1// SPDX-License-Identifier: GPL-2.0-only
  2/* Copyright (c) 2019 Facebook */
  3#define _GNU_SOURCE
  4#include <sched.h>
  5#include <sys/prctl.h>
  6#include <test_progs.h>
  7
  8#define MAX_CNT 100000
  9
 10static __u64 time_get_ns(void)
 11{
 12	struct timespec ts;
 13
 14	clock_gettime(CLOCK_MONOTONIC, &ts);
 15	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
 16}
 17
 18static int test_task_rename(const char *prog)
 19{
 20	int i, fd, duration = 0, err;
 21	char buf[] = "test_overhead";
 22	__u64 start_time;
 23
 24	fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
 25	if (CHECK(fd < 0, "open /proc", "err %d", errno))
 26		return -1;
 27	start_time = time_get_ns();
 28	for (i = 0; i < MAX_CNT; i++) {
 29		err = write(fd, buf, sizeof(buf));
 30		if (err < 0) {
 31			CHECK(err < 0, "task rename", "err %d", errno);
 32			close(fd);
 33			return -1;
 34		}
 35	}
 36	printf("task_rename %s\t%lluK events per sec\n", prog,
 37	       MAX_CNT * 1000000ll / (time_get_ns() - start_time));
 38	close(fd);
 39	return 0;
 40}
 41
 42static void test_run(const char *prog)
 43{
 44	test_task_rename(prog);
 45}
 46
 47static void setaffinity(void)
 48{
 49	cpu_set_t cpuset;
 50	int cpu = 0;
 51
 52	CPU_ZERO(&cpuset);
 53	CPU_SET(cpu, &cpuset);
 54	sched_setaffinity(0, sizeof(cpuset), &cpuset);
 55}
 56
 57void test_test_overhead(void)
 58{
 59	const char *kprobe_name = "prog1";
 60	const char *kretprobe_name = "prog2";
 61	const char *raw_tp_name = "prog3";
 62	const char *fentry_name = "prog4";
 63	const char *fexit_name = "prog5";
 64	const char *kprobe_func = "__set_task_comm";
 65	struct bpf_program *kprobe_prog, *kretprobe_prog, *raw_tp_prog;
 66	struct bpf_program *fentry_prog, *fexit_prog;
 67	struct bpf_object *obj;
 68	struct bpf_link *link;
 69	int err, duration = 0;
 70	char comm[16] = {};
 71
 72	if (CHECK_FAIL(prctl(PR_GET_NAME, comm, 0L, 0L, 0L)))
 73		return;
 74
 75	obj = bpf_object__open_file("./test_overhead.bpf.o", NULL);
 76	if (!ASSERT_OK_PTR(obj, "obj_open_file"))
 77		return;
 78
 79	kprobe_prog = bpf_object__find_program_by_name(obj, kprobe_name);
 80	if (CHECK(!kprobe_prog, "find_probe",
 81		  "prog '%s' not found\n", kprobe_name))
 82		goto cleanup;
 83	kretprobe_prog = bpf_object__find_program_by_name(obj, kretprobe_name);
 84	if (CHECK(!kretprobe_prog, "find_probe",
 85		  "prog '%s' not found\n", kretprobe_name))
 86		goto cleanup;
 87	raw_tp_prog = bpf_object__find_program_by_name(obj, raw_tp_name);
 88	if (CHECK(!raw_tp_prog, "find_probe",
 89		  "prog '%s' not found\n", raw_tp_name))
 90		goto cleanup;
 91	fentry_prog = bpf_object__find_program_by_name(obj, fentry_name);
 92	if (CHECK(!fentry_prog, "find_probe",
 93		  "prog '%s' not found\n", fentry_name))
 94		goto cleanup;
 95	fexit_prog = bpf_object__find_program_by_name(obj, fexit_name);
 96	if (CHECK(!fexit_prog, "find_probe",
 97		  "prog '%s' not found\n", fexit_name))
 98		goto cleanup;
 99	err = bpf_object__load(obj);
100	if (CHECK(err, "obj_load", "err %d\n", err))
101		goto cleanup;
102
103	setaffinity();
104
105	/* base line run */
106	test_run("base");
107
108	/* attach kprobe */
109	link = bpf_program__attach_kprobe(kprobe_prog, false /* retprobe */,
110					  kprobe_func);
111	if (!ASSERT_OK_PTR(link, "attach_kprobe"))
112		goto cleanup;
113	test_run("kprobe");
114	bpf_link__destroy(link);
115
116	/* attach kretprobe */
117	link = bpf_program__attach_kprobe(kretprobe_prog, true /* retprobe */,
118					  kprobe_func);
119	if (!ASSERT_OK_PTR(link, "attach_kretprobe"))
120		goto cleanup;
121	test_run("kretprobe");
122	bpf_link__destroy(link);
123
124	/* attach raw_tp */
125	link = bpf_program__attach_raw_tracepoint(raw_tp_prog, "task_rename");
126	if (!ASSERT_OK_PTR(link, "attach_raw_tp"))
127		goto cleanup;
128	test_run("raw_tp");
129	bpf_link__destroy(link);
130
131	/* attach fentry */
132	link = bpf_program__attach_trace(fentry_prog);
133	if (!ASSERT_OK_PTR(link, "attach_fentry"))
134		goto cleanup;
135	test_run("fentry");
136	bpf_link__destroy(link);
137
138	/* attach fexit */
139	link = bpf_program__attach_trace(fexit_prog);
140	if (!ASSERT_OK_PTR(link, "attach_fexit"))
141		goto cleanup;
142	test_run("fexit");
143	bpf_link__destroy(link);
144
145cleanup:
146	prctl(PR_SET_NAME, comm, 0L, 0L, 0L);
147	bpf_object__close(obj);
148}