From c42eb44c6d3a808ac425cbfbbaa2cf175b72cd55 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 2 Aug 1990 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1990-08-02

---
 gnot/devenv.c   |  2 +-
 gnot/devincon.c |  2 ++
 gnot/errno.h    |  1 +
 gnot/fault.c    |  8 +++++++-
 gnot/fns.h      |  2 +-
 gnot/main.c     |  1 +
 gnot/page.c     | 47 ++++++++++++++++++++++++++++++++++++++---------
 port/devenv.c   |  2 +-
 port/fault.c    |  8 +++++++-
 port/page.c     | 48 +++++++++++++++++++++++++++++++++++++-----------
 power/clock.c   |  2 +-
 power/errno.h   |  1 +
 power/fns.h     |  2 +-
 power/main.c    |  7 ++++++-
 power/trap.c    |  2 +-
 15 files changed, 106 insertions(+), 29 deletions(-)

diff --git a/gnot/devenv.c b/gnot/devenv.c
index 1d6d78ba85e288b6b28d075847a734f383d5d22d..96f3af5ccf7fe927d25dbde4140b85dab426cf9f 100644
--- a/gnot/devenv.c
+++ b/gnot/devenv.c
@@ -143,7 +143,7 @@ compactenv(Env *e, ulong n)
 				goto Free;
 			}
 			if(p2+p2->n > envalloc.end)
-				panic("compactpte copying too much");
+				panic("compactenv copying too much");
 			memcpy(p1, p2, p2->n*sizeof(Envval));
 			p2e->val = p1;
 			if(p2e != e)
diff --git a/gnot/devincon.c b/gnot/devincon.c
index b8cf9b0c8d6d8c4414eb3c1f3e2b853a3772435f..10bf3df2cdd9896d78629dd6c59f75c277358340 100644
--- a/gnot/devincon.c
+++ b/gnot/devincon.c
@@ -493,6 +493,8 @@ inconoput(Queue *q, Block *bp)
 	chan = bp->rptr[0] | (bp->rptr[1]<<8);
 	ctl = bp->rptr[2];
 	bp->rptr += 3;
+	if(chan<=0)
+		print("bad channel %d\n", chan);
 
 	if(incondebug)
 		print("->(%d)%uo %d\n", chan, ctl, bp->wptr - bp->rptr);
diff --git a/gnot/errno.h b/gnot/errno.h
index ee070d757d339a590130a6765dd747ff37150b39..4ac80562c89324daa3612a6731601e569e28c10f 100644
--- a/gnot/errno.h
+++ b/gnot/errno.h
@@ -55,5 +55,6 @@ enum{
 	Ebadmsg,	/* format error or mismatch in message */
 	Ebadcnt,	/* read count greater than requested */
 	Enofont,	/* out of font descriptors */
+	Enovmem,	/* virtual memory allocation failed */
 	Egreg,		/* it's all greg's fault */
 };
diff --git a/gnot/fault.c b/gnot/fault.c
index 6027cdfc1beb30e60341383a3ccc5a893479adc0..0f1cffb263f0022b03a59836520ca421cca5b6e6 100644
--- a/gnot/fault.c
+++ b/gnot/fault.c
@@ -108,9 +108,15 @@ fault(Ureg *ur, FFrame *f)
 		/* grow stack */
 		o = s->o;
 		n = o->npte;
+		lock(o);
+		if(waserror()){
+			unlock(o);
+			pprint("can't allocate stack page\n");
+			goto cant;
+		}
 		growpte(o, (s->maxva-addr)>>PGSHIFT);
+		poperror();
 		/* stacks grown down, sigh */
-		lock(o);
 		memcpy(o->pte+(o->npte-n), o->pte, n*sizeof(PTE));
 		memset(o->pte, 0, (o->npte-n)*sizeof(PTE));
 		unlock(o);
diff --git a/gnot/fns.h b/gnot/fns.h
index d74b10897f92ef49423a5675bc3505cde05edb91..7a086ab0b8ad1098d637048bbde7989104ac5a2f 100644
--- a/gnot/fns.h
+++ b/gnot/fns.h
@@ -15,7 +15,7 @@ void	close(Chan*);
 void	closemount(Mount*);
 void	closepgrp(Pgrp*);
 long	clrfpintr(void);
-void	compactpte(Orig*, ulong);
+int	compactpte(Orig*, ulong);
 void	confinit(void);
 Env	*copyenv(Env*, int);
 int	decref(Ref*);
diff --git a/gnot/main.c b/gnot/main.c
index 37c757e4711ec0c32847d6a3a3c29e38eee1d5ae..3cdaa1970e8a43d5be091bfe55c2b93bce455e7e 100644
--- a/gnot/main.c
+++ b/gnot/main.c
@@ -160,6 +160,7 @@ userinit(void)
 	s->proc = p;
 	s->o = neworig(UTZERO, 1, 0, 0);
 	s->o->pte[0].page = newpage(0, 0, UTZERO);
+	s->o->npage = 1;
 	k = kmap(s->o->pte[0].page);
 	memcpy((ulong*)VA(k), initcode, sizeof initcode);
 	kunmap(k);
diff --git a/gnot/page.c b/gnot/page.c
index e0164e6422dff0e2be3e66857d5b00669bd46ddf..469d9db07098a682e4e81f038ab2163c84a2e6dc 100644
--- a/gnot/page.c
+++ b/gnot/page.c
@@ -4,6 +4,7 @@
 #include	"dat.h"
 #include	"fns.h"
 #include	"ureg.h"
+#include	"errno.h"
 
