tools/perf/tests/mmap-basic.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <errno.h>
   3 #include <inttypes.h>
   4 #include <stdlib.h>
   5 #include <perf/cpumap.h>
   6
   7 #include "debug.h"
   8 #include "event.h"
   9 #include "evlist.h"
  10 #include "evsel.h"
  11 #include "thread_map.h"
  12 #include "tests.h"
  13 #include "util/mmap.h"
  14 #include "util/sample.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 = TEST_FAIL;
  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_online_cpus();
  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                         if (PTR_ERR(evsels[i]) == -EACCES) {
  87                                 /* Permissions failure, flag the failure as a skip. */
  88                                 err = TEST_SKIP;
  89                         }
  90                         goto out_delete_evlist;
  91                 }
  92
  93                 evsels[i]->core.attr.wakeup_events = 1;
  94                 evsel__set_sample_id(evsels[i], false);
  95
  96                 evlist__add(evlist, evsels[i]);
  97
  98                 if (evsel__open(evsels[i], cpus, threads) < 0) {
  99                         pr_debug("failed to open counter: %s, "
 100                                  "tweak /proc/sys/kernel/perf_event_paranoid?\n",
 101                                  str_error_r(errno, sbuf, sizeof(sbuf)));
 102                         goto out_delete_evlist;
 103                 }
 104
 105                 nr_events[i] = 0;
 106                 expected_nr_events[i] = 1 + rand() % 127;
 107         }
 108
 109         if (evlist__mmap(evlist, 128) < 0) {
 110                 pr_debug("failed to mmap events: %d (%s)\n", errno,
 111                          str_error_r(errno, sbuf, sizeof(sbuf)));
 112                 goto out_delete_evlist;
 113         }
 114
 115         for (i = 0; i < nsyscalls; ++i)
 116                 for (j = 0; j < expected_nr_events[i]; ++j) {
 117                         syscalls[i]();
 118                 }
 119
 120         md = &evlist->mmap[0];
 121         if (perf_mmap__read_init(&md->core) < 0)
 122                 goto out_init;
 123
 124         while ((event = perf_mmap__read_event(&md->core)) != NULL) {
 125                 struct perf_sample sample;
 126
 127                 if (event->header.type != PERF_RECORD_SAMPLE) {
 128                         pr_debug("unexpected %s event\n",
 129                                  perf_event__name(event->header.type));
 130                         goto out_delete_evlist;
 131                 }
 132
 133                 err = evlist__parse_sample(evlist, event, &sample);
 134                 if (err) {
 135                         pr_err("Can't parse sample, err = %d\n", err);
 136                         goto out_delete_evlist;
 137                 }
 138
 139                 err = -1;
 140                 evsel = evlist__id2evsel(evlist, sample.id);
 141                 if (evsel == NULL) {
 142                         pr_debug("event with id %" PRIu64
 143                                  " doesn't map to an evsel\n", sample.id);
 144                         goto out_delete_evlist;
 145                 }
 146                 nr_events[evsel->core.idx]++;
 147                 perf_mmap__consume(&md->core);
 148         }
 149         perf_mmap__read_done(&md->core);
 150
 151 out_init:
 152         err = 0;
 153         evlist__for_each_entry(evlist, evsel) {
 154                 if (nr_events[evsel->core.idx] != expected_nr_events[evsel->core.idx]) {
 155                         pr_debug("expected %d %s events, got %d\n",
 156                                  expected_nr_events[evsel->core.idx],
 157                                  evsel__name(evsel), nr_events[evsel->core.idx]);
 158                         err = -1;
 159                         goto out_delete_evlist;
 160                 }
 161         }
 162
 163 out_delete_evlist:
 164         evlist__delete(evlist);
 165 out_free_cpus:
 166         perf_cpu_map__put(cpus);
 167 out_free_threads:
 168         perf_thread_map__put(threads);
 169         return err;
 170 }
 171
 172 static int test_stat_user_read(int event)
 173 {
 174         struct perf_counts_values counts = { .val = 0 };
 175         struct perf_thread_map *threads;
 176         struct perf_evsel *evsel;
 177         struct perf_event_mmap_page *pc;
 178         struct perf_event_attr attr = {
 179                 .type   = PERF_TYPE_HARDWARE,
 180                 .config = event,
 181 #ifdef __aarch64__
 182                 .config1 = 0x2,         /* Request user access */
