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// SPDX-License-Identifier: GPL-2.0-or-later
/******************************************************************************
*
* Copyright © International Business Machines Corp., 2009
*
* DESCRIPTION
* 1. Block a thread using FUTEX_WAIT
* 2. Attempt to use FUTEX_CMP_REQUEUE_PI on the futex from 1.
* 3. The kernel must detect the mismatch and return -EINVAL.
*
* AUTHOR
* Darren Hart <dvhart@linux.intel.com>
*
* HISTORY
* 2009-Nov-9: Initial version by Darren Hart <dvhart@linux.intel.com>
*
*****************************************************************************/
#include <errno.h>
#include <getopt.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "futextest.h"
#include "kselftest_harness.h"
futex_t f1 = FUTEX_INITIALIZER;
futex_t f2 = FUTEX_INITIALIZER;
int child_ret = 0;
void *blocking_child(void *arg)
{
child_ret = futex_wait(&f1, f1, NULL, FUTEX_PRIVATE_FLAG);
if (child_ret < 0) {
child_ret = -errno;
ksft_exit_fail_msg("futex_wait\n");
}
return (void *)&child_ret;
}
TEST(requeue_pi_mismatched_ops)
{
pthread_t child;
int ret;
if (pthread_create(&child, NULL, blocking_child, NULL))
ksft_exit_fail_msg("pthread_create\n");
/* Allow the child to block in the kernel. */
sleep(1);
/*
* The kernel should detect the waiter did not setup the
* q->requeue_pi_key and return -EINVAL. If it does not,
* it likely gave the lock to the child, which is now hung
* in the kernel.
*/
ret = futex_cmp_requeue_pi(&f1, f1, &f2, 1, 0, FUTEX_PRIVATE_FLAG);
if (ret < 0) {
if (errno == EINVAL) {
/*
* The kernel correctly detected the mismatched
* requeue_pi target and aborted. Wake the child with
* FUTEX_WAKE.
*/
ret = futex_wake(&f1, 1, FUTEX_PRIVATE_FLAG);
if (ret == 1)
ret = 0;
else if (ret < 0)
ksft_exit_fail_msg("futex_wake\n");
else
ksft_exit_fail_msg("futex_wake did not wake the child\n");
} else {
ksft_exit_fail_msg("futex_cmp_requeue_pi\n");
}
} else if (ret > 0) {
ksft_test_result_fail("futex_cmp_requeue_pi failed to detect the mismatch\n");
} else {
ksft_exit_fail_msg("futex_cmp_requeue_pi found no waiters\n");
}
pthread_join(child, NULL);
if (!ret && !child_ret)
ksft_test_result_pass("futex_requeue_pi_mismatched_ops passed\n");
else
ksft_test_result_pass("futex_requeue_pi_mismatched_ops failed\n");
}
TEST_HARNESS_MAIN
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