1 // SPDX-License-Identifier: GPL-2.0-only 2 #define _GNU_SOURCE 3 #include <sched.h> 4 #include <sys/prctl.h> 5 #include <test_progs.h> 6 7 #define MAX_TRAMP_PROGS 38 8 9 struct inst { 10 struct bpf_object *obj; 11 struct bpf_link *link_fentry; 12 struct bpf_link *link_fexit; 13 }; 14 15 static int test_task_rename(void) 16 { 17 int fd, duration = 0, err; 18 char buf[] = "test_overhead"; 19 20 fd = open("/proc/self/comm", O_WRONLY|O_TRUNC); 21 if (CHECK(fd < 0, "open /proc", "err %d", errno)) 22 return -1; 23 err = write(fd, buf, sizeof(buf)); 24 if (err < 0) { 25 CHECK(err < 0, "task rename", "err %d", errno); 26 close(fd); 27 return -1; 28 } 29 close(fd); 30 return 0; 31 } 32 33 static struct bpf_link *load(struct bpf_object *obj, const char *name) 34 { 35 struct bpf_program *prog; 36 int duration = 0; 37 38 prog = bpf_object__find_program_by_name(obj, name); 39 if (CHECK(!prog, "find_probe", "prog '%s' not found\n", name)) 40 return ERR_PTR(-EINVAL); 41 return bpf_program__attach_trace(prog); 42 } 43 44 /* TODO: use different target function to run in concurrent mode */ 45 void serial_test_trampoline_count(void) 46 { 47 const char *fentry_name = "prog1"; 48 const char *fexit_name = "prog2"; 49 const char *object = "test_trampoline_count.o"; 50 struct inst inst[MAX_TRAMP_PROGS] = {}; 51 int err, i = 0, duration = 0; 52 struct bpf_object *obj; 53 struct bpf_link *link; 54 char comm[16] = {}; 55 56 /* attach 'allowed' trampoline programs */ 57 for (i = 0; i < MAX_TRAMP_PROGS; i++) { 58 obj = bpf_object__open_file(object, NULL); 59 if (!ASSERT_OK_PTR(obj, "obj_open_file")) { 60 obj = NULL; 61 goto cleanup; 62 } 63 64 err = bpf_object__load(obj); 65 if (CHECK(err, "obj_load", "err %d\n", err)) 66 goto cleanup; 67 inst[i].obj = obj; 68 obj = NULL; 69 70 if (rand() % 2) { 71 link = load(inst[i].obj, fentry_name); 72 if (!ASSERT_OK_PTR(link, "attach_prog")) { 73 link = NULL; 74 goto cleanup; 75 } 76 inst[i].link_fentry = link; 77 } else { 78 link = load(inst[i].obj, fexit_name); 79 if (!ASSERT_OK_PTR(link, "attach_prog")) { 80 link = NULL; 81 goto cleanup; 82 } 83 inst[i].link_fexit = link; 84 } 85 } 86 87 /* and try 1 extra.. */ 88 obj = bpf_object__open_file(object, NULL); 89 if (!ASSERT_OK_PTR(obj, "obj_open_file")) { 90 obj = NULL; 91 goto cleanup; 92 } 93 94 err = bpf_object__load(obj); 95 if (CHECK(err, "obj_load", "err %d\n", err)) 96 goto cleanup_extra; 97 98 /* ..that needs to fail */ 99 link = load(obj, fentry_name); 100 err = libbpf_get_error(link); 101 if (!ASSERT_ERR_PTR(link, "cannot attach over the limit")) { 102 bpf_link__destroy(link); 103 goto cleanup_extra; 104 } 105 106 /* with E2BIG error */ 107 ASSERT_EQ(err, -E2BIG, "proper error check"); 108 ASSERT_EQ(link, NULL, "ptr_is_null"); 109 110 /* and finaly execute the probe */ 111 if (CHECK_FAIL(prctl(PR_GET_NAME, comm, 0L, 0L, 0L))) 112 goto cleanup_extra; 113 CHECK_FAIL(test_task_rename()); 114 CHECK_FAIL(prctl(PR_SET_NAME, comm, 0L, 0L, 0L)); 115 116 cleanup_extra: 117 bpf_object__close(obj); 118 cleanup: 119 if (i >= MAX_TRAMP_PROGS) 120 i = MAX_TRAMP_PROGS - 1; 121 for (; i >= 0; i--) { 122 bpf_link__destroy(inst[i].link_fentry); 123 bpf_link__destroy(inst[i].link_fexit); 124 bpf_object__close(inst[i].obj); 125 } 126 } 127