From 540850800c7417167e74320d4f7319acc7ef114e Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sun, 13 May 1990 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1990-05-13

---
 gnot/devpipe.c | 4 +++-
 gnot/trap.c    | 8 +++++---
 port/chan.c    | 4 +++-
 port/devmnt.c  | 4 ++--
 port/devpipe.c | 4 +++-
 port/stream.c  | 2 ++
 port/sysfile.c | 1 +
 7 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/gnot/devpipe.c b/gnot/devpipe.c
index bd5634ffad95fcbbf841640949790cf680b4daad..30c47fe2bb46c6176b34e48f1a754fc265d74478 100644
--- a/gnot/devpipe.c
+++ b/gnot/devpipe.c
@@ -129,7 +129,9 @@ pipewrite(Chan *c, void *va, long n)
 		postnote(u->p, 1, "sys: write on closed pipe", NExit);
 		error(0, Egreg);
 	}
-	return streamwrite(c, va, n, 0);
+	n = streamwrite(c, va, n, 0);
+	poperror();
+	return n;
 }
 
 void
diff --git a/gnot/trap.c b/gnot/trap.c
index eb50678bcfbe94eb5234abe480dc28eef2657767..9766f66c7400e288ad20196f4ee2d53b765251ce 100644
--- a/gnot/trap.c
+++ b/gnot/trap.c
@@ -5,6 +5,7 @@
 #include	"fns.h"
 #include	"ureg.h"
 #include	"io.h"
+#include	"errno.h"
 
 void	notify(Ureg*);
 void	noted(Ureg**);
@@ -241,6 +242,7 @@ syscall(Ureg *aur)
 	ulong sp;
 	ulong r0;
 	Ureg *ur;
+	char *msg;
 
 	u->p->insyscall = 1;
 	ur = aur;
@@ -263,8 +265,8 @@ syscall(Ureg *aur)
 	u->nerrlab = 0;
 	ret = -1;
 	if(!waserror()){
-		if(r1 >= sizeof systab/BY2WD){
-			pprint("bad sys call number %d pc %lux\n", r1, ((Ureg*)UREGADDR)->pc);
+		if(r0 >= sizeof systab/BY2WD){
+			pprint("bad sys call number %d pc %lux\n", r0, ((Ureg*)UREGADDR)->pc);
 			msg = "bad sys call";
 	    Bad:
 			postnote(u->p, 1, msg, NDebug);
@@ -277,7 +279,7 @@ syscall(Ureg *aur)
 		}
 		if(sp<(USTKTOP-BY2PG) || sp>(USTKTOP-4*BY2WD))
 			validaddr(ur->sp, 4*BY2WD, 0);
-		ret = (*systab[r1])((ulong*)(sp+2*BY2WD));
+		ret = (*systab[r0])((ulong*)(sp+2*BY2WD));
 	}
 	u->nerrlab = 0;
 	u->p->insyscall = 0;
diff --git a/port/chan.c b/port/chan.c
index 374bd4e1cb8c2b82f1ac78eca627093856bc8737..0822cf250e4ec42aede3535030603af913905365 100644
--- a/port/chan.c
+++ b/port/chan.c
@@ -490,8 +490,10 @@ namec(char *name, int amode, int omode, ulong perm)
 
 	switch(amode){
 	case Aaccess:
-		if((nc=walk(c, elem, mntok)) == 0)
+		if((nc=walk(c, elem, mntok)) == 0){
+			print("%d pc %lux\n", u->nerrlab, u->errlab[u->nerrlab-1].pc);
 			error(0, Enonexist);
+		}
 		c = nc;
 		break;
 
diff --git a/port/devmnt.c b/port/devmnt.c
index e2f255d751729a80adf45e58e1f95f67ec2985d4..d870459ae5eebb2fdd5cc260fd6e0b5238f329cc 100644
--- a/port/devmnt.c
+++ b/port/devmnt.c
@@ -255,10 +255,10 @@ mntclone(Chan *c, Chan *nc)
 	nc->mnt = c->mnt;
 	nc->mchan = c->mchan;
 	nc->mqid = c->qid;
-	if(new)
-		poperror();
 	mhfree(mh);
 	poperror();
+	if(new)
+		poperror();
 	incref(m);
 	return nc;
 }
diff --git a/port/devpipe.c b/port/devpipe.c
index bd5634ffad95fcbbf841640949790cf680b4daad..30c47fe2bb46c6176b34e48f1a754fc265d74478 100644
--- a/port/devpipe.c
+++ b/port/devpipe.c
@@ -129,7 +129,9 @@ pipewrite(Chan *c, void *va, long n)
 		postnote(u->p, 1, "sys: write on closed pipe", NExit);
 		error(0, Egreg);
 	}
-	return streamwrite(c, va, n, 0);
+	n = streamwrite(c, va, n, 0);
+	poperror();
+	return n;
 }
 
 void
diff --git a/port/stream.c b/port/stream.c
index 72844a3f170413f4d6968add745d53c221c551e9..16c8e83a0df887775e84c9bbceb5874854f9052d 100644
--- a/port/stream.c
+++ b/port/stream.c
@@ -192,6 +192,8 @@ freeb(Block *bp)
 	Bclass *bcp;
 	int tries;
 
+	if((bp->flags&S_CLASS) >= Nclass)
+		panic("freeb class");
 	bcp = &bclass[bp->flags & S_CLASS];
 	lock(bcp);
 	bp->rptr = bp->wptr = 0;
diff --git a/port/sysfile.c b/port/sysfile.c
index a3f1c6c8a535ee825be9a67316d69830e8662959..fe41dfde5129630c96bc3836c301c7b105ef1d62 100644
--- a/port/sysfile.c
+++ b/port/sysfile.c
@@ -283,6 +283,7 @@ sysstat(ulong *arg)
 	validaddr(arg[0], 1, 0);
 	c = namec((char*)arg[0], Aaccess, 0, 0);
 	if(waserror()){
+print("stat error\n");
 		close(c);
 		nexterror();
 	}