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.

1 files changed, 5 insertions, 31 deletions

diff --git a/sys/src/9/pc64/trap.c b/sys/src/9/pc64/trap.c
index e18790c33..44379160d 100644
--- a/sys/src/9/pc64/trap.c
+++ b/sys/src/9/pc64/trap.c
@@ -554,9 +554,8 @@ syscall(Ureg* ureg)
 int
 notify(Ureg* ureg)
 {
-	int l;
 	uintptr sp;
-	Note *n;
+	char *msg;
 
 	if(up->procctl)
 		procctl();
@@ -564,39 +563,18 @@ notify(Ureg* ureg)
 		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)){
-		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){
+	msg = popnote(ureg);
+	if(msg == nil){
 		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 @@ if(0) print("%s %lud: notify %#p %#p %#p %s\n",
 	*(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 @@ if(0) print("%s %lud: notify %#p %#p %#p %s\n",
 	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){