1// SPDX-License-Identifier: GPL-2.0
  2#include <errno.h>
  3#include <inttypes.h>
  4/* For the CLR_() macros */
  5#include <pthread.h>
  6#include <stdlib.h>
  7#include <perf/cpumap.h>
  8
  9#include "debug.h"
 10#include "evlist.h"
 11#include "evsel.h"
 12#include "thread_map.h"
 13#include "tests.h"
 14#include "util/mmap.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 */
 32int test__basic_mmap(struct test *test __maybe_unused, int subtest __maybe_unused)
 33{
 34	int err = -1;
 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(NULL);
 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(cpus->map[0], &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			 cpus->map[0], str_error_r(errno, sbuf, sizeof(sbuf)));
 67		goto out_free_cpus;
 68	}
 69
 70	evlist = evlist__new();
 71	if (evlist == NULL) {
 72		pr_debug("perf_evlist__new\n");
 73		goto out_free_cpus;
 74	}
 75
 76	perf_evlist__set_maps(&evlist->core, cpus, threads);
 77
 78	for (i = 0; i < nsyscalls; ++i) {
 79		char name[64];
 80
 81		snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
 82		evsels[i] = evsel__newtp("syscalls", name);
 83		if (IS_ERR(evsels[i])) {
 84			pr_debug("evsel__new(%s)\n", name);
 85			goto out_delete_evlist;
 86		}
 87
 88		evsels[i]->core.attr.wakeup_events = 1;
 89		evsel__set_sample_id(evsels[i], false);
 90
 91		evlist__add(evlist, evsels[i]);
 92
 93		if (evsel__open(evsels[i], cpus, threads) < 0) {
 94			pr_debug("failed to open counter: %s, "
 95				 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
 96				 str_error_r(errno, sbuf, sizeof(sbuf)));
 97			goto out_delete_evlist;
 98		}
 99
100		nr_events[i] = 0;
101		expected_nr_events[i] = 1 + rand() % 127;
102	}
103
104	if (evlist__mmap(evlist, 128) < 0) {
105		pr_debug("failed to mmap events: %d (%s)\n", errno,
106			 str_error_r(errno, sbuf, sizeof(sbuf)));
107		goto out_delete_evlist;
108	}
109
110	for (i = 0; i < nsyscalls; ++i)
111		for (j = 0; j < expected_nr_events[i]; ++j) {
112			int foo = syscalls[i]();
113			++foo;
114		}
115
116	md = &evlist->mmap[0];
117	if (perf_mmap__read_init(&md->core) < 0)
118		goto out_init;
119
120	while ((event = perf_mmap__read_event(&md->core)) != NULL) {
121		struct perf_sample sample;
122
123		if (event->header.type != PERF_RECORD_SAMPLE) {
124			pr_debug("unexpected %s event\n",
125				 perf_event__name(event->header.type));
126			goto out_delete_evlist;
127		}
128
129		err = perf_evlist__parse_sample(evlist, event, &sample);
130		if (err) {
131			pr_err("Can't parse sample, err = %d\n", err);
132			goto out_delete_evlist;
133		}
134
135		err = -1;
136		evsel = perf_evlist__id2evsel(evlist, sample.id);
137		if (evsel == NULL) {
138			pr_debug("event with id %" PRIu64
139				 " doesn't map to an evsel\n", sample.id);
140			goto out_delete_evlist;
141		}
142		nr_events[evsel->idx]++;
143		perf_mmap__consume(&md->core);
144	}
145	perf_mmap__read_done(&md->core);
146
147out_init:
148	err = 0;
149	evlist__for_each_entry(evlist, evsel) {
150		if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
151			pr_debug("expected %d %s events, got %d\n",
152				 expected_nr_events[evsel->idx],
153				 evsel__name(evsel), nr_events[evsel->idx]);
154			err = -1;
155			goto out_delete_evlist;
156		}
157	}
158
159out_delete_evlist:
160	evlist__delete(evlist);
161	cpus	= NULL;
162	threads = NULL;
163out_free_cpus:
164	perf_cpu_map__put(cpus);
165out_free_threads:
166	perf_thread_map__put(threads);
167	return err;
168}