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#include	"u.h"
#include	"../port/lib.h"
#include	"mem.h"
#include	"dat.h"
#include	"fns.h"
#include	"ureg.h"
#include	"io.h"
#include	"../port/error.h"

void	noted(Ureg*, ulong);
void	rfnote(Ureg*);

char *regname[]={
	"R0",
	"R1",
	"R2",
	"R3",
	"R4",
	"R5",
	"R6",
	"R7",
	"A0",
	"A1",
	"A2",
	"A3",
	"A4",
	"A5",
	"A6",
	"A7",
};

long	ticks;

char *trapname[]={
	"reset isp",
	"reset ipc",
	"bus error",
	"address error",
	"illegal instruction",
	"zero divide",
	"chk, chk2 instruction",
	"trapcc instruction",
	"privilege violation",
	"trace",
	"line 1010 emulator",
	"line 1111 emulator",
	"reserved",
	"coprocessor protocol violation",
	"format error",
	"uninitialized interrupt",
	"unassigned 0x40",
	"unassigned 0x44",
	"unassigned 0x48",
	"unassigned 0x4C",
	"unassigned 0x50",
	"unassigned 0x54",
	"unassigned 0x58",
	"unassigned 0x5C",
	"spurious interrupt",
	"level 1 autovector (tac)",
	"level 2 autovector (port)",
	"level 3 autovector (incon)",
	"level 4 autovector (mouse)",
	"level 5 autovector (uart)",
	"level 6 autovector (sync)",
	"level 7 autovector",
};

char *fptrapname[]={
[49-49]	"inexact result",
[50-49]	"divide by zero",
[51-49]	"underflow",
[52-49]	"operand error",
[53-49]	"overflow",
[54-49]	"signaling NaN",
};

char*
excname(unsigned vo, ulong pc)
{
	static char buf[32];	/* BUG: not reentrant! */
	ulong fppc;

	vo &= 0x0FFF;
	vo >>= 2;
	if(vo < sizeof trapname/sizeof(char*)){
		/* special case, and pc will be o.k. */
		if(vo==4 && *(ushort*)pc==0x4848)
			return "breakpoint";
		sprint(buf, "trap: %s", trapname[vo]);
		return buf;
	}
	if(49<=vo && vo<=54){
		fppc = 0;
		if(u)
			fppc = *(ulong*)(u->fpsave.reg+8);
		sprint(buf, "fp: %s fppc=0x%lux", fptrapname[vo-49], fppc);
		return buf;
	}
	sprint(buf, "offset 0x%ux", vo<<2);
	return buf;
}

void
trap(Ureg *ur)
{
	int user;
	char buf[64];

	user = !(ur->sr&SUPER);

	if(u)
		u->dbgreg = ur;

	if(user){
		splhi();
		procsave(u->p);
		spllo();
		sprint(buf, "sys: %s", excname(ur->vo, ur->pc));
		postnote(u->p, 1, buf, NDebug);
	}else{
		print("kernel trap %s pc=0x%lux\n", excname(ur->vo, ur->pc), ur->pc);
		dumpregs(ur);
		exit(1);
	}

	if(user)
		notify(ur);
}

void
dumpstack(void)
{
	ulong l, v, i;
	extern ulong etext;

	if(u==0)
		return;

	i = 0;
	for(l=(ulong)&l; l<USERADDR+BY2PG; l+=4){
		v = *(ulong*)l;
		if(KTZERO < v && v < (ulong)&etext){
			print("%lux\t", v);
			if(++i == 4){
				i = 0;
				print("\n");
			}
		}
	}
	print("\n");
}

void
dumpregs(Ureg *ur)
{
	int i;
	ulong *l;

	if(u)
		print("registers for %s %d\n", u->p->text, u->p->pid);
	else
		print("registers for kernel\n");
	print("SR=%ux PC=%lux VO=%lux, USP=%lux\n", ur->sr, ur->pc, ur->vo, ur->usp);
	l = &ur->r0;
	for(i=0; i<sizeof regname/sizeof(char*); i+=2, l+=2)
		print("%s\t%.8lux\t%s\t%.8lux\n", regname[i], l[0], regname[i+1], l[1]);
}

