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kernel: simplify notify() adding common popnote() function

Handlin notes is common for all architectures
except how the note has to be pushed on the user
stack.

This change adds a popnote() function that returns
only the note string or nil if the process should
not be notified (no notes or user notes hold off).

Popnote() also handles common errors like notify
during note handling or missing note handler and
will suicide the process in that case.

--- a/sys/src/9/bcm64/trap.c

+++ b/sys/src/9/bcm64/trap.c

@@ -274,9 +274,8 @@

 int

 notify(Ureg *ureg)

 {

-	int l;

 	uintptr s, sp;

-	Note *n;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -290,32 +289,13 @@

 	s = spllo();

 	qlock(&up->debug);

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0){

-		l = strlen(n->msg);

-		if(l > ERRMAX-23)	/* " pc=0x0123456789abcdef\0" */

-			l = ERRMAX-23;

-		sprint(n->msg+l, " pc=%#p", ureg->pc);

-	}

-

-	if(n->flag!=NUser && (up->notified || up->notify==0)){

+	msg = popnote(ureg);

+	if(msg == nil){

 		qunlock(&up->debug);

-		if(n->flag == NDebug)

-			pprint("suicide: %s\n", n->msg);

-		pexit(n->msg, n->flag!=NDebug);

-	}

-

-	if(up->notified){

-		qunlock(&up->debug);

 		splhi();

 		return 0;

 	}

-	if(!up->notify){

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag!=NDebug);

-	}

 	sp = ureg->sp;

 	sp -= 256;	/* debugging: preserve context causing problem */

 	sp -= sizeof(Ureg);

@@ -335,7 +315,7 @@

 	*(Ureg**)(sp-BY2WD) = up->ureg;	/* word under Ureg is old up->ureg */

 	up->ureg = (void*)sp;

 	sp -= BY2WD+ERRMAX;

-	memmove((char*)sp, up->note[0].msg, ERRMAX);

+	memmove((char*)sp, msg, ERRMAX);

 	sp -= 3*BY2WD;

 	*(uintptr*)(sp+2*BY2WD) = sp+3*BY2WD;

 	*(uintptr*)(sp+1*BY2WD) = (uintptr)up->ureg;

@@ -343,11 +323,6 @@

 	ureg->sp = sp;

 	ureg->pc = (uintptr) up->notify;

 	ureg->link = 0;

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

-

 	qunlock(&up->debug);

 	splx(s);

 	return 1;

--- a/sys/src/9/cycv/trap.c

+++ b/sys/src/9/cycv/trap.c

@@ -285,9 +285,8 @@

 int

 notify(Ureg *ureg)

 {

-	int l;

 	ulong s, sp;

-	Note *n;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -302,32 +301,13 @@

 	s = spllo();

 	qlock(&up->debug);

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0){

-		l = strlen(n->msg);

-		if(l > ERRMAX-15)	/* " pc=0x12345678\0" */

-			l = ERRMAX-15;

-		sprint(n->msg+l, " pc=0x%.8lux", ureg->pc);

-	}

-

-	if(n->flag!=NUser && (up->notified || up->notify==0)){

+	msg = popnote(ureg);

+	if(msg == nil){

 		qunlock(&up->debug);

-		if(n->flag == NDebug)

-			pprint("suicide: %s\n", n->msg);

-		pexit(n->msg, n->flag!=NDebug);

-	}

-

-	if(up->notified){

-		qunlock(&up->debug);

 		splhi();

 		return 0;

 	}

-	if(!up->notify){

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag!=NDebug);

-	}

 	sp = ureg->sp;

 	sp -= 256;	/* debugging: preserve context causing problem */

 	sp -= sizeof(Ureg);

@@ -345,7 +325,7 @@

 	*(Ureg**)(sp-BY2WD) = up->ureg;	/* word under Ureg is old up->ureg */

 	up->ureg = (void*)sp;

 	sp -= BY2WD+ERRMAX;