 struct
 {
@@ -310,7 +311,16 @@ loop:
 			o->mqid = -1;
 			o->mchan = 0;
 		}
+		lock(o);
+		if(u && u->p && waserror()){
+			unlock(o);
+			unlock(&origalloc);
+			nexterror();
+		}
 		growpte(o, npte);
+		if(u && u->p)
+			poperror();
+		unlock(o);
 		unlock(&origalloc);
 		return o;
 	}
@@ -505,8 +515,15 @@ segaddr(Seg *s, ulong min, ulong max)
 		 * Grow
 		 */
 		/* BUG: check spill onto other segments */
+		lock(o);
+		if(waserror()){
+			unlock(o);
+			nexterror();
+		}
 		if(o->va+BY2PG*o->npte < max)
 			growpte(o, (max-o->va)>>PGSHIFT);
+		unlock(o);
+		poperror();
 		s->maxva = max;
 		return 1;
 	}
@@ -558,9 +575,9 @@ growpte(Orig *o, ulong n)
 	ulong nfree;
 
 	lock(&ptealloc);
-	lock(o);
 	if(o->pte){
 		if(o->npte == n){
+if(u && u->p) print("%s: ", u->p->text);
 			print("growpte pointless\n");
 			goto Return;
 		}
@@ -577,11 +594,13 @@ growpte(Orig *o, ulong n)
 		}else{
 			n++;
 			if(p+p->n == ptealloc.free){
-				compactpte(o, n - p->n);
+				if(!compactpte(o, n - p->n))
+					goto Trouble;
 				p = (PTEA*)(o->pte - 1);
 				ptealloc.free += n - p->n;
 			}else{
-				compactpte(o, n);
+				if(!compactpte(o, n))
+					goto Trouble;
 				p = ptealloc.free;
 				ptealloc.free += n;
 				memcpy(p+1, o->pte, o->npte*sizeof(PTE));
@@ -596,7 +615,8 @@ growpte(Orig *o, ulong n)
 		goto Return;
 	}
 	n++;
-	compactpte(o, n);
+	if(!compactpte(o, n))
+		goto Trouble;
 	p = ptealloc.free;
 	ptealloc.free += n;
 	memset(p, 0, n*sizeof(PTE));
@@ -605,18 +625,24 @@ growpte(Orig *o, ulong n)
 	o->pte = p+1;
 	o->npte = n-1;
     Return:
-	unlock(o);
 	unlock(&ptealloc);
+	return;
+
+    Trouble:
+	unlock(&ptealloc);
+	if(u && u->p)
+		error(0, Enovmem);
+	panic("growpte fails %d %lux %d\n", n, o->va, o->npte);
 }
 
-void
+int
 compactpte(Orig *o, ulong n)
 {
 	PTEA *p1, *p2;
 	Orig *p2o;
 
