1 // SPDX-License-Identifier: GPL-2.0
2 #include <inttypes.h>
3 #include <unistd.h>
4 #include <sys/syscall.h>
5 #include <sys/types.h>
6 #include <sys/mman.h>
7 #include <pthread.h>
8 #include <stdlib.h>
9 #include <stdio.h>
10 #include "debug.h"
11 #include "event.h"
12 #include "tests.h"
13 #include "machine.h"
14 #include "thread_map.h"
15 #include "map.h"
16 #include "symbol.h"
17 #include "util/synthetic-events.h"
18 #include "thread.h"
19 #include <internal/lib.h> // page_size
20 
21 #define THREADS 4
22 
23 static int go_away;
24 
25 struct thread_data {
26 	pthread_t	pt;
27 	pid_t		tid;
28 	void		*map;
29 	int		ready[2];
30 };
31 
32 static struct thread_data threads[THREADS];
33 
thread_init(struct thread_data * td)34 static int thread_init(struct thread_data *td)
35 {
36 	void *map;
37 
38 	map = mmap(NULL, page_size,
39 		   PROT_READ|PROT_WRITE|PROT_EXEC,
40 		   MAP_SHARED|MAP_ANONYMOUS, -1, 0);
41 
42 	if (map == MAP_FAILED) {
43 		perror("mmap failed");
44 		return -1;
45 	}
46 
47 	td->map = map;
48 	td->tid = syscall(SYS_gettid);
49 
50 	pr_debug("tid = %d, map = %p\n", td->tid, map);
51 	return 0;
52 }
53 
thread_fn(void * arg)54 static void *thread_fn(void *arg)
55 {
56 	struct thread_data *td = arg;
57 	ssize_t ret;
58 	int go = 0;
59 
60 	if (thread_init(td))
61 		return NULL;
62 
63 	/* Signal thread_create thread is initialized. */
64 	ret = write(td->ready[1], &go, sizeof(int));
65 	if (ret != sizeof(int)) {
66 		pr_err("failed to notify\n");
67 		return NULL;
68 	}
69 
70 	while (!go_away) {
71 		/* Waiting for main thread to kill us. */
72 		usleep(100);
73 	}
74 
75 	munmap(td->map, page_size);
76 	return NULL;
77 }
78 
thread_create(int i)79 static int thread_create(int i)
80 {
81 	struct thread_data *td = &threads[i];
82 	int err, go;
83 
84 	if (pipe(td->ready))
85 		return -1;
86 
87 	err = pthread_create(&td->pt, NULL, thread_fn, td);
88 	if (!err) {
89 		/* Wait for thread initialization. */
90 		ssize_t ret = read(td->ready[0], &go, sizeof(int));
91 		err = ret != sizeof(int);
92 	}
93 
94 	close(td->ready[0]);
95 	close(td->ready[1]);
96 	return err;
97 }
98 
threads_create(void)99 static int threads_create(void)
100 {
101 	struct thread_data *td0 = &threads[0];
102 	int i, err = 0;
103 
104 	go_away = 0;
105 
106 	/* 0 is main thread */
107 	if (thread_init(td0))
108 		return -1;
109 
110 	for (i = 1; !err && i < THREADS; i++)
111 		err = thread_create(i);
112 
113 	return err;
114 }
115 
threads_destroy(void)116 static int threads_destroy(void)
117 {
118 	struct thread_data *td0 = &threads[0];
119 	int i, err = 0;
120 
121 	/* cleanup the main thread */
122 	munmap(td0->map, page_size);
123 
124 	go_away = 1;
125 
126 	for (i = 1; !err && i < THREADS; i++)
127 		err = pthread_join(threads[i].pt, NULL);
128 
129 	return err;
130 }
131 
132 typedef int (*synth_cb)(struct machine *machine);
133 
synth_all(struct machine * machine)134 static int synth_all(struct machine *machine)
135 {
136 	return perf_event__synthesize_threads(NULL,
137 					      perf_event__process,
138 					      machine, 1, 0, 1);
139 }
140 
synth_process(struct machine * machine)141 static int synth_process(struct machine *machine)
142 {
143 	struct perf_thread_map *map;
144 	int err;
145 
146 	map = thread_map__new_by_pid(getpid());
147 
148 	err = perf_event__synthesize_thread_map(NULL, map,
149 						perf_event__process,
150 						machine, 1, 0);
151 
152 	perf_thread_map__put(map);
153 	return err;
154 }
155 
mmap_events(synth_cb synth)156 static int mmap_events(synth_cb synth)
157 {
158 	struct machine *machine;
159 	int err, i;
160 
161 	/*
162 	 * The threads_create will not return before all threads
163 	 * are spawned and all created memory map.
164 	 *
165 	 * They will loop until threads_destroy is called, so we
166 	 * can safely run synthesizing function.
167 	 */
168 	TEST_ASSERT_VAL("failed to create threads", !threads_create());
169 
170 	machine = machine__new_host();
171 
172 	dump_trace = verbose > 1 ? 1 : 0;
173 
174 	err = synth(machine);
175 
176 	dump_trace = 0;
177 
178 	TEST_ASSERT_VAL("failed to destroy threads", !threads_destroy());
179 	TEST_ASSERT_VAL("failed to synthesize maps", !err);
180 
181 	/*
182 	 * All data is synthesized, try to find map for each
183 	 * thread object.
184 	 */
185 	for (i = 0; i < THREADS; i++) {
186 		struct thread_data *td = &threads[i];
187 		struct addr_location al;
188 		struct thread *thread;
189 
190 		addr_location__init(&al);
191 		thread = machine__findnew_thread(machine, getpid(), td->tid);
192 
193 		pr_debug("looking for map %p\n", td->map);
194 
195 		thread__find_map(thread, PERF_RECORD_MISC_USER,
196 				 (unsigned long) (td->map + 1), &al);
197 
198 		thread__put(thread);
199 
200 		if (!al.map) {
201 			pr_debug("failed, couldn't find map\n");
202 			err = -1;
203 			addr_location__exit(&al);
204 			break;
205 		}
206 
207 		pr_debug("map %p, addr %" PRIx64 "\n", al.map, map__start(al.map));
208 		addr_location__exit(&al);
209 	}
210 
211 	machine__delete(machine);
212 	return err;
213 }
214 
215 /*
216  * This test creates 'THREADS' number of threads (including
217  * main thread) and each thread creates memory map.
218  *
219  * When threads are created, we synthesize them with both
220  * (separate tests):
221  *   perf_event__synthesize_thread_map (process based)
222  *   perf_event__synthesize_threads    (global)
223  *
224  * We test we can find all memory maps via:
225  *   thread__find_map
226  *
227  * by using all thread objects.
228  */
test__mmap_thread_lookup(struct test_suite * test __maybe_unused,int subtest __maybe_unused)229 static int test__mmap_thread_lookup(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
230 {
231 	/* perf_event__synthesize_threads synthesize */
232 	TEST_ASSERT_VAL("failed with sythesizing all",
233 			!mmap_events(synth_all));
234 
235 	/* perf_event__synthesize_thread_map synthesize */
236 	TEST_ASSERT_VAL("failed with sythesizing process",
237 			!mmap_events(synth_process));
238 
239 	return 0;
240 }
241 
242 DEFINE_SUITE("Lookup mmap thread", mmap_thread_lookup);
243