mmap-basic.c

  1// SPDX-License-Identifier: GPL-2.0
  2#include <errno.h>
  3#include <fcntl.h>
  4#include <inttypes.h>
  5#include <stdlib.h>
  6#include <perf/cpumap.h>
  7
  8#include "cpumap.h"
  9#include "debug.h"
 10#include "event.h"
 11#include "evlist.h"
 12#include "evsel.h"
 13#include "thread_map.h"
 14#include "tests.h"
 15#include "util/affinity.h"
 16#include "util/mmap.h"
 17#include "util/sample.h"
 18#include <linux/err.h>
 19#include <linux/kernel.h>
 20#include <linux/string.h>
 21#include <perf/evlist.h>
 22#include <perf/mmap.h>
 23
 24/*
 25 * This test will generate random numbers of calls to some getpid syscalls,
 26 * then establish an mmap for a group of events that are created to monitor
 27 * the syscalls.
 28 *
 29 * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
 30 * sample.id field to map back to its respective perf_evsel instance.
 31 *
 32 * Then it checks if the number of syscalls reported as perf events by
 33 * the kernel corresponds to the number of syscalls made.
 34 */
 35static int test__basic_mmap(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
 36{
 37	int err = TEST_FAIL;
 38	union perf_event *event;
 39	struct perf_thread_map *threads;
 40	struct perf_cpu_map *cpus;
 41	struct evlist *evlist;
 42	cpu_set_t cpu_set;
 43	const char *syscall_names[] = { "getsid", "getppid", "getpgid", };
 44	pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
 45#define nsyscalls ARRAY_SIZE(syscall_names)
 46	unsigned int nr_events[nsyscalls],
 47		     expected_nr_events[nsyscalls], i, j;
 48	struct evsel *evsels[nsyscalls], *evsel;
 49	char sbuf[STRERR_BUFSIZE];
 50	struct mmap *md;
 51
 52	threads = thread_map__new_by_tid(getpid());
 53	if (threads == NULL) {
 54		pr_debug("thread_map__new\n");
 55		return -1;
 56	}
 57
 58	cpus = perf_cpu_map__new_online_cpus();
 59	if (cpus == NULL) {
 60		pr_debug("perf_cpu_map__new\n");
 61		goto out_free_threads;
 62	}
 63
 64	CPU_ZERO(&cpu_set);
 65	CPU_SET(perf_cpu_map__cpu(cpus, 0).cpu, &cpu_set);
 66	sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
 67	if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
 68		pr_debug("sched_setaffinity() failed on CPU %d: %s ",
 69			 perf_cpu_map__cpu(cpus, 0).cpu,
 70			 str_error_r(errno, sbuf, sizeof(sbuf)));
 71		goto out_free_cpus;
 72	}
 73
 74	evlist = evlist__new();
 75	if (evlist == NULL) {
 76		pr_debug("evlist__new\n");
 77		goto out_free_cpus;
 78	}
 79
 80	perf_evlist__set_maps(&evlist->core, cpus, threads);
 81
 82	for (i = 0; i < nsyscalls; ++i) {
 83		char name[64];
 84
 85		snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
 86		evsels[i] = evsel__newtp("syscalls", name);
 87		if (IS_ERR(evsels[i])) {
 88			pr_debug("evsel__new(%s)\n", name);
 89			if (PTR_ERR(evsels[i]) == -EACCES) {
 90				/* Permissions failure, flag the failure as a skip. */
 91				err = TEST_SKIP;
 92			}
 93			goto out_delete_evlist;
 94		}
 95
 96		evsels[i]->core.attr.wakeup_events = 1;
 97		evsel__set_sample_id(evsels[i], false);
 98
 99		evlist__add(evlist, evsels[i]);
100
