tests: check decoding of rt_sigreturn syscall

* tests/rt_sigreturn.c: New file.
* tests/rt_sigreturn.test: New test.
* tests/.gitignore: Add rt_sigreturn.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(DECODER_TESTS): Add rt_sigreturn.test.

tests/.gitignore

@@ -270,6 +270,7 @@ rmdir
 rt_sigpending
 rt_sigprocmask
 rt_sigqueueinfo
+rt_sigreturn
 rt_sigsuspend
 rt_sigtimedwait
 rt_tgsigqueueinfo

tests/Makefile.am

@@ -331,6 +331,7 @@ check_PROGRAMS = \
 	rt_sigpending \
 	rt_sigprocmask \
 	rt_sigqueueinfo \
+	rt_sigreturn \
 	rt_sigsuspend \
 	rt_sigtimedwait \
 	rt_tgsigqueueinfo \
@@ -727,6 +728,7 @@ DECODER_TESTS = \
 	rt_sigpending.test \
 	rt_sigprocmask.test \
 	rt_sigqueueinfo.test \
+	rt_sigreturn.test \
 	rt_sigsuspend.test \
 	rt_sigtimedwait.test \
 	rt_tgsigqueueinfo.test \

tests/rt_sigreturn.c

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2015-2017 Dmitry V. Levin <ldv@altlinux.org>
+ * 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 <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef ASM_SIGRTMIN
+# define RT_0 ASM_SIGRTMIN
+#else
+/* Linux kernel >= 3.18 defines SIGRTMIN to 32 on all architectures. */
+# define RT_0 32
+#endif
+
+static void
+handler(int no, siginfo_t *si, void *uc)
+{
+}
+
+int
+main(void)
+{
+	static sigset_t set;
+	sigemptyset(&set);
+	sigaddset(&set, SIGINT);
+	sigaddset(&set, SIGUSR2);
+	sigaddset(&set, SIGCHLD);
+	sigaddset(&set, RT_0 +  3);
+	sigaddset(&set, RT_0 +  4);
+	sigaddset(&set, RT_0 +  5);
+	sigaddset(&set, RT_0 + 26);
+	sigaddset(&set, RT_0 + 27);
+	if (sigprocmask(SIG_SETMASK, &set, NULL))
+		perror_msg_and_fail("sigprocmask");
+	sigemptyset(&set);
+
+	static const struct sigaction sa = {
+		.sa_sigaction = handler,
+		.sa_flags = SA_SIGINFO
+	};
+	if (sigaction(SIGUSR1, &sa, NULL))
+		perror_msg_and_fail("sigaction");
+
+	if (raise(SIGUSR1))
+		perror_msg_and_fail("raise");
+
+	static const char *const sigs =
+		(SIGUSR2 < SIGCHLD) ? "INT USR2 CHLD" : "INT CHLD USR2";
+	static const char *const rt_sigs = "RT_3 RT_4 RT_5 RT_26 RT_27";
+	printf("rt_sigreturn({mask=[%s %s]}) = 0\n", sigs, rt_sigs);
+
+	puts("+++ exited with 0 +++");
+	return 0;
+}

tests/rt_sigreturn.test

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+# Check decoding of rt_sigreturn syscall.
+. "${srcdir=.}/init.sh"
+
+run_strace_match_diff -esignal='!USR1'