1 /* Copyright (c) 2016 Facebook
2  *
3  * This program is free software; you can redistribute it and/or
4  * modify it under the terms of version 2 of the GNU General Public
5  * License as published by the Free Software Foundation.
6  */
7 #include <stdio.h>
8 #include <unistd.h>
9 #include <stdlib.h>
10 #include <stdbool.h>
11 #include <string.h>
12 #include <fcntl.h>
13 #include <poll.h>
14 #include <sys/ioctl.h>
15 #include <linux/perf_event.h>
16 #include <linux/bpf.h>
17 #include <signal.h>
18 #include <assert.h>
19 #include <errno.h>
20 #include <sys/resource.h>
21 #include "libbpf.h"
22 #include "bpf_load.h"
23 #include "perf-sys.h"
24 
25 #define SAMPLE_FREQ 50
26 
27 static bool sys_read_seen, sys_write_seen;
28 
29 static void print_ksym(__u64 addr)
30 {
31 	struct ksym *sym;
32 
33 	if (!addr)
34 		return;
35 	sym = ksym_search(addr);
36 	printf("%s;", sym->name);
37 	if (!strcmp(sym->name, "sys_read"))
38 		sys_read_seen = true;
39 	else if (!strcmp(sym->name, "sys_write"))
40 		sys_write_seen = true;
41 }
42 
43 static void print_addr(__u64 addr)
44 {
45 	if (!addr)
46 		return;
47 	printf("%llx;", addr);
48 }
49 
50 #define TASK_COMM_LEN 16
51 
52 struct key_t {
53 	char comm[TASK_COMM_LEN];
54 	__u32 kernstack;
55 	__u32 userstack;
56 };
57 
58 static void print_stack(struct key_t *key, __u64 count)
59 {
60 	__u64 ip[PERF_MAX_STACK_DEPTH] = {};
61 	static bool warned;
62 	int i;
63 
64 	printf("%3lld %s;", count, key->comm);
65 	if (bpf_map_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {
66 		printf("---;");
67 	} else {
68 		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
69 			print_ksym(ip[i]);
70 	}
71 	printf("-;");
72 	if (bpf_map_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {
73 		printf("---;");
74 	} else {
75 		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
76 			print_addr(ip[i]);
77 	}
78 	if (count < 6)
79 		printf("\r");
80 	else
81 		printf("\n");
82 
83 	if (key->kernstack == -EEXIST && !warned) {
84 		printf("stackmap collisions seen. Consider increasing size\n");
85 		warned = true;
86 	} else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {
87 		printf("err stackid %d %d\n", key->kernstack, key->userstack);
88 	}
89 }
90 
91 static void int_exit(int sig)
92 {
93 	kill(0, SIGKILL);
94 	exit(0);
95 }
96 
97 static void print_stacks(void)
98 {
99 	struct key_t key = {}, next_key;
100 	__u64 value;
101 	__u32 stackid = 0, next_id;
102 	int fd = map_fd[0], stack_map = map_fd[1];
103 
104 	sys_read_seen = sys_write_seen = false;
105 	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
106 		bpf_map_lookup_elem(fd, &next_key, &value);
107 		print_stack(&next_key, value);
108 		bpf_map_delete_elem(fd, &next_key);
109 		key = next_key;
110 	}
111 	printf("\n");
112 	if (!sys_read_seen || !sys_write_seen) {
113 		printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");
114 		int_exit(0);
115 	}
116 
117 	/* clear stack map */
118 	while (bpf_map_get_next_key(stack_map, &stackid, &next_id) == 0) {
119 		bpf_map_delete_elem(stack_map, &next_id);
120 		stackid = next_id;
121 	}
122 }
123 
124 static void test_perf_event_all_cpu(struct perf_event_attr *attr)
125 {
126 	int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
127 	int *pmu_fd = malloc(nr_cpus * sizeof(int));
128 	int i, error = 0;
129 
130 	/* system wide perf event, no need to inherit */
131 	attr->inherit = 0;
132 
133 	/* open perf_event on all cpus */
134 	for (i = 0; i < nr_cpus; i++) {
135 		pmu_fd[i] = sys_perf_event_open(attr, -1, i, -1, 0);
136 		if (pmu_fd[i] < 0) {
137 			printf("sys_perf_event_open failed\n");
138 			error = 1;
139 			goto all_cpu_err;
140 		}
141 		assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
142 		assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE) == 0);
143 	}
144 	system("dd if=/dev/zero of=/dev/null count=5000k status=none");
145 	print_stacks();
146 all_cpu_err:
147 	for (i--; i >= 0; i--) {
148 		ioctl(pmu_fd[i], PERF_EVENT_IOC_DISABLE);
149 		close(pmu_fd[i]);
150 	}
151 	free(pmu_fd);
152 	if (error)
153 		int_exit(0);
154 }
155 
156 static void test_perf_event_task(struct perf_event_attr *attr)
157 {
158 	int pmu_fd;
159 
160 	/* per task perf event, enable inherit so the "dd ..." command can be traced properly.