 	if(ptealloc.end-ptealloc.free >= n)
-		return;
+		return 1;
 	p1 = ptealloc.arena;	/* dest */
 	p2 = ptealloc.arena;	/* source */
 	while(p2 < ptealloc.free){
@@ -645,8 +671,11 @@ compactpte(Orig *o, ulong n)
 	}
 	ptealloc.free = p1;
 	if(ptealloc.end-ptealloc.free >= n)
-		return;
+		return 1;
 	unlock(o);
 	unlock(&ptealloc);
-	panic("compactpte %d %lux %d", n, o->va, o->npte);
+	if(u && u->p)
+		print("%s: %s: ", u->p->text, u->p->pgrp->user);
+	print("compactpte fails addr %lux\n", o->va+n*BY2PG);
+	return 0;
 }
diff --git a/port/devenv.c b/port/devenv.c
index 1d6d78ba85e288b6b28d075847a734f383d5d22d..96f3af5ccf7fe927d25dbde4140b85dab426cf9f 100644
--- a/port/devenv.c
+++ b/port/devenv.c
@@ -143,7 +143,7 @@ compactenv(Env *e, ulong n)
 				goto Free;
 			}
 			if(p2+p2->n > envalloc.end)
-				panic("compactpte copying too much");
+				panic("compactenv copying too much");
 			memcpy(p1, p2, p2->n*sizeof(Envval));
 			p2e->val = p1;
 			if(p2e != e)
diff --git a/port/fault.c b/port/fault.c
index 086bf45030dc1be718a3bb1970e5ac02aeabf05d..0e3be17e8c00a0867acde479cbefaf58b86387d9 100644
--- a/port/fault.c
+++ b/port/fault.c
@@ -43,9 +43,15 @@ fault(Ureg *ur, int user, int code)
 		/* grow stack */
 		o = s->o;
 		n = o->npte;
+		lock(o);
+		if(waserror()){
+			unlock(o);
+			pprint("can't allocate stack page\n");
+			goto cant;
+		}
 		growpte(o, (s->maxva-addr)>>PGSHIFT);
+		poperror();
 		/* stacks grown down, sigh */
-		lock(o);
 		memcpy(o->pte+(o->npte-n), o->pte, n*sizeof(PTE));
 		memset(o->pte, 0, (o->npte-n)*sizeof(PTE));
 		unlock(o);
diff --git a/port/page.c b/port/page.c
index eb85fb0dfeece75d5c97d96fd17632600972ad1c..b8f270c6a3c70ae7ba79f64c4905b8aefb95553c 100644
--- a/port/page.c
+++ b/port/page.c
@@ -4,6 +4,7 @@
 #include	"dat.h"
 #include	"fns.h"
 #include	"ureg.h"
+#include	"errno.h"
 
 struct
 {
@@ -257,7 +258,6 @@ usepage(Page *p, int dolock)
 void
 unusepage(Page *p, int dolock)
 {
-return;
 	if(dolock)
 		lock(&palloc);
 	/*
@@ -339,7 +339,16 @@ o->nmod = 0;
 			o->mqid = -1;
 			o->mchan = 0;
 		}
+		lock(o);
+		if(u && u->p && waserror()){
+			unlock(o);
+			unlock(&origalloc);
+			nexterror();
+		}
 		growpte(o, npte);
+		if(u && u->p)
+			poperror();
+		unlock(o);
 		unlock(&origalloc);
 		return o;
 	}
@@ -527,7 +536,6 @@ segaddr(Seg *s, ulong min, ulong max)
 
 	if(max < min)
 		return 0;
-if(max > 20*1024*1024) {pprint("segaddr %lux\n", max);print("segaddr %lux\n", max);}
 	if(min != s->minva)	/* can't grow down yet (stacks: fault.c) */
 		return 0;
 	max = (max+(BY2PG-1)) & ~(BY2PG-1);
@@ -539,8 +547,15 @@ if(max > 20*1024*1024) {pprint("segaddr %lux\n", max);print("segaddr %lux\n", ma
 		 * Grow
 		 */
 		/* BUG: check spill onto other segments */
+		lock(o);
+		if(waserror()){
+			unlock(o);
+			nexterror();
+		}
 		if(o->va+BY2PG*o->npte < max)
 			growpte(o, (max-o->va)>>PGSHIFT);
+		unlock(o);
+		poperror();
 		s->maxva = max;
 		return 1;
 	}
@@ -593,7 +608,6 @@ growpte(Orig *o, ulong n)
 	ulong nfree;
 
 	lock(&ptealloc);
-	lock(o);
 	if(o->pte){
 		if(o->npte == n){
 if(u && u->p) print("%s: ", u->p->text);
@@ -613,11 +627,13 @@ if(u && u->p) print("%s: ", u->p->text);
 		}else{
 			n++;
 			if(p+p->n == ptealloc.free){
-				compactpte(o, n - p->n);
+				if(!compactpte(o, n - p->n))
+					goto Trouble;
 				p = (PTEA*)(o->pte - 1);
 				ptealloc.free += n - p->n;
 			}else{
-				compactpte(o, n);
+				if(!compactpte(o, n))
+					goto Trouble;
 				p = ptealloc.free;
 				ptealloc.free += n;
 				memcpy(p+1, o->pte, o->npte*sizeof(PTE));
@@ -632,7 +648,8 @@ if(u && u->p) print("%s: ", u->p->text);
 		goto Return;
 	}
 	n++;
-	compactpte(o, n);
+	if(!compactpte(o, n))
+		goto Trouble;
 	p = ptealloc.free;
 	ptealloc.free += n;
 	memset(p, 0, n*sizeof(PTE));
@@ -641,18 +658,24 @@ if(u && u->p) print("%s: ", u->p->text);
 	o->pte = p+1;
 	o->npte = n-1;
     Return:
-	unlock(o);
 	unlock(&ptealloc);
+	return;
+
+    Trouble:
+	unlock(&ptealloc);
+	if(u && u->p)
+		error(0, Enovmem);
+	panic("growpte fails %d %lux %d\n", n, o->va, o->npte);
 }
 
