xref: /linux/tools/perf/tests/mmap-basic.c (revision effa76856f2d7111f8c44de49f15ebdfccea8ccc)
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 "event.h"
9  #include "evlist.h"
10  #include "evsel.h"
11  #include "thread_map.h"
12  #include "tests.h"
13  #include "util/mmap.h"
14  #include "util/sample.h"
15  #include <linux/err.h>
16  #include <linux/kernel.h>
17  #include <linux/string.h>
18  #include <perf/evlist.h>
19  #include <perf/mmap.h>
20  
21  /*
22   * This test will generate random numbers of calls to some getpid syscalls,
23   * then establish an mmap for a group of events that are created to monitor
24   * the syscalls.
25   *
26   * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
27   * sample.id field to map back to its respective perf_evsel instance.
28   *
29   * Then it checks if the number of syscalls reported as perf events by
30   * the kernel corresponds to the number of syscalls made.
31   */
32  static int test__basic_mmap(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
33  {
34  	int err = TEST_FAIL;
35  	union perf_event *event;
36  	struct perf_thread_map *threads;
37  	struct perf_cpu_map *cpus;
38  	struct evlist *evlist;
39  	cpu_set_t cpu_set;
40  	const char *syscall_names[] = { "getsid", "getppid", "getpgid", };
41  	pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
42  #define nsyscalls ARRAY_SIZE(syscall_names)
43  	unsigned int nr_events[nsyscalls],
44  		     expected_nr_events[nsyscalls], i, j;
45  	struct evsel *evsels[nsyscalls], *evsel;
46  	char sbuf[STRERR_BUFSIZE];
47  	struct mmap *md;
48  
49  	threads = thread_map__new(-1, getpid(), UINT_MAX);
50  	if (threads == NULL) {
51  		pr_debug("thread_map__new\n");
52  		return -1;
53  	}
54  
55  	cpus = perf_cpu_map__new(NULL);
56  	if (cpus == NULL) {
57  		pr_debug("perf_cpu_map__new\n");
58  		goto out_free_threads;
59  	}
60  
61  	CPU_ZERO(&cpu_set);
62  	CPU_SET(perf_cpu_map__cpu(cpus, 0).cpu, &cpu_set);
63  	sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
64  	if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
65  		pr_debug("sched_setaffinity() failed on CPU %d: %s ",
66  			 perf_cpu_map__cpu(cpus, 0).cpu,
67  			 str_error_r(errno, sbuf, sizeof(sbuf)));
68  		goto out_free_cpus;
69  	}
70  
71  	evlist = evlist__new();
72  	if (evlist == NULL) {
73  		pr_debug("evlist__new\n");
74  		goto out_free_cpus;
75  	}
76  
77  	perf_evlist__set_maps(&evlist->core, cpus, threads);
78  
79  	for (i = 0; i < nsyscalls; ++i) {
80  		char name[64];
81  
82  		snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
83  		evsels[i] = evsel__newtp("syscalls", name);
84  		if (IS_ERR(evsels[i])) {
85  			pr_debug("evsel__new(%s)\n", name);
86  			if (PTR_ERR(evsels[i]) == -EACCES) {
87  				/* Permissions failure, flag the failure as a skip. */
88  				err = TEST_SKIP;
89  			}
90  			goto out_delete_evlist;
91  		}
92  
93  		evsels[i]->core.attr.wakeup_events = 1;
94  		evsel__set_sample_id(evsels[i], false);
95  
96  		evlist__add(evlist, evsels[i]);
97  
98  		if (evsel__open(evsels[i], cpus, threads) < 0) {
99  			pr_debug("failed to open counter: %s, "
100  				 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
101  				 str_error_r(errno, sbuf, sizeof(sbuf)));
102  			goto out_delete_evlist;
103  		}
104  
105  		nr_events[i] = 0;
106  		expected_nr_events[i] = 1 + rand() % 127;
107  	}
108  
109  	if (evlist__mmap(evlist, 128) < 0) {
110  		pr_debug("failed to mmap events: %d (%s)\n", errno,
111  			 str_error_r(errno, sbuf, sizeof(sbuf)));
112  		goto out_delete_evlist;
113  	}
114  
115  	for (i = 0; i < nsyscalls; ++i)
116  		for (j = 0; j < expected_nr_events[i]; ++j) {
117  			syscalls[i]();
118  		}
119  
120  	md = &evlist->mmap[0];
121  	if (perf_mmap__read_init(&md->core) < 0)
122  		goto out_init;
123  
124  	while ((event = perf_mmap__read_event(&md->core)) != NULL) {
125  		struct perf_sample sample;
126  
127  		if (event->header.type != PERF_RECORD_SAMPLE) {
128  			pr_debug("unexpected %s event\n",
129  				 perf_event__name(event->header.type));
130  			goto out_delete_evlist;
131  		}
132  
133  		err = evlist__parse_sample(evlist, event, &sample);
134  		if (err) {
135  			pr_err("Can't parse sample, err = %d\n", err);
136  			goto out_delete_evlist;
137  		}
138  
139  		err = -1;
140  		evsel = evlist__id2evsel(evlist, sample.id);
141  		if (evsel == NULL) {
142  			pr_debug("event with id %" PRIu64
143  				 " doesn't map to an evsel\n", sample.id);
144  			goto out_delete_evlist;
145  		}
