tests: extend test coverage of waitid syscall

* tests/waitid.c: New file.
* tests/waitid-v.c: Likewise.
* tests/waitid.test: New test.
* tests/waitid-v.test: Likewise.
* tests/.gitignore: Add waitid and waitid-v.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(DECODER_TESTS): Add waitid.test and waitid-v.test.
diff --git a/tests/waitid.c b/tests/waitid.c
new file mode 100644
index 0000000..bd7e8ef
--- /dev/null
+++ b/tests/waitid.c
@@ -0,0 +1,263 @@
+/*
+ * Check decoding of waitid syscall.
+ *
+ * Copyright (c) 2015-2016 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 <assert.h>
+#include <signal.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <sys/resource.h>
+#include <sys/syscall.h>
+
+static const char *
+sprint_rusage(const struct rusage *const ru)
+{
+	static char buf[1024];
+	snprintf(buf, sizeof(buf),
+		 "{ru_utime={%llu, %llu}"
+		 ", ru_stime={%llu, %llu}"
+#ifdef VERBOSE_RUSAGE
+		 ", ru_maxrss=%llu"
+		 ", ru_ixrss=%llu"
+		 ", ru_idrss=%llu"
+		 ", ru_isrss=%llu"
+		 ", ru_minflt=%llu"
+		 ", ru_majflt=%llu"
+		 ", ru_nswap=%llu"
+		 ", ru_inblock=%llu"
+		 ", ru_oublock=%llu"
+		 ", ru_msgsnd=%llu"
+		 ", ru_msgrcv=%llu"
+		 ", ru_nsignals=%llu"
+		 ", ru_nvcsw=%llu"
+		 ", ru_nivcsw=%llu}"
+#else
+		 ", ...}"
+#endif
+		 , widen_to_ull(ru->ru_utime.tv_sec)
+		 , widen_to_ull(ru->ru_utime.tv_usec)
+		 , widen_to_ull(ru->ru_stime.tv_sec)
+		 , widen_to_ull(ru->ru_stime.tv_usec)
+#ifdef VERBOSE_RUSAGE
+		 , widen_to_ull(ru->ru_maxrss)
+		 , widen_to_ull(ru->ru_ixrss)
+		 , widen_to_ull(ru->ru_idrss)
+		 , widen_to_ull(ru->ru_isrss)
+		 , widen_to_ull(ru->ru_minflt)
+		 , widen_to_ull(ru->ru_majflt)
+		 , widen_to_ull(ru->ru_nswap)
+		 , widen_to_ull(ru->ru_inblock)
+		 , widen_to_ull(ru->ru_oublock)
+		 , widen_to_ull(ru->ru_msgsnd)
+		 , widen_to_ull(ru->ru_msgrcv)
+		 , widen_to_ull(ru->ru_nsignals)
+		 , widen_to_ull(ru->ru_nvcsw)
+		 , widen_to_ull(ru->ru_nivcsw)
+#endif
+		 );
+	return buf;
+}
+
+#define CASE(x) case x: return #x
+
+static const char *
+si_code_2_name(const int code)
+{
+	switch (code) {
+#ifdef CLD_EXITED
+	CASE(CLD_EXITED);
+#endif
+#ifdef CLD_KILLED
+	CASE(CLD_KILLED);
+#endif
+#ifdef CLD_DUMPED
+	CASE(CLD_DUMPED);
+#endif
+#ifdef CLD_TRAPPED
+	CASE(CLD_TRAPPED);
+#endif
+#ifdef CLD_STOPPED
+	CASE(CLD_STOPPED);
+#endif
+#ifdef CLD_CONTINUED
+	CASE(CLD_CONTINUED);
+#endif
+	default: perror_msg_and_fail("unknown si_code %d", code);
+	}
+}
+
+static const char *
+sprint_siginfo(const siginfo_t *const si, const char *const status_text)
+{
+	static char buf[1024];
+	snprintf(buf, sizeof(buf),
+		 "{si_signo=SIGCHLD"
+		 ", si_code=%s"
+		 ", si_pid=%u"
+		 ", si_uid=%u"
+		 ", si_status=%s"
+		 ", si_utime=%llu"
+		 ", si_stime=%llu}",
+		 si_code_2_name(si->si_code),
+		 si->si_pid,
+		 si->si_uid,
+		 status_text,
+		 widen_to_ull(si->si_utime),
+		 widen_to_ull(si->si_stime));
+	return buf;
+}
+
+static unsigned long
+poison(unsigned int v)
+{
+	return (unsigned long) 0xfacefeed00000000 | v;
+}
+
+static long
+do_waitid(const unsigned int idtype,
+	  const unsigned int id,
+	  const siginfo_t const *infop,
