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 */ 32 static int test__basic_mmap(struct test_suite *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(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 goto out_delete_evlist; 87 } 88 89 evsels[i]->core.attr.wakeup_events = 1; 90 evsel__set_sample_id(evsels[i], false); 91 92 evlist__add(evlist, evsels[i]); 93 94 if (evsel__open(evsels[i], cpus, threads) < 0) { 95 pr_debug("failed to open counter: %s, " 96 "tweak /proc/sys/kernel/perf_event_paranoid?\n", 97 str_error_r(errno, sbuf, sizeof(sbuf))); 98 goto out_delete_evlist; 99 } 100 101 nr_events[i] = 0; 102 expected_nr_events[i] = 1 + rand() % 127; 103 } 104 105 if (evlist__mmap(evlist, 128) < 0) { 106 pr_debug("failed to mmap events: %d (%s)\n", errno, 107 str_error_r(errno, sbuf, sizeof(sbuf))); 108 goto out_delete_evlist; 109 } 110 111 for (i = 0; i < nsyscalls; ++i) 112 for (j = 0; j < expected_nr_events[i]; ++j) { 113 int foo = syscalls[i](); 114 ++foo; 115 } 116 117 md = &evlist->mmap[0]; 118 if (perf_mmap__read_init(&md->core) < 0) 119 goto out_init; 120 121 while ((event = perf_mmap__read_event(&md->core)) != NULL) { 122 struct perf_sample sample; 123 124 if (event->header.type != PERF_RECORD_SAMPLE) { 125 pr_debug("unexpected %s event\n", 126 perf_event__name(event->header.type)); 127 goto out_delete_evlist; 128 } 129 130 err = evlist__parse_sample(evlist, event, &sample); 131 if (err) { 132 pr_err("Can't parse sample, err = %d\n", err); 133 goto out_delete_evlist; 134 } 135 136 err = -1; 137 evsel = evlist__id2evsel(evlist, sample.id); 138 if (evsel == NULL) { 139 pr_debug("event with id %" PRIu64 140 " doesn't map to an evsel\n", sample.id); 141 goto out_delete_evlist; 142 } 143 nr_events[evsel->core.idx]++; 144 perf_mmap__consume(&md->core); 145 } 146 perf_mmap__read_done(&md->core); 147 148 out_init: 149 err = 0; 150 evlist__for_each_entry(evlist, evsel) { 151 if (nr_events[evsel->core.idx] != expected_nr_events[evsel->core.idx]) { 152 pr_debug("expected %d %s events, got %d\n", 153 expected_nr_events[evsel->core.idx], 154 evsel__name(evsel), nr_events[evsel->core.idx]); 155 err = -1; 156 goto out_delete_evlist; 157 } 158 } 159 160 out_delete_evlist: 161 evlist__delete(evlist); 162 out_free_cpus: 163 perf_cpu_map__put(cpus); 164 out_free_threads: 165 perf_thread_map__put(threads); 166 return err; 167 } 168 169 DEFINE_SUITE("Read samples using the mmap interface", basic_mmap); 170