101		if (evsel__open(evsels[i], cpus, threads) < 0) {
102			pr_debug("failed to open counter: %s, "
103				 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
104				 str_error_r(errno, sbuf, sizeof(sbuf)));
105			goto out_delete_evlist;
106		}
107
108		nr_events[i] = 0;
109		expected_nr_events[i] = 1 + rand() % 127;
110	}
111
112	if (evlist__mmap(evlist, 128) < 0) {
113		pr_debug("failed to mmap events: %d (%s)\n", errno,
114			 str_error_r(errno, sbuf, sizeof(sbuf)));
115		goto out_delete_evlist;
116	}
117
118	for (i = 0; i < nsyscalls; ++i)
119		for (j = 0; j < expected_nr_events[i]; ++j) {
120			syscalls[i]();
121		}
122
123	md = &evlist->mmap[0];
124	if (perf_mmap__read_init(&md->core) < 0)
125		goto out_init;
126
127	while ((event = perf_mmap__read_event(&md->core)) != NULL) {
128		struct perf_sample sample;
129
130		if (event->header.type != PERF_RECORD_SAMPLE) {
131			pr_debug("unexpected %s event\n",
132				 perf_event__name(event->header.type));
133			goto out_delete_evlist;
134		}
135
136		perf_sample__init(&sample, /*all=*/false);
137		err = evlist__parse_sample(evlist, event, &sample);
138		if (err) {
139			pr_err("Can't parse sample, err = %d\n", err);
140			perf_sample__exit(&sample);
141			goto out_delete_evlist;
142		}
143
144		err = -1;
145		evsel = evlist__id2evsel(evlist, sample.id);
146		perf_sample__exit(&sample);
147		if (evsel == NULL) {
148			pr_debug("event with id %" PRIu64
149				 " doesn't map to an evsel\n", sample.id);
150			goto out_delete_evlist;
151		}
152		nr_events[evsel->core.idx]++;
153		perf_mmap__consume(&md->core);
154	}
155	perf_mmap__read_done(&md->core);
156
157out_init:
158	err = 0;
159	evlist__for_each_entry(evlist, evsel) {
160		if (nr_events[evsel->core.idx] != expected_nr_events[evsel->core.idx]) {
161			pr_debug("expected %d %s events, got %d\n",
162				 expected_nr_events[evsel->core.idx],
163				 evsel__name(evsel), nr_events[evsel->core.idx]);
164			err = -1;
165			goto out_delete_evlist;
166		}
167	}
168
169out_delete_evlist:
170	evlist__delete(evlist);
171out_free_cpus:
172	perf_cpu_map__put(cpus);
173out_free_threads:
174	perf_thread_map__put(threads);
175	return err;
176}
177
178enum user_read_state {
179	USER_READ_ENABLED,
180	USER_READ_DISABLED,
181	USER_READ_UNKNOWN,
182};
183
184static enum user_read_state set_user_read(struct perf_pmu *pmu, enum user_read_state enabled)
185{
186	char buf[2] = {0, '\n'};
187	ssize_t len;
188	int events_fd, rdpmc_fd;
189	enum user_read_state old_user_read = USER_READ_UNKNOWN;
190
191	if (enabled == USER_READ_UNKNOWN)
192		return USER_READ_UNKNOWN;
193
194	events_fd = perf_pmu__event_source_devices_fd();
195	if (events_fd < 0)
196		return USER_READ_UNKNOWN;
197
198	rdpmc_fd = perf_pmu__pathname_fd(events_fd, pmu->name, "rdpmc", O_RDWR);
199	if (rdpmc_fd < 0) {
200		close(events_fd);
201		return USER_READ_UNKNOWN;
202	}
203
204	len = read(rdpmc_fd, buf, sizeof(buf));
205	if (len != sizeof(buf))
206		pr_debug("%s read failed\n", __func__);
207
208	// Note, on Intel hybrid disabling on 1 PMU will implicitly disable on
209	// all the core PMUs.
