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
time_get_ns(void)10 static __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
test_task_rename(const char * prog)18 static 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
test_run(const char * prog)42 static void test_run(const char *prog)
43 {
44 test_task_rename(prog);
45 }
46
setaffinity(void)47 static 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
test_test_overhead(void)57 void test_test_overhead(void)
58 {
59 const char *kprobe_name = "kprobe/__set_task_comm";
60 const char *kretprobe_name = "kretprobe/__set_task_comm";
61 const char *raw_tp_name = "raw_tp/task_rename";
62 const char *fentry_name = "fentry/__set_task_comm";
63 const char *fexit_name = "fexit/__set_task_comm";
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.o", NULL);
76 if (CHECK(IS_ERR(obj), "obj_open_file", "err %ld\n", PTR_ERR(obj)))
77 return;
78
79 kprobe_prog = bpf_object__find_program_by_title(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_title(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_title(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_title(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_title(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 (CHECK(IS_ERR(link), "attach_kprobe", "err %ld\n", PTR_ERR(link)))
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 (CHECK(IS_ERR(link), "attach kretprobe", "err %ld\n", PTR_ERR(link)))
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 (CHECK(IS_ERR(link), "attach fentry", "err %ld\n", PTR_ERR(link)))
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 (CHECK(IS_ERR(link), "attach fentry", "err %ld\n", PTR_ERR(link)))
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 (CHECK(IS_ERR(link), "attach fexit", "err %ld\n", PTR_ERR(link)))
141 goto cleanup;
142 test_run("fexit");
143 bpf_link__destroy(link);
144
145 cleanup:
146 prctl(PR_SET_NAME, comm, 0L, 0L, 0L);
147 bpf_object__close(obj);
148 }
149