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1// SPDX-License-Identifier: GPL-2.0-or-later2/******************************************************************************3 *4 * Copyright © International Business Machines Corp., 20095 *6 * DESCRIPTION7 * 1. Block a thread using FUTEX_WAIT8 * 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 * AUTHOR12 * Darren Hart <dvhart@linux.intel.com>13 *14 * HISTORY15 * 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 the92 * q->requeue_pi_key and return -EINVAL. If it does not,93 * it likely gave the lock to the child, which is now hung94 * 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 mismatched101 * requeue_pi target and aborted. Wake the child with102 * 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