trap.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char *sccsid = "@(#)trap.c	4.4	ULTRIX	4/11/91";
#endif lint

/************************************************************************
 *									*
 *		Copyright (c) 1985, 1986, 1988, 1989 by			*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/* ------------------------------------------------------------------------
 * Modification History: /sys/vax/trap.c
 *
 * 11-Apr-91	dlh
 *	syscall():
 *		- on return from a system call, p_affinity was being loaded with
 *		  ALLCPU.  This is wrong if the process is a vector process.
 *
 * 4-Sep-90 dlh
 *	- illegal instruction fault needs to look to see if cpu is vector
 *	  present and if not is the instruction a legal vector instruction
 *	- add vector disabled fault
 *
 * 14-Nov-89 sekhar
 *	Fixes to turn profiling off when scale set to 1.
 *
 * 09-Nov-89 jaw
 *	remove asymmetric syscall support.
 *
 * 04-Oct-89 jaw
 *	release all locks held when "longjmp" out of a syscall occurs.  This
 *	is a tempory fix until code in "soclose" is fixed to handle 
 *	interrupted system calls.
 *
 * 15-Aug-89 scott
 *	check for indirect syscall use for audit and sys_trace codepaths
 *	use callp->sy_narg instead of *(caddr)locr0[AP]
 *
 * 20-Jul-89 jaw
 *	cleanup debug for smp and optimize code in syscall path.
 *
 * 09-Jun-89 -- scott
 *	added audit support
 *
 * 23-Jan-89 -- jmartin
 *	Introduce a new trap type NOACCESS for protection fault on read.
 *
 * 10-Oct-88 -- jaw
 *	check for holding a lock after doing a switch but before restoring
 *	the old lock list.
 *
 * 10-Oct-88 -- jaw
 *	replace switch_to_master with general routine switch_affinity
 *
 * 19 Aug 88 -- miche
 *	Stay out of the idle loop for kernel debugger and pageout
 *	silencing of secondary processors from user mode.  Also,
 *	save the process context for easier debugging.
 *
 * 25 Jul 88 -- jmartin
 *	Allow pagein and grow to happen on any CPU.
 *
 * 18-Jun-88 -- jaw  change to new cpu data format.
 *
 * 14 May 87 -- fred (Fred Canter)
 *	Turn off graphics console loopback of kernel printf's
 *	when the system panics (via trap).
 *
 * 21 Jan 87 -- jaw
 *	performance fixes to syscall.
 *
 * 02-Apr-86 -- jrs
 *	Clean up for better perfomance in single cpu case.
 *	Allow some syscalls to be mp.
 *
 * 18 Mar 86 -- jrs
 *	Change calls to cpuindex/cpuident
 *
 * 24 Feb 86 -- depp
 *	Added code to SIGBUS to pass virtual address to process
 *
 * 16 Jul 85 -- jrs
 *	Add run queue locking and multicpu sched mods
 *
 * 20 Jan 86 -- pmk
 *	Added binary error logging for traps
 *
 * 14 Oct 85 -- reilly
 *	Modified user.h
 *
 * 29 Oct 84 -- jrs
 *	Fix carry bit clear for compat mode problem
 *	Derived from 4.2BSD, labeled:
 *		trap.c 6.2	84/06/10
 *
 * -----------------------------------------------------------------------
 */

#include "../machine/psl.h"
#include "../machine/reg.h"
#include "../machine/pte.h"

#include "../h/param.h"
#include "../h/smp_lock.h"
#include "../h/systm.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "assym.s"
#include "../h/proc.h"
#include "../h/seg.h"
#include "../vax/trap.h"
#include "../h/acct.h"
#include "../h/kernel.h"
#include "../h/errlog.h"
#include "../h/cpudata.h"
#include "../machine/mtpr.h"
#include "../h/systrace.h"
#include "../h/conf.h"
#include "../io/uba/qdioctl.h"	/* for QD_KERN_UNLOOP below */
#include "../h/vmmac.h"
#include "../machine/vmparam.h"
#include "../machine/vectors.h"
#include "../../machine/common/cpuconf.h"

int vm_debug = 1;

#ifdef KDEBUG
#include "../machine/kdb/kdb_trap.h"
#else  !KDEBUG
int in_kdb = 0;  
#endif !KDEBUG

