72f8d0d43a
problem is worked around by using an interrupt gate for the page fault handler. This code was originally made for NetBSD/pc98 by Naofumi Honda <honda@kururu.math.sci.hokudai.ac.jp> and has already been in PC98 tree. Because of this bug, trap_fatal cannot show correct page fault address if %cr2 is obtained in this function. Therefore, trap_fatal uses the value from trap() function. - The trap handler always enables interruption when buggy application or kernel code has disabled interrupts and then trapped. This code was prepared by Bruce Evans <bde@FreeBSD.org>. Submitted by: Bruce Evans <bde@FreeBSD.org> Naofumi Honda <honda@kururu.math.sci.hokudai.ac.jp>
1142 lines
28 KiB
C
1142 lines
28 KiB
C
/*-
|
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* Copyright (C) 1994, David Greenman
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* Copyright (c) 1990, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* the University of Utah, and William Jolitz.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
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* $Id: trap.c,v 1.128 1998/08/23 10:16:26 bde Exp $
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|
*/
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|
|
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/*
|
|
* 386 Trap and System call handling
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|
*/
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|
|
|
#include "opt_cpu.h"
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|
#include "opt_ddb.h"
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|
#include "opt_ktrace.h"
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|
#include "opt_trap.h"
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|
#include "opt_vm86.h"
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|
|
|
#include <sys/param.h>
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|
#include <sys/systm.h>
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|
#include <sys/proc.h>
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|
#include <sys/pioctl.h>
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|
#include <sys/kernel.h>
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|
#include <sys/resourcevar.h>
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|
#include <sys/signalvar.h>
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|
#include <sys/syscall.h>
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|
#include <sys/sysent.h>
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|
#include <sys/uio.h>
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|
#include <sys/vmmeter.h>
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|
#ifdef KTRACE
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|
#include <sys/ktrace.h>
|
|
#endif
|
|
|
|
#include <vm/vm.h>
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|
#include <vm/vm_param.h>
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|
#include <vm/vm_prot.h>
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|
#include <sys/lock.h>
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|
#include <vm/pmap.h>
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|
#include <vm/vm_kern.h>
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|
#include <vm/vm_map.h>
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|
#include <vm/vm_page.h>
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|
#include <vm/vm_extern.h>
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|
|
|
#include <machine/cpu.h>
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|
#include <machine/ipl.h>
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|
#include <machine/md_var.h>
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|
#include <machine/pcb.h>
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|
#ifdef SMP
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|
#include <machine/smp.h>
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|
#endif
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|
#include <machine/tss.h>
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|
|
|
#include <i386/isa/intr_machdep.h>
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|
|
|
#ifdef POWERFAIL_NMI
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|
#include <sys/syslog.h>
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|
#include <machine/clock.h>
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|
#endif
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|
|
|
#ifdef VM86
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|
#include <machine/vm86.h>
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|
#endif
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|
|
|
#include "isa.h"
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|
#include "npx.h"
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|
|
|
extern struct i386tss common_tss;
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|
|
|
int (*pmath_emulate) __P((struct trapframe *));
|
|
|
|
extern void trap __P((struct trapframe frame));
|
|
extern int trapwrite __P((unsigned addr));
|
|
extern void syscall __P((struct trapframe frame));
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|
|
|
static int trap_pfault __P((struct trapframe *, int, vm_offset_t));
|
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static void trap_fatal __P((struct trapframe *, vm_offset_t));
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void dblfault_handler __P((void));
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|
|
|
extern inthand_t IDTVEC(syscall);
|
|
|
|
#define MAX_TRAP_MSG 28
|
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static char *trap_msg[] = {
|
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"", /* 0 unused */
|
|
"privileged instruction fault", /* 1 T_PRIVINFLT */
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|
"", /* 2 unused */
|
|
"breakpoint instruction fault", /* 3 T_BPTFLT */
|
|
"", /* 4 unused */
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|
"", /* 5 unused */
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|
"arithmetic trap", /* 6 T_ARITHTRAP */
|
|
"system forced exception", /* 7 T_ASTFLT */
|
|
"", /* 8 unused */
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|
"general protection fault", /* 9 T_PROTFLT */
|
|
"trace trap", /* 10 T_TRCTRAP */
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|
"", /* 11 unused */
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|
"page fault", /* 12 T_PAGEFLT */
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|
"", /* 13 unused */
|
|
"alignment fault", /* 14 T_ALIGNFLT */
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|
"", /* 15 unused */
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|
"", /* 16 unused */
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|
"", /* 17 unused */
|
|
"integer divide fault", /* 18 T_DIVIDE */
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"non-maskable interrupt trap", /* 19 T_NMI */
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|
"overflow trap", /* 20 T_OFLOW */
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|
"FPU bounds check fault", /* 21 T_BOUND */
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|
"FPU device not available", /* 22 T_DNA */
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"double fault", /* 23 T_DOUBLEFLT */
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"FPU operand fetch fault", /* 24 T_FPOPFLT */
|
|
"invalid TSS fault", /* 25 T_TSSFLT */
|
|
"segment not present fault", /* 26 T_SEGNPFLT */
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|
"stack fault", /* 27 T_STKFLT */
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|
"machine check trap", /* 28 T_MCHK */
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|
};
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|
|
|
static __inline void userret __P((struct proc *p, struct trapframe *frame,
|
|
u_quad_t oticks));
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|
|
|
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
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|
extern struct gate_descriptor *t_idt;
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|
extern int has_f00f_bug;
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|
#endif
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|
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|
static __inline void
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userret(p, frame, oticks)
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struct proc *p;
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struct trapframe *frame;
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u_quad_t oticks;
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{
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|
int sig, s;
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|
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|
while ((sig = CURSIG(p)) != 0)
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|
postsig(sig);
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|
|
|
#if 0
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|
if (!want_resched &&
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(p->p_priority <= p->p_usrpri) &&
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|
(p->p_rtprio.type == RTP_PRIO_NORMAL)) {
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|
int newpriority;
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|
p->p_estcpu += 1;
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newpriority = PUSER + p->p_estcpu / 4 + 2 * p->p_nice;
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|
newpriority = min(newpriority, MAXPRI);
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|
p->p_usrpri = newpriority;
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|
}
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|
#endif
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|
p->p_priority = p->p_usrpri;
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|
if (want_resched) {
|
|
/*
|
|
* Since we are curproc, clock will normally just change
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|
* our priority without moving us from one queue to another
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|
* (since the running process is not on a queue.)