-	memmove((char*)sp, up->note[0].msg, ERRMAX);

+	memmove((char*)sp, msg, ERRMAX);

 	sp -= 3*BY2WD;

 	*(ulong*)(sp+2*BY2WD) = sp+3*BY2WD;

 	*(ulong*)(sp+1*BY2WD) = (ulong)up->ureg;

@@ -353,11 +333,6 @@

 	ureg->sp = sp;

 	ureg->pc = (uintptr) up->notify;

 	ureg->r14 = 0;

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

-

 	qunlock(&up->debug);

 	splx(s);

 	return 1;

--- a/sys/src/9/imx8/trap.c

+++ b/sys/src/9/imx8/trap.c

@@ -274,9 +274,8 @@

 int

 notify(Ureg *ureg)

 {

-	int l;

 	uintptr s, sp;

-	Note *n;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -290,32 +289,13 @@

 	s = spllo();

 	qlock(&up->debug);

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0){

-		l = strlen(n->msg);

-		if(l > ERRMAX-23)	/* " pc=0x0123456789abcdef\0" */

-			l = ERRMAX-23;

-		sprint(n->msg+l, " pc=%#p", ureg->pc);

-	}

-

-	if(n->flag!=NUser && (up->notified || up->notify==0)){

+	msg = popnote(ureg);

+	if(msg == nil){

 		qunlock(&up->debug);

-		if(n->flag == NDebug)

-			pprint("suicide: %s\n", n->msg);

-		pexit(n->msg, n->flag!=NDebug);

-	}

-

-	if(up->notified){

-		qunlock(&up->debug);

 		splhi();

 		return 0;

 	}

-	if(!up->notify){

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag!=NDebug);

-	}

 	sp = ureg->sp;

 	sp -= 256;	/* debugging: preserve context causing problem */

 	sp -= sizeof(Ureg);

@@ -335,7 +315,7 @@

 	*(Ureg**)(sp-BY2WD) = up->ureg;	/* word under Ureg is old up->ureg */

 	up->ureg = (void*)sp;

 	sp -= BY2WD+ERRMAX;

-	memmove((char*)sp, up->note[0].msg, ERRMAX);

+	memmove((char*)sp, msg, ERRMAX);

 	sp -= 3*BY2WD;

 	*(uintptr*)(sp+2*BY2WD) = sp+3*BY2WD;

 	*(uintptr*)(sp+1*BY2WD) = (uintptr)up->ureg;

@@ -343,11 +323,6 @@

 	ureg->sp = sp;

 	ureg->pc = (uintptr) up->notify;

 	ureg->link = 0;

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

-

 	qunlock(&up->debug);

 	splx(s);

 	return 1;

--- a/sys/src/9/kw/syscall.c

+++ b/sys/src/9/kw/syscall.c

@@ -98,11 +98,10 @@

 int

 notify(Ureg* ureg)

 {

-	int l;

-	Note *n;

 	u32int s;

 	uintptr sp;

 	NFrame *nf;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -113,33 +112,13 @@

 	s = spllo();

 	qlock(&up->debug);

-

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0){

-		l = strlen(n->msg);

-		if(l > ERRMAX-23)	/* " pc=0x0123456789abcdef\0" */

-			l = ERRMAX-23;

-		snprint(n->msg + l, sizeof n->msg - l, " pc=%#lux", ureg->pc);

-	}

-

-	if(n->flag != NUser && (up->notified || up->notify == 0)){

+	msg = popnote(ureg);

+	if(msg == nil){

 		qunlock(&up->debug);

-		if(n->flag == NDebug)

-			pprint("suicide: %s\n", n->msg);

-		pexit(n->msg, n->flag != NDebug);

-	}

-

-	if(up->notified){

-		qunlock(&up->debug);

 		splhi();

 		return 0;

 	}

-		

-	if(up->notify == nil){

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag != NDebug);

