/*      $NetBSD: netbsd32_syscall.c,v 1.34 2023/10/05 19:41:03 ad Exp $ */

/*-
 * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Charles M. Hannum.
 *
 * 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.
 */

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

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: netbsd32_syscall.c,v 1.34 2023/10/05 19:41:03 ad Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/signal.h>
/* XXX this file ought to include the netbsd32 version of these 2 headers */
#include <sys/syscall.h>
#include <sys/syscallvar.h>
#include <sys/syscallargs.h>
#include <sys/syscall_stats.h>

#include <machine/cpu.h>
#include <machine/psl.h>
#include <machine/userret.h>

void netbsd32_syscall_intern(struct proc *);
static void netbsd32_syscall(struct trapframe *);

void
netbsd32_syscall_intern(struct proc *p)
{

        p->p_md.md_syscall = netbsd32_syscall;
}

void
netbsd32_syscall(struct trapframe *frame)
{
        char *params;
        const struct sysent *callp;
        struct proc *p;
        struct lwp *l;
        int error;
        int i;
        register32_t code, args[2 + SYS_MAXSYSARGS];
        register_t rval[2];
        register_t args64[SYS_MAXSYSARGS];

        l = curlwp;
        p = l->l_proc;

        code = frame->tf_rax & (SYS_NSYSENT - 1);
        callp = p->p_emul->e_sysent + code;

        SYSCALL_COUNT(syscall_counts, code);
        SYSCALL_TIME_SYS_ENTRY(l, syscall_times, code);

        params = (char *)frame->tf_rsp + sizeof(int);

        if (callp->sy_argsize) {
                error = copyin(params, args, callp->sy_argsize);
                if (__predict_false(error != 0))
                        goto bad;
        }

        if (__predict_false(p->p_trace_enabled || KDTRACE_ENTRY(callp->sy_entry))
            && !__predict_false(callp->sy_flags & SYCALL_INDIRECT)) {
                int narg = callp->sy_argsize >> 2;
                for (i = 0; i < narg; i++)
                        args64[i] = args[i];
                error = trace_enter(code, callp, args64);
                if (__predict_false(error != 0))
                        goto out;
        }

        rval[0] = 0;
        rval[1] = 0;
        error = sy_call(callp, l, args, rval);

out:
        if (__predict_false(p->p_trace_enabled || KDTRACE_ENTRY(callp->sy_return))
            && !__predict_false(callp->sy_flags & SYCALL_INDIRECT)) {
                int narg = callp->sy_argsize >> 2;
                for (i = 0; i < narg; i++)
                        args64[i] = args[i];
                trace_exit(code, callp, args64, rval, error);
        }

        if (__predict_true(error == 0)) {
                frame->tf_rax = rval[0];
                frame->tf_rdx = rval[1];
                frame->tf_rflags &= ~PSL_C;     /* carry bit */
        } else {
                switch (error) {
                case ERESTART:
                        /*
                         * The offset to adjust the PC by depends on whether we
                         * entered the kernel through the trap or call gate.
                         * We saved the instruction size in tf_err on entry.
                         */
                        frame->tf_rip -= frame->tf_err;
                        break;
                case EJUSTRETURN:
                        /* nothing to do */
                        break;
                default:
                bad:
                        frame->tf_rax = error;
                        frame->tf_rflags |= PSL_C;      /* carry bit */
                        break;
                }
        }

        SYSCALL_TIME_SYS_EXIT(l);
        userret(l);
}