perf/tests/mmap-basic.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <errno.h>
0003 #include <inttypes.h>
0004 /* For the CLR_() macros */
0005 #include <pthread.h>
0006 #include <stdlib.h>
0007 #include <perf/cpumap.h>
0008
0009 #include "debug.h"
0010 #include "evlist.h"
0011 #include "evsel.h"
0012 #include "thread_map.h"
0013 #include "tests.h"
0014 #include "util/mmap.h"
0015 #include <linux/err.h>
0016 #include <linux/kernel.h>
0017 #include <linux/string.h>
0018 #include <perf/evlist.h>
0019 #include <perf/mmap.h>
0020
0021 /*
0022  * This test will generate random numbers of calls to some getpid syscalls,
0023  * then establish an mmap for a group of events that are created to monitor
0024  * the syscalls.
0025  *
0026  * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
0027  * sample.id field to map back to its respective perf_evsel instance.
0028  *
0029  * Then it checks if the number of syscalls reported as perf events by
0030  * the kernel corresponds to the number of syscalls made.
0031  */
0032 static int test__basic_mmap(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
0033 {
0034     int err = TEST_FAIL;
0035     union perf_event *event;
0036     struct perf_thread_map *threads;
0037     struct perf_cpu_map *cpus;
0038     struct evlist *evlist;
0039     cpu_set_t cpu_set;
0040     const char *syscall_names[] = { "getsid", "getppid", "getpgid", };
0041     pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
0042 #define nsyscalls ARRAY_SIZE(syscall_names)
0043     unsigned int nr_events[nsyscalls],
0044              expected_nr_events[nsyscalls], i, j;
0045     struct evsel *evsels[nsyscalls], *evsel;
0046     char sbuf[STRERR_BUFSIZE];
0047     struct mmap *md;
0048
0049     threads = thread_map__new(-1, getpid(), UINT_MAX);
0050     if (threads == NULL) {
0051         pr_debug("thread_map__new\n");
0052         return -1;
0053     }
0054
0055     cpus = perf_cpu_map__new(NULL);
0056     if (cpus == NULL) {
0057         pr_debug("perf_cpu_map__new\n");
0058         goto out_free_threads;
0059     }
0060
0061     CPU_ZERO(&cpu_set);
0062     CPU_SET(perf_cpu_map__cpu(cpus, 0).cpu, &cpu_set);
0063     sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
0064     if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
0065         pr_debug("sched_setaffinity() failed on CPU %d: %s ",
0066              perf_cpu_map__cpu(cpus, 0).cpu,
0067              str_error_r(errno, sbuf, sizeof(sbuf)));
0068         goto out_free_cpus;
0069     }
0070
0071     evlist = evlist__new();
0072     if (evlist == NULL) {
0073         pr_debug("evlist__new\n");
0074         goto out_free_cpus;
0075     }
0076
0077     perf_evlist__set_maps(&evlist->core, cpus, threads);
0078
0079     for (i = 0; i < nsyscalls; ++i) {
0080         char name[64];
0081
0082         snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
0083         evsels[i] = evsel__newtp("syscalls", name);
0084         if (IS_ERR(evsels[i])) {
0085             pr_debug("evsel__new(%s)\n", name);
0086             if (PTR_ERR(evsels[i]) == -EACCES) {
0087                 /* Permissions failure, flag the failure as a skip. */
0088                 err = TEST_SKIP;
0089             }
0090             goto out_delete_evlist;
0091         }
0092
0093         evsels[i]->core.attr.wakeup_events = 1;
0094         evsel__set_sample_id(evsels[i], false);
0095
0096         evlist__add(evlist, evsels[i]);
0097
0098         if (evsel__open(evsels[i], cpus, threads) < 0) {
0099             pr_debug("failed to open counter: %s, "
0100                  "tweak /proc/sys/kernel/perf_event_paranoid?\n",
0101                  str_error_r(errno, sbuf, sizeof(sbuf)));
0102             goto out_delete_evlist;
0103         }
0104
0105         nr_events[i] = 0;
0106         expected_nr_events[i] = 1 + rand() % 127;
0107     }
0108
0109     if (evlist__mmap(evlist, 128) < 0) {
0110         pr_debug("failed to mmap events: %d (%s)\n", errno,
0111              str_error_r(errno, sbuf, sizeof(sbuf)));
0112         goto out_delete_evlist;
0113     }
0114
0115     for (i = 0; i < nsyscalls; ++i)
0116         for (j = 0; j < expected_nr_events[i]; ++j) {
0117             syscalls[i]();
0118         }
0119
0120     md = &evlist->mmap[0];
0121     if (perf_mmap__read_init(&md->core) < 0)
0122         goto out_init;
0123
0124     while ((event = perf_mmap__read_event(&md->core)) != NULL) {
0125         struct perf_sample sample;
0126
0127         if (event->header.type != PERF_RECORD_SAMPLE) {
0128             pr_debug("unexpected %s event\n",
0129                  perf_event__name(event->header.type));
0130             goto out_delete_evlist;
0131         }
0132
0133         err = evlist__parse_sample(evlist, event, &sample);
0134         if (err) {
0135             pr_err("Can't parse sample, err = %d\n", err);
0136             goto out_delete_evlist;
0137         }
0138
0139         err = -1;
0140         evsel = evlist__id2evsel(evlist, sample.id);
0141         if (evsel == NULL) {
0142             pr_debug("event with id %" PRIu64
0143                  " doesn't map to an evsel\n", sample.id);
