/*	$NetBSD: syscallvar.h,v 1.12 2018/04/19 21:19:07 christos Exp $	*/

/*-
 * Copyright (c) 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software developed for The NetBSD Foundation
 * by Andrew Doran.
 *
 * 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.
 *
 * 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.
 */

#ifndef _SYS_SYSCALLVAR_H_
#define	_SYS_SYSCALLVAR_H_

#ifndef _KERNEL
#error nothing of interest to userspace here
#endif

#if defined(_KERNEL) && defined(_KERNEL_OPT)
#include "opt_dtrace.h"
#endif

#include <sys/systm.h>
#include <sys/proc.h>

extern struct emul emul_netbsd;

struct syscall_package {
	u_short		sp_code;
	u_short		sp_flags;
	sy_call_t	*sp_call;
};

void	syscall_init(void);
int	syscall_establish(const struct emul *, const struct syscall_package *);
int	syscall_disestablish(const struct emul *, const struct syscall_package *);

static __inline int
sy_call(const struct sysent *sy, struct lwp *l, const void *uap,
	register_t *rval)
{
	int error;

	l->l_sysent = sy;
	error = (*sy->sy_call)(l, uap, rval);
	l->l_sysent = NULL;

	return error;
}

static __inline int
sy_invoke(const struct sysent *sy, struct lwp *l, const void *uap,
	register_t *rval, int code)
{
	const bool do_trace = l->l_proc->p_trace_enabled &&
	    (sy->sy_flags & SYCALL_INDIRECT) == 0;
	int error;

#ifdef KDTRACE_HOOKS
#define KDTRACE_ENTRY(a)	(a)
#else
#define KDTRACE_ENTRY(a)	(0)
#endif
	if (__predict_true(!(do_trace || KDTRACE_ENTRY(sy->sy_entry)))
	    || (error = trace_enter(code, sy, uap)) == 0) {
		rval[0] = 0;
#if !defined(__mips__) && !defined(__m68k__)
		/*
		 * Due to the mips userland code for SYS_break needing v1 to be
		 * preserved, we can't clear this on mips. 
		 */
		rval[1] = 0;
#endif
		error = sy_call(sy, l, uap, rval);
	}

	if (__predict_false(do_trace || KDTRACE_ENTRY(sy->sy_return))) {
		trace_exit(code, sy, uap, rval, error);
	}
	return error;
}

/* inclusion in the kernel currently depends on SYSCALL_DEBUG */
extern const char * const syscallnames[];
extern const char * const altsyscallnames[];

#endif	/* _SYS_SYSCALLVAR_H_ */