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  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
 95	skel = test_ringbuf_lskel__open();
 96	if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
 97		return;
 98
 99	skel->maps.ringbuf.max_entries = page_size;
100
101	err = test_ringbuf_lskel__load(skel);
102	if (CHECK(err != 0, "skel_load", "skeleton load failed\n"))
103		goto cleanup;
104
105	rb_fd = skel->maps.ringbuf.map_fd;
106	/* good read/write cons_pos */
107	mmap_ptr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, rb_fd, 0);
108	ASSERT_OK_PTR(mmap_ptr, "rw_cons_pos");
109	tmp_ptr = mremap(mmap_ptr, page_size, 2 * page_size, MREMAP_MAYMOVE);
110	if (!ASSERT_ERR_PTR(tmp_ptr, "rw_extend"))
111		goto cleanup;
112	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_EXEC), "exec_cons_pos_protect");
113	ASSERT_OK(munmap(mmap_ptr, page_size), "unmap_rw");
114
115	/* bad writeable prod_pos */
116	mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, page_size);
117	err = -errno;
118	ASSERT_ERR_PTR(mmap_ptr, "wr_prod_pos");
119	ASSERT_EQ(err, -EPERM, "wr_prod_pos_err");
120
121	/* bad writeable data pages */
122	mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, 2 * page_size);
123	err = -errno;
124	ASSERT_ERR_PTR(mmap_ptr, "wr_data_page_one");
125	ASSERT_EQ(err, -EPERM, "wr_data_page_one_err");
126	mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, 3 * page_size);
127	ASSERT_ERR_PTR(mmap_ptr, "wr_data_page_two");
128	mmap_ptr = mmap(NULL, 2 * page_size, PROT_WRITE, MAP_SHARED, rb_fd, 2 * page_size);
129	ASSERT_ERR_PTR(mmap_ptr, "wr_data_page_all");
130
131	/* good read-only pages */
132	mmap_ptr = mmap(NULL, 4 * page_size, PROT_READ, MAP_SHARED, rb_fd, 0);
133	if (!ASSERT_OK_PTR(mmap_ptr, "ro_prod_pos"))
134		goto cleanup;
135
136	ASSERT_ERR(mprotect(mmap_ptr, 4 * page_size, PROT_WRITE), "write_protect");
137	ASSERT_ERR(mprotect(mmap_ptr, 4 * page_size, PROT_EXEC), "exec_protect");
138	ASSERT_ERR_PTR(mremap(mmap_ptr, 0, 4 * page_size, MREMAP_MAYMOVE), "ro_remap");
139	ASSERT_OK(munmap(mmap_ptr, 4 * page_size), "unmap_ro");
140
141	/* good read-only pages with initial offset */
142	mmap_ptr = mmap(NULL, page_size, PROT_READ, MAP_SHARED, rb_fd, page_size);
143	if (!ASSERT_OK_PTR(mmap_ptr, "ro_prod_pos"))
144		goto cleanup;
145
146	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_WRITE), "write_protect");
147	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_EXEC), "exec_protect");
148	ASSERT_ERR_PTR(mremap(mmap_ptr, 0, 3 * page_size, MREMAP_MAYMOVE), "ro_remap");
149	ASSERT_OK(munmap(mmap_ptr, page_size), "unmap_ro");
150
151	/* only trigger BPF program for current process */
152	skel->bss->pid = getpid();
153
154	ringbuf = ring_buffer__new(skel->maps.ringbuf.map_fd,
155				   process_sample, NULL, NULL);
156	if (CHECK(!ringbuf, "ringbuf_create", "failed to create ringbuf\n"))
157		goto cleanup;
158
159	err = test_ringbuf_lskel__attach(skel);
160	if (CHECK(err, "skel_attach", "skeleton attachment failed: %d\n", err))
161		goto cleanup;
162
163	trigger_samples();
164
165	/* 2 submitted + 1 discarded records */
166	CHECK(skel->bss->avail_data != 3 * rec_sz,
167	      "err_avail_size", "exp %ld, got %ld\n",
168	      3L * rec_sz, skel->bss->avail_data);
169	CHECK(skel->bss->ring_size != page_size,