0144             goto out_delete_evlist;
0145         }
0146         nr_events[evsel->core.idx]++;
0147         perf_mmap__consume(&md->core);
0148     }
0149     perf_mmap__read_done(&md->core);
0150
0151 out_init:
0152     err = 0;
0153     evlist__for_each_entry(evlist, evsel) {
0154         if (nr_events[evsel->core.idx] != expected_nr_events[evsel->core.idx]) {
0155             pr_debug("expected %d %s events, got %d\n",
0156                  expected_nr_events[evsel->core.idx],
0157                  evsel__name(evsel), nr_events[evsel->core.idx]);
0158             err = -1;
0159             goto out_delete_evlist;
0160         }
0161     }
0162
0163 out_delete_evlist:
0164     evlist__delete(evlist);
0165 out_free_cpus:
0166     perf_cpu_map__put(cpus);
0167 out_free_threads:
0168     perf_thread_map__put(threads);
0169     return err;
0170 }
0171
0172 static int test_stat_user_read(int event)
0173 {
0174     struct perf_counts_values counts = { .val = 0 };
0175     struct perf_thread_map *threads;
0176     struct perf_evsel *evsel;
0177     struct perf_event_mmap_page *pc;
0178     struct perf_event_attr attr = {
0179         .type   = PERF_TYPE_HARDWARE,
0180         .config = event,
0181 #ifdef __aarch64__
0182         .config1 = 0x2,     /* Request user access */
0183 #endif
0184     };
0185     int err, i, ret = TEST_FAIL;
0186     bool opened = false, mapped = false;
0187
0188     threads = perf_thread_map__new_dummy();
0189     TEST_ASSERT_VAL("failed to create threads", threads);
0190
0191     perf_thread_map__set_pid(threads, 0, 0);
0192
0193     evsel = perf_evsel__new(&attr);
0194     TEST_ASSERT_VAL("failed to create evsel", evsel);
0195
0196     err = perf_evsel__open(evsel, NULL, threads);
0197     if (err) {
0198         pr_err("failed to open evsel: %s\n", strerror(-err));
0199         ret = TEST_SKIP;
0200         goto out;
0201     }
0202     opened = true;
0203
0204     err = perf_evsel__mmap(evsel, 0);
0205     if (err) {
0206         pr_err("failed to mmap evsel: %s\n", strerror(-err));
0207         goto out;
0208     }
0209     mapped = true;
0210
0211     pc = perf_evsel__mmap_base(evsel, 0, 0);
0212     if (!pc) {
0213         pr_err("failed to get mmapped address\n");
0214         goto out;
0215     }
0216
0217     if (!pc->cap_user_rdpmc || !pc->index) {
0218         pr_err("userspace counter access not %s\n",
0219             !pc->cap_user_rdpmc ? "supported" : "enabled");
0220         ret = TEST_SKIP;
0221         goto out;
0222     }
0223     if (pc->pmc_width < 32) {
0224         pr_err("userspace counter width not set (%d)\n", pc->pmc_width);
0225         goto out;
0226     }
0227
0228     perf_evsel__read(evsel, 0, 0, &counts);
0229     if (counts.val == 0) {
0230         pr_err("failed to read value for evsel\n");
0231         goto out;
0232     }
0233
0234     for (i = 0; i < 5; i++) {
0235         volatile int count = 0x10000 << i;
0236         __u64 start, end, last = 0;
0237
0238         pr_debug("\tloop = %u, ", count);
0239
0240         perf_evsel__read(evsel, 0, 0, &counts);
0241         start = counts.val;
0242
0243         while (count--) ;
0244
0245         perf_evsel__read(evsel, 0, 0, &counts);
0246         end = counts.val;
0247
0248         if ((end - start) < last) {
0249             pr_err("invalid counter data: end=%llu start=%llu last= %llu\n",
0250                 end, start, last);
0251             goto out;
0252         }
0253         last = end - start;
0254         pr_debug("count = %llu\n", end - start);
0255     }
0256     ret = TEST_OK;
0257
0258 out:
0259     if (mapped)
0260         perf_evsel__munmap(evsel);
0261     if (opened)
0262         perf_evsel__close(evsel);
0263     perf_evsel__delete(evsel);
0264
0265     perf_thread_map__put(threads);
0266     return ret;
0267 }
0268
0269 static int test__mmap_user_read_instr(struct test_suite *test __maybe_unused,
0270                       int subtest __maybe_unused)
0271 {
0272     return test_stat_user_read(PERF_COUNT_HW_INSTRUCTIONS);
0273 }
0274
0275 static int test__mmap_user_read_cycles(struct test_suite *test __maybe_unused,
0276                        int subtest __maybe_unused)
0277 {
0278     return test_stat_user_read(PERF_COUNT_HW_CPU_CYCLES);
0279 }
0280
0281 static struct test_case tests__basic_mmap[] = {
0282     TEST_CASE_REASON("Read samples using the mmap interface",
0283              basic_mmap,
0284              "permissions"),
0285     TEST_CASE_REASON("User space counter reading of instructions",
0286              mmap_user_read_instr,
0287 #if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
0288              "permissions"
0289 #else
0290              "unsupported"
0291 #endif
0292         ),
0293     TEST_CASE_REASON("User space counter reading of cycles",
0294              mmap_user_read_cycles,
0295 #if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
0296              "permissions"
0297 #else
0298              "unsupported"
0299 #endif
0300         ),
0301     {   .name = NULL, }
0302 };
0303
0304 struct test_suite suite__basic_mmap = {
0305     .desc = "mmap interface tests",
0306     .test_cases = tests__basic_mmap,
0307 };