_map_key);
360	if (!ASSERT_OK(err, "test_ringbuf_map_key_lskel__load"))
361		goto cleanup;
362
363	ringbuf = ring_buffer__new(skel_map_key->maps.ringbuf.map_fd,
364				   process_map_key_sample, NULL, NULL);
365	if (!ASSERT_OK_PTR(ringbuf, "ring_buffer__new"))
366		goto cleanup;
367
368	err = test_ringbuf_map_key_lskel__attach(skel_map_key);
369	if (!ASSERT_OK(err, "test_ringbuf_map_key_lskel__attach"))
370		goto cleanup_ringbuf;
371
372	syscall(__NR_getpgid);
373	ASSERT_EQ(skel_map_key->bss->seq, 1, "skel_map_key->bss->seq");
374	err = ring_buffer__poll(ringbuf, -1);
375	ASSERT_EQ(err, -EDONE, "ring_buffer__poll");
376
377cleanup_ringbuf:
378	ring_buffer__free(ringbuf);
379cleanup:
380	test_ringbuf_map_key_lskel__destroy(skel_map_key);
381}
382
383void test_ringbuf(void)
384{
385	if (test__start_subtest("ringbuf"))
386		ringbuf_subtest();
387	if (test__start_subtest("ringbuf_map_key"))
388		ringbuf_map_key_subtest();
389}
390