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|
* If that happened after we setrunqueue ourselves but before we
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|
* mi_switch()'ed, we might not be on the queue indicated by
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|
* our priority.
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|
*/
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|
s = splhigh();
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|
setrunqueue(p);
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|
p->p_stats->p_ru.ru_nivcsw++;
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|
mi_switch();
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|
splx(s);
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|
while ((sig = CURSIG(p)) != 0)
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|
postsig(sig);
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|
}
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|
/*
|
|
* Charge system time if profiling.
|
|
*/
|
|
if (p->p_flag & P_PROFIL)
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|
addupc_task(p, frame->tf_eip,
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(u_int)(p->p_sticks - oticks) * psratio);
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|
curpriority = p->p_priority;
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}
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|
|
|
/*
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|
* Exception, fault, and trap interface to the FreeBSD kernel.
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* This common code is called from assembly language IDT gate entry
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|
* routines that prepare a suitable stack frame, and restore this
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* frame after the exception has been processed.
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|
*/
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|
void
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|
trap(frame)
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|
struct trapframe frame;
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|
{
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|
struct proc *p = curproc;
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|
u_quad_t sticks = 0;
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int i = 0, ucode = 0, type, code;
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vm_offset_t eva;
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|
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if (!(frame.tf_eflags & PSL_I)) {
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/*
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* Buggy application or kernel code has disabled interrupts
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* and then trapped. Enabling interrupts now is wrong, but
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* it is better than running with interrupts disabled until
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* they are accidentally enabled later.
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*/
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type = frame.tf_trapno;
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if (ISPL(frame.tf_cs) == SEL_UPL || (frame.tf_eflags & PSL_VM))
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printf(
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"pid %ld (%s): trap %d with interrupts disabled\n",
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(long)curproc->p_pid, curproc->p_comm, type);
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else if (type != T_BPTFLT && type != T_TRCTRAP)
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/*
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* XXX not quite right, since this may be for a
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* multiple fault in user mode.
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|
*/
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printf("kernel trap %d with interrupts disabled\n",
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type);
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enable_intr();
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}
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|
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|
eva = 0;
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|
if (frame.tf_trapno == T_PAGEFLT) {
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|
/*
|
|
* For some Cyrix CPUs, %cr2 is clobbered by interrupts.
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|
* This problem is worked around by using an interrupt
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|
* gate for the pagefault handler. We are finally ready
|
|
* to read %cr2 and then must reenable interrupts.
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|
*
|
|
* XXX this should be in the switch statement, but the
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|
* NO_FOOF_HACK and VM86 goto and ifdefs obfuscate the
|
|
* flow of control too much for this to be obviously
|
|
* correct.
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*/
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eva = rcr2();
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enable_intr();
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|
}
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|
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|
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
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restart:
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|
#endif
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type = frame.tf_trapno;
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code = frame.tf_err;
|
|
|
|
#ifdef VM86
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|
if (in_vm86call) {
|
|
if (frame.tf_eflags & PSL_VM &&
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(type == T_PROTFLT || type == T_STKFLT)) {
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i = vm86_emulate((struct vm86frame *)&frame);
|
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if (i != 0)
|
|
/*
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|
* returns to original process
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|
*/
|
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vm86_trap((struct vm86frame *)&frame);
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|
return;
|
|
}
|
|
switch (type) {
|
|
/*
|
|
* these traps want either a process context, or
|
|
* assume a normal userspace trap.
