LXR linux/tools/testing/selftests/bpf/prog_tests/perf

   1// SPDX-License-Identifier: GPL-2.0
   2#define _GNU_SOURCE
   3#include <pthread.h>
   4#include <sched.h>
   5#include <sys/socket.h>
   6#include <test_progs.h>
   7#include "test_perf_buffer.skel.h"
   8#include "bpf/libbpf_internal.h"
   9
  10static int duration;
  11
  12/* AddressSanitizer sometimes crashes due to data dereference below, due to
  13 * this being mmap()'ed memory. Disable instrumentation with
  14 * no_sanitize_address attribute
  15 */
  16__attribute__((no_sanitize_address))
  17static void on_sample(void *ctx, int cpu, void *data, __u32 size)
  18{
  19        int cpu_data = *(int *)data, duration = 0;
  20        cpu_set_t *cpu_seen = ctx;
  21
  22        if (cpu_data != cpu)
  23                CHECK(cpu_data != cpu, "check_cpu_data",
  24                      "cpu_data %d != cpu %d\n", cpu_data, cpu);
  25
  26        CPU_SET(cpu, cpu_seen);
  27}
  28
  29int trigger_on_cpu(int cpu)
  30{
  31        cpu_set_t cpu_set;
  32        int err;
  33
  34        CPU_ZERO(&cpu_set);
  35        CPU_SET(cpu, &cpu_set);
  36
  37        err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);
  38        if (err && CHECK(err, "set_affinity", "cpu #%d, err %d\n", cpu, err))
  39                return err;
  40
  41        usleep(1);
  42
  43        return 0;
  44}
  45
  46void test_perf_buffer(void)
  47{
  48        int err, on_len, nr_on_cpus = 0, nr_cpus, i;
  49        struct perf_buffer_opts pb_opts = {};
  50        struct test_perf_buffer *skel;
  51        cpu_set_t cpu_seen;
  52        struct perf_buffer *pb;
  53        int last_fd = -1, fd;
  54        bool *online;
  55
  56        nr_cpus = libbpf_num_possible_cpus();
  57        if (CHECK(nr_cpus < 0, "nr_cpus", "err %d\n", nr_cpus))
  58                return;
  59
  60        err = parse_cpu_mask_file("/sys/devices/system/cpu/online",
  61                                  &online, &on_len);
  62        if (CHECK(err, "nr_on_cpus", "err %d\n", err))
  63                return;
  64
  65        for (i = 0; i < on_len; i++)
  66                if (online[i])
  67                        nr_on_cpus++;
  68
  69        /* load program */
  70        skel = test_perf_buffer__open_and_load();
  71        if (CHECK(!skel, "skel_load", "skeleton open/load failed\n"))
  72                goto out_close;
  73
  74        /* attach probe */
  75        err = test_perf_buffer__attach(skel);
  76        if (CHECK(err, "attach_kprobe", "err %d\n", err))
  77                goto out_close;
  78
  79        /* set up perf buffer */
  80        pb_opts.sample_cb = on_sample;
  81        pb_opts.ctx = &cpu_seen;
  82        pb = perf_buffer__new(bpf_map__fd(skel->maps.perf_buf_map), 1, &pb_opts);
  83        if (!ASSERT_OK_PTR(pb, "perf_buf__new"))
  84                goto out_close;
  85
  86        CHECK(perf_buffer__epoll_fd(pb) < 0, "epoll_fd",
  87              "bad fd: %d\n", perf_buffer__epoll_fd(pb));
  88
  89        /* trigger kprobe on every CPU */
  90        CPU_ZERO(&cpu_seen);
  91        for (i = 0; i < nr_cpus; i++) {
  92                if (i >= on_len || !online[i]) {
  93                        printf("skipping offline CPU #%d\n", i);
  94                        continue;
  95                }
  96
  97                if (trigger_on_cpu(i))
  98                        goto out_close;
  99        }
 100
 101        /* read perf buffer */
 102        err = perf_buffer__poll(pb, 100);
 103        if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
 104                goto out_free_pb;
 105
 106        if (CHECK(CPU_COUNT(&cpu_seen) != nr_on_cpus, "seen_cpu_cnt",
 107                  "expect %d, seen %d\n", nr_on_cpus, CPU_COUNT(&cpu_seen)))
 108                goto out_free_pb;
 109
 110        if (CHECK(perf_buffer__buffer_cnt(pb) != nr_cpus, "buf_cnt",
 111                  "got %zu, expected %d\n", perf_buffer__buffer_cnt(pb), nr_cpus))
 112                goto out_close;
 113
 114        for (i = 0; i < nr_cpus; i++) {
 115                if (i >= on_len || !online[i])
 116                        continue;
 117
 118                fd = perf_buffer__buffer_fd(pb, i);
 119                CHECK(fd < 0 || last_fd == fd, "fd_check", "last fd %d == fd %d\n", last_fd, fd);
 120                last_fd = fd;
 121
 122                err = perf_buffer__consume_buffer(pb, i);
 123                if (CHECK(err, "drain_buf", "cpu %d, err %d\n", i, err))
 124                        goto out_close;
 125
 126                CPU_CLR(i, &cpu_seen);
 127                if (trigger_on_cpu(i))
 128                        goto out_close;
 129
 130                err = perf_buffer__consume_buffer(pb, i);
 131                if (CHECK(err, "consume_buf", "cpu %d, err %d\n", i, err))
 132                        goto out_close;
 133
 134                if (CHECK(!CPU_ISSET(i, &cpu_seen), "cpu_seen", "cpu %d not seen\n", i))
 135                        goto out_close;
 136        }
 137
 138out_free_pb:
 139        perf_buffer__free(pb);
 140out_close:
 141        test_perf_buffer__destroy(skel);
 142        free(online);
 143}
 144