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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /******************************************************************************
   3  *
   4  * Copyright FUJITSU LIMITED 2010
   5  * Copyright KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
   6  *
   7  * DESCRIPTION
   8  *      Wait on uninitialized heap. It shold be zero and FUTEX_WAIT should
   9  *      return immediately. This test is intent to test zero page handling in
  10  *      futex.
  11  *
  12  * AUTHOR
  13  *      KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
  14  *
  15  * HISTORY
  16  *      2010-Jan-6: Initial version by KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
  17  *
  18  *****************************************************************************/
  19
  20 #include <pthread.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <sys/mman.h>
  24 #include <syscall.h>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <unistd.h>
  28 #include <errno.h>
  29 #include <linux/futex.h>
  30 #include <libgen.h>
  31
  32 #include "logging.h"
  33 #include "futextest.h"
  34
  35 #define TEST_NAME "futex-wait-uninitialized-heap"
  36 #define WAIT_US 5000000
  37
  38 static int child_blocked = 1;
  39 static int child_ret;
  40 void *buf;
  41
  42 void usage(char *prog)
  43 {
  44         printf("Usage: %s\n", prog);
  45         printf("  -c    Use color\n");
  46         printf("  -h    Display this help message\n");
  47         printf("  -v L  Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
  48                VQUIET, VCRITICAL, VINFO);
  49 }
  50
  51 void *wait_thread(void *arg)
  52 {
  53         int res;
  54
  55         child_ret = RET_PASS;
  56         res = futex_wait(buf, 1, NULL, 0);
  57         child_blocked = 0;
  58
  59         if (res != 0 && errno != EWOULDBLOCK) {
  60                 error("futex failure\n", errno);
  61                 child_ret = RET_ERROR;
  62         }
  63         pthread_exit(NULL);
  64 }
  65
  66 int main(int argc, char **argv)
  67 {
  68         int c, ret = RET_PASS;
  69         long page_size;
  70         pthread_t thr;
  71
  72         while ((c = getopt(argc, argv, "chv:")) != -1) {
  73                 switch (c) {
  74                 case 'c':
  75                         log_color(1);
  76                         break;
  77                 case 'h':
  78                         usage(basename(argv[0]));
  79                         exit(0);
  80                 case 'v':
  81                         log_verbosity(atoi(optarg));
  82                         break;
  83                 default:
  84                         usage(basename(argv[0]));
  85                         exit(1);
  86                 }
  87         }
  88
  89         page_size = sysconf(_SC_PAGESIZE);
  90
  91         buf = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
  92                    MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
  93         if (buf == (void *)-1) {
  94                 error("mmap\n", errno);
  95                 exit(1);
  96         }
  97
  98         ksft_print_header();
  99         ksft_set_plan(1);
 100         ksft_print_msg("%s: Test the uninitialized futex value in FUTEX_WAIT\n",
 101                basename(argv[0]));
 102
 103
 104         ret = pthread_create(&thr, NULL, wait_thread, NULL);
 105         if (ret) {
 106                 error("pthread_create\n", errno);
 107                 ret = RET_ERROR;
 108                 goto out;
 109         }
 110
 111         info("waiting %dus for child to return\n", WAIT_US);
 112         usleep(WAIT_US);
 113
 114         ret = child_ret;
 115         if (child_blocked) {
 116                 fail("child blocked in kernel\n");
 117                 ret = RET_FAIL;
 118         }
 119
 120  out:
 121         print_result(TEST_NAME, ret);
 122         return ret;
 123 }