146  		nr_events[evsel->core.idx]++;
147  		perf_mmap__consume(&md->core);
148  	}
149  	perf_mmap__read_done(&md->core);
150  
151  out_init:
152  	err = 0;
153  	evlist__for_each_entry(evlist, evsel) {
154  		if (nr_events[evsel->core.idx] != expected_nr_events[evsel->core.idx]) {
155  			pr_debug("expected %d %s events, got %d\n",
156  				 expected_nr_events[evsel->core.idx],
157  				 evsel__name(evsel), nr_events[evsel->core.idx]);
158  			err = -1;
159  			goto out_delete_evlist;
160  		}
161  	}
162  
163  out_delete_evlist:
164  	evlist__delete(evlist);
165  out_free_cpus:
166  	perf_cpu_map__put(cpus);
167  out_free_threads:
168  	perf_thread_map__put(threads);
169  	return err;
170  }
171  
172  static int test_stat_user_read(int event)
173  {
174  	struct perf_counts_values counts = { .val = 0 };
175  	struct perf_thread_map *threads;
176  	struct perf_evsel *evsel;
177  	struct perf_event_mmap_page *pc;
178  	struct perf_event_attr attr = {
179  		.type	= PERF_TYPE_HARDWARE,
180  		.config	= event,
181  #ifdef __aarch64__
182  		.config1 = 0x2,		/* Request user access */
183  #endif
184  	};
185  	int err, i, ret = TEST_FAIL;
186  	bool opened = false, mapped = false;
187  
188  	threads = perf_thread_map__new_dummy();
189  	TEST_ASSERT_VAL("failed to create threads", threads);
190  
191  	perf_thread_map__set_pid(threads, 0, 0);
192  
193  	evsel = perf_evsel__new(&attr);
194  	TEST_ASSERT_VAL("failed to create evsel", evsel);
195  
196  	err = perf_evsel__open(evsel, NULL, threads);
197  	if (err) {
198  		pr_err("failed to open evsel: %s\n", strerror(-err));
199  		ret = TEST_SKIP;
200  		goto out;
201  	}
202  	opened = true;
203  
204  	err = perf_evsel__mmap(evsel, 0);
205  	if (err) {
206  		pr_err("failed to mmap evsel: %s\n", strerror(-err));
207  		goto out;
208  	}
209  	mapped = true;
210  
211  	pc = perf_evsel__mmap_base(evsel, 0, 0);
212  	if (!pc) {
213  		pr_err("failed to get mmapped address\n");
214  		goto out;
215  	}
216  
217  	if (!pc->cap_user_rdpmc || !pc->index) {
218  		pr_err("userspace counter access not %s\n",
219  			!pc->cap_user_rdpmc ? "supported" : "enabled");
220  		ret = TEST_SKIP;
221  		goto out;
222  	}
223  	if (pc->pmc_width < 32) {
224  		pr_err("userspace counter width not set (%d)\n", pc->pmc_width);
225  		goto out;
226  	}
227  
228  	perf_evsel__read(evsel, 0, 0, &counts);
229  	if (counts.val == 0) {
230  		pr_err("failed to read value for evsel\n");
231  		goto out;
232  	}
233  
234  	for (i = 0; i < 5; i++) {
235  		volatile int count = 0x10000 << i;
236  		__u64 start, end, last = 0;
237  
238  		pr_debug("\tloop = %u, ", count);
239  
240  		perf_evsel__read(evsel, 0, 0, &counts);
241  		start = counts.val;
242  
243  		while (count--) ;
244  
245  		perf_evsel__read(evsel, 0, 0, &counts);
246  		end = counts.val;
247  
248  		if ((end - start) < last) {
249  			pr_err("invalid counter data: end=%llu start=%llu last= %llu\n",
250  				end, start, last);
251  			goto out;
252  		}
253  		last = end - start;
254  		pr_debug("count = %llu\n", end - start);
255  	}
256  	ret = TEST_OK;
257  
258  out:
259  	if (mapped)
260  		perf_evsel__munmap(evsel);
261  	if (opened)
262  		perf_evsel__close(evsel);
263  	perf_evsel__delete(evsel);
264  
265  	perf_thread_map__put(threads);
266  	return ret;
267  }
268  
269  static int test__mmap_user_read_instr(struct test_suite *test __maybe_unused,
270  				      int subtest __maybe_unused)
271  {
272  	return test_stat_user_read(PERF_COUNT_HW_INSTRUCTIONS);
273  }
274  
275  static int test__mmap_user_read_cycles(struct test_suite *test __maybe_unused,
276  				       int subtest __maybe_unused)
277  {
278  	return test_stat_user_read(PERF_COUNT_HW_CPU_CYCLES);
279  }
280  
281  static struct test_case tests__basic_mmap[] = {
282  	TEST_CASE_REASON("Read samples using the mmap interface",
283  			 basic_mmap,
284  			 "permissions"),
285  	TEST_CASE_REASON("User space counter reading of instructions",
286  			 mmap_user_read_instr,
287  #if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
288  			 "permissions"
289  #else
290  			 "unsupported"
291  #endif
292  		),
293  	TEST_CASE_REASON("User space counter reading of cycles",
294  			 mmap_user_read_cycles,
295  #if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
296  			 "permissions"
297  #else
298  			 "unsupported"
299  #endif
300  		),
301  	{	.name = NULL, }
302  };
303  
304  struct test_suite suite__basic_mmap = {
305  	.desc = "mmap interface tests",
306  	.test_cases = tests__basic_mmap,
307  };
308