From b8f5620387e59e51d65b9b46335611a490cc799b Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 15 Nov 1990 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1990-11-15

---
 gnot/devpipe.c | 18 ++++++++++++++++--
 gnot/devproc.c |  2 +-
 gnot/main.c    | 10 +++++-----
 gnot/sysproc.c | 10 ++++++++--
 port/devpipe.c | 34 +++++++++++++++++++++-------------
 port/devproc.c |  2 +-
 port/page.c    |  2 +-
 power/lock.c   |  1 +
 8 files changed, 54 insertions(+), 25 deletions(-)

diff --git a/gnot/devpipe.c b/gnot/devpipe.c
index c213aeb57863341a463519e99372e9888b8d03bc..db04fb3a7a565a13766283001aa89307acc4f865 100644
--- a/gnot/devpipe.c
+++ b/gnot/devpipe.c
@@ -27,7 +27,14 @@ struct Pipealloc
 static void pipeiput(Queue*, Block*);
 static void pipeoput(Queue*, Block*);
 static void pipestclose(Queue *);
-Qinfo pipeinfo = { pipeiput, pipeoput, 0, pipestclose, "pipe" };
+Qinfo pipeinfo =
+{
+	pipeiput,
+	pipeoput,
+	0,
+	pipestclose,
+	"pipe"
+};
 
 Dirtab pipedir[]={
 	"data",		Sdataqid,	0,			0600,
@@ -171,7 +178,7 @@ pipeopen(Chan *c, int omode)
 		 *  pointer from the other stream.
 		 */
 		if(streamenter(local)<0)
-			panic("pipeattach");
+			panic("pipeopen");
 	}
 	unlock(p);
 	poperror();
@@ -221,6 +228,11 @@ pipeclose(Chan *c)
 	Pipe *p;
 
 	p = &pipealloc.pipe[STREAMID(c->qid)/2];
+	lock(p);
+	if(waserror()){
+		unlock(p);
+		nexterror();
+	}
 
 	/*
 	 *  take care of associated streams
@@ -230,6 +242,8 @@ pipeclose(Chan *c)
 		streamclose(c);		/* close this stream */
 		streamexit(remote, 0);	/* release stream for other half of pipe */
 	}
+	unlock(p);
+	poperror();
 	pipeexit(p);
 }
 
diff --git a/gnot/devproc.c b/gnot/devproc.c
index 9160c06aece3a8a86bdb9f4e5773d5fd66d9c705..8fb07ed1b380f2f66f590fbfd081d0fff140c057 100644
--- a/gnot/devproc.c
+++ b/gnot/devproc.c
@@ -152,7 +152,7 @@ procopen(Chan *c, int omode)
 		break;
 
 	case Qnotepg:
-		if(omode != OWRITE)
+		if(omode!=OWRITE || pg->pgrpid==1)	/* easy to do by mistake */
 			error(0, Eperm);
 		c->pgrpid = (pg->pgrpid<<PIDSHIFT)|((pg->index+1)<<QSHIFT);
 		break;
diff --git a/gnot/main.c b/gnot/main.c
index 4aa404fb337568341d66ead3d97f6d84a8e44c97..1a35571f38a1ba9fb813443d662a23e209c5b107 100644
--- a/gnot/main.c
+++ b/gnot/main.c
@@ -316,10 +316,10 @@ confinit(void)
 	conf.nmntdev = 10*mul;
 	conf.nmntbuf = 2*conf.nmntdev;
 	conf.nmnthdr = 2*conf.nmntdev;
-	conf.nstream = 64;
-	conf.nqueue = 5 * conf.nstream;
-	conf.nblock = 32 * conf.nstream;
-	conf.nsrv = 32*mul;
+	conf.nstream = 40 + 16*mul;		/* was 64 */
+	conf.nqueue = 4 * conf.nstream;		/* was 5 */
+	conf.nblock = 24 * conf.nstream;	/* was 32 */
+	conf.nsrv = 16*mul;			/* was 32 */
 	conf.nbitmap = 300*mul;
 	conf.nbitbyte = 300*1024*mul;
 	if(*(uchar*)MOUSE & (1<<4))
@@ -328,6 +328,6 @@ confinit(void)
 	conf.nurp = 32;
 	conf.nasync = 1;
 	conf.npipe = conf.nstream/2;
-	conf.nservice = conf.nproc/5;
+	conf.nservice = 3*mul;			/* was conf.nproc/5 */
 	conf.nfsyschan = 31 + conf.nchan/20;
 }
diff --git a/gnot/sysproc.c b/gnot/sysproc.c
index a2998e765fd4046341b7aa7b314698ec6e33fbbb..bee29d20c82be3a7d13ec272a8787488355ae73f 100644
--- a/gnot/sysproc.c
+++ b/gnot/sysproc.c
@@ -533,12 +533,18 @@ sysbrk_(ulong *arg)
 	Seg *s;
 