#define	USER	040		/* user-mode flag added to type */

struct	sysent	sysent[];
int	nsysent;
#ifdef SYS_TRACE
int	traceopens = 0;
#endif SYS_TRACE

char	*trap_type[] = {
	"Reserved addressing mode",
	"Privileged instruction",
	"Reserved operand",
	"Breakpoint",
	"Xfc trap",
	"Syscall trap",
	"Arithmetic fault",
	"Ast trap",
	"Segmentation fault",
	"Protection fault",
	"Trace trap",
	"Compatibility mode trap",
#ifdef notdef
	"Page fault",
	"Page table fault",
#endif
};
#define	TRAP_TYPES	(sizeof trap_type / sizeof trap_type[0])


extern	int	ws_display_type;
/*
 * Called from the trap handler when a processor trap occurs.
 */
/*ARGSUSED*/
trap(sp, type, code, pc, psl)
	int sp, type;
	unsigned code;
	int pc, psl;
{
#ifdef KDEBUG
	register int *kdb_local_regptr;
#define REG_11 kdb_local_regptr
	extern int *kdb_regs_ptr;
#endif KDEBUG
	register int *locr0 = ((int *)&psl)-PS;
	register int i;
	register struct proc *p;
	register int s;
	struct el_rec *elrp;
	struct timeval syst;
	struct cpudata *pcpu;

	int	new_affinity;	/* new affinity mask of a process becoming a 
				 * vector process or of a process which needs
  				 * to switch it's affinity for some other 
				 * reason.
				 */
#ifdef KDEBUG
	asm("movl fp,r11");
	kdb_regs_ptr = kdb_local_regptr;
#endif KDEBUG

	syst = u.u_ru.ru_stime;
	if (USERMODE(locr0[PS])) {
		type |= USER;
		u.u_ar0 = locr0;
	} 

	switch (type) {

	default:
#ifdef KDEBUG
kdb_goto_label:
#endif KDEBUG
		elrp = ealloc(EL_EXPTFLTSIZE,EL_PRISEVERE);
		if (elrp != 0) {
		    LSUBID(elrp,ELCT_EXPTFLT,(type + 1),EL_UNDEF,EL_UNDEF,EL_UNDEF,EL_UNDEF);
		    elrp->el_body.elexptflt.exptflt_va = code;
		    elrp->el_body.elexptflt.exptflt_pc = pc;
		    elrp->el_body.elexptflt.exptflt_psl = psl;
		    EVALID(elrp);
		}
		/*
		 * If console is a graphics device,
		 * force cprintf messages directly to screen.
		 */
		if (ws_display_type) {
		    i = ws_display_type << 8;
		    (*cdevsw[ws_display_type].d_ioctl)(i, QD_KERN_UNLOOP, 0, 0);
		}
		cprintf("trap type %d, code = %x, pc = %x\n", type, code, pc);
		type &= ~USER;
		if ((unsigned)type < TRAP_TYPES) {
			panic(trap_type[type]);
			
		}
		panic("trap");
#ifdef KDEBUG
	include_kdb();
#endif KDEBUG

	case T_NOACCESS+USER:
		if (
		    vm_debug &&
		    isatsv(u.u_procp, btop(code)))
			panic("no access to shared text");
		else	/* fall through to protection fault */	;
	case T_PROTFLT+USER:	/* protection fault */
		i = SIGBUS;
		u.u_code = code;
		break;

	case T_PRIVINFLT+USER:	/* privileged instruction fault */

                if (is_legal_vector_instruction(pc) == is_vect_inst) {
                    if (vptotal > 0) {
                            /*
                             * if this process is not already a vector
                             * process, then call vp_allocate to convert this
                             * process to vector process.  This is done by
                             * allocating the space to store the vector
                             * context.
                             */
                   
                            if (u.u_procp->p_vpcontext == NULL) {
			        if (vp_allocate (u.u_procp) == VP_FAILURE) {
				    goto out;
			        }
                            }
                   
                   
                            /*
                             * change the processes affinity
                             */
                   
                            new_affinity = u.u_procp->p_affinity & vpmask;
                            if (new_affinity == 0) {
                                    panic ("trap(): vector affinity problem");
                            } 
                            else {
                                    (void) switch_affinity (new_affinity);
                            }
			    goto out;
                    } else { /* there are no vector processors in the system */
                            u.u_code = ILL_VECINST_FAULT;
                            uprintf ("No vector processor available\n");
			    i = SIGILL;
                    }
                } else { /* this is not a vector instruction */
                    u.u_code = type &~ USER;
		    i = SIGILL;
                }

		break;

	case T_RESADFLT+USER:	/* reserved addressing fault */
	case T_RESOPFLT+USER:	/* resereved operand fault */
		u.u_code = type &~ USER;
		i = SIGILL;
		break;

	case T_ASTFLT+USER:
		astoff();
		if ((u.u_oweupc & SOWEUPC) && (u.u_prof.pr_scale > 1)) {
			addupc(pc, &u.u_prof, 1);