LXR linux/tools/testing/selftests/futex/functional/futex_wait_uninitialized

   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
  41static int child_blocked = 1;
  42static int child_ret;
  43void *buf;
  44
  45void 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
  54void *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
  69int 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}
 125