plan 9 kernel history: overview | file list | diff list

1991/0720/pc/trap.c (diff list | history)

1991/0720/sys/src/9/pc/trap.c:1,369 – 1991/0722/sys/src/9/pc/trap.c:1,375 (short | long | prev | next)
1991/0613    
#include	"u.h" 
#include	"lib.h" 
#include	"mem.h" 
#include	"dat.h" 
#include	"fns.h" 
#include	"io.h"
1991/0703    
#include	"ureg.h"
1991/0720    
#include	"errno.h"
1991/0613    
1991/0720    
void	noted(Ureg*, ulong); 
void	notify(Ureg*);
1991/0613    
/*
1991/0709    
 *  8259 interrupt controllers 
 */ 
enum 
{ 
	Int0ctl=	0x20,		/* control port (ICW1, OCW2, OCW3) */ 
	Int0aux=	0x21,		/* everything else (ICW2, ICW3, ICW4, OCW1) */ 
	Int1ctl=	0xA0,		/* control port */ 
	Int1aux=	0xA1,		/* everything else (ICW2, ICW3, ICW4, OCW1) */ 
 
	EOI=		0x20,		/* non-specific end of interrupt */ 
}; 
 
int	int0mask = 7;		/* interrupts enabled for first 8259 */ 
int	int1mask = 7;		/* interrupts enabled for second 8259 */ 
 
/*
1991/0614    
 *  trap/interrupt gates
1991/0613    
 */
1991/0703    
Segdesc ilt[256]; 
void	(*ivec[256])(void*); 
 
void
1991/0710    
sethvec(int v, void (*r)(void), int type, int pri)
1991/0613    
{
1991/0703    
	ilt[v].d0 = ((ulong)r)&0xFFFF|(KESEL<<16);
1991/0710    
	ilt[v].d1 = ((ulong)r)&0xFFFF0000|SEGP|SEGPL(pri)|type;
1991/0703    
}
1991/0614    
1991/0703    
void
1991/0716    
setvec(int v, void (*r)(Ureg*))
1991/0703    
{ 
	ivec[v] = r;
1991/0709    
 
	/* 
	 *  enable corresponding interrupt in 8259 
	 */ 
	if((v&~0x7) == Int0vec){ 
		int0mask &= ~(1<<(v&7)); 
		outb(Int0aux, int0mask); 
	}
1991/0703    
}
1991/0614    
/*
1991/0703    
 *  set up the interrupt/trap gates
1991/0614    
 */
1991/0703    
void 
trapinit(void) 
{ 
	int i;
1991/0614    
1991/0703    
	/* 
	 *  set the standard traps 
	 */
1991/0719    
	sethvec(0, intr0, SEGIG, 0); 
	sethvec(1, intr1, SEGIG, 0); 
	sethvec(2, intr2, SEGIG, 0); 
	sethvec(3, intr3, SEGIG, 0); 
	sethvec(4, intr4, SEGIG, 0); 
	sethvec(5, intr5, SEGIG, 0); 
	sethvec(6, intr6, SEGIG, 0); 
	sethvec(7, intr7, SEGIG, 0); 
	sethvec(8, intr8, SEGIG, 0); 
	sethvec(9, intr9, SEGIG, 0); 
	sethvec(10, intr10, SEGIG, 0); 
	sethvec(11, intr11, SEGIG, 0); 
	sethvec(12, intr12, SEGIG, 0); 
	sethvec(13, intr13, SEGIG, 0); 
	sethvec(14, intr14, SEGIG, 0); 
	sethvec(15, intr15, SEGIG, 0); 
	sethvec(16, intr16, SEGIG, 0); 
	sethvec(17, intr17, SEGIG, 0); 
	sethvec(18, intr18, SEGIG, 0); 
	sethvec(19, intr19, SEGIG, 0); 
	sethvec(20, intr20, SEGIG, 0); 
	sethvec(21, intr21, SEGIG, 0); 
	sethvec(22, intr22, SEGIG, 0); 
	sethvec(23, intr23, SEGIG, 0);
1991/0703    
 
	/*
1991/0718    
	 *  set all others to unknown interrupts
1991/0703    
	 */
1991/0706    
	for(i = 24; i < 256; i++)
1991/0710    
		sethvec(i, intrbad, SEGIG, 0);
1991/0703    
 
	/*
1991/0710    
	 *  system calls 
	 */ 
	sethvec(64, intr64, SEGTG, 3);
1991/0716    
	setvec(64, (void (*)(Ureg*))syscall);
1991/0710    
 
	/*
1991/0703    
	 *  tell the hardware where the table is (and how long) 
	 */
1991/0718    
	putidt(ilt, sizeof(ilt));
1991/0704    
 
