root/tools/testing/selftests/bpf/prog_tests/task_fd_query_tp.c

DEFINITIONS

1. test_task_fd_query_tp_core
2. test_task_fd_query_tp

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <test_progs.h>
   3 
   4 static void test_task_fd_query_tp_core(const char *probe_name,
   5                                        const char *tp_name)
   6 {
   7         const char *file = "./test_tracepoint.o";
   8         int err, bytes, efd, prog_fd, pmu_fd;
   9         struct perf_event_attr attr = {};
  10         __u64 probe_offset, probe_addr;
  11         __u32 len, prog_id, fd_type;
  12         struct bpf_object *obj = NULL;
  13         __u32 duration = 0;
  14         char buf[256];
  15 
  16         err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
  17         if (CHECK(err, "bpf_prog_load", "err %d errno %d\n", err, errno))
  18                 goto close_prog;
  19 
  20         snprintf(buf, sizeof(buf),
  21                  "/sys/kernel/debug/tracing/events/%s/id", probe_name);
  22         efd = open(buf, O_RDONLY, 0);
  23         if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno))
  24                 goto close_prog;
  25         bytes = read(efd, buf, sizeof(buf));
  26         close(efd);
  27         if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "read",
  28                   "bytes %d errno %d\n", bytes, errno))
  29                 goto close_prog;
  30 
  31         attr.config = strtol(buf, NULL, 0);
  32         attr.type = PERF_TYPE_TRACEPOINT;
  33         attr.sample_type = PERF_SAMPLE_RAW;
  34         attr.sample_period = 1;
  35         attr.wakeup_events = 1;
  36         pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
  37                          0 /* cpu 0 */, -1 /* group id */,
  38                          0 /* flags */);
  39         if (CHECK(err, "perf_event_open", "err %d errno %d\n", err, errno))
  40                 goto close_pmu;
  41 
  42         err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
  43         if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n", err,
  44                   errno))
  45                 goto close_pmu;
  46 
  47         err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
  48         if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n", err,
  49                   errno))
  50                 goto close_pmu;
  51 
  52         /* query (getpid(), pmu_fd) */
  53         len = sizeof(buf);
  54         err = bpf_task_fd_query(getpid(), pmu_fd, 0, buf, &len, &prog_id,
  55                                 &fd_type, &probe_offset, &probe_addr);
  56         if (CHECK(err < 0, "bpf_task_fd_query", "err %d errno %d\n", err,
  57                   errno))
  58                 goto close_pmu;
  59 
  60         err = (fd_type == BPF_FD_TYPE_TRACEPOINT) && !strcmp(buf, tp_name);
  61         if (CHECK(!err, "check_results", "fd_type %d tp_name %s\n",
  62                   fd_type, buf))
  63                 goto close_pmu;
  64 
  65 close_pmu:
  66         close(pmu_fd);
  67 close_prog:
  68         bpf_object__close(obj);
  69 }
  70 
  71 void test_task_fd_query_tp(void)
  72 {
  73         test_task_fd_query_tp_core("sched/sched_switch",
  74                                    "sched_switch");
  75         test_task_fd_query_tp_core("syscalls/sys_enter_read",
  76                                    "sys_enter_read");
  77 }