-	}

+

 	if(!okaddr((uintptr)up->notify, 1, 0)){

 		qunlock(&up->debug);

 		pprint("suicide: notify function address %#p\n", up->notify);

@@ -157,7 +136,7 @@

 	memmove(&nf->ureg, ureg, sizeof(Ureg));

 	nf->old = up->ureg;

 	up->ureg = nf;

-	memmove(nf->msg, up->note[0].msg, ERRMAX);

+	memmove(nf->msg, msg, ERRMAX);

 	nf->arg1 = nf->msg;

 	nf->arg0 = &nf->ureg;

 	nf->ip = 0;

@@ -165,11 +144,6 @@

 	ureg->sp = sp;

 	ureg->pc = (uintptr)up->notify;

 	ureg->r0 = (uintptr)nf->arg0;

-

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

 	qunlock(&up->debug);

 	splx(s);

--- a/sys/src/9/mtx/trap.c

+++ b/sys/src/9/mtx/trap.c

@@ -677,9 +677,8 @@

 int

 notify(Ureg* ur)

 {

-	int l;

 	ulong s, sp;

-	Note *n;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -688,32 +687,13 @@

 	s = spllo();

 	qlock(&up->debug);

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0){

-		l = strlen(n->msg);

-		if(l > ERRMAX-15)	/* " pc=0x12345678\0" */

-			l = ERRMAX-15;

-		sprint(n->msg+l, " pc=0x%.8lux", ur->pc);

-	}

-

-	if(n->flag!=NUser && (up->notified || up->notify==0)){

+	msg = popnote(ur);

+	if(msg == nil){

 		qunlock(&up->debug);

-		if(n->flag == NDebug)

-			pprint("suicide: %s\n", n->msg);

-		pexit(n->msg, n->flag!=NDebug);

-	}

-

-	if(up->notified) {

-		qunlock(&up->debug);

 		splhi();

 		return 0;

 	}

-	if(!up->notify) {

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag!=NDebug);

-	}

 	sp = ur->usp & ~(BY2V-1);

 	sp -= sizeof(Ureg);

@@ -728,7 +708,7 @@

 	*(Ureg**)(sp-BY2WD) = up->ureg;	/* word under Ureg is old up->ureg */

 	up->ureg = (void*)sp;

 	sp -= BY2WD+ERRMAX;

-	memmove((char*)sp, up->note[0].msg, ERRMAX);

+	memmove((char*)sp, msg, ERRMAX);

 	sp -= 3*BY2WD;

 	*(ulong*)(sp+2*BY2WD) = sp+3*BY2WD;	/* arg 2 is string */

 	ur->r1 = (long)up->ureg;		/* arg 1 is ureg* */

@@ -736,11 +716,6 @@

 	((ulong*)sp)[0] = 0;			/* arg 0 is pc */

 	ur->usp = sp;

 	ur->pc = (ulong)up->notify;

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

-

 	qunlock(&up->debug);

 	splx(s);

 	return 1;

--- a/sys/src/9/omap/syscall.c

+++ b/sys/src/9/omap/syscall.c

@@ -98,11 +98,10 @@

 int

 notify(Ureg* ureg)

 {

-	int l;

-	Note *n;

 	u32int s;

 	uintptr sp;

 	NFrame *nf;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -113,33 +112,13 @@

 	s = spllo();

 	qlock(&up->debug);

-

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0){

-		l = strlen(n->msg);

-		if(l > ERRMAX-23)	/* " pc=0x0123456789abcdef\0" */

-			l = ERRMAX-23;

-		snprint(n->msg + l, sizeof n->msg - l, " pc=%#lux", ureg->pc);

-	}

-

-	if(n->flag != NUser && (up->notified || up->notify == 0)){

+	msg = popnote(ureg);

+	if(msg == nil){

 		qunlock(&up->debug);

-		if(n->flag == NDebug)

-			pprint("suicide: %s\n", n->msg);

-		pexit(n->msg, n->flag != NDebug);

