NetBSD/sys/kern/sys_syscall.c

/*	$NetBSD: sys_syscall.c,v 1.2 2007/12/11 12:16:34 lukem Exp $	*/

/*-
 * Copyright (c) 2006 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by David Laight.
 *
 * 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. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 FOUNDATION OR CONTRIBUTORS
 * 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sys_syscall.c,v 1.2 2007/12/11 12:16:34 lukem Exp $");

#include <sys/syscall_stats.h>

/*
 * MI indirect system call support.
 * Included from sys_indirect.c and compat/netbsd32/netbsd32_indirect.c
 *
 * SYS_SYSCALL is set to the required function name.
 */

#define CONCAT(a,b) __CONCAT(a,b)

int
SYS_SYSCALL(struct lwp *l, void *v, register_t *rval)
{
	struct CONCAT(SYS_SYSCALL, _args) /* {
		syscallarg(int) code;
		syscallarg(register_t) args[SYS_MAXSYSARGS];
	} */ *uap = v;
	const struct sysent *callp;
	struct proc *p = l->l_proc;
	int code;
	int error;
#ifdef NETBSD32_SYSCALL
	register_t args64[SYS_MAXSYSARGS];
	int i, narg;
	#define TRACE_ARGS args64
#else
	#define TRACE_ARGS &uap->args
#endif

	callp = p->p_emul->e_sysent;

	code = SCARG(uap, code) & (SYS_NSYSENT - 1);
	SYSCALL_COUNT(syscall_counts, code);
	callp += code;

	if (__predict_false(callp->sy_flags & SYCALL_INDIRECT))
		return ENOSYS;

	if (__predict_true(!p->p_trace_enabled))
		return callp->sy_call(l, &uap->args, rval);

#ifdef NETBSD32_SYSCALL
	narg = callp->sy_argsize >> 2;
	for (i = 0; i < narg; i++)
		args64[i] = SCARG(uap, args[i]);
	/* XXX systrace will not modify the correct arguments! */
#endif

	error = trace_enter(l, code, code, NULL, TRACE_ARGS);
	if (__predict_false(error != 0))
		return error;
	error = callp->sy_call(l, &uap->args, rval);
	trace_exit(l, code, TRACE_ARGS, rval, error);
	return error;

	#undef TRACE_ARGS
}