 183 #endif
 184         };
 185         int err, i, ret = TEST_FAIL;
 186         bool opened = false, mapped = false;
 187
 188         threads = perf_thread_map__new_dummy();
 189         TEST_ASSERT_VAL("failed to create threads", threads);
 190
 191         perf_thread_map__set_pid(threads, 0, 0);
 192
 193         evsel = perf_evsel__new(&attr);
 194         TEST_ASSERT_VAL("failed to create evsel", evsel);
 195
 196         err = perf_evsel__open(evsel, NULL, threads);
 197         if (err) {
 198                 pr_err("failed to open evsel: %s\n", strerror(-err));
 199                 ret = TEST_SKIP;
 200                 goto out;
 201         }
 202         opened = true;
 203
 204         err = perf_evsel__mmap(evsel, 0);
 205         if (err) {
 206                 pr_err("failed to mmap evsel: %s\n", strerror(-err));
 207                 goto out;
 208         }
 209         mapped = true;
 210
 211         pc = perf_evsel__mmap_base(evsel, 0, 0);
 212         if (!pc) {
 213                 pr_err("failed to get mmapped address\n");
 214                 goto out;
 215         }
 216
 217         if (!pc->cap_user_rdpmc || !pc->index) {
 218                 pr_err("userspace counter access not %s\n",
 219                         !pc->cap_user_rdpmc ? "supported" : "enabled");
 220                 ret = TEST_SKIP;
 221                 goto out;
 222         }
 223         if (pc->pmc_width < 32) {
 224                 pr_err("userspace counter width not set (%d)\n", pc->pmc_width);
 225                 goto out;
 226         }
 227
 228         perf_evsel__read(evsel, 0, 0, &counts);
 229         if (counts.val == 0) {
 230                 pr_err("failed to read value for evsel\n");
 231                 goto out;
 232         }
 233
 234         for (i = 0; i < 5; i++) {
 235                 volatile int count = 0x10000 << i;
 236                 __u64 start, end, last = 0;
 237
 238                 pr_debug("\tloop = %u, ", count);
 239
 240                 perf_evsel__read(evsel, 0, 0, &counts);
 241                 start = counts.val;
 242
 243                 while (count--) ;
 244
 245                 perf_evsel__read(evsel, 0, 0, &counts);
 246                 end = counts.val;
 247
 248                 if ((end - start) < last) {
 249                         pr_err("invalid counter data: end=%llu start=%llu last= %llu\n",
 250                                 end, start, last);
 251                         goto out;
 252                 }
 253                 last = end - start;
 254                 pr_debug("count = %llu\n", end - start);
 255         }
 256         ret = TEST_OK;
 257
 258 out:
 259         if (mapped)
 260                 perf_evsel__munmap(evsel);
 261         if (opened)
 262                 perf_evsel__close(evsel);
 263         perf_evsel__delete(evsel);
 264
 265         perf_thread_map__put(threads);
 266         return ret;
 267 }
 268
 269 static int test__mmap_user_read_instr(struct test_suite *test __maybe_unused,
 270                                       int subtest __maybe_unused)
 271 {
 272         return test_stat_user_read(PERF_COUNT_HW_INSTRUCTIONS);
 273 }
 274
 275 static int test__mmap_user_read_cycles(struct test_suite *test __maybe_unused,
 276                                        int subtest __maybe_unused)
 277 {
 278         return test_stat_user_read(PERF_COUNT_HW_CPU_CYCLES);
 279 }
 280
 281 static struct test_case tests__basic_mmap[] = {
 282         TEST_CASE_REASON("Read samples using the mmap interface",
 283                          basic_mmap,
 284                          "permissions"),
 285         TEST_CASE_REASON("User space counter reading of instructions",
 286                          mmap_user_read_instr,
 287 #if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || \
 288                          (defined(__riscv) && __riscv_xlen == 64)
 289                          "permissions"
 290 #else
 291                          "unsupported"
 292 #endif
 293                 ),
 294         TEST_CASE_REASON("User space counter reading of cycles",
 295                          mmap_user_read_cycles,
 296 #if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || \
 297                          (defined(__riscv) && __riscv_xlen == 64)
 298                          "permissions"
 299 #else
 300                          "unsupported"
 301 #endif
 302                 ),
 303         {       .name = NULL, }
 304 };
 305
 306 struct test_suite suite__basic_mmap = {
 307         .desc = "mmap interface tests",
 308         .test_cases = tests__basic_mmap,
 309 };