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

   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);
 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);
 145
 146         thread_map__delete(map);
 147         return err;
 148 }
 149
 150 static int mmap_events(synth_cb synth)
 151 {
 152         struct machines machines;
 153         struct machine *machine;
 154         int err, i;
 155
 156         /*
 157          * The threads_create will not return before all threads
 158          * are spawned and all created memory map.
 159          *
 160          * They will loop until threads_destroy is called, so we
 161          * can safely run synthesizing function.
 162          */
 163         TEST_ASSERT_VAL("failed to create threads", !threads_create());
 164
 165         machines__init(&machines);
 166         machine = &machines.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                 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         machines__exit(&machines);
 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(void)
 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 }