-void
+int
 compactpte(Orig *o, ulong n)
 {
 	PTEA *p1, *p2;
 	Orig *p2o;
 
 	if(ptealloc.end-ptealloc.free >= n)
-		return;
+		return 1;
 	p1 = ptealloc.arena;	/* dest */
 	p2 = ptealloc.arena;	/* source */
 	while(p2 < ptealloc.free){
@@ -681,8 +704,11 @@ compactpte(Orig *o, ulong n)
 	}
 	ptealloc.free = p1;
 	if(ptealloc.end-ptealloc.free >= n)
-		return;
+		return 1;
 	unlock(o);
 	unlock(&ptealloc);
-	panic("compactpte %d %lux %d", n, o->va, o->npte);
+	if(u && u->p)
+		print("%s: %s: ", u->p->text, u->p->pgrp->user);
+	print("compactpte fails addr %lux\n", o->va+n*BY2PG);
+	return 0;
 }
diff --git a/power/clock.c b/power/clock.c
index a5f3d37e4ad4a9e7b76165973da9db67e97f00fb..78671a3e57cfa808d99f21b098066ffd6ad56811 100644
--- a/power/clock.c
+++ b/power/clock.c
@@ -116,7 +116,7 @@ struct Timer{
 #define	MODE2	0x04		/* interval timer */
 
 
-#define	PROFILING
+/* #define	PROFILING /**/
 #ifdef PROFILING
 #undef TIME1
 #define	TIME1	211		/* profiling clock; prime; about 10ms per tick */
diff --git a/power/errno.h b/power/errno.h
index beb69e232b20047a1a19bc943fe8a21cbb9b369b..f83ad0c595e287bcafe0cd5e8fa214ef5c0f002f 100644
--- a/power/errno.h
+++ b/power/errno.h
@@ -50,5 +50,6 @@ enum{
 	Ebadmsg,	/* format error or mismatch in message */
 	Ebadcnt,	/* read count greater than requested */
 	Enoannounce,	/* listening on an unannounced network connection */
+	Enovmem,	/* virtual memory allocation failed */
 	Egreg,		/* it's all greg's fault */
 };
diff --git a/power/fns.h b/power/fns.h
index e546eae3c81842b1370da7087c1bc1b3b07674a8..4cfdc937dca57fc266b77c3410cd0c72e3e5f7c7 100644
--- a/power/fns.h
+++ b/power/fns.h
@@ -16,7 +16,7 @@ void	close(Chan*);
 void	closemount(Mount*);
 void	closepgrp(Pgrp*);
 long	clrfpintr(void);
-void	compactpte(Orig*, ulong);
+int	compactpte(Orig*, ulong);
 ulong	confeval(char*);
 void	confprint(void);
 void	confinit(void);
diff --git a/power/main.c b/power/main.c
index c738d35e607f7992bfb1b441c1fde6b79c8e6b11..897688ab0c309f1c95e6f1dc5ad1a53ab57f8749 100644
--- a/power/main.c
+++ b/power/main.c
@@ -246,8 +246,13 @@ userinit(void)
 	 */
 	s = &p->seg[TSEG];
 	s->proc = p;
-	s->o = neworig(UTZERO, 1, 0, 0);
+	/*
+	 * On the mips, init text must be OCACHED to avoid reusing page
+	 * and getting in trouble with the hardware instruction cache.
+	 */
+	s->o = neworig(UTZERO, 1, OCACHED, 0);
 	s->o->pte[0].page = newpage(0, 0, UTZERO);
+	s->o->npage = 1;
 	k = kmap(s->o->pte[0].page);
 	memcpy((ulong*)VA(k), initcode, sizeof initcode);
 	kunmap(k);
diff --git a/power/trap.c b/power/trap.c
index 77cad73217f6c1828fff025347541a4220affdcd..741f4eb2b262ed51983af215889d35a6582625b8 100644
--- a/power/trap.c
+++ b/power/trap.c
@@ -113,7 +113,7 @@ trap(Ureg *ur)
 	case CTLBL:
 	case CTLBS:
 		if(u == 0)
-			panic("fault");
+			panic("fault u==0 pc %lux addr %lux", ur->pc, ur->badvaddr);
 		if(u->p->fpstate == FPactive) {
 			savefpregs(&u->fpsave);
 			u->p->fpstate = FPinactive;