xref: /linux/tools/perf/tests/mmap-basic.c (revision 4f9786035f9e519db41375818e1d0b5f20da2f10)
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 		perf_sample__init(&sample, /*all=*/false);
134 		err = evlist__parse_sample(evlist, event, &sample);
135 		if (err) {
136 			pr_err("Can't parse sample, err = %d\n", err);
137 			perf_sample__exit(&sample);
138 			goto out_delete_evlist;
139 		}
140 
141 		err = -1;
142 		evsel = evlist__id2evsel(evlist, sample.id);
143 		perf_sample__exit(&sample);
144 		if (evsel == NULL) {
145 			pr_debug("event with id %" PRIu64
146 				 " doesn't map to an evsel\n", sample.id);
147 			goto out_delete_evlist;
148 		}
149 		nr_events[evsel->core.idx]++;
150 		perf_mmap__consume(&md->core);
151 	}
152 	perf_mmap__read_done(&md->core);
153 
154 out_init:
155 	err = 0;
156 	evlist__for_each_entry(evlist, evsel) {
157 		if (nr_events[evsel->core.idx] != expected_nr_events[evsel->core.idx]) {
158 			pr_debug("expected %d %s events, got %d\n",
159 				 expected_nr_events[evsel->core.idx],
160 				 evsel__name(evsel), nr_events[evsel->core.idx]);
161 			err = -1;
162 			goto out_delete_evlist;
163 		}
164 	}
165 
166 out_delete_evlist:
167 	evlist__delete(evlist);
168 out_free_cpus:
169 	perf_cpu_map__put(cpus);
170 out_free_threads:
171 	perf_thread_map__put(threads);
172 	return err;
173 }
174 
175 static int test_stat_user_read(int event)
176 {
177 	struct perf_counts_values counts = { .val = 0 };
178 	struct perf_thread_map *threads;
179 	struct perf_evsel *evsel;
180 	struct perf_event_mmap_page *pc;
181 	struct perf_event_attr attr = {
182 		.type	= PERF_TYPE_HARDWARE,
183 		.config	= event,
184 #ifdef __aarch64__
185 		.config1 = 0x2,		/* Request user access */
186 #endif
187 	};
188 	int err, i, ret = TEST_FAIL;
189 	bool opened = false, mapped = false;
190 
191 	threads = perf_thread_map__new_dummy();
192 	TEST_ASSERT_VAL("failed to create threads", threads);
193 
194 	perf_thread_map__set_pid(threads, 0, 0);
195 
196 	evsel = perf_evsel__new(&attr);
197 	TEST_ASSERT_VAL("failed to create evsel", evsel);
198 
199 	err = perf_evsel__open(evsel, NULL, threads);
200 	if (err) {
201 		pr_err("failed to open evsel: %s\n", strerror(-err));
202 		ret = TEST_SKIP;
203 		goto out;
204 	}
205 	opened = true;
206 
207 	err = perf_evsel__mmap(evsel, 0);
208 	if (err) {
209 		pr_err("failed to mmap evsel: %s\n", strerror(-err));
210 		goto out;
211 	}
212 	mapped = true;
213 
214 	pc = perf_evsel__mmap_base(evsel, 0, 0);
215 	if (!pc) {
216 		pr_err("failed to get mmapped address\n");
217 		goto out;
218 	}
219 
220 	if (!pc->cap_user_rdpmc || !pc->index) {
221 		pr_err("userspace counter access not %s\n",
222 			!pc->cap_user_rdpmc ? "supported" : "enabled");
223 		ret = TEST_SKIP;
224 		goto out;
225 	}
226 	if (pc->pmc_width < 32) {
227 		pr_err("userspace counter width not set (%d)\n", pc->pmc_width);
228 		goto out;
229 	}
230 
231 	perf_evsel__read(evsel, 0, 0, &counts);
232 	if (counts.val == 0) {
233 		pr_err("failed to read value for evsel\n");
234 		goto out;
235 	}
236 
237 	for (i = 0; i < 5; i++) {
238 		volatile int count = 0x10000 << i;
239 		__u64 start, end, last = 0;
240 
241 		pr_debug("\tloop = %u, ", count);
242 
243 		perf_evsel__read(evsel, 0, 0, &counts);
244 		start = counts.val;
245 
246 		while (count--) ;
247 
248 		perf_evsel__read(evsel, 0, 0, &counts);
249 		end = counts.val;
250 
251 		if ((end - start) < last) {
252 			pr_err("invalid counter data: end=%llu start=%llu last= %llu\n",
253 				end, start, last);
254 			goto out;
255 		}
256 		last = end - start;
257 		pr_debug("count = %llu\n", end - start);
258 	}
259 	ret = TEST_OK;
260 
261 out:
262 	if (mapped)
263 		perf_evsel__munmap(evsel);
264 	if (opened)
265 		perf_evsel__close(evsel);
266 	perf_evsel__delete(evsel);
267 
268 	perf_thread_map__put(threads);
269 	return ret;
270 }
271 
272 static int test__mmap_user_read_instr(struct test_suite *test __maybe_unused,
273 				      int subtest __maybe_unused)
274 {
275 	return test_stat_user_read(PERF_COUNT_HW_INSTRUCTIONS);
276 }
277 
278 static int test__mmap_user_read_cycles(struct test_suite *test __maybe_unused,
279 				       int subtest __maybe_unused)
280 {
281 	return test_stat_user_read(PERF_COUNT_HW_CPU_CYCLES);
282 }
283 
284 static struct test_case tests__basic_mmap[] = {
285 	TEST_CASE_REASON("Read samples using the mmap interface",
286 			 basic_mmap,
287 			 "permissions"),
288 	TEST_CASE_REASON("User space counter reading of instructions",
289 			 mmap_user_read_instr,
290 #if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || \
291 			 (defined(__riscv) && __riscv_xlen == 64)
292 			 "permissions"
293 #else
294 			 "unsupported"
295 #endif
296 		),
297 	TEST_CASE_REASON("User space counter reading of cycles",
298 			 mmap_user_read_cycles,
299 #if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || \
300 			 (defined(__riscv) && __riscv_xlen == 64)
301 			 "permissions"
302 #else
303 			 "unsupported"
304 #endif
305 		),
306 	{	.name = NULL, }
307 };
308 
309 struct test_suite suite__basic_mmap = {
310 	.desc = "mmap interface tests",
311 	.test_cases = tests__basic_mmap,
312 };
313