xref: /linux/tools/perf/tests/mmap-thread-lookup.c (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
1 #include <inttypes.h>
2 #include <unistd.h>
3 #include <sys/syscall.h>
4 #include <sys/types.h>
5 #include <sys/mman.h>
6 #include <pthread.h>
7 #include <stdlib.h>
8 #include <stdio.h>
9 #include "debug.h"
10 #include "tests.h"
11 #include "machine.h"
12 #include "thread_map.h"
13 #include "symbol.h"
14 #include "thread.h"
15 #include "util.h"
16 
17 #define THREADS 4
18 
19 static int go_away;
20 
21 struct thread_data {
22 	pthread_t	pt;
23 	pid_t		tid;
24 	void		*map;
25 	int		ready[2];
26 };
27 
28 static struct thread_data threads[THREADS];
29 
30 static int thread_init(struct thread_data *td)
31 {
32 	void *map;
33 
34 	map = mmap(NULL, page_size,
35 		   PROT_READ|PROT_WRITE|PROT_EXEC,
36 		   MAP_SHARED|MAP_ANONYMOUS, -1, 0);
37 
38 	if (map == MAP_FAILED) {
39 		perror("mmap failed");
40 		return -1;
41 	}
42 
43 	td->map = map;
44 	td->tid = syscall(SYS_gettid);
45 
46 	pr_debug("tid = %d, map = %p\n", td->tid, map);
47 	return 0;
48 }
49 
50 static void *thread_fn(void *arg)
51 {
52 	struct thread_data *td = arg;
53 	ssize_t ret;
54 	int go;
55 
56 	if (thread_init(td))
57 		return NULL;
58 
59 	/* Signal thread_create thread is initialized. */
60 	ret = write(td->ready[1], &go, sizeof(int));
61 	if (ret != sizeof(int)) {
62 		pr_err("failed to notify\n");
63 		return NULL;
64 	}
65 
66 	while (!go_away) {
67 		/* Waiting for main thread to kill us. */
68 		usleep(100);
69 	}
70 
71 	munmap(td->map, page_size);
72 	return NULL;
73 }
74 
75 static int thread_create(int i)
76 {
77 	struct thread_data *td = &threads[i];
78 	int err, go;
79 
80 	if (pipe(td->ready))
81 		return -1;
82 
83 	err = pthread_create(&td->pt, NULL, thread_fn, td);
84 	if (!err) {
85 		/* Wait for thread initialization. */
86 		ssize_t ret = read(td->ready[0], &go, sizeof(int));
87 		err = ret != sizeof(int);
88 	}
89 
90 	close(td->ready[0]);
91 	close(td->ready[1]);
92 	return err;
93 }
94 
95 static int threads_create(void)
96 {
97 	struct thread_data *td0 = &threads[0];
98 	int i, err = 0;
99 
100 	go_away = 0;
101 
102 	/* 0 is main thread */
103 	if (thread_init(td0))
104 		return -1;
105 
106 	for (i = 1; !err && i < THREADS; i++)
107 		err = thread_create(i);
108 
109 	return err;
110 }
111 
112 static int threads_destroy(void)
113 {
114 	struct thread_data *td0 = &threads[0];
115 	int i, err = 0;
116 
117 	/* cleanup the main thread */
118 	munmap(td0->map, page_size);
119 
120 	go_away = 1;
121 
122 	for (i = 1; !err && i < THREADS; i++)
123 		err = pthread_join(threads[i].pt, NULL);
124 
125 	return err;
126 }
127 
128 typedef int (*synth_cb)(struct machine *machine);
129 
130 static int synth_all(struct machine *machine)
131 {
132 	return perf_event__synthesize_threads(NULL,
133 					      perf_event__process,
134 					      machine, 0, 500);
135 }
136 
137 static int synth_process(struct machine *machine)
138 {
139 	struct thread_map *map;
140 	int err;
141 
142 	map = thread_map__new_by_pid(getpid());
143 
144 	err = perf_event__synthesize_thread_map(NULL, map,
145 						perf_event__process,
146 						machine, 0, 500);
147 
148 	thread_map__put(map);
149 	return err;
150 }
151 
152 static int mmap_events(synth_cb synth)
153 {
154 	struct machine *machine;
155 	int err, i;
156 
157 	/*
158 	 * The threads_create will not return before all threads
159 	 * are spawned and all created memory map.
160 	 *
161 	 * They will loop until threads_destroy is called, so we
162 	 * can safely run synthesizing function.
163 	 */
164 	TEST_ASSERT_VAL("failed to create threads", !threads_create());
165 
166 	machine = machine__new_host();
167 
168 	dump_trace = verbose > 1 ? 1 : 0;
169 
170 	err = synth(machine);
171 
172 	dump_trace = 0;
173 
174 	TEST_ASSERT_VAL("failed to destroy threads", !threads_destroy());
175 	TEST_ASSERT_VAL("failed to synthesize maps", !err);
176 
177 	/*
178 	 * All data is synthesized, try to find map for each
179 	 * thread object.
180 	 */
181 	for (i = 0; i < THREADS; i++) {
182 		struct thread_data *td = &threads[i];
183 		struct addr_location al;
184 		struct thread *thread;
185 
186 		thread = machine__findnew_thread(machine, getpid(), td->tid);
187 
188 		pr_debug("looking for map %p\n", td->map);
189 
190 		thread__find_addr_map(thread,
191 				      PERF_RECORD_MISC_USER, MAP__FUNCTION,
192 				      (unsigned long) (td->map + 1), &al);
193 
194 		thread__put(thread);
195 
196 		if (!al.map) {
197 			pr_debug("failed, couldn't find map\n");
198 			err = -1;
199 			break;
200 		}
201 
202 		pr_debug("map %p, addr %" PRIx64 "\n", al.map, al.map->start);
203 	}
204 
205 	machine__delete_threads(machine);
206 	machine__delete(machine);
207 	return err;
208 }
209 
210 /*
211  * This test creates 'THREADS' number of threads (including
212  * main thread) and each thread creates memory map.
213  *
214  * When threads are created, we synthesize them with both
215  * (separate tests):
216  *   perf_event__synthesize_thread_map (process based)
217  *   perf_event__synthesize_threads    (global)
218  *
219  * We test we can find all memory maps via:
220  *   thread__find_addr_map
221  *
222  * by using all thread objects.
223  */
224 int test__mmap_thread_lookup(int subtest __maybe_unused)
225 {
226 	/* perf_event__synthesize_threads synthesize */
227 	TEST_ASSERT_VAL("failed with sythesizing all",
228 			!mmap_events(synth_all));
229 
230 	/* perf_event__synthesize_thread_map synthesize */
231 	TEST_ASSERT_VAL("failed with sythesizing process",
232 			!mmap_events(synth_process));
233 
234 	return 0;
235 }
236