tests: extend test coverage of setuid syscall

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

tests/.gitignore

@@ -143,6 +143,7 @@ sendfile
 sendfile64
 set_ptracer_any
 sethostname
+setuid
 shmxt
 sigaction
 sigaltstack

tests/Makefile.am

@@ -193,6 +193,7 @@ check_PROGRAMS = \
 	sendfile64 \
 	set_ptracer_any \
 	sethostname \
+	setuid \
 	shmxt \
 	sigaction \
 	sigaltstack \
@@ -400,6 +401,7 @@ DECODER_TESTS = \
 	sendfile.test \
 	sendfile64.test \
 	sethostname.test \
+	setuid.test \
 	shmxt.test \
 	sigaction.test \
 	sigaltstack.test \
@@ -506,6 +508,7 @@ EXTRA_DIST = init.sh run.sh match.awk \
 	     pipe.expected \
 	     ppoll.expected \
 	     ppoll-v.expected \
+	     setugid.c \
 	     sigaction.awk \
 	     sigaltstack.expected \
 	     signalfd.expected \

tests/setugid.c

@@ -0,0 +1,98 @@
+/*
+ * Check decoding of setuid/setgid/setuid32/setgid32 syscalls.
+ *
+ * Copyright (c) 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 <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+
+static int
+ugid2int(const unsigned UGID_TYPE ugid)
+{
+	if ((unsigned UGID_TYPE) -1U == ugid)
+		return -1;
+	else
+		return ugid;
+}
+
+int
+main(void)
+{
+	unsigned int ugid = GETUGID;
+	CHECK_OVERFLOWUGID(ugid);
+
+	const long tests[] = {
+		ugid,
+		0xffff0000U | ugid,
+		(unsigned long) 0xffffffff00000000ULL | ugid,
+		0xffffU,
+		-1U,
+		-1L
+	};
+
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(tests); ++i) {
+		const unsigned int num = ugid2int(tests[i]);
+		long expected;
+
+		if (num == ugid)
+			expected = 0;
+		else if (num == -1U)
+			expected = -1;
+		else
+			continue;
+
+		const long rc = syscall(SYSCALL_NR, tests[i]);
+		int saved_errno = errno;
+		if (rc != expected) {
+			if (!i && ENOSYS == errno) {
+				printf("%s(%u) = -1 ENOSYS (%m)\n",
+				       SYSCALL_NAME, ugid);
+				break;
+			}
+			perror_msg_and_fail("%s(%#lx) != %ld",
+					    SYSCALL_NAME, tests[i], expected);
+		}
+
+		printf("%s(", SYSCALL_NAME);
+		if (num == -1U)
+			printf("-1");
+		else
+			printf("%u", num);
+		errno = saved_errno;
+		if (expected)
+			printf(") = -1 %s (%m)\n",
+			       errno == EPERM ? "EPERM" : "EINVAL");
+		else
+			printf(") = 0\n");
+	}
+
+	puts("+++ exited with 0 +++");
+	return 0;
+}

tests/setuid.c

@@ -0,0 +1,25 @@
+#include "tests.h"
+#include <sys/syscall.h>
+
+#ifdef __NR_setuid
+
+# define SYSCALL_NR	__NR_setuid
+# define SYSCALL_NAME	"setuid"
+
+# if defined __NR_setuid32 && __NR_setuid != __NR_setuid32
+#  define UGID_TYPE	short
+#  define GETUGID	syscall(__NR_geteuid)
+#  define CHECK_OVERFLOWUGID(arg)	check_overflowuid(arg)
+# else
+#  define UGID_TYPE	int
+#  define GETUGID	geteuid()
+#  define CHECK_OVERFLOWUGID(arg)
+# endif
+
+# include "setugid.c"
+
+#else
+
+SKIP_MAIN_UNDEFINED("__NR_setuid")
+
+#endif

tests/setuid.test

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+# Check setuid syscall decoding.
+
+. "${srcdir=.}/init.sh"
+run_strace_match_diff -a10