|
|
*/
|
|
case T_PROTFLT:
|
|
case T_SEGNPFLT:
|
|
trap_fatal(&frame, eva);
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|
return;
|
|
case T_TRCTRAP:
|
|
type = T_BPTFLT; /* kernel breakpoint */
|
|
/* FALL THROUGH */
|
|
}
|
|
goto kernel_trap; /* normal kernel trap handling */
|
|
}
|
|
#endif
|
|
|
|
if ((ISPL(frame.tf_cs) == SEL_UPL) || (frame.tf_eflags & PSL_VM)) {
|
|
/* user trap */
|
|
|
|
sticks = p->p_sticks;
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p->p_md.md_regs = &frame;
|
|
|
|
switch (type) {
|
|
case T_PRIVINFLT: /* privileged instruction fault */
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|
ucode = type;
|
|
i = SIGILL;
|
|
break;
|
|
|
|
case T_BPTFLT: /* bpt instruction fault */
|
|
case T_TRCTRAP: /* trace trap */
|
|
frame.tf_eflags &= ~PSL_T;
|
|
i = SIGTRAP;
|
|
break;
|
|
|
|
case T_ARITHTRAP: /* arithmetic trap */
|
|
ucode = code;
|
|
i = SIGFPE;
|
|
break;
|
|
|
|
case T_ASTFLT: /* Allow process switch */
|
|
astoff();
|
|
cnt.v_soft++;
|
|
if (p->p_flag & P_OWEUPC) {
|
|
p->p_flag &= ~P_OWEUPC;
|
|
addupc_task(p, p->p_stats->p_prof.pr_addr,
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p->p_stats->p_prof.pr_ticks);
|
|
}
|
|
goto out;
|
|
|
|
/*
|
|
* The following two traps can happen in
|
|
* vm86 mode, and, if so, we want to handle
|
|
* them specially.
|
|
*/
|
|
case T_PROTFLT: /* general protection fault */
|
|
case T_STKFLT: /* stack fault */
|
|
#ifdef VM86
|
|
if (frame.tf_eflags & PSL_VM) {
|
|
i = vm86_emulate((struct vm86frame *)&frame);
|
|
if (i == 0)
|
|
goto out;
|
|
break;
|
|
}
|
|
#endif /* VM86 */
|
|
/* FALL THROUGH */
|
|
|
|
case T_SEGNPFLT: /* segment not present fault */
|
|
case T_TSSFLT: /* invalid TSS fault */
|
|
case T_DOUBLEFLT: /* double fault */
|
|
default:
|
|
ucode = code + BUS_SEGM_FAULT ;
|
|
i = SIGBUS;
|
|
break;
|
|
|
|
case T_PAGEFLT: /* page fault */
|
|
i = trap_pfault(&frame, TRUE, eva);
|
|
if (i == -1)
|
|
return;
|
|
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
|
|
if (i == -2)
|
|
goto restart;
|
|
#endif
|
|
if (i == 0)
|
|
goto out;
|
|
|
|
ucode = T_PAGEFLT;
|
|
break;
|
|
|
|
case T_DIVIDE: /* integer divide fault */
|
|
ucode = FPE_INTDIV_TRAP;
|
|
i = SIGFPE;
|
|
break;
|
|
|
|
#if NISA > 0
|
|
case T_NMI:
|
|
#ifdef POWERFAIL_NMI
|
|
goto handle_powerfail;
|
|
#else /* !POWERFAIL_NMI */
|
|
#ifdef DDB
|
|
/* NMI can be hooked up to a pushbutton for debugging */
|
|
printf ("NMI ... going to debugger\n");
|
|
if (kdb_trap (type, 0, &frame))
|
|
return;
|
|
#endif /* DDB */
|
|
/* machine/parity/power fail/"kitchen sink" faults */
|
|
if (isa_nmi(code) == 0) return;
|
|
panic("NMI indicates hardware failure");
|
|
#endif /* POWERFAIL_NMI */
|
|
#endif /* NISA > 0 */
|
|
|
|
case T_OFLOW: /* integer overflow fault */
|
|
ucode = FPE_INTOVF_TRAP;
|
|
i = SIGFPE;
|
|
break;
|
|
|
|
case T_BOUND: /* bounds check fault */
|
|
ucode = FPE_SUBRNG_TRAP;
|
|
i = SIGFPE;
|
|
break;
|
|
|
|
case T_DNA:
|
|
#if NNPX > 0
|
|
/* if a transparent fault (due to context switch "late") */
|
|
if (npxdna())
|
|
return;
|
|
#endif
|
|
if (!pmath_emulate) {
|
|
i = SIGFPE;
|
|
ucode = FPE_FPU_NP_TRAP;
|
|
break;
|
|
}
|
|
i = (*pmath_emulate)(&frame);
|
|
if (i == 0) {
|
|
if (!(frame.tf_eflags & PSL_T))
|
|
return;
|
|
frame.tf_eflags &= ~PSL_T;
|
|
i = SIGTRAP;
|
|
}
|
|
/* else ucode = emulator_only_knows() XXX */
|
|
break;
|
|
|
|
case T_FPOPFLT: /* FPU operand fetch fault */
|
|
ucode = T_FPOPFLT;
|
|
i = SIGILL;
|
|
break;
|
|
}
|
|
} else {
|
|
#ifdef VM86
|
|
kernel_trap:
|
|
#endif
|
|
/* kernel trap */
|
|
|
|
switch (type) {
|
|
case T_PAGEFLT: /* page fault */
|
|
(void) trap_pfault(&frame, FALSE, eva);
|
|
return;
|
|
|
|
case T_DNA:
|
|
#if NNPX > 0
|
|
/*
|
|
* The kernel is apparently using npx for copying.