-	}

-

-	if(up->notified){

-		qunlock(&up->debug);

 		splhi();

 		return 0;

 	}

-		

-	if(up->notify == nil){

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag != NDebug);

-	}

+

 	if(!okaddr((uintptr)up->notify, 1, 0)){

 		qunlock(&up->debug);

 		pprint("suicide: notify function address %#p\n", up->notify);

@@ -157,7 +136,7 @@

 	memmove(&nf->ureg, ureg, sizeof(Ureg));

 	nf->old = up->ureg;

 	up->ureg = nf;

-	memmove(nf->msg, up->note[0].msg, ERRMAX);

+	memmove(nf->msg, msg, ERRMAX);

 	nf->arg1 = nf->msg;

 	nf->arg0 = &nf->ureg;

 	nf->ip = 0;

@@ -165,11 +144,6 @@

 	ureg->sp = sp;

 	ureg->pc = (uintptr)up->notify;

 	ureg->r0 = (uintptr)nf->arg0;

-

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

 	qunlock(&up->debug);

 	splx(s);

--- a/sys/src/9/pc/trap.c

+++ b/sys/src/9/pc/trap.c

@@ -565,9 +565,8 @@

 int

 notify(Ureg* ureg)

 {

-	int l;

 	ulong s, sp;

-	Note *n;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -582,37 +581,18 @@

 	s = spllo();

 	qlock(&up->debug);

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0){

-		l = strlen(n->msg);

-		if(l > ERRMAX-15)	/* " pc=0x12345678\0" */

-			l = ERRMAX-15;

-		sprint(n->msg+l, " pc=0x%.8lux", ureg->pc);

-	}

-

-	if(n->flag!=NUser && (up->notified || up->notify==0)){

+	msg = popnote(ureg);

+	if(msg == nil){

 		qunlock(&up->debug);

-		if(n->flag == NDebug)

-			pprint("suicide: %s\n", n->msg);

-		pexit(n->msg, n->flag!=NDebug);

-	}

-

-	if(up->notified){

-		qunlock(&up->debug);

 		splhi();

 		return 0;

 	}

-	if(!up->notify){

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag!=NDebug);

-	}

 	sp = ureg->usp;

 	sp -= 256;	/* debugging: preserve context causing problem */

 	sp -= sizeof(Ureg);

 if(0) print("%s %lud: notify %.8lux %.8lux %.8lux %s\n",

-	up->text, up->pid, ureg->pc, ureg->usp, sp, n->msg);

+	up->text, up->pid, ureg->pc, ureg->usp, sp, msg);

 	if(!okaddr((uintptr)up->notify, 1, 0)

 	|| !okaddr(sp-ERRMAX-4*BY2WD, sizeof(Ureg)+ERRMAX+4*BY2WD, 1)){

@@ -625,7 +605,7 @@

 	*(Ureg**)(sp-BY2WD) = up->ureg;	/* word under Ureg is old up->ureg */

 	up->ureg = (void*)sp;

 	sp -= BY2WD+ERRMAX;

-	memmove((char*)sp, up->note[0].msg, ERRMAX);

+	memmove((char*)sp, msg, ERRMAX);

 	sp -= 3*BY2WD;

 	*(ulong*)(sp+2*BY2WD) = sp+3*BY2WD;		/* arg 2 is string */

 	*(ulong*)(sp+1*BY2WD) = (ulong)up->ureg;	/* arg 1 is ureg* */

@@ -634,11 +614,6 @@

 	ureg->pc = (ulong)up->notify;

 	ureg->cs = UESEL;

 	ureg->ss = ureg->ds = ureg->es = UDSEL;

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

-

 	qunlock(&up->debug);

 	splx(s);

 	return 1;

--- a/sys/src/9/pc64/trap.c

+++ b/sys/src/9/pc64/trap.c

@@ -554,9 +554,8 @@

 int

 notify(Ureg* ureg)

 {

-	int l;

 	uintptr sp;