/*
 * Call user, if necessary, with note
 */
int
notify(Ureg *ur)
{
	int l;
	ulong s, sp;
	Note *n;

	if(u->p->procctl)
		procctl(u->p);
	if(u->nnote == 0)
		return 0;

	s = spllo();
	qlock(&u->p->debug);
	u->p->notepending = 0;
	n = &u->note[0];
	if(strncmp(n->msg, "sys:", 4) == 0){
		l = strlen(n->msg);
		if(l > ERRLEN-15)	/* " pc=0x12345678\0" */
			l = ERRLEN-15;
		sprint(n->msg+l, " pc=0x%lux", ur->pc);
	}
	if(n->flag!=NUser && (u->notified || u->notify==0)){
		if(n->flag == NDebug){
			qunlock(&u->p->debug);
			pprint("suicide: %s\n", n->msg);
		}else
			qunlock(&u->p->debug);
		pexit(n->msg, n->flag!=NDebug);
	}

	if(u->notified){
		qunlock(&u->p->debug);
		splx(s);
		return 0;
	}

	if(!u->notify){
		qunlock(&u->p->debug);
		pexit(n->msg, n->flag!=NDebug);
	}

	sp = ur->usp - sizeof(Ureg);

	if(!okaddr((ulong)u->notify, BY2WD, 0)
	|| !okaddr(sp-ERRLEN-4*BY2WD, sizeof(Ureg)+ERRLEN+4*BY2WD, 1)){
		qunlock(&u->p->debug);
		pprint("suicide: bad address in notify\n");
		pexit("Suicide", 0);
	}

	memmove((Ureg*)sp, ur, sizeof(Ureg));
	*(Ureg**)(sp-BY2WD) = u->ureg;	/* word under Ureg is old u->ureg */
	u->ureg = (void*)sp;
	sp -= BY2WD+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;
	ur->vo = 0x0080;	/* pretend we're returning from syscall */
	u->notified = 1;
	u->nnote--;
	memmove(&u->lastnote, &u->note[0], sizeof(Note));
	memmove(&u->note[0], &u->note[1], u->nnote*sizeof(Note));
	qunlock(&u->p->debug);
	splx(s);
	return 1;
}

/*
 * Check that sr and vo are OK to return from note.
 */
int
validstatus(ushort usr, ushort uvo)
{
	ushort fmt, vector;
	static char okfmt[] = { 1, 1, 1, 0,  0, 0, 0, 0,  0, 1, 1, 1,  0, 0, 0, 0 };

	fmt = uvo>>12;
	if(!okfmt[fmt])
		return 0;
	if(uvo & 3)	/* offset must be even */
		return 0;
	vector = (uvo & 0xFFF) >> 2;
	if(vector<2 || vector >58)	/* <2 is reset; greater than 58 is undefined */
		return 0;
	if(usr & 0xFF00)	/* system byte must be clear */
		return 0;
	return 1;
}

/*
 * Return user to state before notify()
 */
void
noted(Ureg *ur, ulong arg0)
{
	Ureg *nur;
	ulong oureg, sp;

	qlock(&u->p->debug);
	if(arg0!=NRSTR && !u->notified){
		qunlock(&u->p->debug);
		pprint("call to noted() when not notified\n");
		pexit("Suicide", 0);
	}
	u->notified = 0;

	nur = u->ureg;

	oureg = (ulong)nur;
	if((oureg & (BY2WD-1))
	|| !okaddr((ulong)oureg-BY2WD, BY2WD+sizeof(Ureg), 0)){
		qunlock(&u->p->debug);
		pprint("bad ureg in noted or call to noted() when not notified\n");
		pexit("Suicide", 0);
	}

	if(!validstatus(nur->sr, nur->vo)){
		qunlock(&u->p->debug);
		pprint("bad noted ureg sr %ux vo %ux\n", nur->sr, nur->vo);
		pexit("Suicide", 0);
	}

	memmove(ur, u->ureg, sizeof(Ureg));
	switch(arg0){
	case NCONT:
	case NRSTR:
		if(!okaddr(nur->pc, 2, 0) || !okaddr(nur->usp, BY2WD, 0)){
			qunlock(&u->p->debug);
			pprint("suicide: trap in noted\n");
			pexit("Suicide", 0);
		}
		u->ureg = (Ureg*)(*(ulong*)(oureg-BY2WD));
		qunlock(&u->p->debug);
		splhi();
		rfnote(ur);
		break;
		/* never returns */

