tools/testing/selftests/bpf/prog_tests/tp_attach_query.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <test_progs.h>
   3
   4 void test_tp_attach_query(void)
   5 {
   6         const int num_progs = 3;
   7         int i, j, bytes, efd, err, prog_fd[num_progs], pmu_fd[num_progs];
   8         __u32 duration = 0, info_len, saved_prog_ids[num_progs];
   9         const char *file = "./test_tracepoint.o";
  10         struct perf_event_query_bpf *query;
  11         struct perf_event_attr attr = {};
  12         struct bpf_object *obj[num_progs];
  13         struct bpf_prog_info prog_info;
  14         char buf[256];
  15
  16         snprintf(buf, sizeof(buf),
  17                  "/sys/kernel/debug/tracing/events/sched/sched_switch/id");
  18         efd = open(buf, O_RDONLY, 0);
  19         if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno))
  20                 return;
  21         bytes = read(efd, buf, sizeof(buf));
  22         close(efd);
  23         if (CHECK(bytes <= 0 || bytes >= sizeof(buf),
  24                   "read", "bytes %d errno %d\n", bytes, errno))
  25                 return;
  26
  27         attr.config = strtol(buf, NULL, 0);
  28         attr.type = PERF_TYPE_TRACEPOINT;
  29         attr.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CALLCHAIN;
  30         attr.sample_period = 1;
  31         attr.wakeup_events = 1;
  32
  33         query = malloc(sizeof(*query) + sizeof(__u32) * num_progs);
  34         for (i = 0; i < num_progs; i++) {
  35                 err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj[i],
  36                                     &prog_fd[i]);
  37                 if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno))
  38                         goto cleanup1;
  39
  40                 bzero(&prog_info, sizeof(prog_info));
  41                 prog_info.jited_prog_len = 0;
  42                 prog_info.xlated_prog_len = 0;
  43                 prog_info.nr_map_ids = 0;
  44                 info_len = sizeof(prog_info);
  45                 err = bpf_obj_get_info_by_fd(prog_fd[i], &prog_info, &info_len);
  46                 if (CHECK(err, "bpf_obj_get_info_by_fd", "err %d errno %d\n",
  47                           err, errno))
  48                         goto cleanup1;
  49                 saved_prog_ids[i] = prog_info.id;
  50
  51                 pmu_fd[i] = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
  52                                     0 /* cpu 0 */, -1 /* group id */,
  53                                     0 /* flags */);
  54                 if (CHECK(pmu_fd[i] < 0, "perf_event_open", "err %d errno %d\n",
  55                           pmu_fd[i], errno))
  56                         goto cleanup2;
  57                 err = ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0);
  58                 if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n",
  59                           err, errno))
  60                         goto cleanup3;
  61
  62                 if (i == 0) {
  63                         /* check NULL prog array query */
  64                         query->ids_len = num_progs;
  65                         err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF, query);
  66                         if (CHECK(err || query->prog_cnt != 0,
  67                                   "perf_event_ioc_query_bpf",
  68                                   "err %d errno %d query->prog_cnt %u\n",
  69                                   err, errno, query->prog_cnt))
  70                                 goto cleanup3;
  71                 }
  72
  73                 err = ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[i]);
  74                 if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n",
  75                           err, errno))
  76                         goto cleanup3;
  77
  78                 if (i == 1) {
  79                         /* try to get # of programs only */
  80                         query->ids_len = 0;
  81                         err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF, query);
  82                         if (CHECK(err || query->prog_cnt != 2,
  83                                   "perf_event_ioc_query_bpf",
  84                                   "err %d errno %d query->prog_cnt %u\n",
  85                                   err, errno, query->prog_cnt))
  86                                 goto cleanup3;
  87
  88                         /* try a few negative tests */
  89                         /* invalid query pointer */
  90                         err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF,
  91                                     (struct perf_event_query_bpf *)0x1);
  92                         if (CHECK(!err || errno != EFAULT,
  93                                   "perf_event_ioc_query_bpf",
  94                                   "err %d errno %d\n", err, errno))
  95                                 goto cleanup3;
  96
  97                         /* no enough space */
  98                         query->ids_len = 1;
  99                         err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF, query);
 100                         if (CHECK(!err || errno != ENOSPC || query->prog_cnt != 2,
 101                                   "perf_event_ioc_query_bpf",
 102                                   "err %d errno %d query->prog_cnt %u\n",
 103                                   err, errno, query->prog_cnt))
 104                                 goto cleanup3;
 105                 }
 106
 107                 query->ids_len = num_progs;
 108                 err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF, query);
 109                 if (CHECK(err || query->prog_cnt != (i + 1),
 110                           "perf_event_ioc_query_bpf",
 111                           "err %d errno %d query->prog_cnt %u\n",
 112                           err, errno, query->prog_cnt))
 113                         goto cleanup3;
 114                 for (j = 0; j < i + 1; j++)
 115                         if (CHECK(saved_prog_ids[j] != query->ids[j],
 116                                   "perf_event_ioc_query_bpf",
 117                                   "#%d saved_prog_id %x query prog_id %x\n",
 118                                   j, saved_prog_ids[j], query->ids[j]))
 119                                 goto cleanup3;
 120         }
 121
 122         i = num_progs - 1;
 123         for (; i >= 0; i--) {
 124  cleanup3:
 125                 ioctl(pmu_fd[i], PERF_EVENT_IOC_DISABLE);
 126  cleanup2:
 127                 close(pmu_fd[i]);
 128  cleanup1:
 129                 bpf_object__close(obj[i]);
 130         }
 131         free(query);
 132 }