xref: /linux/tools/perf/tests/mmap-basic.c (revision 4f77c3462308c62ffe7129cc18b9ac937f44b5a5)
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_online_cpus();
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 			 (defined(__riscv) && __riscv_xlen == 64)
289 			 "permissions"
290 #else
291 			 "unsupported"
292 #endif
293 		),
294 	TEST_CASE_REASON("User space counter reading of cycles",
295 			 mmap_user_read_cycles,
296 #if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || \
297 			 (defined(__riscv) && __riscv_xlen == 64)
298 			 "permissions"
299 #else
300 			 "unsupported"
301 #endif
302 		),
303 	{	.name = NULL, }
304 };
305 
306 struct test_suite suite__basic_mmap = {
307 	.desc = "mmap interface tests",
308 	.test_cases = tests__basic_mmap,
309 };
310