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