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

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/******************************************************************************
   3 *
   4 *   Copyright © International Business Machines  Corp., 2009
   5 *
   6 * DESCRIPTION
   7 *      1. Block a thread using FUTEX_WAIT
   8 *      2. Attempt to use FUTEX_CMP_REQUEUE_PI on the futex from 1.
   9 *      3. The kernel must detect the mismatch and return -EINVAL.
  10 *
  11 * AUTHOR
  12 *      Darren Hart <dvhart@linux.intel.com>
  13 *
  14 * HISTORY
  15 *      2009-Nov-9: Initial version by Darren Hart <dvhart@linux.intel.com>
  16 *
  17 *****************************************************************************/
  18
  19#include <errno.h>
  20#include <getopt.h>
  21#include <pthread.h>
  22#include <stdio.h>
  23#include <stdlib.h>
  24#include <string.h>
  25#include <time.h>
  26#include "futextest.h"
  27#include "logging.h"
  28
  29#define TEST_NAME "futex-requeue-pi-mismatched-ops"
  30
  31futex_t f1 = FUTEX_INITIALIZER;
  32futex_t f2 = FUTEX_INITIALIZER;
  33int child_ret = 0;
  34
  35void usage(char *prog)
  36{
  37        printf("Usage: %s\n", prog);
  38        printf("  -c    Use color\n");
  39        printf("  -h    Display this help message\n");
  40        printf("  -v L  Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
  41               VQUIET, VCRITICAL, VINFO);
  42}
  43
  44void *blocking_child(void *arg)
  45{
  46        child_ret = futex_wait(&f1, f1, NULL, FUTEX_PRIVATE_FLAG);
  47        if (child_ret < 0) {
  48                child_ret = -errno;
  49                error("futex_wait\n", errno);
  50        }
  51        return (void *)&child_ret;
  52}
  53
  54int main(int argc, char *argv[])
  55{
  56        int ret = RET_PASS;
  57        pthread_t child;
  58        int c;
  59
  60        while ((c = getopt(argc, argv, "chv:")) != -1) {
  61                switch (c) {
  62                case 'c':
  63                        log_color(1);
  64                        break;
  65                case 'h':
  66                        usage(basename(argv[0]));
  67                        exit(0);
  68                case 'v':
  69                        log_verbosity(atoi(optarg));
  70                        break;
  71                default:
  72                        usage(basename(argv[0]));
  73                        exit(1);
  74                }
  75        }
  76
  77        ksft_print_header();
  78        ksft_set_plan(1);
  79        ksft_print_msg("%s: Detect mismatched requeue_pi operations\n",
  80               basename(argv[0]));
  81
  82        if (pthread_create(&child, NULL, blocking_child, NULL)) {
  83                error("pthread_create\n", errno);
  84                ret = RET_ERROR;
  85                goto out;
  86        }
  87        /* Allow the child to block in the kernel. */
  88        sleep(1);
  89
  90        /*
  91         * The kernel should detect the waiter did not setup the
  92         * q->requeue_pi_key and return -EINVAL. If it does not,
  93         * it likely gave the lock to the child, which is now hung
  94         * in the kernel.
  95         */
  96        ret = futex_cmp_requeue_pi(&f1, f1, &f2, 1, 0, FUTEX_PRIVATE_FLAG);
  97        if (ret < 0) {
  98                if (errno == EINVAL) {
  99                        /*
 100                         * The kernel correctly detected the mismatched
 101                         * requeue_pi target and aborted. Wake the child with
 102                         * FUTEX_WAKE.
 103                         */
 104                        ret = futex_wake(&f1, 1, FUTEX_PRIVATE_FLAG);
 105                        if (ret == 1) {
 106                                ret = RET_PASS;
 107                        } else if (ret < 0) {
 108                                error("futex_wake\n", errno);
 109                                ret = RET_ERROR;
 110                        } else {
 111                                error("futex_wake did not wake the child\n", 0);
 112                                ret = RET_ERROR;
 113                        }
 114                } else {
 115                        error("futex_cmp_requeue_pi\n", errno);
 116                        ret = RET_ERROR;
 117                }
 118        } else if (ret > 0) {
 119                fail("futex_cmp_requeue_pi failed to detect the mismatch\n");
 120                ret = RET_FAIL;
 121        } else {
 122                error("futex_cmp_requeue_pi found no waiters\n", 0);
 123                ret = RET_ERROR;
 124        }
 125
 126        pthread_join(child, NULL);
 127
 128        if (!ret)
 129                ret = child_ret;
 130
 131 out:
 132        /* If the kernel crashes, we shouldn't return at all. */
 133        print_result(TEST_NAME, ret);
 134        return ret;
 135}
 136