|
|
* XXX this should be fatal unless the kernel has
|
|
* registered such use.
|
|
*/
|
|
if (npxdna())
|
|
return;
|
|
#endif
|
|
break;
|
|
|
|
case T_PROTFLT: /* general protection fault */
|
|
case T_SEGNPFLT: /* segment not present fault */
|
|
/*
|
|
* Invalid segment selectors and out of bounds
|
|
* %eip's and %esp's can be set up in user mode.
|
|
* This causes a fault in kernel mode when the
|
|
* kernel tries to return to user mode. We want
|
|
* to get this fault so that we can fix the
|
|
* problem here and not have to check all the
|
|
* selectors and pointers when the user changes
|
|
* them.
|
|
*/
|
|
#define MAYBE_DORETI_FAULT(where, whereto) \
|
|
do { \
|
|
if (frame.tf_eip == (int)where) { \
|
|
frame.tf_eip = (int)whereto; \
|
|
return; \
|
|
} \
|
|
} while (0)
|
|
|
|
if (intr_nesting_level == 0) {
|
|
/*
|
|
* Invalid %fs's and %gs's can be created using
|
|
* procfs or PT_SETREGS or by invalidating the
|
|
* underlying LDT entry. This causes a fault
|
|
* in kernel mode when the kernel attempts to
|
|
* switch contexts. Lose the bad context
|
|
* (XXX) so that we can continue, and generate
|
|
* a signal.
|
|
*/
|
|
if (frame.tf_eip == (int)cpu_switch_load_fs) {
|
|
curpcb->pcb_fs = 0;
|
|
psignal(p, SIGBUS);
|
|
return;
|
|
}
|
|
if (frame.tf_eip == (int)cpu_switch_load_gs) {
|
|
curpcb->pcb_gs = 0;
|
|
psignal(p, SIGBUS);
|
|
return;
|
|
}
|
|
MAYBE_DORETI_FAULT(doreti_iret,
|
|
doreti_iret_fault);
|
|
MAYBE_DORETI_FAULT(doreti_popl_ds,
|
|
doreti_popl_ds_fault);
|
|
MAYBE_DORETI_FAULT(doreti_popl_es,
|
|
doreti_popl_es_fault);
|
|
if (curpcb && curpcb->pcb_onfault) {
|
|
frame.tf_eip = (int)curpcb->pcb_onfault;
|
|
return;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case T_TSSFLT:
|
|
/*
|
|
* PSL_NT can be set in user mode and isn't cleared
|
|
* automatically when the kernel is entered. This
|
|
* causes a TSS fault when the kernel attempts to
|
|
* `iret' because the TSS link is uninitialized. We
|
|
* want to get this fault so that we can fix the
|
|
* problem here and not every time the kernel is
|
|
* entered.
|
|
*/
|
|
if (frame.tf_eflags & PSL_NT) {
|
|
frame.tf_eflags &= ~PSL_NT;
|
|
return;
|
|
}
|
|
break;
|
|
|
|
case T_TRCTRAP: /* trace trap */
|
|
if (frame.tf_eip == (int)IDTVEC(syscall)) {
|
|
/*
|
|
* We've just entered system mode via the
|
|
* syscall lcall. Continue single stepping
|
|
* silently until the syscall handler has
|
|
* saved the flags.
|
|
*/
|
|
return;
|
|
}
|
|
if (frame.tf_eip == (int)IDTVEC(syscall) + 1) {
|
|
/*
|
|
* The syscall handler has now saved the
|
|
* flags. Stop single stepping it.
|
|
*/
|
|
frame.tf_eflags &= ~PSL_T;
|
|
return;
|
|
}
|
|
/*
|
|
* Fall through.
|
|
*/
|
|
case T_BPTFLT:
|
|
/*
|
|
* If DDB is enabled, let it handle the debugger trap.
|
|
* Otherwise, debugger traps "can't happen".