170	      "err_ring_size", "exp %ld, got %ld\n",
171	      (long)page_size, skel->bss->ring_size);
172	CHECK(skel->bss->cons_pos != 0,
173	      "err_cons_pos", "exp %ld, got %ld\n",
174	      0L, skel->bss->cons_pos);
175	CHECK(skel->bss->prod_pos != 3 * rec_sz,
176	      "err_prod_pos", "exp %ld, got %ld\n",
177	      3L * rec_sz, skel->bss->prod_pos);
178
179	/* poll for samples */
180	err = ring_buffer__poll(ringbuf, -1);
181
182	/* -EDONE is used as an indicator that we are done */
183	if (CHECK(err != -EDONE, "err_done", "done err: %d\n", err))
184		goto cleanup;
185	cnt = atomic_xchg(&sample_cnt, 0);
186	CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt);
187
188	/* we expect extra polling to return nothing */
189	err = ring_buffer__poll(ringbuf, 0);
190	if (CHECK(err != 0, "extra_samples", "poll result: %d\n", err))
191		goto cleanup;
192	cnt = atomic_xchg(&sample_cnt, 0);
193	CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt);
194
195	CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n",
196	      0L, skel->bss->dropped);
197	CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n",
198	      2L, skel->bss->total);
199	CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n",
200	      1L, skel->bss->discarded);
201
202	/* now validate consumer position is updated and returned */
203	trigger_samples();
204	CHECK(skel->bss->cons_pos != 3 * rec_sz,
205	      "err_cons_pos", "exp %ld, got %ld\n",
206	      3L * rec_sz, skel->bss->cons_pos);
207	err = ring_buffer__poll(ringbuf, -1);
208	CHECK(err <= 0, "poll_err", "err %d\n", err);
209	cnt = atomic_xchg(&sample_cnt, 0);
210	CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt);
211
212	/* start poll in background w/ long timeout */
213	err = pthread_create(&thread, NULL, poll_thread, (void *)(long)10000);
214	if (CHECK(err, "bg_poll", "pthread_create failed: %d\n", err))
215		goto cleanup;
216
217	/* turn off notifications now */
218	skel->bss->flags = BPF_RB_NO_WAKEUP;
219
220	/* give background thread a bit of a time */
221	usleep(50000);
222	trigger_samples();
223	/* sleeping arbitrarily is bad, but no better way to know that
224	 * epoll_wait() **DID NOT** unblock in background thread
225	 */
226	usleep(50000);
227	/* background poll should still be blocked */
228	err = pthread_tryjoin_np(thread, (void **)&bg_ret);
229	if (CHECK(err != EBUSY, "try_join", "err %d\n", err))
230		goto cleanup;
231
232	/* BPF side did everything right */
233	CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n",
234	      0L, skel->bss->dropped);
235	CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n",
236	      2L, skel->bss->total);
237	CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n",
238	      1L, skel->bss->discarded);
239	cnt = atomic_xchg(&sample_cnt, 0);
240	CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt);
241
242	/* clear flags to return to "adaptive" notification mode */
243	skel->bss->flags = 0;
244
245	/* produce new samples, no notification should be triggered, because
246	 * consumer is now behind
247	 */
248	trigger_samples();
249
250	/* background poll should still be blocked */
251	err = pthread_tryjoin_np(thread, (void **)&bg_ret);
252	if (CHECK(err != EBUSY, "try_join", "err %d\n", err))
253		goto cleanup;
254
255	/* still no samples, because consumer is behind */
