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/*
* Check delay injection.
*
* Copyright (c) 2018-2023 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "tests.h"
#include <inttypes.h>
#include <limits.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>
#include <sys/wait.h>
#include "scno.h"
#include "kernel_timeval.h"
static int64_t
usecs_from_tv(const kernel_old_timeval_t *const tv)
{
return (int64_t) tv->tv_sec * 1000000 + tv->tv_usec;
}
static int64_t
usecs_from_ts(const struct timespec *const ts)
{
return (int64_t) ts->tv_sec * 1000000 + ts->tv_nsec / 1000;
}
static void
check_(const int64_t got, const bool ge, const int64_t orig, const int nproc,
const int exitcode)
{
const int64_t thresh = (orig * (ge ? nproc - 1 : nproc + 1)) / nproc;
if (ge ? got >= thresh : got <= thresh)
return;
fprintf(stderr, "Got delay of %" PRId64 ", %s than threshold value of "
"%" PRId64 " (expected nominal delay value is %" PRId64
")\n", got, ge ? "less" : "more", thresh, orig);
_exit(exitcode);
}
static void
check_delay(const kernel_old_timeval_t *const tv0,
const struct timespec *const ts,
const kernel_old_timeval_t *const tv1,
const int nproc,
const int64_t delay_enter,
const int64_t delay_exit)
{
const int64_t us0 = usecs_from_tv(tv0);
const int64_t us = usecs_from_ts(ts);
const int64_t us1 = usecs_from_tv(tv1);
check_(us - us0, true, delay_exit, nproc, 1);
check_(us - us0, false, delay_exit, nproc, 2);
check_(us1 - us, true, delay_enter, nproc, 3);
check_(us1 - us, false, delay_enter, nproc, 4);
}
static void
run(const int nproc, const int delay_enter, const int delay_exit)
{
kernel_old_timeval_t prev = { 0, 0 }, now;
for (int i = 0; i < nproc; ++i, prev = now) {
struct timespec ts;
if (i && clock_gettime(CLOCK_REALTIME, &ts))
perror_msg_and_fail("clock_gettime");
if (syscall(__NR_gettimeofday, &now, NULL))
perror_msg_and_fail("gettimeofday");
if (!i)
continue;
check_delay(&prev, &ts, &now, nproc, delay_enter, delay_exit);
}
_exit(0);
}
int
main(int ac, char *av[])
{
if (ac != 4)
error_msg_and_fail("usage: delay <nproc> <delay_enter> <delay_exit>");
const int nproc = atoi(av[1]);
if (nproc <= 1)
perror_msg_and_fail("invalid nproc: %s", av[1]);
const int delay_enter = atoi(av[2]);
if (delay_enter <= 0)
perror_msg_and_fail("invalid delay_enter: %s", av[2]);
const int delay_exit = atoi(av[3]);
if (delay_exit <= 0)
perror_msg_and_fail("invalid delay_exit: %s", av[3]);
for (int i = 0; i < nproc; ++i) {
pid_t pid = fork();
if (pid)
usleep(MAX(delay_enter, delay_exit) / nproc);
else
run(nproc, delay_enter, delay_exit);
}
int status;
while (wait(&status) > 0) {
if (status)
perror_msg_and_fail("wait status %d", status);
}
return 0;
}
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