Source to arch/i386/i386/trap.c
/*-
* Copyright (c) 1990 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
* 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.
* 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.
*
* @(#)trap.c 7.4 (Berkeley) 5/13/91
*/
static char rcsid[] = "$Header: /usr/bill/working/sys/i386/i386/RCS/trap.c,v 1.2 92/01/21 14:22:13 william Exp $";
/*
* 386 Trap and System call handleing
*/
#include "machine/cpu.h"
#include "machine/psl.h"
#include "machine/reg.h"
#include "param.h"
#include "systm.h"
#include "proc.h"
#include "user.h"
#include "acct.h"
#include "kernel.h"
#ifdef KTRACE
#include "ktrace.h"
#endif
#include "vm/vm_param.h"
#include "vm/pmap.h"
#include "vm/vm_map.h"
#include "sys/vmmeter.h"
#include "machine/trap.h"
struct sysent sysent[];
int nsysent;
int dostacklimits;
unsigned rcr2();
extern short cpl;
/*
* trap(frame):
* Exception, fault, and trap interface to BSD 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. Note that the
* effect is as if the arguments were passed call by reference.
*/
/*ARGSUSED*/
trap(frame)
struct trapframe frame;
{
register int i;
register struct proc *p = curproc;
struct timeval syst;
int ucode, type, code, eva;
frame.tf_eflags &= ~PSL_NT; /* clear nested trap XXX */
type = frame.tf_trapno;
#include "ddb.h"
#if NDDB > 0
if (curpcb && curpcb->pcb_onfault) {
if (frame.tf_trapno == T_BPTFLT
|| frame.tf_trapno == T_TRCTRAP)
if (kdb_trap (type, 0, &frame))
return;
}
#endif
/*pg("trap type %d code = %x eip = %x cs = %x eva = %x esp %x",
frame.tf_trapno, frame.tf_err, frame.tf_eip,
frame.tf_cs, rcr2(), frame.tf_esp);*/
if(curpcb == 0 || curproc == 0) goto we_re_toast;
if (curpcb->pcb_onfault && frame.tf_trapno != 0xc) {
copyfault:
frame.tf_eip = (int)curpcb->pcb_onfault;
return;
}
syst = p->p_stime;
if (ISPL(frame.tf_cs) == SEL_UPL) {
type |= T_USER;
p->p_regs = (int *)&frame;
curpcb->pcb_flags |= FM_TRAP; /* used by sendsig */
}
ucode=0;
eva = rcr2();
code = frame.tf_err;
switch (type) {
default:
we_re_toast:
#ifdef KDB
if (kdb_trap(&psl))
return;
#endif
#if NDDB > 0
if (kdb_trap (type, 0, &frame))
return;
#endif
printf("trap type %d code = %x eip = %x cs = %x eflags = %x ",
frame.tf_trapno, frame.tf_err, frame.tf_eip,
frame.tf_cs, frame.tf_eflags);
eva = rcr2();
printf("cr2 %x cpl %x\n", eva, cpl);
/* type &= ~T_USER; */ /* XXX what the hell is this */
panic("trap");
/*NOTREACHED*/
case T_SEGNPFLT|T_USER:
case T_STKFLT|T_USER:
case T_PROTFLT|T_USER: /* protection fault */
ucode = code + BUS_SEGM_FAULT ;
i = SIGBUS;
break;
case T_PRIVINFLT|T_USER: /* privileged instruction fault */
case T_RESADFLT|T_USER: /* reserved addressing fault */
case T_RESOPFLT|T_USER: /* reserved operand fault */
case T_FPOPFLT|T_USER: /* coprocessor operand fault */
ucode = type &~ T_USER;
i = SIGILL;
break;
case T_ASTFLT|T_USER: /* Allow process switch */
astoff();
if ((p->p_flag & SOWEUPC) && p->p_stats->p_prof.pr_scale) {
addupc(frame.tf_eip, &p->p_stats->p_prof, 1);
p->p_flag &= ~SOWEUPC;
}
goto out;
case T_DNA|T_USER:
#ifdef NPX
/* if a transparent fault (due to context switch "late") */
if (npxdna()) return;
#endif
i = math_emulate(&frame);
if (i == 0) return;
ucode = FPE_FPU_NP_TRAP;
break;
case T_BOUND|T_USER:
ucode = FPE_SUBRNG_TRAP;
i = SIGFPE;
break;
case T_OFLOW|T_USER:
ucode = FPE_INTOVF_TRAP;
i = SIGFPE;
break;
case T_DIVIDE|T_USER:
ucode = FPE_INTDIV_TRAP;
i = SIGFPE;
break;
case T_ARITHTRAP|T_USER:
ucode = code;
i = SIGFPE;
break;
case T_PAGEFLT: /* allow page faults in kernel mode */
if (code & PGEX_P) goto we_re_toast;
/* fall into */
case T_PAGEFLT|T_USER: /* page fault */
{
register vm_offset_t va;
register struct vmspace *vm = p->p_vmspace;
register vm_map_t map;
int rv;
vm_prot_t ftype;
extern vm_map_t kernel_map;
unsigned nss,v;
va = trunc_page((vm_offset_t)eva);
/*
* It is only a kernel address space fault iff:
* 1. (type & T_USER) == 0 and
* 2. pcb_onfault not set or
* 3. pcb_onfault set but supervisor space fault
* The last can occur during an exec() copyin where the
* argument space is lazy-allocated.
