NetBSD-5.0.2/sys/arch/i386/i386/compat_16_machdep.c
/* $NetBSD: compat_16_machdep.c,v 1.17 2008/09/19 19:15:58 christos 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_16_machdep.c,v 1.17 2008/09/19 19:15:58 christos Exp $");
#include "opt_vm86.h"
#include "opt_compat_netbsd.h"
#include "opt_compat_ibcs2.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/signal.h>
#include <sys/signalvar.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
#ifdef VM86
#include <machine/mcontext.h>
#include <machine/vm86.h>
#endif
#include <uvm/uvm_extern.h>
#include <uvm/uvm_page.h>
#include <machine/pmap.h>
#include <machine/vmparam.h>
#if defined(COMPAT_16) || defined(COMPAT_IBCS2)
#include <compat/sys/signal.h>
#include <compat/sys/signalvar.h>
/*
* System call to cleanup state after a signal
* has been taken. Reset signal mask and
* stack state from context left by sendsig (above).
* Return to previous pc and psl as specified by
* context left by sendsig. Check carefully to
* make sure that the user has not modified the
* psl to gain improper privileges or to cause
* a machine fault.
*/
int compat_16_sys___sigreturn14(struct lwp *, const struct compat_16_sys___sigreturn14_args *, register_t *);
int
compat_16_sys___sigreturn14(struct lwp *l, const struct compat_16_sys___sigreturn14_args *uap, register_t *retval)
{
/* {
syscallarg(struct sigcontext *) sigcntxp;
} */
struct proc *p = l->l_proc;
struct sigcontext *scp, context;
struct trapframe *tf;
/*
* 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;
#ifdef VM86
if (context.sc_eflags & PSL_VM) {
void syscall_vm86(struct trapframe *);
tf->tf_vm86_gs = context.sc_gs;
tf->tf_vm86_fs = context.sc_fs;
tf->tf_vm86_es = context.sc_es;
tf->tf_vm86_ds = context.sc_ds;
set_vflags(l, context.sc_eflags);
p->p_md.md_syscall = syscall_vm86;
} else
#endif
{
/*
* 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, context.sc_eflags))
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;
/* Restore signal stack. */
mutex_enter(p->p_lock);
if (context.sc_onstack & SS_ONSTACK)
l->l_sigstk.ss_flags |= SS_ONSTACK;
else
l->l_sigstk.ss_flags &= ~SS_ONSTACK;
/* Restore signal mask. */
(void) sigprocmask1(l, SIG_SETMASK, &context.sc_mask, 0);
mutex_exit(p->p_lock);
return (EJUSTRETURN);
}
#endif
#ifdef COMPAT_16
/*
* Send an interrupt to process.
*
* Stack is set up to allow sigcode stored
* in u. to call routine, followed by kcall
* to sigreturn routine below. After sigreturn
* resets the signal mask, the stack, and the
* frame pointer, it returns to the user
* specified pc, psl.
*/
void
sendsig_sigcontext(const ksiginfo_t *ksi, const sigset_t *mask)
{
struct lwp *l = curlwp;
struct proc *p = l->l_proc;
struct pmap *pmap = vm_map_pmap(&p->p_vmspace->vm_map);
int sel = pmap->pm_hiexec > I386_MAX_EXE_ADDR ?
GUCODEBIG_SEL : GUCODE_SEL;
struct sigacts *ps = p->p_sigacts;
struct trapframe *tf = l->l_md.md_regs;
int onstack, error;
int sig = ksi->ksi_signo;
u_long code = KSI_TRAPCODE(ksi);
struct sigframe_sigcontext *fp = getframe(l, sig, &onstack), frame;
sig_t catcher = SIGACTION(p, sig).sa_handler;
fp--;
/* Build stack frame for signal trampoline. */
switch (ps->sa_sigdesc[sig].sd_vers) {
case 0: /* legacy on-stack sigtramp */
frame.sf_ra = (int)p->p_sigctx.ps_sigcode;
break;
case 1:
frame.sf_ra = (int)ps->sa_sigdesc[sig].sd_tramp;
break;
default:
/* Don't know what trampoline version; kill it. */
sigexit(l, SIGILL);
}
frame.sf_signum = sig;
frame.sf_code = code;
frame.sf_scp = &fp->sf_sc;
/* Save register context. */
#ifdef VM86
if (tf->tf_eflags & PSL_VM) {
frame.sf_sc.sc_gs = tf->tf_vm86_gs;
frame.sf_sc.sc_fs = tf->tf_vm86_fs;
frame.sf_sc.sc_es = tf->tf_vm86_es;
frame.sf_sc.sc_ds = tf->tf_vm86_ds;
frame.sf_sc.sc_eflags = get_vflags(l);
(*p->p_emul->e_syscall_intern)(p);
} else
#endif
{
frame.sf_sc.sc_gs = tf->tf_gs;
frame.sf_sc.sc_fs = tf->tf_fs;
frame.sf_sc.sc_es = tf->tf_es;
frame.sf_sc.sc_ds = tf->tf_ds;
frame.sf_sc.sc_eflags = tf->tf_eflags;
}
frame.sf_sc.sc_edi = tf->tf_edi;
frame.sf_sc.sc_esi = tf->tf_esi;
frame.sf_sc.sc_ebp = tf->tf_ebp;
frame.sf_sc.sc_ebx = tf->tf_ebx;
frame.sf_sc.sc_edx = tf->tf_edx;
frame.sf_sc.sc_ecx = tf->tf_ecx;
frame.sf_sc.sc_eax = tf->tf_eax;
frame.sf_sc.sc_eip = tf->tf_eip;
frame.sf_sc.sc_cs = tf->tf_cs;
frame.sf_sc.sc_esp = tf->tf_esp;
frame.sf_sc.sc_ss = tf->tf_ss;
frame.sf_sc.sc_trapno = tf->tf_trapno;
frame.sf_sc.sc_err = tf->tf_err;
/* Save signal stack. */
frame.sf_sc.sc_onstack = l->l_sigstk.ss_flags & SS_ONSTACK;
/* Save signal mask. */
frame.sf_sc.sc_mask = *mask;
#ifdef COMPAT_13
/*
* XXX We always have to save an old style signal mask because
* XXX we might be delivering a signal to a process which will
* XXX escape from the signal in a non-standard way and invoke
* XXX sigreturn() directly.