-	Note *n;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -564,39 +563,18 @@

 		return 0;

 	spllo();

 	qlock(&up->debug);

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0){

-		l = strlen(n->msg);

-		if(l > ERRMAX-15)	/* " pc=0x12345678\0" */

-			l = ERRMAX-15;

-		sprint(n->msg+l, " pc=%#p", ureg->pc);

-	}

-

-	if(n->flag!=NUser && (up->notified || up->notify==0)){

+	msg = popnote(ureg);

+	if(msg == nil){

 		qunlock(&up->debug);

-		if(n->flag == NDebug){

-			up->fpstate &= ~FPillegal;

-			pprint("suicide: %s\n", n->msg);

-		}

-		pexit(n->msg, n->flag!=NDebug);

-	}

-

-	if(up->notified){

-		qunlock(&up->debug);

 		splhi();

 		return 0;

 	}

-	if(!up->notify){

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag!=NDebug);

-	}

 	sp = ureg->sp;

 	sp -= 256;	/* debugging: preserve context causing problem */

 	sp -= sizeof(Ureg);

 if(0) print("%s %lud: notify %#p %#p %#p %s\n",

-	up->text, up->pid, ureg->pc, ureg->sp, sp, n->msg);

+	up->text, up->pid, ureg->pc, ureg->sp, sp, msg);

 	if(!okaddr((uintptr)up->notify, 1, 0)

 	|| !okaddr(sp-ERRMAX-4*BY2WD, sizeof(Ureg)+ERRMAX+4*BY2WD, 1)){

@@ -610,7 +588,7 @@

 	*(Ureg**)(sp-BY2WD) = up->ureg;	/* word under Ureg is old up->ureg */

 	up->ureg = (void*)sp;

 	sp -= BY2WD+ERRMAX;

-	memmove((char*)sp, up->note[0].msg, ERRMAX);

+	memmove((char*)sp, msg, ERRMAX);

 	sp -= 3*BY2WD;

 	((uintptr*)sp)[2] = sp + 3*BY2WD;	/* arg2 string */

 	((uintptr*)sp)[1] = (uintptr)up->ureg;	/* arg1 is ureg* */

@@ -620,10 +598,6 @@

 	ureg->bp = (uintptr)up->ureg;		/* arg1 passed in RARG */

 	ureg->cs = UESEL;

 	ureg->ss = UDSEL;

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

 	qunlock(&up->debug);

 	splhi();

 	if(up->fpstate == FPactive){

--- a/sys/src/9/port/portfns.h

+++ b/sys/src/9/port/portfns.h

@@ -235,6 +235,7 @@

 #define		waserror()		setlabel(&up->errlab[up->nerrlab++])

 #define		poperror()		up->nerrlab--

 void		portcountpagerefs(ulong*, int);

+char*		popnote(Ureg*);

 int		postnote(Proc*, int, char*, int);

 int		pprint(char*, ...);

 int		preempted(void);

--- a/sys/src/9/port/proc.c

+++ b/sys/src/9/port/proc.c

@@ -899,6 +899,48 @@

 }

 /*

+ *  pop a note from the calling process or suicide if theres

+ *  no note handler or notify during note handling. 

+ *  Called from notify() with up->debug lock held.

+ */

+char*

+popnote(Ureg *u)

+{

+	assert(!canqlock(&up->debug));

+

+	up->notepending = 0;

+	if(up->nnote == 0)

+		return nil;

+	assert(up->nnote > 0);

+

+	/* hold off user notes during note handling */

+	if(up->notified && up->note[0].flag == NUser)

+		return nil;

+

+	memmove(&up->lastnote, &up->note[0], sizeof(Note));

+	if(--up->nnote)

+		memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

+

+	if(u != nil && strncmp(up->lastnote.msg, "sys:", 4) == 0){

+		int l = strlen(up->lastnote.msg);

+		assert(l < ERRMAX);

