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 struct perf_mmap *md; 42 43 threads = thread_map__new(-1, getpid(), UINT_MAX); 44 if (threads == NULL) { 45 pr_debug("thread_map__new\n"); 46 return -1; 47 } 48 49 cpus = cpu_map__new(NULL); 50 if (cpus == NULL) { 51 pr_debug("cpu_map__new\n"); 52 goto out_free_threads; 53 } 54 55 CPU_ZERO(&cpu_set); 56 CPU_SET(cpus->map[0], &cpu_set); 57 sched_setaffinity(0, sizeof(cpu_set), &cpu_set); 58 if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) { 59 pr_debug("sched_setaffinity() failed on CPU %d: %s ", 60 cpus->map[0], str_error_r(errno, sbuf, sizeof(sbuf))); 61 goto out_free_cpus; 62 } 63 64 evlist = perf_evlist__new(); 65 if (evlist == NULL) { 66 pr_debug("perf_evlist__new\n"); 67 goto out_free_cpus; 68 } 69 70 perf_evlist__set_maps(evlist, cpus, threads); 71 72 for (i = 0; i < nsyscalls; ++i) { 73 char name[64]; 74 75 snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]); 76 evsels[i] = perf_evsel__newtp("syscalls", name); 77 if (IS_ERR(evsels[i])) { 78 pr_debug("perf_evsel__new(%s)\n", name); 79 goto out_delete_evlist; 80 } 81 82 evsels[i]->attr.wakeup_events = 1; 83 perf_evsel__set_sample_id(evsels[i], false); 84 85 perf_evlist__add(evlist, evsels[i]); 86 87 if (perf_evsel__open(evsels[i], cpus, threads) < 0) { 88 pr_debug("failed to open counter: %s, " 89 "tweak /proc/sys/kernel/perf_event_paranoid?\n", 90 str_error_r(errno, sbuf, sizeof(sbuf))); 91 goto out_delete_evlist; 92 } 93 94 nr_events[i] = 0; 95 expected_nr_events[i] = 1 + rand() % 127; 96 } 97 98 if (perf_evlist__mmap(evlist, 128) < 0) { 99 pr_debug("failed to mmap events: %d (%s)\n", errno, 100 str_error_r(errno, sbuf, sizeof(sbuf))); 101 goto out_delete_evlist; 102 } 103 104 for (i = 0; i < nsyscalls; ++i) 105 for (j = 0; j < expected_nr_events[i]; ++j) { 106 int foo = syscalls[i](); 107 ++foo; 108 } 109 110 md = &evlist->mmap[0]; 111 if (perf_mmap__read_init(md) < 0) 112 goto out_init; 113 114 while ((event = perf_mmap__read_event(md)) != NULL) { 115 struct perf_sample sample; 116 117 if (event->header.type != PERF_RECORD_SAMPLE) { 118 pr_debug("unexpected %s event\n", 119 perf_event__name(event->header.type)); 120 goto out_delete_evlist; 121 } 122 123 err = perf_evlist__parse_sample(evlist, event, &sample); 124 if (err) { 125 pr_err("Can't parse sample, err = %d\n", err); 126 goto out_delete_evlist; 127 } 128 129 err = -1; 130 evsel = perf_evlist__id2evsel(evlist, sample.id); 131 if (evsel == NULL) { 132 pr_debug("event with id %" PRIu64 133 " doesn't map to an evsel\n", sample.id); 134 goto out_delete_evlist; 135 } 136 nr_events[evsel->idx]++; 137 perf_mmap__consume(md); 138 } 139 perf_mmap__read_done(md); 140 141 out_init: 142 err = 0; 143 evlist__for_each_entry(evlist, evsel) { 144 if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) { 145 pr_debug("expected %d %s events, got %d\n", 146 expected_nr_events[evsel->idx], 147 perf_evsel__name(evsel), nr_events[evsel->idx]); 148 err = -1; 149 goto out_delete_evlist; 150 } 151 } 152 153 out_delete_evlist: 154 perf_evlist__delete(evlist); 155 cpus = NULL; 156 threads = NULL; 157 out_free_cpus: 158 cpu_map__put(cpus); 159 out_free_threads: 160 thread_map__put(threads); 161 return err; 162 } 163