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