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 TEST_NAME "futex-wait-uninitialized-heap"
  40#define WAIT_US 5000000
  41
  42static int child_blocked = 1;
  43static int child_ret;
  44void *buf;
  45
  46void usage(char *prog)
  47{
  48        printf("Usage: %s\n", prog);
  49        printf("  -c    Use color\n");
  50        printf("  -h    Display this help message\n");
  51        printf("  -v L  Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
  52               VQUIET, VCRITICAL, VINFO);
  53}
  54
  55void *wait_thread(void *arg)
  56{
  57        int res;
  58
  59        child_ret = RET_PASS;
  60        res = futex_wait(buf, 1, NULL, 0);
  61        child_blocked = 0;
  62
  63        if (res != 0 && errno != EWOULDBLOCK) {
  64                error("futex failure\n", errno);
  65                child_ret = RET_ERROR;
  66        }
  67        pthread_exit(NULL);
  68}
  69
  70int main(int argc, char **argv)
  71{
  72        int c, ret = RET_PASS;
  73        long page_size;
  74        pthread_t thr;
  75
  76        while ((c = getopt(argc, argv, "chv:")) != -1) {
  77                switch (c) {
  78                case 'c':
  79                        log_color(1);
  80                        break;
  81                case 'h':
  82                        usage(basename(argv[0]));
  83                        exit(0);
  84                case 'v':
  85                        log_verbosity(atoi(optarg));
  86                        break;
  87                default:
  88                        usage(basename(argv[0]));
  89                        exit(1);
  90                }
  91        }
  92
  93        page_size = sysconf(_SC_PAGESIZE);
  94
  95        buf = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
  96                   MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
  97        if (buf == (void *)-1) {
  98                error("mmap\n", errno);
  99                exit(1);
 100        }
 101
 102        ksft_print_header();
 103        ksft_print_msg("%s: Test the uninitialized futex value in FUTEX_WAIT\n",
 104               basename(argv[0]));
 105
 106
 107        ret = pthread_create(&thr, NULL, wait_thread, NULL);
 108        if (ret) {
 109                error("pthread_create\n", errno);
 110                ret = RET_ERROR;
 111                goto out;
 112        }
 113
 114        info("waiting %dus for child to return\n", WAIT_US);
 115        usleep(WAIT_US);
 116
 117        ret = child_ret;
 118        if (child_blocked) {
 119                fail("child blocked in kernel\n");
 120                ret = RET_FAIL;
 121        }
 122
 123 out:
 124        print_result(TEST_NAME, ret);
 125        return ret;
 126}
 127