kernel/tools/testing/selftests/futex/functional/futex_wait_uninitialized_heap.c

   1 /******************************************************************************
   2  *
   3  * Copyright FUJITSU LIMITED 2010
   4  * Copyright KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
   5  *
   6  *   This program is free software;  you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  * DESCRIPTION
  12  *      Wait on uninitialized heap. It shold be zero and FUTEX_WAIT should
  13  *      return immediately. This test is intent to test zero page handling in
  14  *      futex.
  15  *
  16  * AUTHOR
  17  *      KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
  18  *
  19  * HISTORY
  20  *      2010-Jan-6: Initial version by KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
  21  *
  22  *****************************************************************************/
  23
  24 #include <pthread.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <sys/mman.h>
  28 #include <syscall.h>
  29 #include <sys/types.h>
  30 #include <sys/stat.h>
  31 #include <unistd.h>
  32 #include <errno.h>
  33 #include <linux/futex.h>
  34 #include <libgen.h>
  35
  36 #include "logging.h"
  37 #include "futextest.h"
  38
  39 #define WAIT_US 5000000
  40
  41 static int child_blocked = 1;
  42 static int child_ret;
  43 void *buf;
  44
  45 void usage(char *prog)
  46 {
  47         printf("Usage: %s\n", prog);
  48         printf("  -c    Use color\n");
  49         printf("  -h    Display this help message\n");
  50         printf("  -v L  Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
  51                VQUIET, VCRITICAL, VINFO);
  52 }
  53
  54 void *wait_thread(void *arg)
  55 {
  56         int res;
  57
  58         child_ret = RET_PASS;
  59         res = futex_wait(buf, 1, NULL, 0);
  60         child_blocked = 0;
  61
  62         if (res != 0 && errno != EWOULDBLOCK) {
  63                 error("futex failure\n", errno);
  64                 child_ret = RET_ERROR;
  65         }
  66         pthread_exit(NULL);
  67 }
  68
  69 int main(int argc, char **argv)
  70 {
  71         int c, ret = RET_PASS;
  72         long page_size;
  73         pthread_t thr;
  74
  75         while ((c = getopt(argc, argv, "chv:")) != -1) {
  76                 switch (c) {
  77                 case 'c':
  78                         log_color(1);
  79                         break;
  80                 case 'h':
  81                         usage(basename(argv[0]));
  82                         exit(0);
  83                 case 'v':
  84                         log_verbosity(atoi(optarg));
  85                         break;
  86                 default:
  87                         usage(basename(argv[0]));
  88                         exit(1);
  89                 }
  90         }
  91
  92         page_size = sysconf(_SC_PAGESIZE);
  93
  94         buf = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
  95                    MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
  96         if (buf == (void *)-1) {
  97                 error("mmap\n", errno);
  98                 exit(1);
  99         }
 100
 101         printf("%s: Test the uninitialized futex value in FUTEX_WAIT\n",
 102                basename(argv[0]));
 103
 104
 105         ret = pthread_create(&thr, NULL, wait_thread, NULL);
 106         if (ret) {
 107                 error("pthread_create\n", errno);
 108                 ret = RET_ERROR;
 109                 goto out;
 110         }
 111
 112         info("waiting %dus for child to return\n", WAIT_US);
 113         usleep(WAIT_US);
 114
 115         ret = child_ret;
 116         if (child_blocked) {
 117                 fail("child blocked in kernel\n");
 118                 ret = RET_FAIL;
 119         }
 120
 121  out:
 122         print_result(ret);
 123         return ret;
 124 }