|
|
*/
|
|
#ifdef DDB
|
|
if (kdb_trap (type, 0, &frame))
|
|
return;
|
|
#endif
|
|
break;
|
|
|
|
#if NISA > 0
|
|
case T_NMI:
|
|
#ifdef POWERFAIL_NMI
|
|
#ifndef TIMER_FREQ
|
|
# define TIMER_FREQ 1193182
|
|
#endif
|
|
handle_powerfail:
|
|
{
|
|
static unsigned lastalert = 0;
|
|
|
|
if(time_second - lastalert > 10)
|
|
{
|
|
log(LOG_WARNING, "NMI: power fail\n");
|
|
sysbeep(TIMER_FREQ/880, hz);
|
|
lastalert = time_second;
|
|
}
|
|
return;
|
|
}
|
|
#else /* !POWERFAIL_NMI */
|
|
#ifdef DDB
|
|
/* NMI can be hooked up to a pushbutton for debugging */
|
|
printf ("NMI ... going to debugger\n");
|
|
if (kdb_trap (type, 0, &frame))
|
|
return;
|
|
#endif /* DDB */
|
|
/* machine/parity/power fail/"kitchen sink" faults */
|
|
if (isa_nmi(code) == 0) return;
|
|
/* FALL THROUGH */
|
|
#endif /* POWERFAIL_NMI */
|
|
#endif /* NISA > 0 */
|
|
}
|
|
|
|
trap_fatal(&frame, eva);
|
|
return;
|
|
}
|
|
|
|
/* Translate fault for emulators (e.g. Linux) */
|
|
if (*p->p_sysent->sv_transtrap)
|
|
i = (*p->p_sysent->sv_transtrap)(i, type);
|
|
|
|
trapsignal(p, i, ucode);
|
|
|
|
#ifdef DEBUG
|
|
if (type <= MAX_TRAP_MSG) {
|
|
uprintf("fatal process exception: %s",
|
|
trap_msg[type]);
|
|
if ((type == T_PAGEFLT) || (type == T_PROTFLT))
|
|
uprintf(", fault VA = 0x%lx", eva);
|
|
uprintf("\n");
|
|
}
|
|
#endif
|
|
|
|
out:
|
|
userret(p, &frame, sticks);
|
|
}
|
|
|
|
#ifdef notyet
|
|
/*
|
|
* This version doesn't allow a page fault to user space while
|
|
* in the kernel. The rest of the kernel needs to be made "safe"
|
|
* before this can be used. I think the only things remaining
|
|
* to be made safe are the iBCS2 code and the process tracing/
|
|
* debugging code.
|
|
*/
|
|
static int
|
|
trap_pfault(frame, usermode, eva)
|
|
struct trapframe *frame;
|
|
int usermode;
|
|
vm_offset_t eva;
|
|
{
|
|
vm_offset_t va;
|
|
struct vmspace *vm = NULL;
|
|
vm_map_t map = 0;
|
|
int rv = 0;
|
|
vm_prot_t ftype;
|
|
struct proc *p = curproc;
|
|
|
|
if (frame->tf_err & PGEX_W)
|
|
ftype = VM_PROT_READ | VM_PROT_WRITE;
|
|
else
|
|
ftype = VM_PROT_READ;
|
|
|
|
va = trunc_page(eva);
|
|
if (va < VM_MIN_KERNEL_ADDRESS) {
|
|
vm_offset_t v;
|
|
vm_page_t mpte;
|
|
|
|
if (p == NULL ||
|
|
(!usermode && va < VM_MAXUSER_ADDRESS &&
|
|
(intr_nesting_level != 0 || curpcb == NULL ||
|
|
curpcb->pcb_onfault == NULL))) {
|
|
trap_fatal(frame, eva);
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* This is a fault on non-kernel virtual memory.
|
|
* vm is initialized above to NULL. If curproc is NULL
|
|
* or curproc->p_vmspace is NULL the fault is fatal.
|
|
*/
|
|
vm = p->p_vmspace;
|
|
if (vm == NULL)
|
|
goto nogo;
|
|
|
|
map = &vm->vm_map;
|
|
|
|
/*
|
|
* Keep swapout from messing with us during this
|
|
* critical time.
|
|
*/
|
|
++p->p_lock;
|
|
|
|
/*
|
|
* Grow the stack if necessary
|
|
*/
|
|
if ((caddr_t)va > vm->vm_maxsaddr
|
|
&& (caddr_t)va < (caddr_t)USRSTACK) {
|
|
if (!grow(p, va)) {
|
|
rv = KERN_FAILURE;
|
|
--p->p_lock;
|
|
goto nogo;
|
|
}
|
|
}
|
|
|
|
/* Fault in the user page: */
|
|
rv = vm_fault(map, va, ftype,
|
|
(ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY : 0);
|
|
|
|
--p->p_lock;
|
|
} else {
|
|
/*
|
|
* Don't allow user-mode faults in kernel address space.
|
|
*/
|
|
if (usermode)
|
|
goto nogo;
|
|
|
|
/*
|
|
* Since we know that kernel virtual address addresses
|
|
* always have pte pages mapped, we just have to fault
|
|
* the page.
|
|
*/
|
|
rv = vm_fault(kernel_map, va, ftype, FALSE);
|
|
}
|
|
|
|
if (rv == KERN_SUCCESS)
|
|
return (0);
|
|
nogo:
|
|
if (!usermode) {
|
|
if (intr_nesting_level == 0 && curpcb && curpcb->pcb_onfault) {
|
|
frame->tf_eip = (int)curpcb->pcb_onfault;
|
|
return (0);
|
|
}
|
|
trap_fatal(frame, eva);
|
|
return (-1);
|
|
}
|
|
|
|
/* kludge to pass faulting virtual address to sendsig */
|
|
frame->tf_err = eva;
|
|
|
|
return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
|
|
}
|
|
#endif
|
|
|
|
int
|
|
trap_pfault(frame, usermode, eva)
|
|
struct trapframe *frame;
|
|
int usermode;
|
|
vm_offset_t eva;
|
|
{
|
|
vm_offset_t va;
|
|
struct vmspace *vm = NULL;
|
|
vm_map_t map = 0;
|
|
int rv = 0;
|
|
vm_prot_t ftype;
|
|
struct proc *p = curproc;
|
|
|
|
va = trunc_page(eva);
|
|
if (va >= KERNBASE) {
|
|
/*
|
|
* Don't allow user-mode faults in kernel address space.
