tests: check delay injection

* tests/delay.c: New file.
* tests/delay.test: New test.
* tests/.gitignore: Add delay.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(delay_LDADD): New variable.
(MISC_TESTS): Add delay.test.

Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>

tests/.gitignore

@@ -39,6 +39,7 @@ clone_ptrace
 copy_file_range
 count-f
 creat
+delay
 delete_module
 dev-yy
 dup

tests/Makefile.am

@@ -97,6 +97,7 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	clone_parent \
 	clone_ptrace \
 	count-f \
+	delay \
 	execve-v \
 	execveat-v \
 	filter-unavailable \
@@ -166,6 +167,7 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 
 attach_f_p_LDADD = -lpthread $(LDADD)
 count_f_LDADD = -lpthread $(LDADD)
+delay_LDADD = $(clock_LIBS) $(LDADD)
 filter_unavailable_LDADD = -lpthread $(LDADD)
 fstat64_CPPFLAGS = $(AM_CPPFLAGS) -D_FILE_OFFSET_BITS=64
 fstatat64_CPPFLAGS = $(AM_CPPFLAGS) -D_FILE_OFFSET_BITS=64
@@ -271,6 +273,7 @@ MISC_TESTS = \
 	clone_ptrace.test \
 	count-f.test \
 	count.test \
+	delay.test \
 	detach-running.test \
 	detach-sleeping.test \
 	detach-stopped.test \

tests/delay.c

@@ -0,0 +1,135 @@
+/*
+ * Check delay injection.
+ *
+ * Copyright (c) 2018 The strace developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "tests.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 <asm/unistd.h>
+
+static int64_t
+usecs_from_tv(const struct timeval *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_delay(const struct timeval *const tv0,
+	    const struct timespec *const ts,
+	    const struct timeval *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);
+
+	if (us - us0 < delay_exit * (nproc - 1) / nproc)
+		_exit(1);
+
+	if (us - us0 > delay_exit * (nproc + 1) / nproc)
+		_exit(2);
+
+	if (us1 - us < delay_enter * (nproc - 1) / nproc)
+		_exit(3);
+
+	if (us1 - us > delay_enter * (nproc + 1) / nproc)
+		_exit(4);
+}
+
+static void
+run(const int nproc, const int delay_enter, const int delay_exit)
+{
+	struct timeval 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;
+}

tests/delay.test

@@ -0,0 +1,10 @@
+#!/bin/sh
+# Check delay injection.
+
+. "${srcdir=.}/init.sh"
+
+delay_enter=800000
+delay_exit=1600000
+run_strace -f -r -egettimeofday \
+	-einject=gettimeofday:delay_enter=$delay_enter:delay_exit=$delay_exit \
+	../delay 4 $delay_enter $delay_exit