tools/perf/tests/mmap-thread-lookup.c

   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(struct test *test __maybe_unused, 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 }