|
|
* An exception: if the faulting address is the invalid
|
|
* instruction entry in the IDT, then the Intel Pentium
|
|
* F00F bug workaround was triggered, and we need to
|
|
* treat it is as an illegal instruction, and not a page
|
|
* fault.
|
|
*/
|
|
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
|
|
if ((eva == (unsigned int)&t_idt[6]) && has_f00f_bug) {
|
|
frame->tf_trapno = T_PRIVINFLT;
|
|
return -2;
|
|
}
|
|
#endif
|
|
if (usermode)
|
|
goto nogo;
|
|
|
|
map = kernel_map;
|
|
} else {
|
|
/*
|
|
* This is a fault on non-kernel virtual memory.
|
|
* vm is initialized above to NULL. If curproc is NULL
|
|
* or curproc->p_vmspace is NULL the fault is fatal.
|
|
*/
|
|
if (p != NULL)
|
|
vm = p->p_vmspace;
|
|
|
|
if (vm == NULL)
|
|
goto nogo;
|
|
|
|
map = &vm->vm_map;
|
|
}
|
|
|
|
if (frame->tf_err & PGEX_W)
|
|
ftype = VM_PROT_READ | VM_PROT_WRITE;
|
|
else
|
|
ftype = VM_PROT_READ;
|
|
|
|
if (map != kernel_map) {
|
|
/*
|
|
* Keep swapout from messing with us during this
|
|
* critical time.
|
|
*/
|
|
++p->p_lock;
|
|
|
|
/*
|
|
* Grow the stack if necessary
|
|
*/
|
|
if ((caddr_t)va > vm->vm_maxsaddr
|
|
&& (caddr_t)va < (caddr_t)USRSTACK) {
|
|
if (!grow(p, va)) {
|
|
rv = KERN_FAILURE;
|
|
--p->p_lock;
|
|
goto nogo;
|
|
}
|
|
}
|
|
|
|
/* Fault in the user page: */
|
|
rv = vm_fault(map, va, ftype,
|
|
(ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY : 0);
|
|
|
|
--p->p_lock;
|
|
} else {
|
|
/*
|
|
* Don't have to worry about process locking or stacks in the kernel.
|
|
*/
|
|
rv = vm_fault(map, va, ftype, FALSE);
|
|
}
|
|
|
|
if (rv == KERN_SUCCESS)
|
|
return (0);
|
|
nogo:
|
|
if (!usermode) {
|
|
if (intr_nesting_level == 0 && curpcb && curpcb->pcb_onfault) {
|
|
frame->tf_eip = (int)curpcb->pcb_onfault;
|
|
return (0);
|
|
}
|
|
trap_fatal(frame, eva);
|
|
return (-1);
|
|
}
|
|
|
|
/* kludge to pass faulting virtual address to sendsig */
|
|
frame->tf_err = eva;
|
|
|
|
return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
|
|
}
|
|
|
|
static void
|
|
trap_fatal(frame, eva)
|
|
struct trapframe *frame;
|
|
vm_offset_t eva;
|
|
{
|
|
int code, type, ss, esp;
|
|
struct soft_segment_descriptor softseg;
|
|
|
|
code = frame->tf_err;
|
|
type = frame->tf_trapno;
|
|
sdtossd(&gdt[IDXSEL(frame->tf_cs & 0xffff)].sd, &softseg);
|
|
|
|
if (type <= MAX_TRAP_MSG)
|
|
printf("\n\nFatal trap %d: %s while in %s mode\n",
|
|
type, trap_msg[type],
|
|
frame->tf_eflags & PSL_VM ? "vm86" :
|
|
ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel");
|
|
#ifdef SMP
|
|
/* three seperate prints in case of a trap on an unmapped page */
|
|
printf("mp_lock = %08x; ", mp_lock);
|
|
printf("cpuid = %d; ", cpuid);
|
|
printf("lapic.id = %08x\n", lapic.id);
|
|
#endif
|
|
if (type == T_PAGEFLT) {
|
|
printf("fault virtual address = 0x%x\n", eva);
|
|
printf("fault code = %s %s, %s\n",
|
|
code & PGEX_U ? "user" : "supervisor",
|
|
code & PGEX_W ? "write" : "read",
|
|
code & PGEX_P ? "protection violation" : "page not present");
|
|
}
|
|
printf("instruction pointer = 0x%x:0x%x\n",
|
|
frame->tf_cs & 0xffff, frame->tf_eip);
|
|
if ((ISPL(frame->tf_cs) == SEL_UPL) || (frame->tf_eflags & PSL_VM)) {
|
|
ss = frame->tf_ss & 0xffff;
|
|
esp = frame->tf_esp;
|
|
} else {
|
|
ss = GSEL(GDATA_SEL, SEL_KPL);
|
|
esp = (int)&frame->tf_esp;
|
|
}
|
|
printf("stack pointer = 0x%x:0x%x\n", ss, esp);
|
|
printf("frame pointer = 0x%x:0x%x\n", ss, frame->tf_ebp);
|
|
printf("code segment = base 0x%x, limit 0x%x, type 0x%x\n",
|
|
softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type);
|
|
printf(" = DPL %d, pres %d, def32 %d, gran %d\n",
|
|
softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_def32,
|
|
softseg.ssd_gran);
|
|
printf("processor eflags = ");
|
|
if (frame->tf_eflags & PSL_T)
|
|
printf("trace trap, ");
|
|
if (frame->tf_eflags & PSL_I)
|
|
printf("interrupt enabled, ");
|
|
if (frame->tf_eflags & PSL_NT)
|
|
printf("nested task, ");
|
|
if (frame->tf_eflags & PSL_RF)
|
|
printf("resume, ");
|
|
if (frame->tf_eflags & PSL_VM)
|
|
printf("vm86, ");
|
|
printf("IOPL = %d\n", (frame->tf_eflags & PSL_IOPL) >> 12);
|
|
printf("current process = ");
|
|
if (curproc) {
|
|
printf("%lu (%s)\n",
|
|
(u_long)curproc->p_pid, curproc->p_comm ?
