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 7 #include "evlist.h" 8 #include "evsel.h" 9 #include "thread_map.h" 10 #include "cpumap.h" 11 #include "tests.h" 12 #include <linux/err.h> 13 #include <linux/kernel.h> 14 15 /* 16 * This test will generate random numbers of calls to some getpid syscalls, 17 * then establish an mmap for a group of events that are created to monitor 18 * the syscalls. 19 * 20 * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated 21 * sample.id field to map back to its respective perf_evsel instance. 22 * 23 * Then it checks if the number of syscalls reported as perf events by 24 * the kernel corresponds to the number of syscalls made. 25 */ 26 int test__basic_mmap(struct test *test __maybe_unused, int subtest __maybe_unused) 27 { 28 int err = -1; 29 union perf_event *event; 30 struct thread_map *threads; 31 struct cpu_map *cpus; 32 struct perf_evlist *evlist; 33 cpu_set_t cpu_set; 34 const char *syscall_names[] = { "getsid", "getppid", "getpgid", }; 35 pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid }; 36 #define nsyscalls ARRAY_SIZE(syscall_names) 37 unsigned int nr_events[nsyscalls], 38 expected_nr_events[nsyscalls], i, j; 39 struct perf_evsel *evsels[nsyscalls], *evsel; 40 char sbuf[STRERR_BUFSIZE]; 41 42 threads = thread_map__new(-1, getpid(), UINT_MAX); 43 if (threads == NULL) { 44 pr_debug("thread_map__new\n"); 45 return -1; 46 } 47 48 cpus = cpu_map__new(NULL); 49 if (cpus == NULL) { 50 pr_debug("cpu_map__new\n"); 51 goto out_free_threads; 52 } 53 54 CPU_ZERO(&cpu_set); 55 CPU_SET(cpus->map[0], &cpu_set); 56 sched_setaffinity(0, sizeof(cpu_set), &cpu_set); 57 if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) { 58 pr_debug("sched_setaffinity() failed on CPU %d: %s ", 59 cpus->map[0], str_error_r(errno, sbuf, sizeof(sbuf))); 60 goto out_free_cpus; 61 } 62 63 evlist = perf_evlist__new(); 64 if (evlist == NULL) { 65 pr_debug("perf_evlist__new\n"); 66 goto out_free_cpus; 67 } 68 69 perf_evlist__set_maps(evlist, cpus, threads); 70 71 for (i = 0; i < nsyscalls; ++i) { 72 char name[64]; 73 74 snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]); 75 evsels[i] = perf_evsel__newtp("syscalls", name); 76 if (IS_ERR(evsels[i])) { 77 pr_debug("perf_evsel__new\n"); 78 goto out_delete_evlist; 79 } 80 81 evsels[i]->attr.wakeup_events = 1; 82 perf_evsel__set_sample_id(evsels[i], false); 83 84 perf_evlist__add(evlist, evsels[i]); 85 86 if (perf_evsel__open(evsels[i], cpus, threads) < 0) { 87 pr_debug("failed to open counter: %s, " 88 "tweak /proc/sys/kernel/perf_event_paranoid?\n", 89 str_error_r(errno, sbuf, sizeof(sbuf))); 90 goto out_delete_evlist; 91 } 92 93 nr_events[i] = 0; 94 expected_nr_events[i] = 1 + rand() % 127; 95 } 96 97 if (perf_evlist__mmap(evlist, 128) < 0) { 98 pr_debug("failed to mmap events: %d (%s)\n", errno, 99 str_error_r(errno, sbuf, sizeof(sbuf))); 100 goto out_delete_evlist; 101 } 102 103 for (i = 0; i < nsyscalls; ++i) 104 for (j = 0; j < expected_nr_events[i]; ++j) { 105 int foo = syscalls[i](); 106 ++foo; 107 } 108 109 while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) { 110 struct perf_sample sample; 111 112 if (event->header.type != PERF_RECORD_SAMPLE) { 113 pr_debug("unexpected %s event\n", 114 perf_event__name(event->header.type)); 115 goto out_delete_evlist; 116 } 117 118 err = perf_evlist__parse_sample(evlist, event, &sample); 119 if (err) { 120 pr_err("Can't parse sample, err = %d\n", err); 121 goto out_delete_evlist; 122 } 123 124 err = -1; 125 evsel = perf_evlist__id2evsel(evlist, sample.id); 126 if (evsel == NULL) { 127 pr_debug("event with id %" PRIu64 128 " doesn't map to an evsel\n", sample.id); 129 goto out_delete_evlist; 130 } 131 nr_events[evsel->idx]++; 132 perf_evlist__mmap_consume(evlist, 0); 133 } 134 135 err = 0; 136 evlist__for_each_entry(evlist, evsel) { 137 if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) { 138 pr_debug("expected %d %s events, got %d\n", 139 expected_nr_events[evsel->idx], 140 perf_evsel__name(evsel), nr_events[evsel->idx]); 141 err = -1; 142 goto out_delete_evlist; 143 } 144 } 145 146 out_delete_evlist: 147 perf_evlist__delete(evlist); 148 cpus = NULL; 149 threads = NULL; 150 out_free_cpus: 151 cpu_map__put(cpus); 152 out_free_threads: 153 thread_map__put(threads); 154 return err; 155 } 156