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