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