 	addr = arg[0];
-	if(addr < u->p->bssend)
+	if(addr < u->p->bssend){
+		pprint("addr below bss\n");
+		pexit("Suicide", 0);
 		error(0, Esegaddr);
+	}
 	if(addr <= ((u->p->bssend+(BY2PG-1))&~(BY2PG-1)))	/* still in DSEG */
 		goto Return;
-	if(segaddr(&u->p->seg[BSEG], u->p->seg[BSEG].minva, arg[0]) == 0)
+	if(segaddr(&u->p->seg[BSEG], u->p->seg[BSEG].minva, arg[0]) == 0){
+		pprint("bad segaddr in brk\n");
+		pexit("Suicide", 0);
 		error(0, Esegaddr);
+	}
     Return:
 	u->p->bssend = addr;
 	return 0;
diff --git a/port/devpipe.c b/port/devpipe.c
index 5f6ced88435a35555edfa07e5ff239debafdfca8..404d4a51544bef7ba639d4cf433201137f3c7016 100644
--- a/port/devpipe.c
+++ b/port/devpipe.c
@@ -82,10 +82,8 @@ pipeattach(char *spec)
 	}
 	p = pipealloc.free;
 	pipealloc.free = p->next;
-	if(++(p->ref) != 1){
-		print("pipattach pipe half %d ref %d\n", p - pipealloc.pipe, p->ref);
+	if(incref(p) != 1)
 		panic("pipeattach");
-	}
 	unlock(&pipealloc);
 
 	c->qid = CHDIR|STREAMQID(2*(p - pipealloc.pipe), 0);
@@ -209,6 +207,19 @@ pipewstat(Chan *c, char *db)
 	error(0, Eperm);
 }
 
+void
+pipeexit(Pipe *p)
+{
+	if(decref(p) < 0)
+		panic("pipeexit");
+	if(p->ref == 0){
+		lock(&pipealloc);
+		p->next = pipealloc.free;
+		pipealloc.free = p;
+		unlock(&pipealloc);
+	}
+}
+
 void
 pipeclose(Chan *c)
 {
@@ -217,6 +228,11 @@ pipeclose(Chan *c)
 	Pipe *p;
 
 	p = &pipealloc.pipe[STREAMID(c->qid)/2];
+	lock(p);
+	if(waserror()){
+		unlock(p);
+		nexterror();
+	}
 
 	/*
 	 *  take care of associated streams
@@ -226,17 +242,9 @@ pipeclose(Chan *c)
 		streamclose(c);		/* close this stream */
 		streamexit(remote, 0);	/* release stream for other half of pipe */
 	}
-
-	lock(p);
-	if(--(p->ref) < 0)
-		panic("pipeexit");
-	if(p->ref == 0){
-		lock(&pipealloc);
-		p->next = pipealloc.free;
-		pipealloc.free = p;
-		unlock(&pipealloc);
-	}
 	unlock(p);
+	poperror();
+	pipeexit(p);
 }
 
 long
diff --git a/port/devproc.c b/port/devproc.c
index 8aeb84d4e25b7fc1a32ba192830f833b99fdb53e..3944efcc42b12596929157a94ccf97c6d45889bf 100644
--- a/port/devproc.c
+++ b/port/devproc.c
@@ -155,7 +155,7 @@ procopen(Chan *c, int omode)
 		break;
 
 	case Qnotepg:
-		if(omode != OWRITE)
+		if(omode!=OWRITE || pg->pgrpid==1)	/* easy to do by mistake */
 			error(0, Eperm);
 		c->pgrpid = (pg->pgrpid<<PIDSHIFT)|((pg->index+1)<<QSHIFT);
 		break;
diff --git a/port/page.c b/port/page.c
index f4f991761c35c245f95765149fad2e3be863a078..79ee798667892a6b5484f0d24f5a8b6e40d98381 100644
--- a/port/page.c
+++ b/port/page.c
@@ -559,7 +559,7 @@ segaddr(Seg *s, ulong min, ulong max)
 	 * Shrink
 	 */
 	print("segaddr shrink");
-	for(;;);
+	pexit("Suicide", 0);
 }
 
 /*
diff --git a/power/lock.c b/power/lock.c
index 21f8fc23ea25a512c5d8065533bc429a0f960eab..b84e1dc93555e2fd86f492fa8e7e7864d1b1b751 100644
--- a/power/lock.c
+++ b/power/lock.c
@@ -72,6 +72,7 @@ int addr;
 	}
 	*sbsem = 0;
 	print("lock loop %lux pc %lux held by pc %lux\n", l, ((ulong*)&addr)[-7], l->pc);
+dumpstack();
 }
 
 int