*/
if (type == T_PAGEFLT && va >= 0xfe000000)
map = kernel_map;
else
map = &vm->vm_map;
if (code & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
#ifdef DEBUG
if (map == kernel_map && va == 0) {
printf("trap: bad kernel access at %x\n", va);
goto we_re_toast;
}
#endif
/*
* XXX: rude hack to make stack limits "work"
*/
nss = 0;
if ((caddr_t)va >= vm->vm_maxsaddr && map != kernel_map
&& dostacklimits) {
nss = clrnd(btoc((unsigned)vm->vm_maxsaddr
+ MAXSSIZ - (unsigned)va));
if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
/*pg("trap rlimit %d, maxsaddr %x va %x ", nss, vm->vm_maxsaddr, va);*/
rv = KERN_FAILURE;
goto nogo;
}
}
/* check if page table is mapped, if not, fault it first */
#define pde_v(v) (PTD[((v)>>PD_SHIFT)&1023].pd_v)
if (!pde_v(va)) {
v = trunc_page(vtopte(va));
rv = vm_fault(map, v, ftype, FALSE);
if (rv != KERN_SUCCESS) goto nogo;
/* check if page table fault, increment wiring */
vm_map_pageable(map, v, round_page(v+1), FALSE);
} else v=0;
rv = vm_fault(map, va, ftype, FALSE);
if (rv == KERN_SUCCESS) {
/*
* XXX: continuation of rude stack hack
*/
if (nss > vm->vm_ssize)
vm->vm_ssize = nss;
va = trunc_page(vtopte(va));
/* for page table, increment wiring
as long as not a page table fault as well */
if (!v && type != T_PAGEFLT)
vm_map_pageable(map, va, round_page(va+1), FALSE);
if (type == T_PAGEFLT)
return;
goto out;
}
nogo:
if (type == T_PAGEFLT) {
if (curpcb->pcb_onfault)
goto copyfault;
printf("vm_fault(%x, %x, %x, 0) -> %x\n",
map, va, ftype, rv);
printf(" type %x, code %x\n",
type, code);
goto we_re_toast;
}
i = (rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV;
break;
}
#if NDDB == 0
case T_TRCTRAP: /* trace trap -- someone single stepping lcall's */
frame.tf_eflags &= ~PSL_T;
/* Q: how do we turn it on again? */
return;
#endif
case T_BPTFLT|T_USER: /* bpt instruction fault */
case T_TRCTRAP|T_USER: /* trace trap */
frame.tf_eflags &= ~PSL_T;
i = SIGTRAP;
break;
#include "isa.h"
#if NISA > 0
case T_NMI:
case T_NMI|T_USER:
#if NDDB > 0
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif
/* machine/parity/power fail/"kitchen sink" faults */
if(isa_nmi(code) == 0) return;
else goto we_re_toast;
#endif
}
trapsignal(p, i, ucode);
if ((type & T_USER) == 0)
return;
out:
while (i = CURSIG(p))
psig(i);
p->p_pri = 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 setrq ourselves but before we
* swtch()'ed, we might not be on the queue indicated by
* our priority.