	/*
1991/0709    
	 *  Set up the first 8259 interrupt processor. 
	 *  Make 8259 interrupts start at CPU vector Int0vec. 
	 *  Set the 8259 as master with edge triggered 
	 *  input with fully nested interrupts.
1991/0704    
	 */
1991/0709    
	outb(Int0ctl, 0x11);		/* ICW1 - edge triggered, master, 
					   ICW4 will be sent */ 
	outb(Int0aux, Int0vec);		/* ICW2 - interrupt vector offset */
1991/0705    
	outb(Int0aux, 0x04);		/* ICW3 - master level 2 */
1991/0709    
	outb(Int0aux, 0x01);		/* ICW4 - 8086 mode, not buffered */
1991/0703    
}
1991/0614    
/*
1991/0703    
 *  All traps
1991/0614    
 */
1991/0710    
void
1991/0703    
trap(Ureg *ur)
1991/0614    
{
1991/0703    
	if(ur->trap>=256 || ivec[ur->trap] == 0)
1991/0711    
		panic("bad trap type %d %lux\n", ur->trap, ur->pc);
1991/0703    
1991/0709    
	/* 
	 *  call the trap routine 
	 */
1991/0703    
	(*ivec[ur->trap])(ur);
1991/0709    
 
	/* 
	 *  tell the 8259 that we're done with the 
	 *  highest level interrupt 
	 */ 
	outb(Int0ctl, EOI);
1991/0710    
} 
 
/*
1991/0718    
 *  dump registers 
 */ 
void 
dumpregs(Ureg *ur) 
{ 
	if(u) 
		print("registers for %s %d\n", u->p->text, u->p->pid); 
	else 
		print("registers for kernel\n"); 
	print("FLAGS=%lux ECODE=%lux CS=%lux PC=%lux SS=%lux USP=%lux\n", ur->flags, 
		ur->ecode, ur->cs, ur->pc, ur->ss, ur->usp); 
 
	print("  AX %8.8lux  BX %8.8lux  CX %8.8lux  DX %8.8lux\n", 
		ur->ax, ur->bx, ur->cx, ur->dx); 
	print("  SI %8.8lux  DI %8.8lux  BP %8.8lux  DS %8.8lux\n", 
		ur->si, ur->di, ur->bp, ur->ds); 
}
1991/0720    
void 
dumpstack(void) 
{ 
} 
 
void 
execpc(ulong entry) 
{ 
	((Ureg*)UREGADDR)->pc = entry; 
}
1991/0718    
/*
1991/0710    
 *  system calls 
 */
1991/0720    
#undef	CHDIR	/* BUG */ 
#include "/sys/src/libc/9syscall/sys.h" 
 
typedef long Syscall(ulong*); 
Syscall	sysr1, sysfork, sysexec, sysgetpid, syssleep, sysexits, sysdeath, syswait; 
Syscall	sysopen, sysclose, sysread, syswrite, sysseek, syserrstr, sysaccess, sysstat, sysfstat; 
Syscall sysdup, syschdir, sysforkpgrp, sysbind, sysmount, syspipe, syscreate; 
Syscall	sysbrk_, sysremove, syswstat, sysfwstat, sysnotify, sysnoted, sysalarm; 
 
Syscall *systab[]={ 
	sysr1, 
	syserrstr, 
	sysbind, 
	syschdir, 
	sysclose, 
	sysdup, 
	sysalarm, 
	sysexec, 
	sysexits, 
	sysfork, 
	sysforkpgrp, 
	sysfstat, 
	sysdeath, 
	sysmount, 
	sysopen, 
	sysread, 
	sysseek, 
	syssleep, 
	sysstat, 
	syswait, 
	syswrite, 
	syspipe, 
	syscreate, 
	sysdeath, 
	sysbrk_, 
	sysremove, 
	syswstat, 
	sysfwstat, 
	sysnotify, 
	sysnoted, 
	sysdeath,	/* sysfilsys */ 
};
1991/0710    
long 
syscall(Ureg *ur) 
{
1991/0720    
	ulong	ax; 
	ulong	sp; 
	long	ret; 
	int	i; 
	static int times; 
ulong	*z;
1991/0718    
	u->p->insyscall = 1; 
	u->p->pc = ur->pc;
1991/0720    
	if((ur->cs)&0xffff == KESEL) 
		panic("recursive system call"); 
	u->p->insyscall = 0;
1991/0718    
1991/0720    
	/* 
	 *  do something about floating point!!! 
	 */ 
 
