From 2aa8470f02a9b9e6a410d1264fe6c8fa6c402eff Mon Sep 17 00:00:00 2001 From: Darren Hart Date: Tue, 12 May 2015 21:07:52 -0700 Subject: selftests: Add futex functional tests The futextest testsuite [1] provides functional, stress, and performance tests for the various futex op codes. Those tests will be of more use to futex developers if they are included with the kernel source. Copy the core infrastructure and the functional tests into selftests, but adapt them for inclusion in the kernel: - Update the Makefile to include the run_tests target, remove reference to the performance and stress tests from the contributed sources. - Replace my dead IBM email address with my current Intel email address. - Remove the warrantee and write-to paragraphs from the license blurbs. - Remove the NAME section as the filename is easily determined. ;-) - Make the whitespace usage consistent in a couple of places. - Cleanup various CodingStyle violations. A future effort will explore moving the performance and stress tests into the kernel. 1. http://git.kernel.org/cgit/linux/kernel/git/dvhart/futextest.git Cc: Shuah Khan Cc: linux-api@vger.kernel.org Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Davidlohr Bueso Cc: KOSAKI Motohiro Signed-off-by: Darren Hart Signed-off-by: Shuah Khan --- .../functional/futex_requeue_pi_signal_restart.c | 223 +++++++++++++++++++++ 1 file changed, 223 insertions(+) create mode 100644 tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c (limited to 'tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c') diff --git a/tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c b/tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c new file mode 100644 index 000000000000..7f0c756993af --- /dev/null +++ b/tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c @@ -0,0 +1,223 @@ +/****************************************************************************** + * + * Copyright © International Business Machines Corp., 2006-2008 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * DESCRIPTION + * This test exercises the futex_wait_requeue_pi() signal handling both + * before and after the requeue. The first should be restarted by the + * kernel. The latter should return EWOULDBLOCK to the waiter. + * + * AUTHORS + * Darren Hart + * + * HISTORY + * 2008-May-5: Initial version by Darren Hart + * + *****************************************************************************/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include "atomic.h" +#include "futextest.h" +#include "logging.h" + +#define DELAY_US 100 + +futex_t f1 = FUTEX_INITIALIZER; +futex_t f2 = FUTEX_INITIALIZER; +atomic_t requeued = ATOMIC_INITIALIZER; + +int waiter_ret = 0; + +void usage(char *prog) +{ + printf("Usage: %s\n", prog); + printf(" -c Use color\n"); + printf(" -h Display this help message\n"); + printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n", + VQUIET, VCRITICAL, VINFO); +} + +int create_rt_thread(pthread_t *pth, void*(*func)(void *), void *arg, + int policy, int prio) +{ + struct sched_param schedp; + pthread_attr_t attr; + int ret; + + pthread_attr_init(&attr); + memset(&schedp, 0, sizeof(schedp)); + + ret = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED); + if (ret) { + error("pthread_attr_setinheritsched\n", ret); + return -1; + } + + ret = pthread_attr_setschedpolicy(&attr, policy); + if (ret) { + error("pthread_attr_setschedpolicy\n", ret); + return -1; + } + + schedp.sched_priority = prio; + ret = pthread_attr_setschedparam(&attr, &schedp); + if (ret) { + error("pthread_attr_setschedparam\n", ret); + return -1; + } + + ret = pthread_create(pth, &attr, func, arg); + if (ret) { + error("pthread_create\n", ret); + return -1; + } + return 0; +} + +void handle_signal(int signo) +{ + info("signal received %s requeue\n", + requeued.val ? "after" : "prior to"); +} + +void *waiterfn(void *arg) +{ + unsigned int old_val; + int res; + + waiter_ret = RET_PASS; + + info("Waiter running\n"); + info("Calling FUTEX_LOCK_PI on f2=%x @ %p\n", f2, &f2); + old_val = f1; + res = futex_wait_requeue_pi(&f1, old_val, &(f2), NULL, + FUTEX_PRIVATE_FLAG); + if (!requeued.val || errno != EWOULDBLOCK) { + fail("unexpected return from futex_wait_requeue_pi: %d (%s)\n", + res, strerror(errno)); + info("w2:futex: %x\n", f2); + if (!res) + futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG); + waiter_ret = RET_FAIL; + } + + info("Waiter exiting with %d\n", waiter_ret); + pthread_exit(NULL); +} + + +int main(int argc, char *argv[]) +{ + unsigned int old_val; + struct sigaction sa; + pthread_t waiter; + int c, res, ret = RET_PASS; + + while ((c = getopt(argc, argv, "chv:")) != -1) { + switch (c) { + case 'c': + log_color(1); + break; + case 'h': + usage(basename(argv[0])); + exit(0); + case 'v': + log_verbosity(atoi(optarg)); + break; + default: + usage(basename(argv[0])); + exit(1); + } + } + + printf("%s: Test signal handling during requeue_pi\n", + basename(argv[0])); + printf("\tArguments: \n"); + + sa.sa_handler = handle_signal; + sigemptyset(&sa.sa_mask); + sa.sa_flags = 0; + if (sigaction(SIGUSR1, &sa, NULL)) { + error("sigaction\n", errno); + exit(1); + } + + info("m1:f2: %x\n", f2); + info("Creating waiter\n"); + res = create_rt_thread(&waiter, waiterfn, NULL, SCHED_FIFO, 1); + if (res) { + error("Creating waiting thread failed", res); + ret = RET_ERROR; + goto out; + } + + info("Calling FUTEX_LOCK_PI on f2=%x @ %p\n", f2, &f2); + info("m2:f2: %x\n", f2); + futex_lock_pi(&f2, 0, 0, FUTEX_PRIVATE_FLAG); + info("m3:f2: %x\n", f2); + + while (1) { + /* + * signal the waiter before requeue, waiter should automatically + * restart futex_wait_requeue_pi() in the kernel. Wait for the + * waiter to block on f1 again. + */ + info("Issuing SIGUSR1 to waiter\n"); + pthread_kill(waiter, SIGUSR1); + usleep(DELAY_US); + + info("Requeueing waiter via FUTEX_CMP_REQUEUE_PI\n"); + old_val = f1; + res = futex_cmp_requeue_pi(&f1, old_val, &(f2), 1, 0, + FUTEX_PRIVATE_FLAG); + /* + * If res is non-zero, we either requeued the waiter or hit an + * error, break out and handle it. If it is zero, then the + * signal may have hit before the the waiter was blocked on f1. + * Try again. + */ + if (res > 0) { + atomic_set(&requeued, 1); + break; + } else if (res > 0) { + error("FUTEX_CMP_REQUEUE_PI failed\n", errno); + ret = RET_ERROR; + break; + } + } + info("m4:f2: %x\n", f2); + + /* + * Signal the waiter after requeue, waiter should return from + * futex_wait_requeue_pi() with EWOULDBLOCK. Join the thread here so the + * futex_unlock_pi() can't happen before the signal wakeup is detected + * in the kernel. + */ + info("Issuing SIGUSR1 to waiter\n"); + pthread_kill(waiter, SIGUSR1); + info("Waiting for waiter to return\n"); + pthread_join(waiter, NULL); + + info("Calling FUTEX_UNLOCK_PI on mutex=%x @ %p\n", f2, &f2); + futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG); + info("m5:f2: %x\n", f2); + + out: + if (ret == RET_PASS && waiter_ret) + ret = waiter_ret; + + print_result(ret); + return ret; +} -- cgit v1.2.3-59-g8ed1b