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

   1// SPDX-License-Identifier: GPL-2.0
   2#include <test_progs.h>
   3
   4void test_stacktrace_map(void)
   5{
   6        int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd;
   7        const char *prog_name = "tracepoint/sched/sched_switch";
   8        int err, prog_fd, stack_trace_len;
   9        const char *file = "./test_stacktrace_map.o";
  10        __u32 key, val, duration = 0;
  11        struct bpf_program *prog;
  12        struct bpf_object *obj;
  13        struct bpf_link *link;
  14
  15        err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
  16        if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno))
  17                return;
  18
  19        prog = bpf_object__find_program_by_title(obj, prog_name);
  20        if (CHECK(!prog, "find_prog", "prog '%s' not found\n", prog_name))
  21                goto close_prog;
  22
  23        link = bpf_program__attach_tracepoint(prog, "sched", "sched_switch");
  24        if (CHECK(IS_ERR(link), "attach_tp", "err %ld\n", PTR_ERR(link)))
  25                goto close_prog;
  26
  27        /* find map fds */
  28        control_map_fd = bpf_find_map(__func__, obj, "control_map");
  29        if (CHECK_FAIL(control_map_fd < 0))
  30                goto disable_pmu;
  31
  32        stackid_hmap_fd = bpf_find_map(__func__, obj, "stackid_hmap");
  33        if (CHECK_FAIL(stackid_hmap_fd < 0))
  34                goto disable_pmu;
  35
  36        stackmap_fd = bpf_find_map(__func__, obj, "stackmap");
  37        if (CHECK_FAIL(stackmap_fd < 0))
  38                goto disable_pmu;
  39
  40        stack_amap_fd = bpf_find_map(__func__, obj, "stack_amap");
  41        if (CHECK_FAIL(stack_amap_fd < 0))
  42                goto disable_pmu;
  43
  44        /* give some time for bpf program run */
  45        sleep(1);
  46
  47        /* disable stack trace collection */
  48        key = 0;
  49        val = 1;
  50        bpf_map_update_elem(control_map_fd, &key, &val, 0);
  51
  52        /* for every element in stackid_hmap, we can find a corresponding one
  53         * in stackmap, and vise versa.
  54         */
  55        err = compare_map_keys(stackid_hmap_fd, stackmap_fd);
  56        if (CHECK(err, "compare_map_keys stackid_hmap vs. stackmap",
  57                  "err %d errno %d\n", err, errno))
  58                goto disable_pmu;
  59
  60        err = compare_map_keys(stackmap_fd, stackid_hmap_fd);
  61        if (CHECK(err, "compare_map_keys stackmap vs. stackid_hmap",
  62                  "err %d errno %d\n", err, errno))
  63                goto disable_pmu;
  64
  65        stack_trace_len = PERF_MAX_STACK_DEPTH * sizeof(__u64);
  66        err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len);
  67        if (CHECK(err, "compare_stack_ips stackmap vs. stack_amap",
  68                  "err %d errno %d\n", err, errno))
  69                goto disable_pmu;
  70
  71disable_pmu:
  72        bpf_link__destroy(link);
  73close_prog:
  74        bpf_object__close(obj);
  75}
  76