640c4313af
everything is contained inside #ifdef VM86, so this option must be present in the config file to use this functionality. Thanks to Tor Egge, these changes should work on SMP machines. However, it may not be throughly SMP-safe. Currently, the only BIOS calls made are memory-sizing routines at bootup, these replace reading the RTC values.
1105 lines
26 KiB
C
1105 lines
26 KiB
C
/*-
|
|
* Copyright (C) 1994, David Greenman
|
|
* Copyright (c) 1990, 1993
|
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* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* the University of Utah, and William Jolitz.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
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|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
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|
* 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.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
|
|
*
|
|
* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
|
|
* $Id: trap.c,v 1.122 1998/02/06 12:13:10 eivind Exp $
|
|
*/
|
|
|
|
/*
|
|
* 386 Trap and System call handling
|
|
*/
|
|
|
|
#include "opt_cpu.h"
|
|
#include "opt_ddb.h"
|
|
#include "opt_ktrace.h"
|
|
#include "opt_trap.h"
|
|
#include "opt_vm86.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/pioctl.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/resourcevar.h>
|
|
#include <sys/signalvar.h>
|
|
#include <sys/syscall.h>
|
|
#include <sys/sysent.h>
|
|
#include <sys/vmmeter.h>
|
|
#ifdef KTRACE
|
|
#include <sys/ktrace.h>
|
|
#endif
|
|
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_param.h>
|
|
#include <vm/vm_prot.h>
|
|
#include <sys/lock.h>
|
|
#include <vm/pmap.h>
|
|
#include <vm/vm_kern.h>
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|
#include <vm/vm_map.h>
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|
#include <vm/vm_page.h>
|
|
#include <vm/vm_extern.h>
|
|
|
|
#include <machine/cpu.h>
|
|
#include <machine/ipl.h>
|
|
#include <machine/md_var.h>
|
|
#include <machine/pcb.h>
|
|
#ifdef SMP
|
|
#include <machine/smp.h>
|
|
#endif
|
|
#include <machine/tss.h>
|
|
|
|
#include <i386/isa/intr_machdep.h>
|
|
|
|
#ifdef POWERFAIL_NMI
|
|
#include <sys/syslog.h>
|
|
#include <machine/clock.h>
|
|
#endif
|
|
|
|
#ifdef VM86
|
|
#include <machine/vm86.h>
|
|
#endif
|
|
|
|
#include "isa.h"
|
|
#include "npx.h"
|
|
|
|
extern struct i386tss common_tss;
|
|
|
|
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));
|
|
|
|
static int trap_pfault __P((struct trapframe *, int));
|
|
static void trap_fatal __P((struct trapframe *));
|
|
void dblfault_handler __P((void));
|
|
|
|
extern inthand_t IDTVEC(syscall);
|
|
|
|
#define MAX_TRAP_MSG 28
|
|
static char *trap_msg[] = {
|
|
"", /* 0 unused */
|
|
"privileged instruction fault", /* 1 T_PRIVINFLT */
|
|
"", /* 2 unused */
|
|
"breakpoint instruction fault", /* 3 T_BPTFLT */
|
|
"", /* 4 unused */
|
|
"", /* 5 unused */
|
|
"arithmetic trap", /* 6 T_ARITHTRAP */
|
|
"system forced exception", /* 7 T_ASTFLT */
|
|
"", /* 8 unused */
|
|
"general protection fault", /* 9 T_PROTFLT */
|
|
"trace trap", /* 10 T_TRCTRAP */
|
|
"", /* 11 unused */
|
|
"page fault", /* 12 T_PAGEFLT */
|
|
"", /* 13 unused */
|
|
"alignment fault", /* 14 T_ALIGNFLT */
|
|
"", /* 15 unused */
|
|
"", /* 16 unused */
|
|
"", /* 17 unused */
|
|
"integer divide fault", /* 18 T_DIVIDE */
|
|
"non-maskable interrupt trap", /* 19 T_NMI */
|
|
"overflow trap", /* 20 T_OFLOW */
|
|
"FPU bounds check fault", /* 21 T_BOUND */
|
|
"FPU device not available", /* 22 T_DNA */
|
|
"double fault", /* 23 T_DOUBLEFLT */
|
|
"FPU operand fetch fault", /* 24 T_FPOPFLT */
|
|
"invalid TSS fault", /* 25 T_TSSFLT */
|
|
"segment not present fault", /* 26 T_SEGNPFLT */
|
|
"stack fault", /* 27 T_STKFLT */
|
|
"machine check trap", /* 28 T_MCHK */
|
|
};
|
|
|
|
static void userret __P((struct proc *p, struct trapframe *frame,
|
|
u_quad_t oticks));
|
|
|
|
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
|
|
extern struct gate_descriptor *t_idt;
|
|
extern int has_f00f_bug;
|
|
#endif
|
|
|
|
static inline void
|
|
userret(p, frame, oticks)
|
|
struct proc *p;
|
|
struct trapframe *frame;
|
|
u_quad_t oticks;
|
|
{
|
|
int sig, s;
|
|
|
|
while ((sig = CURSIG(p)) != 0)
|
|
postsig(sig);
|
|
|
|
#if 0
|
|
if (!want_resched &&
|
|
(p->p_priority <= p->p_usrpri) &&
|
|
(p->p_rtprio.type == RTP_PRIO_NORMAL)) {
|
|
int newpriority;
|
|
p->p_estcpu += 1;
|
|
newpriority = PUSER + p->p_estcpu / 4 + 2 * p->p_nice;
|
|
newpriority = min(newpriority, MAXPRI);
|
|
p->p_usrpri = newpriority;
|
|
}
|
|
#endif
|
|
|
|
p->p_priority = p->p_usrpri;
|
|
if (want_resched) {
|
|
/*
|
|
* Since we are curproc, clock will normally just change
|
|
* our priority without moving us from one queue to another
|
|
* (since the running process is not on a queue.)