161 	 * Enabling inherit will cause bpf_perf_prog_read_time helper failure.
162 	 */
163 	attr->inherit = 1;
164 
165 	/* open task bound event */
166 	pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0);
167 	if (pmu_fd < 0) {
168 		printf("sys_perf_event_open failed\n");
169 		int_exit(0);
170 	}
171 	assert(ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
172 	assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE) == 0);
173 	system("dd if=/dev/zero of=/dev/null count=5000k status=none");
174 	print_stacks();
175 	ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
176 	close(pmu_fd);
177 }
178 
179 static void test_bpf_perf_event(void)
180 {
181 	struct perf_event_attr attr_type_hw = {
182 		.sample_freq = SAMPLE_FREQ,
183 		.freq = 1,
184 		.type = PERF_TYPE_HARDWARE,
185 		.config = PERF_COUNT_HW_CPU_CYCLES,
186 	};
187 	struct perf_event_attr attr_type_sw = {
188 		.sample_freq = SAMPLE_FREQ,
189 		.freq = 1,
190 		.type = PERF_TYPE_SOFTWARE,
191 		.config = PERF_COUNT_SW_CPU_CLOCK,
192 	};
193 	struct perf_event_attr attr_hw_cache_l1d = {
194 		.sample_freq = SAMPLE_FREQ,
195 		.freq = 1,
196 		.type = PERF_TYPE_HW_CACHE,
197 		.config =
198 			PERF_COUNT_HW_CACHE_L1D |
199 			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
200 			(PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
201 	};
202 	struct perf_event_attr attr_hw_cache_branch_miss = {
203 		.sample_freq = SAMPLE_FREQ,
204 		.freq = 1,
205 		.type = PERF_TYPE_HW_CACHE,
206 		.config =
207 			PERF_COUNT_HW_CACHE_BPU |
208 			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
209 			(PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
210 	};
211 	struct perf_event_attr attr_type_raw = {
212 		.sample_freq = SAMPLE_FREQ,
213 		.freq = 1,
214 		.type = PERF_TYPE_RAW,
215 		/* Intel Instruction Retired */
216 		.config = 0xc0,
217 	};
218 
219 	printf("Test HW_CPU_CYCLES\n");
220 	test_perf_event_all_cpu(&attr_type_hw);
221 	test_perf_event_task(&attr_type_hw);
222 
223 	printf("Test SW_CPU_CLOCK\n");
224 	test_perf_event_all_cpu(&attr_type_sw);
225 	test_perf_event_task(&attr_type_sw);
226 
227 	printf("Test HW_CACHE_L1D\n");
228 	test_perf_event_all_cpu(&attr_hw_cache_l1d);
229 	test_perf_event_task(&attr_hw_cache_l1d);
230 
231 	printf("Test HW_CACHE_BPU\n");
232 	test_perf_event_all_cpu(&attr_hw_cache_branch_miss);
233 	test_perf_event_task(&attr_hw_cache_branch_miss);
234 
235 	printf("Test Instruction Retired\n");
236 	test_perf_event_all_cpu(&attr_type_raw);
237 	test_perf_event_task(&attr_type_raw);
238 
239 	printf("*** PASS ***\n");
240 }
241 
242 
243 int main(int argc, char **argv)
244 {
245 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
246 	char filename[256];
247 
248 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
249 	setrlimit(RLIMIT_MEMLOCK, &r);
250 
251 	signal(SIGINT, int_exit);
252 	signal(SIGTERM, int_exit);
253 
254 	if (load_kallsyms()) {
255 		printf("failed to process /proc/kallsyms\n");
256 		return 1;
257 	}
258 
259 	if (load_bpf_file(filename)) {
260 		printf("%s", bpf_log_buf);
261 		return 2;
262 	}
263 
264 	if (fork() == 0) {
265 		read_trace_pipe();
266 		return 0;
267 	}
268 	test_bpf_perf_event();
269 	int_exit(0);
270 	return 0;
271 }
272