1/* For the CLR_() macros */
  2#include <pthread.h>
  3
  4#include "evlist.h"
  5#include "evsel.h"
  6#include "thread_map.h"
  7#include "cpumap.h"
  8#include "tests.h"
  9#include <linux/err.h>
 10
 11/*
 12 * This test will generate random numbers of calls to some getpid syscalls,
 13 * then establish an mmap for a group of events that are created to monitor
 14 * the syscalls.
 15 *
 16 * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
 17 * sample.id field to map back to its respective perf_evsel instance.
 18 *
 19 * Then it checks if the number of syscalls reported as perf events by
 20 * the kernel corresponds to the number of syscalls made.
 21 */
 22int test__basic_mmap(int subtest __maybe_unused)
 23{
 24	int err = -1;
 25	union perf_event *event;
 26	struct thread_map *threads;
 27	struct cpu_map *cpus;
 28	struct perf_evlist *evlist;
 29	cpu_set_t cpu_set;
 30	const char *syscall_names[] = { "getsid", "getppid", "getpgid", };
 31	pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
 32#define nsyscalls ARRAY_SIZE(syscall_names)
 33	unsigned int nr_events[nsyscalls],
 34		     expected_nr_events[nsyscalls], i, j;
 35	struct perf_evsel *evsels[nsyscalls], *evsel;
 36	char sbuf[STRERR_BUFSIZE];
 37
 38	threads = thread_map__new(-1, getpid(), UINT_MAX);
 39	if (threads == NULL) {
 40		pr_debug("thread_map__new\n");
 41		return -1;
 42	}
 43
 44	cpus = cpu_map__new(NULL);
 45	if (cpus == NULL) {
 46		pr_debug("cpu_map__new\n");
 47		goto out_free_threads;
 48	}
 49
 50	CPU_ZERO(&cpu_set);
 51	CPU_SET(cpus->map[0], &cpu_set);
 52	sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
 53	if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
 54		pr_debug("sched_setaffinity() failed on CPU %d: %s ",
 55			 cpus->map[0], str_error_r(errno, sbuf, sizeof(sbuf)));
 56		goto out_free_cpus;
 57	}
 58
 59	evlist = perf_evlist__new();
 60	if (evlist == NULL) {
 61		pr_debug("perf_evlist__new\n");
 62		goto out_free_cpus;
 63	}
 64
 65	perf_evlist__set_maps(evlist, cpus, threads);
 66
 67	for (i = 0; i < nsyscalls; ++i) {
 68		char name[64];
 69
 70		snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
 71		evsels[i] = perf_evsel__newtp("syscalls", name);
 72		if (IS_ERR(evsels[i])) {
 73			pr_debug("perf_evsel__new\n");
 74			goto out_delete_evlist;
 75		}
 76
 77		evsels[i]->attr.wakeup_events = 1;
 78		perf_evsel__set_sample_id(evsels[i], false);
 79
 80		perf_evlist__add(evlist, evsels[i]);
 81
 82		if (perf_evsel__open(evsels[i], cpus, threads) < 0) {
 83			pr_debug("failed to open counter: %s, "
 84				 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
 85				 str_error_r(errno, sbuf, sizeof(sbuf)));
 86			goto out_delete_evlist;
 87		}
 88
 89		nr_events[i] = 0;
 90		expected_nr_events[i] = 1 + rand() % 127;
 91	}
 92
 93	if (perf_evlist__mmap(evlist, 128, true) < 0) {
 94		pr_debug("failed to mmap events: %d (%s)\n", errno,
 95			 str_error_r(errno, sbuf, sizeof(sbuf)));
 96		goto out_delete_evlist;
 97	}
 98
 99	for (i = 0; i < nsyscalls; ++i)
100		for (j = 0; j < expected_nr_events[i]; ++j) {
101			int foo = syscalls[i]();
102			++foo;
103		}
104
105	while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
106		struct perf_sample sample;
107
108		if (event->header.type != PERF_RECORD_SAMPLE) {
109			pr_debug("unexpected %s event\n",
110				 perf_event__name(event->header.type));
111			goto out_delete_evlist;
112		}
113
114		err = perf_evlist__parse_sample(evlist, event, &sample);
115		if (err) {
116			pr_err("Can't parse sample, err = %d\n", err);
117			goto out_delete_evlist;
118		}
119
120		err = -1;
121		evsel = perf_evlist__id2evsel(evlist, sample.id);
122		if (evsel == NULL) {
123			pr_debug("event with id %" PRIu64
124				 " doesn't map to an evsel\n", sample.id);
125			goto out_delete_evlist;
126		}
127		nr_events[evsel->idx]++;
128		perf_evlist__mmap_consume(evlist, 0);
129	}
130
131	err = 0;
132	evlist__for_each_entry(evlist, evsel) {
133		if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
134			pr_debug("expected %d %s events, got %d\n",
135				 expected_nr_events[evsel->idx],
136				 perf_evsel__name(evsel), nr_events[evsel->idx]);
137			err = -1;
138			goto out_delete_evlist;
139		}
140	}
141
142out_delete_evlist:
143	perf_evlist__delete(evlist);
144	cpus	= NULL;
145	threads = NULL;
146out_free_cpus:
147	cpu_map__put(cpus);
148out_free_threads:
149	thread_map__put(threads);
150	return err;
151}