210	old_user_read = (buf[0] == '1') ? USER_READ_ENABLED : USER_READ_DISABLED;
211
212	if (enabled != old_user_read) {
213		buf[0] = (enabled == USER_READ_ENABLED) ? '1' : '0';
214		len = write(rdpmc_fd, buf, sizeof(buf));
215		if (len != sizeof(buf))
216			pr_debug("%s write failed\n", __func__);
217	}
218	close(rdpmc_fd);
219	close(events_fd);
220	return old_user_read;
221}
222
223static int test_stat_user_read(u64 event, enum user_read_state enabled)
224{
225	struct perf_pmu *pmu = NULL;
226	struct perf_thread_map *threads = perf_thread_map__new_dummy();
227	int ret = TEST_OK;
228
229	pr_err("User space counter reading %" PRIu64 "\n", event);
230	if (!threads) {
231		pr_err("User space counter reading [Failed to create threads]\n");
232		return TEST_FAIL;
233	}
234	perf_thread_map__set_pid(threads, 0, 0);
235
236	while ((pmu = perf_pmus__scan_core(pmu)) != NULL) {
237		enum user_read_state saved_user_read_state = set_user_read(pmu, enabled);
238		struct perf_event_attr attr = {
239			.type	= PERF_TYPE_HARDWARE,
240			.config	= perf_pmus__supports_extended_type()
241			? event | ((u64)pmu->type << PERF_PMU_TYPE_SHIFT)
242				: event,
243#ifdef __aarch64__
244			.config1 = 0x2,		/* Request user access */
245#endif
246		};
247		struct perf_evsel *evsel = NULL;
248		int err;
249		struct perf_event_mmap_page *pc;
250		bool mapped = false, opened = false, rdpmc_supported;
251		struct perf_counts_values counts = { .val = 0 };
252
253
254		pr_debug("User space counter reading for PMU %s\n", pmu->name);
255		/*
256		 * Restrict scheduling to only use the rdpmc on the CPUs the
257		 * event can be on. If the test doesn't run on the CPU of the
258		 * event then the event will be disabled and the pc->index test
259		 * will fail.
260		 */
261		if (pmu->cpus != NULL)
262			cpu_map__set_affinity(pmu->cpus);
263
264		/* Make the evsel. */
265		evsel = perf_evsel__new(&attr);
266		if (!evsel) {
267			pr_err("User space counter reading for PMU %s [Failed to allocate evsel]\n",
268				pmu->name);
269			ret = TEST_FAIL;
270			goto cleanup;
271		}
272
273		err = perf_evsel__open(evsel, NULL, threads);
274		if (err) {
275			pr_err("User space counter reading for PMU %s [Failed to open evsel]\n",
276				pmu->name);
277			ret = TEST_SKIP;
278			goto cleanup;
279		}
280		opened = true;
281		err = perf_evsel__mmap(evsel, 0);
282		if (err) {
283			pr_err("User space counter reading for PMU %s [Failed to mmap evsel]\n",
284				pmu->name);
285			ret = TEST_FAIL;
286			goto cleanup;
287		}
288		mapped = true;
289
290		pc = perf_evsel__mmap_base(evsel, 0, 0);
291		if (!pc) {
292			pr_err("User space counter reading for PMU %s [Failed to get mmaped address]\n",
293				pmu->name);
294			ret = TEST_FAIL;
295			goto cleanup;
296		}
297
298		if (saved_user_read_state == USER_READ_UNKNOWN)
299			rdpmc_supported = pc->cap_user_rdpmc && pc->index;
300		else
301			rdpmc_supported = (enabled == USER_READ_ENABLED);
302
303		if (rdpmc_supported && (!pc->cap_user_rdpmc || !pc->index)) {
304			pr_err("User space counter reading for PMU %s [Failed unexpected supported counter access %d %d]\n",
305				pmu->name, pc->cap_user_rdpmc, pc->index);
306			ret = TEST_FAIL;
307			goto cleanup;
308		}
309
310		if (!rdpmc_supported && pc->cap_user_rdpmc) {
311			pr_err("User space counter reading for PMU %s [Failed unexpected unsupported counter access %d]\n",
312				pmu->name, pc->cap_user_rdpmc);
313			ret = TEST_FAIL;
314			goto cleanup;
315		}
316
317		if (rdpmc_supported && pc->pmc_width < 32) {
318			pr_err("User space counter reading for PMU %s [Failed width not set %d]\n",
319				pmu->name, pc->pmc_width);
320			ret = TEST_FAIL;
321			goto cleanup;
322		}
323
324		perf_evsel__read(evsel, 0, 0, &counts);