	case NSAVE:
		if(!okaddr(nur->pc, 2, 0) || !okaddr(nur->usp, BY2WD, 0)){
			qunlock(&u->p->debug);
			pprint("suicide: trap in noted\n");
			pexit("Suicide", 0);
		}
		qunlock(&u->p->debug);
		sp = oureg-4*BY2WD-ERRLEN;
		splhi();
		ur->vo = 0x0080;	/* we're returning from syscall */
		ur->usp = sp;
		((ulong*)sp)[1] = oureg;	/* arg 1 0(FP) is ureg* */
		((ulong*)sp)[0] = 0;			/* arg 0 is pc */
		rfnote(ur);
		break;

	default:
		u->lastnote.flag = NDebug;
		qunlock(&u->p->debug);
		pprint("unknown noted arg 0x%lux\n", arg0);
		pprint("suicide: %s\n", u->lastnote.msg);
		pexit(u->lastnote.msg, 0);
		
	case NDFLT:
		if(u->lastnote.flag == NDebug){
			qunlock(&u->p->debug);
			pprint("suicide: %s\n", u->lastnote.msg);
		}else
			qunlock(&u->p->debug);
		pexit(u->lastnote.msg, u->lastnote.flag!=NDebug);
	}
}

#include "../port/systab.h"

long
syscall(Ureg *aur)
{
	long ret;
	ulong sp;
	Ureg *ur;

	u->p->insyscall = 1;
	ur = aur;
	u->dbgreg = aur;
	u->p->pc = ur->pc;
	if(ur->sr & SUPER)
		panic("recursive system call");

	/* must save FP registers before fork */
	if(u->p->fpstate==FPactive && ur->r0==RFORK){
		splhi();
		procsave(u->p);
		spllo();
	}

	if(u->p->procctl)
		procctl(u->p);

	u->scallnr = ur->r0;
	sp = ur->usp;

	u->nerrlab = 0;
	ret = -1;
	if(!waserror()){
		if(u->scallnr >= sizeof systab/sizeof systab[0]){
			pprint("bad sys call number %d pc %lux\n", u->scallnr, ur->pc);
			postnote(u->p, 1, "sys: bad sys call", NDebug);
			error(Ebadarg);
		}

		if(sp & (BY2WD-1)){
			pprint("odd sp in sys call pc %lux sp %lux\n", ur->pc, ur->sp);
			postnote(u->p, 1, "sys: odd stack", NDebug);
			error(Ebadarg);
		}

		if(sp<(USTKTOP-BY2PG) || sp>(USTKTOP-sizeof(Sargs)))
			validaddr(sp, sizeof(Sargs), 0);

		u->s = *((Sargs*)(sp+1*BY2WD));
		u->p->psstate = sysctab[u->scallnr];

		ret = (*systab[u->scallnr])(u->s.args);
		poperror();
	}

	u->nerrlab = 0;
	u->p->insyscall = 0;
	u->p->psstate = 0;

	if(u->scallnr == NOTED)		/* ugly hack */
		noted(aur, *(ulong*)(sp+BY2WD));	/* doesn't return */
	splhi();
	if(u->scallnr!=RFORK && (u->p->procctl || u->nnote)){
		ur->r0 = ret;
		notify(ur);
	}
	return ret;
}

long
execregs(ulong entry, ulong ssize, ulong nargs)
{
	ulong *sp;

	sp = (ulong*)(USTKTOP - ssize);
	*--sp = nargs;
	((Ureg*)UREGADDR)->usp = (ulong)sp;
	((Ureg*)UREGADDR)->pc = entry;
	return USTKTOP-BY2WD;			/* address of user-level clock */
}

ulong
userpc(void)
{
	return ((Ureg*)UREGADDR)->pc;
}

/* This routine must save the values of registers the user is not permitted to write
 * from devproc and the restore the saved values before returning
 */
void
setregisters(Ureg *xp, char *pureg, char *uva, int n)
{
	ushort sr;
	ulong magic;
	ushort vo;
	char microstate[UREGVARSZ];

	sr = xp->sr;
	vo = xp->vo;
	magic = xp->magic;
	memmove(microstate, xp->microstate, UREGVARSZ);

	memmove(pureg, uva, n);

	xp->sr = (sr&0xff00) |(xp->sr&0xff);
	xp->vo = vo;
	xp->magic = magic;
	memmove(xp->microstate, microstate, UREGVARSZ);
}

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