+	  const unsigned int options,
+	  const struct rusage *const rusage)
+{
+	sigset_t mask = {};
+	sigaddset(&mask, SIGCHLD);
+
+	assert(sigprocmask(SIG_BLOCK, &mask, NULL) == 0);
+	long rc = syscall(__NR_waitid, poison(idtype), poison(id),
+			  infop, poison(options), rusage);
+	assert(sigprocmask(SIG_UNBLOCK, &mask, NULL) == 0);
+	return rc;
+}
+
+int
+main(void)
+{
+	tprintf("%s", "");
+
+	int fds[2];
+	if (pipe(fds))
+		perror_msg_and_fail("pipe");
+
+	pid_t pid;
+	pid = fork();
+	if (pid < 0)
+		perror_msg_and_fail("fork");
+
+	if (!pid) {
+		char c;
+		(void) close(1);
+		assert(read(0, &c, sizeof(c)) == 1);
+		return 42;
+	}
+
+	(void) close(0);
+
+	if (do_waitid(P_PID, pid, 0, WNOHANG|WEXITED, 0))
+		perror_msg_and_fail("waitid #1");
+	tprintf("waitid(P_PID, %d, NULL, WNOHANG|WEXITED, NULL) = 0\n", pid);
+
+	siginfo_t *const sinfo = tail_alloc(sizeof(*sinfo));
+	memset(sinfo, 0, sizeof(*sinfo));
+	struct rusage *const rusage = tail_alloc(sizeof(*rusage));
+	if (do_waitid(P_PID, pid, sinfo, WNOHANG|WEXITED|WSTOPPED, rusage))
+		perror_msg_and_fail("waitid #2");
+	tprintf("waitid(P_PID, %d, {}, WNOHANG|WEXITED|WSTOPPED, %s) = 0\n",
+		pid, sprint_rusage(rusage));
+
+	assert(write(1, "", 1) == 1);
+	(void) close(1);
+
+	if (do_waitid(P_PID, pid, sinfo, WEXITED, rusage))
+		perror_msg_and_fail("waitid #3");
+	tprintf("waitid(P_PID, %d, %s, WEXITED, %s) = 0\n",
+		pid, sprint_siginfo(sinfo, "42"), sprint_rusage(rusage));
+
+	pid = fork();
+	if (pid < 0)
+		perror_msg_and_fail("fork");
+
+	if (!pid) {
+		(void) raise(SIGUSR1);
+		return 1;
+	}
+
+	if (do_waitid(P_PID, pid, sinfo, WEXITED, rusage))
+		perror_msg_and_fail("waitid #4");
+	tprintf("waitid(P_PID, %d, %s, WEXITED, %s) = 0\n",
+		pid, sprint_siginfo(sinfo, "SIGUSR1"), sprint_rusage(rusage));
+
+	if (pipe(fds))
+		perror_msg_and_fail("pipe");
+	pid = fork();
+	if (pid < 0)
+		perror_msg_and_fail("fork");
+
+	if (!pid) {
+		(void) close(1);
+		raise(SIGSTOP);
+		char c;
+		assert(read(0, &c, sizeof(c)) == 1);
+		return 0;
+	}
+
+	(void) close(0);
+
+	if (do_waitid(P_PID, pid, sinfo, WSTOPPED, rusage))
+		perror_msg_and_fail("waitid #5");
+	tprintf("waitid(P_PID, %d, %s, WSTOPPED, %s) = 0\n",
+		pid, sprint_siginfo(sinfo, "SIGSTOP"), sprint_rusage(rusage));
+
+	if (kill(pid, SIGCONT))
+		perror_msg_and_fail("kill(SIGCONT)");
+
+#if defined WCONTINUED
+	if (do_waitid(P_PID, pid, sinfo, WCONTINUED, rusage))
+		perror_msg_and_fail("waitid #6");
+	tprintf("waitid(P_PID, %d, %s, WCONTINUED, %s) = 0\n",
+		pid, sprint_siginfo(sinfo, "SIGCONT"), sprint_rusage(rusage));
+#endif /* WCONTINUED */
+
+	assert(write(1, "", 1) == 1);
+	(void) close(1);
+
+	if (do_waitid(P_PID, pid, sinfo, WEXITED, rusage))
+		perror_msg_and_fail("waitid #7");
+	tprintf("waitid(P_PID, %d, %s, WEXITED, %s) = 0\n",
+		pid, sprint_siginfo(sinfo, "0"), sprint_rusage(rusage));
+
+	long rc = do_waitid(P_ALL, -1, sinfo, WEXITED|WSTOPPED, rusage);
+	tprintf("waitid(P_ALL, -1, %p, WEXITED|WSTOPPED, %p)"
+		" = %ld %s (%m)\n", sinfo, rusage, rc, errno2name());
+
+	tprintf("%s\n", "+++ exited with 0 +++");
+	return 0;
+}