+		snprint(up->lastnote.msg+l, ERRMAX-l, " pc=%#p", u->pc);

+	}

+

+	if(up->notify == nil || up->notified){

+		qunlock(&up->debug);

+		if(up->lastnote.flag == NDebug){

+			up->fpstate &= ~FPillegal;

+			pprint("suicide: %s\n", up->lastnote.msg);

+		}

+		pexit(up->lastnote.msg, up->lastnote.flag!=NDebug);

+	}

+	up->notified = 1;

+

+	return up->lastnote.msg;

+}

+

+/*

  *  if waking a sleeping process, this routine must hold both

  *  p->rlock and r->lock.  However, it can't know them in

  *  the same order as wakeup causing a possible lock ordering

--- a/sys/src/9/ppc/trap.c

+++ b/sys/src/9/ppc/trap.c

@@ -666,9 +666,8 @@

 int

 notify(Ureg* ur)

 {

-	int l;

 	ulong s, sp;

-	Note *n;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -683,33 +682,13 @@

 	s = spllo();

 	qlock(&up->debug);

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0){

-		l = strlen(n->msg);

-		if(l > ERRMAX-15)	/* " pc=0x12345678\0" */

-			l = ERRMAX-15;

-		sprint(n->msg+l, " pc=0x%.8lux", ur->pc);

-	}

-

-	if(n->flag!=NUser && (up->notified || up->notify==0)){

+	msg = popnote(ur);

+	if(msg == nil){

 		qunlock(&up->debug);

-		if(n->flag == NDebug)

-			pprint("suicide: %s\n", n->msg);

-		pexit(n->msg, n->flag!=NDebug);

-	}

-

-	if(up->notified) {

-		qunlock(&up->debug);

 		splhi();

 		return 0;

 	}

-	if(!up->notify) {

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag!=NDebug);

-	}

-

 	sp = ur->usp & ~(BY2V-1);

 	sp -= sizeof(Ureg);

@@ -724,7 +703,7 @@

 	*(Ureg**)(sp-BY2WD) = up->ureg;	/* word under Ureg is old up->ureg */

 	up->ureg = (void*)sp;

 	sp -= BY2WD+ERRMAX;

-	memmove((char*)sp, up->note[0].msg, ERRMAX);

+	memmove((char*)sp, msg, ERRMAX);

 	sp -= 3*BY2WD;

 	*(ulong*)(sp+2*BY2WD) = sp+3*BY2WD;	/* arg 2 is string */

 	ur->r1 = (long)up->ureg;		/* arg 1 is ureg* */

@@ -732,11 +711,6 @@

 	((ulong*)sp)[0] = 0;			/* arg 0 is pc */

 	ur->usp = sp;

 	ur->pc = (ulong)up->notify;

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

-

 	qunlock(&up->debug);

 	splx(s);

 	return 1;

--- a/sys/src/9/sgi/trap.c

+++ b/sys/src/9/sgi/trap.c

@@ -470,9 +470,9 @@

 int

 notify(Ureg *ur)

 {

-	int l, s;

+	int s;

 	ulong sp;

-	Note *n;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -487,34 +487,13 @@

 	s = spllo();

 	qlock(&up->debug);

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0) {

-		l = strlen(n->msg);

-		if(l > ERRMAX-15)	/* " pc=0x12345678\0" */

-			l = ERRMAX-15;

-

-		seprint(n->msg+l, &n->msg[sizeof n->msg], " pc=%#lux", ur->pc);

-	}

-

-	if(n->flag != NUser && (up->notified || up->notify==0)) {

-		if(n->flag == NDebug)

-			pprint("suicide: %s\n", n->msg);

-

+	msg = popnote(ur);

+	if(msg == nil){

 		qunlock(&up->debug);

-		pexit(n->msg, n->flag!=NDebug);

-	}

-

-	if(up->notified) {

-		qunlock(&up->debug);

 		splx(s);

 		return 0;

 	}

-	if(!up->notify) {

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag!=NDebug);