	ax = ur->ax; 
	sp = ur->usp; 
	u->nerrlab = 0; 
	ret = -1; 
z = (ulong *)sp; 
print("syscall %lux %lux %lux %lux\n", *z, *(z+1), *(z+2), *(z+3)); 
dumpregs(ur); 
if(++times==3) 
	panic("3rd time in syscall"); 
	if(!waserror()){ 
		if(ax >= sizeof systab/BY2WD){ 
			pprint("bad sys call number %d pc %lux\n", ax, ur->pc); 
			postnote(u->p, 1, "sys: bad sys call", NDebug); 
			error(Ebadarg); 
		} 
		if(sp<(USTKTOP-BY2PG) || sp>(USTKTOP-(1+MAXSYSARG)*BY2WD)) 
			validaddr(sp, (1+MAXSYSARG)*BY2WD, 0); 
		ret = (*systab[ax])((ulong*)(sp+BY2WD)); 
		poperror(); 
	} 
print("return from syscall\n"); 
	if(u->nerrlab){ 
		print("bad errstack [%d]: %d extra\n", ax, u->nerrlab); 
		for(i = 0; i < NERR; i++) 
			print("sp=%lux pc=%lux\n", u->errlab[i].sp, u->errlab[i].pc); 
		panic("error stack"); 
	} 
	u->p->insyscall = 0; 
	if(ax == NOTED){ 
		noted(ur, *(ulong*)(sp+BY2WD)); 
		ret = -1; 
	} else if(u->nnote){ 
		ur->ax = ret; 
		notify(ur); 
	} 
	return ret;
1991/0710    
}
1991/0720    
/* 
 *  Call user, if necessary, with note. 
 *  Pass user the Ureg struct and the note on his stack. 
 */
1991/0710    
void
1991/0720    
notify(Ureg *ur)
1991/0710    
{
1991/0720    
	ulong sp; 
 
	lock(&u->p->debug); 
	if(u->nnote==0){ 
		unlock(&u->p->debug); 
		return; 
	} 
	if(u->note[0].flag!=NUser && (u->notified || u->notify==0)){ 
		if(u->note[0].flag == NDebug) 
			pprint("suicide: %s\n", u->note[0].msg); 
    Die: 
		unlock(&u->p->debug); 
		pexit(u->note[0].msg, u->note[0].flag!=NDebug); 
	} 
	if(!u->notified){ 
		if(!u->notify) 
			goto Die; 
		u->svcs = ur->cs; 
		u->svss = ur->ss; 
		u->svflags = ur->flags; 
		sp = ur->usp; 
		sp -= sizeof(Ureg);
1991/0722    
		if(waserror()){ 
			pprint("suicide: trap in notify\n"); 
			unlock(&u->p->debug); 
			pexit("Suicide", 0); 
		} 
		validaddr((ulong)u->notify, 1, 0); 
		validaddr(sp-ERRLEN-3*BY2WD, sizeof(Ureg)+ERRLEN-3*BY2WD, 0); 
		poperror();
1991/0720    
		u->ureg = (void*)sp; 
		memmove((Ureg*)sp, ur, sizeof(Ureg)); 
		sp -= ERRLEN; 
		memmove((char*)sp, u->note[0].msg, ERRLEN); 
		sp -= 3*BY2WD; 
		*(ulong*)(sp+2*BY2WD) = sp+3*BY2WD;	/* arg 2 is string */ 
		*(ulong*)(sp+1*BY2WD) = (ulong)u->ureg;	/* arg 1 is ureg* */ 
		*(ulong*)(sp+0*BY2WD) = 0;		/* arg 0 is pc */ 
		ur->usp = sp; 
		ur->pc = (ulong)u->notify; 
		u->notified = 1; 
		u->nnote--; 
		memmove(&u->lastnote, &u->note[0], sizeof(Note)); 
		memmove(&u->note[0], &u->note[1], u->nnote*sizeof(Note)); 
	} 
	unlock(&u->p->debug);
1991/0710    
}
1991/0720    
/* 
 *   Return user to state before notify() 
 */
1991/0710    
void
1991/0720    
noted(Ureg *ur, ulong arg0)
1991/0710    
{
1991/0720    
	Ureg *nur; 
 
	nur = u->ureg; 
	validaddr(nur->pc, 1, 0); 
	validaddr(nur->usp, BY2WD, 0); 
	if(nur->cs!=u->svcs || nur->ss!=u->svss 
	|| (nur->flags&0xff)!=(u->svflags&0xff)){ 
		pprint("bad noted ureg cs %ux ss %ux flags %ux\n", nur->cs, nur->ss, 
			nur->flags); 
		pexit("Suicide", 0); 
	} 
	lock(&u->p->debug); 
	if(!u->notified){ 
		unlock(&u->p->debug); 
		return; 
	} 
	u->notified = 0; 
	nur->flags = (u->svflags&0xffffff00) | (ur->flags&0xff); 
	memmove(ur, u->ureg, sizeof(Ureg)); 
	ur->ax = -1;	/* return error from the interrupted call */ 
	switch(arg0){ 
	case NCONT: 
		splhi(); 
		unlock(&u->p->debug); 
		rfnote(ur); 
		break; 
		/* never returns */
1991/0722    
		return;
1991/0720    
 
	default: 
		pprint("unknown noted arg 0x%lux\n", arg0); 
		u->lastnote.flag = NDebug; 
		/* fall through */ 
		 
	case NDFLT: 
		if(u->lastnote.flag == NDebug) 
			pprint("suicide: %s\n", u->lastnote.msg); 
		unlock(&u->p->debug); 
		pexit(u->lastnote.msg, u->lastnote.flag!=NDebug); 
	}
1991/0614    
}


source code copyright © 1990-2005 Lucent Technologies; see license
Plan 9 distribution
comments to russ cox (rsc@swtch.com)