tests/seccomp-strict.c

/*
 * Check how seccomp SECCOMP_SET_MODE_STRICT is decoded.
 *
 * 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 "tests.h"
#include <sys/syscall.h>

#if defined __NR_seccomp && defined __NR_exit

# include <assert.h>
# include <errno.h>
# include <stdio.h>
# include <unistd.h>

int
main(void)
{
# if defined __x86_64__ && defined __ILP32__
	/*
	 * Syscall numbers are hardcoded in
	 * kernel/seccomp.c:__secure_computing_strict(),
	 * but x32 syscall numbers are not supported.
	 */
	error_msg_and_skip("SECCOMP_SET_MODE_STRICT is not supported on x32");
# else
	static const char text1[] =
		"seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL) = 0\n";
	static const char text2[] = "+++ exited with 0 +++\n";
	const unsigned long addr = (unsigned long) 0xfacefeeddeadbeef;
	int rc = 0;

	assert(syscall(__NR_seccomp, -1L, -1L, addr) == -1);
	printf("seccomp(%#x /* SECCOMP_SET_MODE_??? */, %u, %#lx) = -1 %s (%m)\n",
	       -1, -1, addr, ENOSYS == errno ? "ENOSYS" : "EINVAL");
	fflush(stdout);

	if (syscall(__NR_seccomp, 0, 0, 0)) {
		printf("seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL) = -1 %s (%m)\n",
		       ENOSYS == errno ? "ENOSYS" : "EINVAL");
		fflush(stdout);
	} else {
		rc += write(1, text1, LENGTH_OF(text1)) != LENGTH_OF(text1);
	}

	rc += write(1, text2, LENGTH_OF(text2)) != LENGTH_OF(text2);
	return !!syscall(__NR_exit, rc);
# endif
}

#else

SKIP_MAIN_UNDEFINED("__NR_seccomp && __NR_exit")

#endif