From c31dff689b53ba518ff7e25f31505660ac3ef735 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Wed, 21 Jul 1999 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1999-07-21

---
 carrera/trap.c | 28 +++++++++++++++++-----------
 pc/devastar.c  |  4 ++--
 pc/trap.c      | 27 +++++++++++++++++++--------
 port/portfns.h |  1 +
 4 files changed, 39 insertions(+), 21 deletions(-)

diff --git a/carrera/trap.c b/carrera/trap.c
index 5d37e2a709fbed70b706c56f89932f1d73d75119..4cd1354cbbb9526169ce944aa82fc76419c40f72 100644
--- a/carrera/trap.c
+++ b/carrera/trap.c
@@ -469,30 +469,36 @@ kernfault(Ureg *ur, int code)
 	panic("kfault");
 }
 
-note rsc_wrote_this_but_has_not_checked_it yet;
-void
+static void
 getpcsp(ulong *pc, ulong *sp)
 {
 	*pc = getcallerpc(&pc);
-	sp = (ulong)&pc-4;
+	*sp = (ulong)&pc-4;
+}
+
+void
+callwithureg(void (*fn)(Ureg*))
+{
+	Ureg ureg;
+
+	getpcsp((ulong*)&ureg.pc, (ulong*)&ureg.sp);
+	ureg.r31 = getcallerpc(&fn);
+	fn(&ureg);
 }
 
 static void
-_dumpstack(ulong dummy)
+_dumpstack(Ureg *ureg)
 {
-	ulong pc, sp, link, l, v, top, i;
+	ulong l, v, top, i;
 	extern ulong etext;
 
 	if(up == 0)
 		return;
 
-	getpcsp(&pc, &sp);
-	link = getcallerpc(&dummy);
-
-	print("ktrace /kernel/path %.8lux %.8lux %.8lux\n", pc, sp, r31);
+	print("ktrace /kernel/path %.8lux %.8lux %.8lux\n", ureg->pc, ureg->sp, ureg->r31);
 	top = (ulong)up->kstack + KSTACK;
 	i = 0;
-	for(l=(ulong)&l; l < top; l += BY2WD) {
+	for(l=ureg->sp; l < top; l += BY2WD) {
 		v = *(ulong*)l;
 		if(KTZERO < v && v < (ulong)&etext) {
 			print("%.8lux=%.8lux ", l, v);
@@ -508,7 +514,7 @@ _dumpstack(ulong dummy)
 void
 dumpstack(void)
 {
-	_dumpstack(0);
+	callwithureg(_dumpstack);
 }
 
 ulong
diff --git a/pc/devastar.c b/pc/devastar.c
index 8193180f755e28682e175ff089d8a8a4fd851cff..f403f87761629ae9a5c0c02d5fbdf207cc4143ca 100644
--- a/pc/devastar.c
+++ b/pc/devastar.c
@@ -458,8 +458,8 @@ astarreset(void)
 			a->gcb = (GCB*)(a->mem+0x10000);
 
 			sprint(name, "astar%d", i);
-			if(ioalloc(a->port, p->mem[2].size, 0, name) < 0){
-				print("#G%d: port 0x%lux in use", a->id, a->port);
+			if(ioalloc(a->port, p->mem[1].size, 0, name) < 0){
+				print("#G%d: port 0x%lux in use\n", a->id, a->port);
 				xfree(a);
 				astar[nastar] = 0;
 				continue;
diff --git a/pc/trap.c b/pc/trap.c
index 9389a3bb3bc7c4f6c0c83dc0e654d5d25f1bd0be..dfb1e5b44e69bf5526389dcdbc6b045cb6ecfb1e 100644
--- a/pc/trap.c
+++ b/pc/trap.c
@@ -314,26 +314,31 @@ dumpregs(Ureg* ureg)
 	print("\n  ur %lux up %lux\n", ureg, up);
 }
 
+
+/*
+ * Fill in enough of Ureg to get a stack trace, and call a function.
+ * Used by debugging interface rdb.
+ */
 void
-getpcsp(ulong *pc, ulong *sp)
+callwithureg(void (*fn)(Ureg*))
 {
-	*pc = getcallerpc(&pc);
-	*sp = (ulong)&pc;
+	Ureg ureg;
+	ureg.pc = getcallerpc(&fn);
+	ureg.sp = (ulong)&fn;
+	fn(&ureg);
 }
 
-void
-dumpstack(void)
+static void
+_dumpstack(Ureg *ureg)
 {
 	ulong l, v, i;
-	ulong sp, pc;
 	uchar *p;
 	extern ulong etext;
 
 	if(up == 0)
 		return;
 
-	getpcsp(&pc, &sp);
-	print("ktrace /kernel/path %.8lux %.8lux\n", pc, sp);
+	print("ktrace /kernel/path %.8lux %.8lux\n", ureg->pc, ureg->sp);
 	i = 0;
 	for(l=(ulong)&l; l<(ulong)(up->kstack+KSTACK); l+=4){
 		v = *(ulong*)l;
@@ -358,6 +363,12 @@ dumpstack(void)
 		print("\n");
 }
 
+void
+dumpstack(void)
+{
+	callwithureg(_dumpstack);
+}
+
 static void
 debugbpt(Ureg* ureg, void*)
 {
diff --git a/port/portfns.h b/port/portfns.h
index bb419b2f679222b16a39c5e27db7a4a6d53ebce6..f9873ccf434a27305807b8d323bd7b938602c3be 100644
--- a/port/portfns.h
+++ b/port/portfns.h
@@ -22,6 +22,7 @@ Page*		auxpage(void);
 int		blocklen(Block*);
 void		cachedel(Image*, ulong);
 void		cachepage(Page*, Image*);
+void		callwithureg(void(*)(Ureg*));
 int		cangetc(void*);
 int		canlock(Lock*);
 int		canpage(Proc*);