-	}

 	sp = ur->usp & ~(BY2V-1);

 	sp -= sizeof(Ureg);

@@ -530,7 +509,7 @@

 	up->ureg = (void*)sp;

 	sp -= BY2WD+ERRMAX;

-	memmove((char*)sp, up->note[0].msg, ERRMAX);	/* push err string */

+	memmove((char*)sp, msg, ERRMAX);	/* push err string */

 	sp -= 3*BY2WD;

 	*(ulong*)(sp+2*BY2WD) = sp+3*BY2WD;	/* arg 2 is string */

@@ -543,11 +522,6 @@

 	 * were being called.

 	 */

 	ur->pc = (ulong)up->notify;

-

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

 	qunlock(&up->debug);

 	splx(s);

--- a/sys/src/9/teg2/syscall.c

+++ b/sys/src/9/teg2/syscall.c

@@ -104,11 +104,10 @@

 int

 notify(Ureg* ureg)

 {

-	int l;

-	Note *n;

 	u32int s;

 	uintptr sp;

 	NFrame *nf;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -119,33 +118,13 @@

 	s = spllo();

 	qlock(&up->debug);

-

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0){

-		l = strlen(n->msg);

-		if(l > ERRMAX-23)	/* " pc=0x0123456789abcdef\0" */

-			l = ERRMAX-23;

-		snprint(n->msg + l, sizeof n->msg - l, " pc=%#lux", ureg->pc);

-	}

-

-	if(n->flag != NUser && (up->notified || up->notify == 0)){

+	msg = popnote(ureg);

+	if(msg == nil){

 		qunlock(&up->debug);

-		if(n->flag == NDebug)

-			pprint("suicide: %s\n", n->msg);

-		pexit(n->msg, n->flag != NDebug);

-	}

-

-	if(up->notified){

-		qunlock(&up->debug);

 		splhi();

 		return 0;

 	}

-		

-	if(up->notify == nil){

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag != NDebug);

-	}

+

 	if(!okaddr((uintptr)up->notify, 1, 0)){

 		qunlock(&up->debug);

 		pprint("suicide: notify function address %#p\n", up->notify);

@@ -163,7 +142,7 @@

 	memmove(&nf->ureg, ureg, sizeof(Ureg));

 	nf->old = up->ureg;

 	up->ureg = nf;

-	memmove(nf->msg, up->note[0].msg, ERRMAX);

+	memmove(nf->msg, msg, ERRMAX);

 	nf->arg1 = nf->msg;

 	nf->arg0 = &nf->ureg;

 	nf->ip = 0;

@@ -171,11 +150,6 @@

 	ureg->sp = sp;

 	ureg->pc = (uintptr)up->notify;

 	ureg->r0 = (uintptr)nf->arg0;

-

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

 	qunlock(&up->debug);

 	splx(s);

--- a/sys/src/9/xen/trap.c

+++ b/sys/src/9/xen/trap.c

@@ -480,9 +480,8 @@

 int

 notify(Ureg* ureg)

 {

-	int l;

 	ulong s, sp;

-	Note *n;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -497,39 +496,20 @@

 	s = spllo();

 	qlock(&up->debug);

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0){

-		l = strlen(n->msg);

-		if(l > ERRMAX-15)	/* " pc=0x12345678\0" */

-			l = ERRMAX-15;

-		sprint(n->msg+l, " pc=0x%.8lux", ureg->pc);

-	}

-

-	if(n->flag!=NUser && (up->notified || up->notify==0)){

-		if(n->flag == NDebug)

-			pprint("suicide: %s\n", n->msg);

+	msg = popnote(ureg);

+	if(msg == nil){

 		qunlock(&up->debug);

-		pexit(n->msg, n->flag!=NDebug);

-	}

-

-	if(up->notified){

-		qunlock(&up->debug);

 		splhi();

 		return 0;

 	}

-		

-	if(!up->notify){

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag!=NDebug);

