/*      $OpenBSD: syscall.c,v 1.14 2024/01/11 19:16:27 miod Exp $       */

/*
 * Copyright (c) 2015 Dale Rahn <drahn@dalerahn.com>
 * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/syscall.h>
#include <sys/syscall_mi.h>

void
syscall(struct trapframe *frame)
{
        struct proc *p = curproc;
        const struct sysent *callp = sysent;
        int code, error = ENOSYS;
        register_t *args, rval[2];

        code = frame->fixreg[0];
        if (code <= 0 || code >= SYS_MAXSYSCALL)
                goto bad;

        callp += code;

        args = &frame->fixreg[3];

        rval[0] = 0;
        rval[1] = 0;

        error = mi_syscall(p, code, callp, args, rval);

        switch (error) {
        case 0:
                frame->fixreg[0] = 0;
                frame->fixreg[3] = rval[0];
                frame->cr &= ~0x10000000;
                break;
        case ERESTART:
                frame->srr0 -= 4;
                break;
        case EJUSTRETURN:
                /* nothing to do */
                break;
        default:
        bad:
                frame->fixreg[0] = error;
                frame->cr |= 0x10000000;
                break;
        }

        mi_syscall_return(p, code, error, rval);
}

void
child_return(void *arg)
{
        struct proc *p = (struct proc *)arg;
        struct trapframe *frame = p->p_md.md_regs;

        frame->fixreg[0] = 0;
        frame->fixreg[3] = 0;
        frame->cr &= ~0x10000000;

        KERNEL_UNLOCK();

        mi_child_return(p);
}