|
|
curproc->p_comm : "");
|
|
} else {
|
|
printf("Idle\n");
|
|
}
|
|
printf("interrupt mask = ");
|
|
if ((cpl & net_imask) == net_imask)
|
|
printf("net ");
|
|
if ((cpl & tty_imask) == tty_imask)
|
|
printf("tty ");
|
|
if ((cpl & bio_imask) == bio_imask)
|
|
printf("bio ");
|
|
if ((cpl & cam_imask) == cam_imask)
|
|
printf("cam ");
|
|
if (cpl == 0)
|
|
printf("none");
|
|
#ifdef SMP
|
|
/**
|
|
* XXX FIXME:
|
|
* we probably SHOULD have stopped the other CPUs before now!
|
|
* another CPU COULD have been touching cpl at this moment...
|
|
*/
|
|
printf(" <- SMP: XXX");
|
|
#endif
|
|
printf("\n");
|
|
|
|
#ifdef KDB
|
|
if (kdb_trap(&psl))
|
|
return;
|
|
#endif
|
|
#ifdef DDB
|
|
if (kdb_trap (type, 0, frame))
|
|
return;
|
|
#endif
|
|
printf("trap number = %d\n", type);
|
|
if (type <= MAX_TRAP_MSG)
|
|
panic(trap_msg[type]);
|
|
else
|
|
panic("unknown/reserved trap");
|
|
}
|
|
|
|
/*
|
|
* Double fault handler. Called when a fault occurs while writing
|
|
* a frame for a trap/exception onto the stack. This usually occurs
|
|
* when the stack overflows (such is the case with infinite recursion,
|
|
* for example).
|
|
*
|
|
* XXX Note that the current PTD gets replaced by IdlePTD when the
|
|
* task switch occurs. This means that the stack that was active at
|
|
* the time of the double fault is not available at <kstack> unless
|
|
* the machine was idle when the double fault occurred. The downside
|
|
* of this is that "trace <ebp>" in ddb won't work.
|
|
*/
|
|
void
|
|
dblfault_handler()
|
|
{
|
|
printf("\nFatal double fault:\n");
|
|
printf("eip = 0x%x\n", common_tss.tss_eip);
|
|
printf("esp = 0x%x\n", common_tss.tss_esp);
|
|
printf("ebp = 0x%x\n", common_tss.tss_ebp);
|
|
#ifdef SMP
|
|
/* three seperate prints in case of a trap on an unmapped page */
|
|
printf("mp_lock = %08x; ", mp_lock);
|
|
printf("cpuid = %d; ", cpuid);
|
|
printf("lapic.id = %08x\n", lapic.id);
|
|
#endif
|
|
panic("double fault");
|
|
}
|
|
|
|
/*
|
|
* Compensate for 386 brain damage (missing URKR).
|
|
* This is a little simpler than the pagefault handler in trap() because
|
|
* it the page tables have already been faulted in and high addresses
|
|
* are thrown out early for other reasons.
|
|
*/
|
|
int trapwrite(addr)
|
|
unsigned addr;
|
|
{
|
|
struct proc *p;
|
|
vm_offset_t va;
|
|
struct vmspace *vm;
|
|
int rv;
|
|
|
|
va = trunc_page((vm_offset_t)addr);
|
|
/*
|
|
* XXX - MAX is END. Changed > to >= for temp. fix.
|
|
*/
|
|
if (va >= VM_MAXUSER_ADDRESS)
|
|
return (1);
|
|
|
|
p = curproc;
|
|
vm = p->p_vmspace;
|
|
|
|
++p->p_lock;
|
|
|
|
if ((caddr_t)va >= vm->vm_maxsaddr
|
|
&& (caddr_t)va < (caddr_t)USRSTACK) {
|
|
if (!grow(p, va)) {
|
|
--p->p_lock;
|
|
return (1);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* fault the data page
|
|
*/
|
|
rv = vm_fault(&vm->vm_map, va, VM_PROT_READ|VM_PROT_WRITE, VM_FAULT_DIRTY);
|
|
|
|
--p->p_lock;
|
|
|
|
if (rv != KERN_SUCCESS)
|
|
return 1;
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* System call request from POSIX system call gate interface to kernel.
|
|
* Like trap(), argument is call by reference.