|
|
* If that happened after we setrunqueue ourselves but before we
|
|
* mi_switch()'ed, we might not be on the queue indicated by
|
|
* our priority.
|
|
*/
|
|
s = splhigh();
|
|
setrunqueue(p);
|
|
p->p_stats->p_ru.ru_nivcsw++;
|
|
mi_switch();
|
|
splx(s);
|
|
while ((sig = CURSIG(p)) != 0)
|
|
postsig(sig);
|
|
}
|
|
/*
|
|
* Charge system time if profiling.
|
|
*/
|
|
if (p->p_flag & P_PROFIL)
|
|
addupc_task(p, frame->tf_eip,
|
|
(u_int)(p->p_sticks - oticks) * psratio);
|
|
|
|
curpriority = p->p_priority;
|
|
}
|
|
|
|
/*
|
|
* Exception, fault, and trap interface to the FreeBSD kernel.
|
|
* This common code is called from assembly language IDT gate entry
|
|
* routines that prepare a suitable stack frame, and restore this
|
|
* frame after the exception has been processed.
|
|
*/
|
|
|
|
void
|
|
trap(frame)
|
|
struct trapframe frame;
|
|
{
|
|
struct proc *p = curproc;
|
|
u_quad_t sticks = 0;
|
|
int i = 0, ucode = 0, type, code;
|
|
#ifdef DEBUG
|
|
u_long eva;
|
|
#endif
|
|
|
|
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
|
|
restart:
|
|
#endif
|
|
type = frame.tf_trapno;
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|
code = frame.tf_err;
|
|
|
|
#ifdef VM86
|
|
if (in_vm86call) {
|
|
if (frame.tf_eflags & PSL_VM &&
|
|
(type == T_PROTFLT || type == T_STKFLT)) {
|
|
i = vm86_emulate((struct vm86frame *)&frame);
|
|
if (i != 0)
|
|
/*
|
|
* returns to original process
|
|
*/
|
|
vm86_trap((struct vm86frame *)&frame);
|
|
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);
|
|
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;
|
|
p->p_md.md_regs = &frame;
|
|
|
|
switch (type) {
|
|
case T_PRIVINFLT: /* privileged instruction fault */
|
|
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,
|
|
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);
|
|
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);
|
|
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.tv_sec - lastalert > 10)
|
|
{
|
|
log(LOG_WARNING, "NMI: power fail\n");
|
|
sysbeep(TIMER_FREQ/880, hz);
|
|
lastalert = time.tv_sec;
|
|
}
|
|
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);
|
|
return;
|
|
}
|
|
|
|
trapsignal(p, i, ucode);
|
|
|
|
#ifdef DEBUG
|
|
eva = rcr2();
|
|
if (type <= MAX_TRAP_MSG) {
|
|
uprintf("fatal process exception: %s",
|
|
trap_msg[type]);
|
|
if ((type == T_PAGEFLT) || (type == T_PROTFLT))
|
|
uprintf(", fault VA = 0x%x", 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)
|
|
struct trapframe *frame;
|
|
int usermode;
|
|
{
|
|
vm_offset_t va;
|
|
struct vmspace *vm = NULL;
|
|
vm_map_t map = 0;
|
|
int rv = 0;
|
|
vm_prot_t ftype;
|
|
int eva;
|
|
struct proc *p = curproc;
|
|
|
|
if (frame->tf_err & PGEX_W)
|
|
ftype = VM_PROT_READ | VM_PROT_WRITE;
|
|
else
|
|
ftype = VM_PROT_READ;
|
|
|
|
eva = rcr2();
|
|
va = trunc_page((vm_offset_t)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);
|
|
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);
|
|
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)
|
|
struct trapframe *frame;
|
|
int usermode;
|
|
{
|
|
vm_offset_t va;
|
|
struct vmspace *vm = NULL;
|
|
vm_map_t map = 0;
|
|
int rv = 0;
|
|
vm_prot_t ftype;
|
|
int eva;
|
|
struct proc *p = curproc;
|
|
|
|
eva = rcr2();
|
|
va = trunc_page((vm_offset_t)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);
|
|
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)
|
|
struct trapframe *frame;
|
|
{
|
|
int code, type, eva, ss, esp;
|
|
struct soft_segment_descriptor softseg;
|
|
|
|
code = frame->tf_err;
|
|
type = frame->tf_trapno;
|
|
eva = rcr2();
|
|
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
|
|
}
|