325		if (rdpmc_supported && counts.val == 0) {
326			pr_err("User space counter reading for PMU %s [Failed read]\n", pmu->name);
327			ret = TEST_FAIL;
328			goto cleanup;
329		}
330
331		for (int i = 0; i < 5; i++) {
332			volatile int count = 0x10000 << i;
333			__u64 start, end, last = 0;
334
335			pr_debug("\tloop = %u, ", count);
336
337			perf_evsel__read(evsel, 0, 0, &counts);
338			start = counts.val;
339
340			while (count--) ;
341
342			perf_evsel__read(evsel, 0, 0, &counts);
343			end = counts.val;
344
345			if ((end - start) < last) {
346				pr_err("User space counter reading for PMU %s [Failed invalid counter data: end=%llu start=%llu last= %llu]\n",
347					pmu->name, end, start, last);
348				ret = TEST_FAIL;
349				goto cleanup;
350			}
351			last = end - start;
352			pr_debug("count = %llu\n", last);
353		}
354		pr_debug("User space counter reading for PMU %s [Success]\n", pmu->name);
355cleanup:
356		if (mapped)
357			perf_evsel__munmap(evsel);
358		if (opened)
359			perf_evsel__close(evsel);
360		perf_evsel__delete(evsel);
361
362		/* If the affinity was changed, then put it back to all CPUs. */
363		if (pmu->cpus != NULL) {
364			struct perf_cpu_map *cpus = cpu_map__online();
365
366			cpu_map__set_affinity(cpus);
367			perf_cpu_map__put(cpus);
368		}
369		set_user_read(pmu, saved_user_read_state);
370	}
371	perf_thread_map__put(threads);
372	return ret;
373}
374
375static int test__mmap_user_read_instr(struct test_suite *test __maybe_unused,
376				      int subtest __maybe_unused)
377{
378	return test_stat_user_read(PERF_COUNT_HW_INSTRUCTIONS, USER_READ_ENABLED);
379}
380
381static int test__mmap_user_read_cycles(struct test_suite *test __maybe_unused,
382				       int subtest __maybe_unused)
383{
384	return test_stat_user_read(PERF_COUNT_HW_CPU_CYCLES, USER_READ_ENABLED);
385}
386
387static int test__mmap_user_read_instr_disabled(struct test_suite *test __maybe_unused,
388					       int subtest __maybe_unused)
389{
390	return test_stat_user_read(PERF_COUNT_HW_INSTRUCTIONS, USER_READ_DISABLED);
391}
392
393static int test__mmap_user_read_cycles_disabled(struct test_suite *test __maybe_unused,
394						int subtest __maybe_unused)
395{
396	return test_stat_user_read(PERF_COUNT_HW_CPU_CYCLES, USER_READ_DISABLED);
397}
398
399static struct test_case tests__basic_mmap[] = {
400	TEST_CASE_REASON("Read samples using the mmap interface",
401			 basic_mmap,
402			 "permissions"),
403	TEST_CASE_REASON_EXCLUSIVE("User space counter reading of instructions",
404			 mmap_user_read_instr,
405#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || \
406			 (defined(__riscv) && __riscv_xlen == 64)
407			 "permissions"
408#else
409			 "unsupported"
410#endif
411		),
412	TEST_CASE_REASON_EXCLUSIVE("User space counter reading of cycles",
413			 mmap_user_read_cycles,
414#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || \
415			 (defined(__riscv) && __riscv_xlen == 64)
416			 "permissions"
417#else
418			 "unsupported"
419#endif
420		),
421	TEST_CASE_REASON_EXCLUSIVE("User space counter disabling instructions",
422			 mmap_user_read_instr_disabled,
423#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || \
424			 (defined(__riscv) && __riscv_xlen == 64)
425			 "permissions"
426#else
427			 "unsupported"
428#endif
429		),
430	TEST_CASE_REASON_EXCLUSIVE("User space counter disabling cycles",
431			 mmap_user_read_cycles_disabled,
432#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || \
433			 (defined(__riscv) && __riscv_xlen == 64)
434			 "permissions"
435#else
436			 "unsupported"
437#endif
438		),
439	{	.name = NULL, }
440};
441
442struct test_suite suite__basic_mmap = {
443	.desc = "mmap interface tests",
444	.test_cases = tests__basic_mmap,
445};