*/
native_sigset_to_sigset13(mask, &frame.sf_sc.__sc_mask13);
#endif
sendsig_reset(l, sig);
mutex_exit(p->p_lock);
error = copyout(&frame, fp, sizeof(frame));
mutex_enter(p->p_lock);
if (error != 0) {
/*
* Process has trashed its stack; give it an illegal
* instruction to halt it in its tracks.
*/
sigexit(l, SIGILL);
/* NOTREACHED */
}
buildcontext(l, sel, catcher, fp);
/* Remember that we're now on the signal stack. */
if (onstack)
l->l_sigstk.ss_flags |= SS_ONSTACK;
}
#endif
#if defined(COMPAT_16) && defined(VM86)
struct compat_16_vm86_kern {
struct sigcontext regs;
unsigned long ss_cpu_type;
};
struct compat_16_vm86_struct {
struct compat_16_vm86_kern substr;
unsigned long screen_bitmap; /* not used/supported (yet) */
unsigned long flags; /* not used/supported (yet) */
unsigned char int_byuser[32]; /* 256 bits each: pass control to user */
unsigned char int21_byuser[32]; /* otherwise, handle directly */
};
int
compat_16_x86_vm86(struct lwp *l, char *args, register_t *retval)
{
struct trapframe *tf = l->l_md.md_regs;
struct pcb *pcb = &l->l_addr->u_pcb;
struct compat_16_vm86_kern vm86s;
struct proc *p = l->l_proc;
int error;
error = copyin(args, &vm86s, sizeof(vm86s));
if (error)
return (error);
pcb->vm86_userp = (void *)(args +
(offsetof(struct compat_16_vm86_struct, screen_bitmap)
- offsetof(struct vm86_struct, screen_bitmap)));
printf("offsetting by %lu\n", (unsigned long)
(offsetof(struct compat_16_vm86_struct, screen_bitmap)
- offsetof(struct vm86_struct, screen_bitmap)));
/*
* Keep mask of flags we simulate to simulate a particular type of
* processor.
*/
switch (vm86s.ss_cpu_type) {
case VCPU_086:
case VCPU_186:
case VCPU_286:
pcb->vm86_flagmask = PSL_ID|PSL_AC|PSL_NT|PSL_IOPL;
break;
case VCPU_386:
pcb->vm86_flagmask = PSL_ID|PSL_AC;
break;
case VCPU_486:
pcb->vm86_flagmask = PSL_ID;
break;
case VCPU_586:
pcb->vm86_flagmask = 0;
break;
default:
return (EINVAL);
}
#define DOVREG(reg) tf->tf_vm86_##reg = (u_short) vm86s.regs.sc_##reg
#define DOREG(reg) tf->tf_##reg = (u_short) vm86s.regs.sc_##reg
DOVREG(ds);
DOVREG(es);
DOVREG(fs);
DOVREG(gs);
DOREG(edi);
DOREG(esi);
DOREG(ebp);
DOREG(eax);
DOREG(ebx);
DOREG(ecx);
DOREG(edx);
DOREG(eip);
DOREG(cs);
DOREG(esp);
DOREG(ss);
#undef DOVREG
#undef DOREG
mutex_enter(p->p_lock);
/* Going into vm86 mode jumps off the signal stack. */
l->l_sigstk.ss_flags &= ~SS_ONSTACK;
mutex_exit(p->p_lock);
set_vflags(l, vm86s.regs.sc_eflags | PSL_VM);
return (EJUSTRETURN);
}
#endif