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/* $NetBSD: freebsd_syscall.c,v 1.6 2019/04/06 17:42:28 kre 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: freebsd_syscall.c,v 1.6 2019/04/06 17:42:28 kre Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/signal.h>
#include <sys/syscall.h>
#include <sys/syscallvar.h>
#include <uvm/uvm_extern.h>
#include <machine/cpu.h>
#include <machine/psl.h>
#include <machine/userret.h>
#include <compat/sys/signal.h>
#include <compat/freebsd/freebsd_machdep.h>
#include <compat/freebsd/freebsd_syscall.h>
void freebsd_syscall(struct trapframe *);
void
freebsd_syscall_intern(struct proc *p)
{
p->p_md.md_syscall = freebsd_syscall;
}
/*
* syscall(frame):
* System call request from POSIX system call gate interface to kernel.
* Like trap(), argument is call by reference.
*/
void
freebsd_syscall(struct trapframe *frame)
{
char *params;
const struct sysent *callp;
struct lwp *l;
struct proc *p;
int error;
size_t argsize;
register_t code, args[8], rval[2];
l = curlwp;
p = l->l_proc;
LWP_CACHE_CREDS(l, p);
code = frame->tf_eax;
callp = p->p_emul->e_sysent;
params = (char *)frame->tf_esp + sizeof(int);
switch (code) {
case SYS_syscall:
/*
* Code is first argument, followed by actual args.
*/
error = ufetch_long((void *)params, (u_long *)&code);
if (error)
goto bad;
params += sizeof(int);
break;
case SYS___syscall:
/*
* Like syscall, but code is a quad, so as to maintain
* quad alignment for the rest of the arguments.
*/
error = ufetch_long((void *)(params +
_QUAD_LOWWORD * sizeof(int)),
(u_long *)&code);
if (error)
goto bad;
params += sizeof(quad_t);
break;
default:
break;
}
code &= (SYS_NSYSENT - 1);
callp += code;
argsize = callp->sy_argsize;
if (argsize) {
error = copyin(params, (void *)args, argsize);
if (error)
goto bad;
}
if (!__predict_false(p->p_trace_enabled || KDTRACE_ENTRY(callp->sy_entry))
|| (error = trace_enter(code, callp, args)) == 0) {
rval[0] = 0;
rval[1] = frame->tf_edx; /* need to keep edx for shared FreeBSD bins */
error = sy_call(callp, l, args, rval);
}
switch (error) {
case 0:
frame->tf_eax = rval[0];
frame->tf_edx = rval[1];
frame->tf_eflags &= ~PSL_C; /* carry bit */
break;
case ERESTART:
/*
* The offset to adjust the PC by depends on whether we entered
* the kernel through the trap or call gate. We pushed the
* size of the instruction into tf_err on entry.
*/
frame->tf_eip -= frame->tf_err;
break;
case EJUSTRETURN:
/* nothing to do */
break;
default:
bad:
frame->tf_eax = error;
frame->tf_eflags |= PSL_C; /* carry bit */
break;
}
if (__predict_false(p->p_trace_enabled || KDTRACE_ENTRY(callp->sy_return)))
trace_exit(code, callp, args, rval, error);
userret(l);
}
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