xref: /linux/tools/perf/tests/mmap-basic.c (revision d6e9aa6e1ea872d1bbdf08ac78245cf8efeda19c)
1  // SPDX-License-Identifier: GPL-2.0
2  #include <errno.h>
3  #include <inttypes.h>
4  #include <stdlib.h>
5  #include <perf/cpumap.h>
6  
7  #include "debug.h"
8  #include "evlist.h"
9  #include "evsel.h"
10  #include "thread_map.h"
11  #include "tests.h"
12  #include "util/mmap.h"
13  #include <linux/err.h>
14  #include <linux/kernel.h>
15  #include <linux/string.h>
16  #include <perf/evlist.h>
17  #include <perf/mmap.h>
18  
19  /*
20   * This test will generate random numbers of calls to some getpid syscalls,
21   * then establish an mmap for a group of events that are created to monitor
22   * the syscalls.
23   *
24   * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
25   * sample.id field to map back to its respective perf_evsel instance.
26   *
27   * Then it checks if the number of syscalls reported as perf events by
28   * the kernel corresponds to the number of syscalls made.
29   */
30  static int test__basic_mmap(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
31  {
32  	int err = TEST_FAIL;
33  	union perf_event *event;
34  	struct perf_thread_map *threads;
35  	struct perf_cpu_map *cpus;
36  	struct evlist *evlist;
37  	cpu_set_t cpu_set;
38  	const char *syscall_names[] = { "getsid", "getppid", "getpgid", };
39  	pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
40  #define nsyscalls ARRAY_SIZE(syscall_names)
41  	unsigned int nr_events[nsyscalls],
42  		     expected_nr_events[nsyscalls], i, j;
43  	struct evsel *evsels[nsyscalls], *evsel;
44  	char sbuf[STRERR_BUFSIZE];
45  	struct mmap *md;
46  
47  	threads = thread_map__new(-1, getpid(), UINT_MAX);
48  	if (threads == NULL) {
49  		pr_debug("thread_map__new\n");
50  		return -1;
51  	}
52  
53  	cpus = perf_cpu_map__new(NULL);
54  	if (cpus == NULL) {
55  		pr_debug("perf_cpu_map__new\n");
56  		goto out_free_threads;
57  	}
58  
59  	CPU_ZERO(&cpu_set);
60  	CPU_SET(perf_cpu_map__cpu(cpus, 0).cpu, &cpu_set);
61  	sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
62  	if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
63  		pr_debug("sched_setaffinity() failed on CPU %d: %s ",
64  			 perf_cpu_map__cpu(cpus, 0).cpu,
65  			 str_error_r(errno, sbuf, sizeof(sbuf)));
66  		goto out_free_cpus;
67  	}
68  
69  	evlist = evlist__new();
70  	if (evlist == NULL) {
71  		pr_debug("evlist__new\n");
72  		goto out_free_cpus;
73  	}
74  
75  	perf_evlist__set_maps(&evlist->core, cpus, threads);
76  
77  	for (i = 0; i < nsyscalls; ++i) {
78  		char name[64];
79  
80  		snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
81  		evsels[i] = evsel__newtp("syscalls", name);
82  		if (IS_ERR(evsels[i])) {
83  			pr_debug("evsel__new(%s)\n", name);
84  			if (PTR_ERR(evsels[i]) == -EACCES) {
85  				/* Permissions failure, flag the failure as a skip. */
86  				err = TEST_SKIP;
87  			}
88  			goto out_delete_evlist;
89  		}
90  
91  		evsels[i]->core.attr.wakeup_events = 1;
92  		evsel__set_sample_id(evsels[i], false);
93  
94  		evlist__add(evlist, evsels[i]);
95  
96  		if (evsel__open(evsels[i], cpus, threads) < 0) {
97  			pr_debug("failed to open counter: %s, "
98  				 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
99  				 str_error_r(errno, sbuf, sizeof(sbuf)));
100  			goto out_delete_evlist;
101  		}
102  
103  		nr_events[i] = 0;
104  		expected_nr_events[i] = 1 + rand() % 127;
105  	}
106  
107  	if (evlist__mmap(evlist, 128) < 0) {
108  		pr_debug("failed to mmap events: %d (%s)\n", errno,
109  			 str_error_r(errno, sbuf, sizeof(sbuf)));
110  		goto out_delete_evlist;
111  	}
112  
113  	for (i = 0; i < nsyscalls; ++i)
114  		for (j = 0; j < expected_nr_events[i]; ++j) {
115  			syscalls[i]();
116  		}
117  
118  	md = &evlist->mmap[0];
119  	if (perf_mmap__read_init(&md->core) < 0)
120  		goto out_init;
121  
122  	while ((event = perf_mmap__read_event(&md->core)) != NULL) {
123  		struct perf_sample sample;
124  
125  		if (event->header.type != PERF_RECORD_SAMPLE) {
126  			pr_debug("unexpected %s event\n",
127  				 perf_event__name(event->header.type));
128  			goto out_delete_evlist;
129  		}
130  
131  		err = evlist__parse_sample(evlist, event, &sample);
132  		if (err) {
133  			pr_err("Can't parse sample, err = %d\n", err);
134  			goto out_delete_evlist;
135  		}
136  
137  		err = -1;
138  		evsel = evlist__id2evsel(evlist, sample.id);
139  		if (evsel == NULL) {
140  			pr_debug("event with id %" PRIu64
141  				 " doesn't map to an evsel\n", sample.id);
142  			goto out_delete_evlist;
