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

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <test_progs.h>
   3
   4 ssize_t get_base_addr() {
   5         size_t start;
   6         char buf[256];
   7         FILE *f;
   8
   9         f = fopen("/proc/self/maps", "r");
  10         if (!f)
  11                 return -errno;
  12
  13         while (fscanf(f, "%zx-%*x %s %*s\n", &start, buf) == 2) {
  14                 if (strcmp(buf, "r-xp") == 0) {
  15                         fclose(f);
  16                         return start;
  17                 }
  18         }
  19
  20         fclose(f);
  21         return -EINVAL;
  22 }
  23
  24 void test_attach_probe(void)
  25 {
  26         const char *kprobe_name = "kprobe/sys_nanosleep";
  27         const char *kretprobe_name = "kretprobe/sys_nanosleep";
  28         const char *uprobe_name = "uprobe/trigger_func";
  29         const char *uretprobe_name = "uretprobe/trigger_func";
  30         const int kprobe_idx = 0, kretprobe_idx = 1;
  31         const int uprobe_idx = 2, uretprobe_idx = 3;
  32         const char *file = "./test_attach_probe.o";
  33         struct bpf_program *kprobe_prog, *kretprobe_prog;
  34         struct bpf_program *uprobe_prog, *uretprobe_prog;
  35         struct bpf_object *obj;
  36         int err, prog_fd, duration = 0, res;
  37         struct bpf_link *kprobe_link = NULL;
  38         struct bpf_link *kretprobe_link = NULL;
  39         struct bpf_link *uprobe_link = NULL;
  40         struct bpf_link *uretprobe_link = NULL;
  41         int results_map_fd;
  42         size_t uprobe_offset;
  43         ssize_t base_addr;
  44
  45         base_addr = get_base_addr();
  46         if (CHECK(base_addr < 0, "get_base_addr",
  47                   "failed to find base addr: %zd", base_addr))
  48                 return;
  49         uprobe_offset = (size_t)&get_base_addr - base_addr;
  50
  51         /* load programs */
  52         err = bpf_prog_load(file, BPF_PROG_TYPE_KPROBE, &obj, &prog_fd);
  53         if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno))
  54                 return;
  55
  56         kprobe_prog = bpf_object__find_program_by_title(obj, kprobe_name);
  57         if (CHECK(!kprobe_prog, "find_probe",
  58                   "prog '%s' not found\n", kprobe_name))
  59                 goto cleanup;
  60         kretprobe_prog = bpf_object__find_program_by_title(obj, kretprobe_name);
  61         if (CHECK(!kretprobe_prog, "find_probe",
  62                   "prog '%s' not found\n", kretprobe_name))
  63                 goto cleanup;
  64         uprobe_prog = bpf_object__find_program_by_title(obj, uprobe_name);
  65         if (CHECK(!uprobe_prog, "find_probe",
  66                   "prog '%s' not found\n", uprobe_name))
  67                 goto cleanup;
  68         uretprobe_prog = bpf_object__find_program_by_title(obj, uretprobe_name);
  69         if (CHECK(!uretprobe_prog, "find_probe",
  70                   "prog '%s' not found\n", uretprobe_name))
  71                 goto cleanup;
  72
  73         /* load maps */
  74         results_map_fd = bpf_find_map(__func__, obj, "results_map");
  75         if (CHECK(results_map_fd < 0, "find_results_map",
  76                   "err %d\n", results_map_fd))
  77                 goto cleanup;
  78
  79         kprobe_link = bpf_program__attach_kprobe(kprobe_prog,
  80                                                  false /* retprobe */,
  81                                                  SYS_NANOSLEEP_KPROBE_NAME);
  82         if (CHECK(IS_ERR(kprobe_link), "attach_kprobe",
  83                   "err %ld\n", PTR_ERR(kprobe_link))) {
  84                 kprobe_link = NULL;
  85                 goto cleanup;
  86         }
  87         kretprobe_link = bpf_program__attach_kprobe(kretprobe_prog,
  88                                                     true /* retprobe */,
  89                                                     SYS_NANOSLEEP_KPROBE_NAME);
  90         if (CHECK(IS_ERR(kretprobe_link), "attach_kretprobe",
  91                   "err %ld\n", PTR_ERR(kretprobe_link))) {
  92                 kretprobe_link = NULL;
  93                 goto cleanup;
  94         }
  95         uprobe_link = bpf_program__attach_uprobe(uprobe_prog,
  96                                                  false /* retprobe */,
  97                                                  0 /* self pid */,
  98                                                  "/proc/self/exe",
  99                                                  uprobe_offset);
 100         if (CHECK(IS_ERR(uprobe_link), "attach_uprobe",
 101                   "err %ld\n", PTR_ERR(uprobe_link))) {
 102                 uprobe_link = NULL;
 103                 goto cleanup;
 104         }
 105         uretprobe_link = bpf_program__attach_uprobe(uretprobe_prog,
 106                                                     true /* retprobe */,
 107                                                     -1 /* any pid */,
 108                                                     "/proc/self/exe",
 109                                                     uprobe_offset);
 110         if (CHECK(IS_ERR(uretprobe_link), "attach_uretprobe",
 111                   "err %ld\n", PTR_ERR(uretprobe_link))) {
 112                 uretprobe_link = NULL;
 113                 goto cleanup;
 114         }
 115
 116         /* trigger & validate kprobe && kretprobe */
 117         usleep(1);
 118
 119         err = bpf_map_lookup_elem(results_map_fd, &kprobe_idx, &res);
 120         if (CHECK(err, "get_kprobe_res",
 121                   "failed to get kprobe res: %d\n", err))
 122                 goto cleanup;
 123         if (CHECK(res != kprobe_idx + 1, "check_kprobe_res",
 124                   "wrong kprobe res: %d\n", res))
 125                 goto cleanup;
 126
 127         err = bpf_map_lookup_elem(results_map_fd, &kretprobe_idx, &res);
 128         if (CHECK(err, "get_kretprobe_res",
 129                   "failed to get kretprobe res: %d\n", err))
 130                 goto cleanup;
 131         if (CHECK(res != kretprobe_idx + 1, "check_kretprobe_res",
 132                   "wrong kretprobe res: %d\n", res))
 133                 goto cleanup;
 134
 135         /* trigger & validate uprobe & uretprobe */
 136         get_base_addr();
 137
 138         err = bpf_map_lookup_elem(results_map_fd, &uprobe_idx, &res);
 139         if (CHECK(err, "get_uprobe_res",
 140                   "failed to get uprobe res: %d\n", err))
 141                 goto cleanup;
 142         if (CHECK(res != uprobe_idx + 1, "check_uprobe_res",
 143                   "wrong uprobe res: %d\n", res))
 144                 goto cleanup;
 145
 146         err = bpf_map_lookup_elem(results_map_fd, &uretprobe_idx, &res);
 147         if (CHECK(err, "get_uretprobe_res",
 148                   "failed to get uretprobe res: %d\n", err))
 149                 goto cleanup;
 150         if (CHECK(res != uretprobe_idx + 1, "check_uretprobe_res",
 151                   "wrong uretprobe res: %d\n", res))
 152                 goto cleanup;
 153
 154 cleanup:
 155         bpf_link__destroy(kprobe_link);
 156         bpf_link__destroy(kretprobe_link);
 157         bpf_link__destroy(uprobe_link);
 158         bpf_link__destroy(uretprobe_link);
 159         bpf_object__close(obj);
 160 }