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Use pcb_onfault only in the specific cases of protection, alignment, and 

page faults.  For all other kernel-mode faults and traps, ignore it.  For
user-mode faults and traps, always ignore it.
Some other minor cleanup.
This commit is contained in:
mycroft 1994-10-26 17:38:44 +00:00
parent 4e9c2720e2
commit e65f99d726
1 changed files with 18 additions and 24 deletions
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42
sys/arch/i386/i386/trap.c
View File

@ -36,7 +36,7 @@
* SUCH DAMAGE.
*
* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
* $Id: trap.c,v 1.54 1994/10/26 01:32:51 mycroft Exp $
* $Id: trap.c,v 1.55 1994/10/26 17:38:44 mycroft Exp $
*/
/*
@ -71,10 +71,6 @@
#include "npx.h"
struct sysent sysent[];
int nsysent;
extern int cpl;
/*
* Define the code needed before returning to user mode, for
* trap and syscall.
@ -163,7 +159,7 @@ trap(frame)
{
register struct proc *p;
register struct pcb *pcb;
int type, code;
int type;
u_quad_t sticks;
extern char fusubail[];
@ -187,25 +183,12 @@ trap(frame)
anyway */
pcb = &p->p_addr->u_pcb;
if (pcb == 0)
goto we_re_toast;
/* fusubail is used by [fs]uswintr to avoid page faulting */
if (pcb->pcb_onfault &&
(type != T_PAGEFLT || pcb->pcb_onfault == fusubail)) {
copyfault:
frame.tf_eip = (int)pcb->pcb_onfault;
return;
}
if (ISPL(frame.tf_cs) != SEL_KPL) {
type |= T_USER;
sticks = p->p_sticks;
p->p_md.md_regs = (int *)&frame;
}
code = frame.tf_err;
switch (type) {
default:
@ -225,11 +208,19 @@ trap(frame)
printf("unknown trap %d", frame.tf_trapno);
printf(" in %s mode\n", (type & T_USER) ? "user" : "supervisor");
printf("trap type %d code %x eip %x cs %x eflags %x cr2 %x cpl %x\n",
type, code, frame.tf_eip, frame.tf_cs, frame.tf_eflags, rcr2(), cpl);
type, frame.tf_err, frame.tf_eip, frame.tf_cs, frame.tf_eflags, rcr2(), cpl);
panic("trap");
/*NOTREACHED*/
case T_PROTFLT:
case T_ALIGNFLT:
if (pcb->pcb_onfault == 0)
goto we_re_toast;
copyfault:
frame.tf_eip = (int)pcb->pcb_onfault;
break;
case T_SEGNPFLT|T_USER:
case T_STKFLT|T_USER:
case T_PROTFLT|T_USER: /* protection fault */
@ -280,17 +271,19 @@ trap(frame)
break;
case T_ARITHTRAP|T_USER:
trapsignal(p, SIGFPE, code);
trapsignal(p, SIGFPE, frame.tf_err);
break;
case T_PAGEFLT: /* allow page faults in kernel mode */
if (pcb->pcb_onfault == fusubail)
goto copyfault;
#if 0
/* XXX - check only applies to 386's and 486's with WP off */
if (code & PGEX_P)
if (frame.tf_err & PGEX_P)
goto we_re_toast;
#endif
/* FALLTHROUGH */
case T_PAGEFLT|T_USER: { /* page fault */
register vm_offset_t va;
register struct vmspace *vm = p->p_vmspace;
@ -313,7 +306,7 @@ trap(frame)
map = kernel_map;
else
map = &vm->vm_map;
if (code & PGEX_W)
if (frame.tf_err & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
@ -361,6 +354,7 @@ trap(frame)
return;
goto out;
}
nogo:
if (type == T_PAGEFLT) {
if (pcb->pcb_onfault)