|
|
*/
|
|
void
|
|
syscall(frame)
|
|
struct trapframe frame;
|
|
{
|
|
caddr_t params;
|
|
int i;
|
|
struct sysent *callp;
|
|
struct proc *p = curproc;
|
|
u_quad_t sticks;
|
|
int error;
|
|
int args[8];
|
|
u_int code;
|
|
|
|
#ifdef DIAGNOSTIC
|
|
if (ISPL(frame.tf_cs) != SEL_UPL)
|
|
panic("syscall");
|
|
#endif
|
|
sticks = p->p_sticks;
|
|
p->p_md.md_regs = &frame;
|
|
params = (caddr_t)frame.tf_esp + sizeof(int);
|
|
code = frame.tf_eax;
|
|
if (p->p_sysent->sv_prepsyscall) {
|
|
(*p->p_sysent->sv_prepsyscall)(&frame, args, &code, ¶ms);
|
|
} else {
|
|
/*
|
|
* Need to check if this is a 32 bit or 64 bit syscall.
|
|
*/
|
|
if (code == SYS_syscall) {
|
|
/*
|
|
* Code is first argument, followed by actual args.
|
|
*/
|
|
code = fuword(params);
|
|
params += sizeof(int);
|
|
} else if (code == SYS___syscall) {
|
|
/*
|
|
* Like syscall, but code is a quad, so as to maintain
|
|
* quad alignment for the rest of the arguments.
|
|
*/
|
|
code = fuword(params);
|
|
params += sizeof(quad_t);
|
|
}
|
|
}
|
|
|
|
if (p->p_sysent->sv_mask)
|
|
code &= p->p_sysent->sv_mask;
|
|
|
|
if (code >= p->p_sysent->sv_size)
|
|
callp = &p->p_sysent->sv_table[0];
|
|
else
|
|
callp = &p->p_sysent->sv_table[code];
|
|
|
|
if (params && (i = callp->sy_narg * sizeof(int)) &&
|
|
(error = copyin(params, (caddr_t)args, (u_int)i))) {
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(p, KTR_SYSCALL))
|
|
ktrsyscall(p->p_tracep, code, callp->sy_narg, args);
|
|
#endif
|
|
goto bad;
|
|
}
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(p, KTR_SYSCALL))
|
|
ktrsyscall(p->p_tracep, code, callp->sy_narg, args);
|
|
#endif
|
|
p->p_retval[0] = 0;
|
|
p->p_retval[1] = frame.tf_edx;
|
|
|
|
STOPEVENT(p, S_SCE, callp->sy_narg);
|
|
|
|
error = (*callp->sy_call)(p, args);
|
|
|
|
switch (error) {
|
|
|
|
case 0:
|
|
/*
|
|
* Reinitialize proc pointer `p' as it may be different
|
|
* if this is a child returning from fork syscall.
|
|
*/
|
|
p = curproc;
|
|
frame.tf_eax = p->p_retval[0];
|
|
frame.tf_edx = p->p_retval[1];
|
|
frame.tf_eflags &= ~PSL_C;
|
|
break;
|
|
|
|
case ERESTART:
|
|
/*
|
|
* Reconstruct pc, assuming lcall $X,y is 7 bytes,
|
|
* int 0x80 is 2 bytes. We saved this in tf_err.
|
|
*/
|
|
frame.tf_eip -= frame.tf_err;
|
|
break;
|
|
|
|
case EJUSTRETURN:
|
|
break;
|
|
|
|
default:
|
|
bad:
|
|
if (p->p_sysent->sv_errsize)
|
|
if (error >= p->p_sysent->sv_errsize)
|
|
error = -1; /* XXX */
|
|
else
|
|
error = p->p_sysent->sv_errtbl[error];
|
|
frame.tf_eax = error;
|
|
frame.tf_eflags |= PSL_C;
|
|
break;
|
|
}
|
|
|
|
if ((frame.tf_eflags & PSL_T) && !(frame.tf_eflags & PSL_VM)) {
|
|
/* Traced syscall. */
|
|
frame.tf_eflags &= ~PSL_T;
|
|
trapsignal(p, SIGTRAP, 0);
|
|
}
|
|
|
|
userret(p, &frame, sticks);
|
|
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(p, KTR_SYSRET))
|
|
ktrsysret(p->p_tracep, code, error, p->p_retval[0]);
|
|
#endif
|
|
|
|
/*
|
|
* This works because errno is findable through the
|
|
* register set. If we ever support an emulation where this
|
|
* is not the case, this code will need to be revisited.
|
|
*/
|
|
STOPEVENT(p, S_SCX, code);
|
|
|
|
}
|
|
|
|
/*
|
|
* Simplified back end of syscall(), used when returning from fork()
|
|
* directly into user mode.
|
|
*/
|
|
void
|
|
fork_return(p, frame)
|
|
struct proc *p;
|
|
struct trapframe frame;
|
|
{
|
|
frame.tf_eax = 0; /* Child returns zero */
|
|
frame.tf_eflags &= ~PSL_C; /* success */
|
|
frame.tf_edx = 1;
|
|
|
|
userret(p, &frame, 0);
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(p, KTR_SYSRET))
|
|
ktrsysret(p->p_tracep, SYS_fork, 0, 0);
|
|
#endif
|
|
}
|