143  		}
144  		nr_events[evsel->core.idx]++;
145  		perf_mmap__consume(&md->core);
146  	}
147  	perf_mmap__read_done(&md->core);
148  
149  out_init:
150  	err = 0;
151  	evlist__for_each_entry(evlist, evsel) {
152  		if (nr_events[evsel->core.idx] != expected_nr_events[evsel->core.idx]) {
153  			pr_debug("expected %d %s events, got %d\n",
154  				 expected_nr_events[evsel->core.idx],
155  				 evsel__name(evsel), nr_events[evsel->core.idx]);
156  			err = -1;
157  			goto out_delete_evlist;
158  		}
159  	}
160  
161  out_delete_evlist:
162  	evlist__delete(evlist);
163  out_free_cpus:
164  	perf_cpu_map__put(cpus);
165  out_free_threads:
166  	perf_thread_map__put(threads);
167  	return err;
168  }
169  
170  static int test_stat_user_read(int event)
171  {
172  	struct perf_counts_values counts = { .val = 0 };
173  	struct perf_thread_map *threads;
174  	struct perf_evsel *evsel;
175  	struct perf_event_mmap_page *pc;
176  	struct perf_event_attr attr = {
177  		.type	= PERF_TYPE_HARDWARE,
178  		.config	= event,
179  #ifdef __aarch64__
180  		.config1 = 0x2,		/* Request user access */
181  #endif
182  	};
183  	int err, i, ret = TEST_FAIL;
184  	bool opened = false, mapped = false;
185  
186  	threads = perf_thread_map__new_dummy();
187  	TEST_ASSERT_VAL("failed to create threads", threads);
188  
189  	perf_thread_map__set_pid(threads, 0, 0);
190  
191  	evsel = perf_evsel__new(&attr);
192  	TEST_ASSERT_VAL("failed to create evsel", evsel);
193  
194  	err = perf_evsel__open(evsel, NULL, threads);
195  	if (err) {
196  		pr_err("failed to open evsel: %s\n", strerror(-err));
197  		ret = TEST_SKIP;
198  		goto out;
199  	}
200  	opened = true;
201  
202  	err = perf_evsel__mmap(evsel, 0);
203  	if (err) {
204  		pr_err("failed to mmap evsel: %s\n", strerror(-err));
205  		goto out;
206  	}
207  	mapped = true;
208  
209  	pc = perf_evsel__mmap_base(evsel, 0, 0);
210  	if (!pc) {
211  		pr_err("failed to get mmapped address\n");
212  		goto out;
213  	}
214  
215  	if (!pc->cap_user_rdpmc || !pc->index) {
216  		pr_err("userspace counter access not %s\n",
217  			!pc->cap_user_rdpmc ? "supported" : "enabled");
218  		ret = TEST_SKIP;
219  		goto out;
220  	}
221  	if (pc->pmc_width < 32) {
222  		pr_err("userspace counter width not set (%d)\n", pc->pmc_width);
223  		goto out;
224  	}
225  
226  	perf_evsel__read(evsel, 0, 0, &counts);
227  	if (counts.val == 0) {
228  		pr_err("failed to read value for evsel\n");
229  		goto out;
230  	}
231  
232  	for (i = 0; i < 5; i++) {
233  		volatile int count = 0x10000 << i;
234  		__u64 start, end, last = 0;
235  
236  		pr_debug("\tloop = %u, ", count);
237  
238  		perf_evsel__read(evsel, 0, 0, &counts);
239  		start = counts.val;
240  
241  		while (count--) ;
242  
243  		perf_evsel__read(evsel, 0, 0, &counts);
244  		end = counts.val;
245  
246  		if ((end - start) < last) {
247  			pr_err("invalid counter data: end=%llu start=%llu last= %llu\n",
248  				end, start, last);
249  			goto out;
250  		}
251  		last = end - start;
252  		pr_debug("count = %llu\n", end - start);
253  	}
254  	ret = TEST_OK;
255  
256  out:
257  	if (mapped)
258  		perf_evsel__munmap(evsel);
259  	if (opened)
260  		perf_evsel__close(evsel);
261  	perf_evsel__delete(evsel);
262  
263  	perf_thread_map__put(threads);
264  	return ret;
265  }
266  
267  static int test__mmap_user_read_instr(struct test_suite *test __maybe_unused,
268  				      int subtest __maybe_unused)
269  {
270  	return test_stat_user_read(PERF_COUNT_HW_INSTRUCTIONS);
271  }
272  
273  static int test__mmap_user_read_cycles(struct test_suite *test __maybe_unused,
274  				       int subtest __maybe_unused)
275  {
276  	return test_stat_user_read(PERF_COUNT_HW_CPU_CYCLES);
277  }
278  
279  static struct test_case tests__basic_mmap[] = {
280  	TEST_CASE_REASON("Read samples using the mmap interface",
281  			 basic_mmap,
282  			 "permissions"),
283  	TEST_CASE_REASON("User space counter reading of instructions",
284  			 mmap_user_read_instr,
285  #if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
286  			 "permissions"
287  #else
288  			 "unsupported"
289  #endif
290  		),
291  	TEST_CASE_REASON("User space counter reading of cycles",
292  			 mmap_user_read_cycles,
293  #if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
294  			 "permissions"
295  #else
296  			 "unsupported"
297  #endif
298  		),
299  	{	.name = NULL, }
300  };
301  
302  struct test_suite suite__basic_mmap = {
303  	.desc = "mmap interface tests",
304  	.test_cases = tests__basic_mmap,
305  };
306