*/
(void) splclock();
setrq(p);
p->p_stats->p_ru.ru_nivcsw++;
swtch();
(void) splnone();
while (i = CURSIG(p))
psig(i);
}
if (p->p_stats->p_prof.pr_scale) {
int ticks;
struct timeval *tv = &p->p_stime;
ticks = ((tv->tv_sec - syst.tv_sec) * 1000 +
(tv->tv_usec - syst.tv_usec) / 1000) / (tick / 1000);
if (ticks) {
#ifdef PROFTIMER
extern int profscale;
addupc(frame.tf_eip, &p->p_stats->p_prof,
ticks * profscale);
#else
addupc(frame.tf_eip, &p->p_stats->p_prof, ticks);
#endif
}
}
curpri = p->p_pri;
curpcb->pcb_flags &= ~FM_TRAP; /* used by sendsig */
}
/*
* Compensate for 386 brain damage (missing URKR)
*/
int trapwrite(unsigned addr) {
int rv;
vm_offset_t va;
va = trunc_page((vm_offset_t)addr);
if (va > VM_MAXUSER_ADDRESS) return(1);
rv = vm_fault(&curproc->p_vmspace->vm_map, va,
VM_PROT_READ | VM_PROT_WRITE, FALSE);
if (rv == KERN_SUCCESS) return(0);
else return(1);
}
/*
* syscall(frame):
* System call request from POSIX system call gate interface to kernel.
* Like trap(), argument is call by reference.
*/
/*ARGSUSED*/
syscall(frame)
volatile struct syscframe frame;
{
register int *locr0 = ((int *)&frame);
register caddr_t params;
register int i;
register struct sysent *callp;
register struct proc *p = curproc;
struct timeval syst;
int error, opc;
int args[8], rval[2];
int code;
#ifdef lint
r0 = 0; r0 = r0; r1 = 0; r1 = r1;
#endif
syst = p->p_stime;
if (ISPL(frame.sf_cs) != SEL_UPL)
panic("syscall");
code = frame.sf_eax;
curpcb->pcb_flags &= ~FM_TRAP; /* used by sendsig */
p->p_regs = (int *)&frame;
params = (caddr_t)frame.sf_esp + sizeof (int) ;
/*
* Reconstruct pc, assuming lcall $X,y is 7 bytes, as it is always.
*/
opc = frame.sf_eip - 7;
callp = (code >= nsysent) ? &sysent[63] : &sysent[code];
if (callp == sysent) {
i = fuword(params);
params += sizeof (int);
callp = (code >= nsysent) ? &sysent[63] : &sysent[code];
}
if ((i = callp->sy_narg * sizeof (int)) &&
(error = copyin(params, (caddr_t)args, (u_int)i))) {
frame.sf_eax = error;
frame.sf_eflags |= PSL_C; /* carry bit */
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, &args);
#endif
goto done;
}
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, &args);
#endif
rval[0] = 0;
rval[1] = frame.sf_edx;
/*pg("%d. s %d\n", p->p_pid, code);*/
error = (*callp->sy_call)(p, args, rval);
if (error == ERESTART)
frame.sf_eip = opc;
else if (error != EJUSTRETURN) {
if (error) {
/*pg("error %d", error);*/
frame.sf_eax = error;
frame.sf_eflags |= PSL_C; /* carry bit */
} else {
frame.sf_eax = rval[0];
frame.sf_edx = rval[1];
frame.sf_eflags &= ~PSL_C; /* carry bit */
}
}
/* else if (error == EJUSTRETURN) */
/* nothing to do */
done:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
while (i = CURSIG(p))
psig(i);
p->p_pri = 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 setrq ourselves but before we
* swtch()'ed, we might not be on the queue indicated by
* our priority.
*/
(void) splclock();
setrq(p);
p->p_stats->p_ru.ru_nivcsw++;
swtch();
(void) splnone();
while (i = CURSIG(p))
psig(i);
}
if (p->p_stats->p_prof.pr_scale) {
int ticks;
struct timeval *tv = &p->p_stime;
ticks = ((tv->tv_sec - syst.tv_sec) * 1000 +
(tv->tv_usec - syst.tv_usec) / 1000) / (tick / 1000);
if (ticks) {
#ifdef PROFTIMER
extern int profscale;
addupc(frame.sf_eip, &p->p_stats->p_prof,
ticks * profscale);
#else
addupc(frame.sf_eip, &p->p_stats->p_prof, ticks);
#endif
}
}
curpri = p->p_pri;
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET))
ktrsysret(p->p_tracep, code, error, rval[0]);
#endif
#ifdef DIAGNOSTICx
{ extern int _udatasel, _ucodesel;
if (frame.sf_ss != _udatasel)
printf("ss %x call %d\n", frame.sf_ss, code);
if ((frame.sf_cs&0xffff) != _ucodesel)
printf("cs %x call %d\n", frame.sf_cs, code);
if (frame.sf_eip > VM_MAXUSER_ADDRESS) {
printf("eip %x call %d\n", frame.sf_eip, code);
frame.sf_eip = 0;
}
}
#endif
}