256	cnt = atomic_xchg(&sample_cnt, 0);
257	CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt);
258
259	skel->bss->dropped = 0;
260	skel->bss->total = 0;
261	skel->bss->discarded = 0;
262
263	skel->bss->value = 333;
264	syscall(__NR_getpgid);
265	/* now force notifications */
266	skel->bss->flags = BPF_RB_FORCE_WAKEUP;
267	skel->bss->value = 777;
268	syscall(__NR_getpgid);
269
270	/* now we should get a pending notification */
271	usleep(50000);
272	err = pthread_tryjoin_np(thread, (void **)&bg_ret);
273	if (CHECK(err, "join_bg", "err %d\n", err))
274		goto cleanup;
275
276	if (CHECK(bg_ret <= 0, "bg_ret", "epoll_wait result: %ld", bg_ret))
277		goto cleanup;
278
279	/* due to timing variations, there could still be non-notified
280	 * samples, so consume them here to collect all the samples
281	 */
282	err = ring_buffer__consume(ringbuf);
283	CHECK(err < 0, "rb_consume", "failed: %d\b", err);
284
285	/* 3 rounds, 2 samples each */
286	cnt = atomic_xchg(&sample_cnt, 0);
287	CHECK(cnt != 6, "cnt", "exp %d samples, got %d\n", 6, cnt);
288
289	/* BPF side did everything right */
290	CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n",
291	      0L, skel->bss->dropped);
292	CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n",
293	      2L, skel->bss->total);
294	CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n",
295	      1L, skel->bss->discarded);
296
297	test_ringbuf_lskel__detach(skel);
298cleanup:
299	ring_buffer__free(ringbuf);
300	test_ringbuf_lskel__destroy(skel);
301}
302
303static int process_map_key_sample(void *ctx, void *data, size_t len)
304{
305	struct sample *s;
306	int err, val;
307
308	s = data;
309	switch (s->seq) {
310	case 1:
311		ASSERT_EQ(s->value, 42, "sample_value");
312		err = bpf_map_lookup_elem(skel_map_key->maps.hash_map.map_fd,
313					  s, &val);
314		ASSERT_OK(err, "hash_map bpf_map_lookup_elem");
315		ASSERT_EQ(val, 1, "hash_map val");
316		return -EDONE;
317	default:
318		return 0;
319	}
320}
321
322static void ringbuf_map_key_subtest(void)
323{
324	int err;
325
326	skel_map_key = test_ringbuf_map_key_lskel__open();
327	if (!ASSERT_OK_PTR(skel_map_key, "test_ringbuf_map_key_lskel__open"))
328		return;
329
330	skel_map_key->maps.ringbuf.max_entries = getpagesize();
331	skel_map_key->bss->pid = getpid();
332
333	err = test_ringbuf_map_key_lskel__load(skel_map_key);
334	if (!ASSERT_OK(err, "test_ringbuf_map_key_lskel__load"))
335		goto cleanup;
336
337	ringbuf = ring_buffer__new(skel_map_key->maps.ringbuf.map_fd,
338				   process_map_key_sample, NULL, NULL);
339	if (!ASSERT_OK_PTR(ringbuf, "ring_buffer__new"))
340		goto cleanup;
341
342	err = test_ringbuf_map_key_lskel__attach(skel_map_key);
343	if (!ASSERT_OK(err, "test_ringbuf_map_key_lskel__attach"))
344		goto cleanup_ringbuf;
345
346	syscall(__NR_getpgid);
347	ASSERT_EQ(skel_map_key->bss->seq, 1, "skel_map_key->bss->seq");
348	err = ring_buffer__poll(ringbuf, -1);
349	ASSERT_EQ(err, -EDONE, "ring_buffer__poll");
350
351cleanup_ringbuf:
352	ring_buffer__free(ringbuf);
353cleanup:
354	test_ringbuf_map_key_lskel__destroy(skel_map_key);
355}
356
357void test_ringbuf(void)
358{
359	if (test__start_subtest("ringbuf"))
360		ringbuf_subtest();
361	if (test__start_subtest("ringbuf_map_key"))
362		ringbuf_map_key_subtest();
363}