/* $NetBSD: compat_13_machdep.c,v 1.27 2017/09/17 09:41:35 maxv Exp $ */
/*-
* Copyright (c) 1996, 1997, 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: compat_13_machdep.c,v 1.27 2017/09/17 09:41:35 maxv Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
#include <compat/sys/signal.h>
#include <compat/sys/signalvar.h>
int
compat_13_sys_sigreturn(struct lwp *l, const struct compat_13_sys_sigreturn_args *uap, register_t *retval)
{
/* {
syscallarg(struct sigcontext13 *) sigcntxp;
} */
struct proc *p = l->l_proc;
struct sigcontext13 *scp, context;
struct trapframe *tf;
sigset_t mask;
/*
* The trampoline code hands us the context.
* It is unsafe to keep track of it ourselves, in the event that a
* program jumps out of a signal handler.
*/
scp = SCARG(uap, sigcntxp);
if (copyin((void *)scp, &context, sizeof(*scp)) != 0)
return (EFAULT);
/* Restore register context. */
tf = l->l_md.md_regs;
/*
* Check for security violations. If we're returning to
* protected mode, the CPU will validate the segment registers
* automatically and generate a trap on violations. We handle
* the trap, rather than doing all of the checking here.
*/
if (((context.sc_eflags ^ tf->tf_eflags) & PSL_USERSTATIC) != 0 ||
!USERMODE(context.sc_cs))
return (EINVAL);
tf->tf_gs = context.sc_gs;
tf->tf_fs = context.sc_fs;
tf->tf_es = context.sc_es;
tf->tf_ds = context.sc_ds;
tf->tf_eflags &= ~PSL_USER;
tf->tf_eflags |= context.sc_eflags & PSL_USER;
tf->tf_edi = context.sc_edi;
tf->tf_esi = context.sc_esi;
tf->tf_ebp = context.sc_ebp;
tf->tf_ebx = context.sc_ebx;
tf->tf_edx = context.sc_edx;
tf->tf_ecx = context.sc_ecx;
tf->tf_eax = context.sc_eax;
tf->tf_eip = context.sc_eip;
tf->tf_cs = context.sc_cs;
tf->tf_esp = context.sc_esp;
tf->tf_ss = context.sc_ss;
mutex_enter(p->p_lock);
/* Restore signal stack. */
if (context.sc_onstack & SS_ONSTACK)
l->l_sigstk.ss_flags |= SS_ONSTACK;
else
l->l_sigstk.ss_flags &= ~SS_ONSTACK;
/* Restore signal mask. */
native_sigset13_to_sigset(&context.sc_mask, &mask);
(void) sigprocmask1(l, SIG_SETMASK, &mask, 0);
mutex_exit(p->p_lock);
return (EJUSTRETURN);
}