-	}

+

 	sp = ureg->usp;

 	sp -= sizeof(Ureg);

 	if(!okaddr((ulong)up->notify, 1, 0)

 	|| !okaddr(sp-ERRMAX-4*BY2WD, sizeof(Ureg)+ERRMAX+4*BY2WD, 1)){

-		pprint("suicide: bad address in notify\n");

 		qunlock(&up->debug);

+		pprint("suicide: bad address in notify\n");

 		pexit("Suicide", 0);

 	}

@@ -538,7 +518,7 @@

 	*(Ureg**)(sp-BY2WD) = up->ureg;	/* word under Ureg is old up->ureg */

 	up->ureg = (void*)sp;

 	sp -= BY2WD+ERRMAX;

-	memmove((char*)sp, up->note[0].msg, ERRMAX);

+	memmove((char*)sp, msg, ERRMAX);

 	sp -= 3*BY2WD;

 	*(ulong*)(sp+2*BY2WD) = sp+3*BY2WD;		/* arg 2 is string */

 	*(ulong*)(sp+1*BY2WD) = (ulong)up->ureg;	/* arg 1 is ureg* */

@@ -545,11 +525,6 @@

 	*(ulong*)(sp+0*BY2WD) = 0;			/* arg 0 is pc */

 	ureg->usp = sp;

 	ureg->pc = (ulong)up->notify;

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

-

 	qunlock(&up->debug);

 	splx(s);

 	return 1;

--- a/sys/src/9/zynq/trap.c

+++ b/sys/src/9/zynq/trap.c

@@ -285,9 +285,8 @@

 int

 notify(Ureg *ureg)

 {

-	int l;

 	ulong s, sp;

-	Note *n;

+	char *msg;

 	if(up->procctl)

 		procctl();

@@ -302,32 +301,13 @@

 	s = spllo();

 	qlock(&up->debug);

-	up->notepending = 0;

-	n = &up->note[0];

-	if(strncmp(n->msg, "sys:", 4) == 0){

-		l = strlen(n->msg);

-		if(l > ERRMAX-15)	/* " pc=0x12345678\0" */

-			l = ERRMAX-15;

-		sprint(n->msg+l, " pc=0x%.8lux", ureg->pc);

-	}

-

-	if(n->flag!=NUser && (up->notified || up->notify==0)){

+	msg = popnote(ureg);

+	if(msg == nil){

 		qunlock(&up->debug);

-		if(n->flag == NDebug)

-			pprint("suicide: %s\n", n->msg);

-		pexit(n->msg, n->flag!=NDebug);

-	}

-

-	if(up->notified){

-		qunlock(&up->debug);

 		splhi();

 		return 0;

 	}

-	if(!up->notify){

-		qunlock(&up->debug);

-		pexit(n->msg, n->flag!=NDebug);

-	}

 	sp = ureg->sp;

 	sp -= 256;	/* debugging: preserve context causing problem */

 	sp -= sizeof(Ureg);

@@ -345,7 +325,7 @@

 	*(Ureg**)(sp-BY2WD) = up->ureg;	/* word under Ureg is old up->ureg */

 	up->ureg = (void*)sp;

 	sp -= BY2WD+ERRMAX;

-	memmove((char*)sp, up->note[0].msg, ERRMAX);

+	memmove((char*)sp, msg, ERRMAX);

 	sp -= 3*BY2WD;

 	*(ulong*)(sp+2*BY2WD) = sp+3*BY2WD;

 	*(ulong*)(sp+1*BY2WD) = (ulong)up->ureg;

@@ -353,11 +333,6 @@

 	ureg->sp = sp;

 	ureg->pc = (uintptr) up->notify;

 	ureg->r14 = 0;

-	up->notified = 1;

-	up->nnote--;

-	memmove(&up->lastnote, &up->note[0], sizeof(Note));

-	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));

-

 	qunlock(&up->debug);

 	splx(s);

 	return 1;