From 9d3c58daadbbf85d6bab95ac8302f21551d7601e Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Wed, 8 Jan 1992 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1992-01-08

---
 gnot/trap.c    |  8 ++++----
 pc/trap.c      | 10 +++++-----
 port/portfns.h |  2 +-
 power/trap.c   |  9 +++++----
 ss/trap.c      | 12 ++++++------
 5 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/gnot/trap.c b/gnot/trap.c
index dc50a367a3efa2cd0a5c9b165af44854e4945e5c..046faa2c1b7854009b397ce3747c8b5ef34947c1 100644
--- a/gnot/trap.c
+++ b/gnot/trap.c
@@ -7,7 +7,6 @@
 #include	"io.h"
 #include	"errno.h"
 
-void	notify(Ureg*);
 void	noted(Ureg*, ulong);
 void	rfnote(Ureg*);
 
@@ -156,7 +155,7 @@ dumpregs(Ureg *ur)
 /*
  * Call user, if necessary, with note
  */
-void
+int
 notify(Ureg *ur)
 {
 	int l;
@@ -165,8 +164,8 @@ notify(Ureg *ur)
 
 	if(u->p->procctl)
 		procctl(u->p);
-	if(u->nnote==0)
-		return;
+	if(u->nnote == 0)
+		return 0;
 
 	s = spllo();
 	qlock(&u->p->debug);
@@ -218,6 +217,7 @@ notify(Ureg *ur)
 	}
 	qunlock(&u->p->debug);
 	splx(s);
+	return 1;
 }
 
 /*
diff --git a/pc/trap.c b/pc/trap.c
index 1c9aab201e19bc6701ff4c21c50be922366ae00d..1fb754a54829244ae8b262f9750938672c3b1ff8 100644
--- a/pc/trap.c
+++ b/pc/trap.c
@@ -8,7 +8,6 @@
 #include	"errno.h"
 
 void	noted(Ureg*, ulong);
-void	notify(Ureg*);
 
 void	intr0(void), intr1(void), intr2(void), intr3(void);
 void	intr4(void), intr5(void), intr6(void), intr7(void);
@@ -242,7 +241,7 @@ trap(Ureg *ur)
 	(*ivec[v])(ur);
 
 	/*
-	 *  check user since syscall does it's own notifying
+	 *  check user since syscall does its own notifying
 	 */
 	if(user && (u->p->procctl || u->nnote))
 		notify(ur);
@@ -352,7 +351,7 @@ syscall(Ureg *ur)
  *  Call user, if necessary, with note.
  *  Pass user the Ureg struct and the note on his stack.
  */
-void
+int
 notify(Ureg *ur)
 {
 	int l;
@@ -361,8 +360,8 @@ notify(Ureg *ur)
 
 	if(u->p->procctl)
 		procctl(u->p);
-	if(u->nnote==0)
-		return;
+	if(u->nnote == 0)
+		return 0;
 
 	s = spllo();
 	qlock(&u->p->debug);
@@ -414,6 +413,7 @@ notify(Ureg *ur)
 	}
 	qunlock(&u->p->debug);
 	splx(s);
+	return 1;
 }
 
 /*
diff --git a/port/portfns.h b/port/portfns.h
index de3735387a44c64ade3a9801b762c00462630e45..ee006bae21e8ca9b857cba2241f56d3dc9b3f057 100644
--- a/port/portfns.h
+++ b/port/portfns.h
@@ -143,7 +143,7 @@ Segment*	newseg(int, ulong, ulong);
 Waitq*	newwaitq(void);
 char*	nextelem(char*, char*);
 void	nexterror(void);
-void	notify(Ureg*);
+int	notify(Ureg*);
 int	nrand(int);
 void	nullput(Queue*, Block*);
 int	openmode(ulong);
diff --git a/power/trap.c b/power/trap.c
index 0c86ed21314821a7e1f9392147eeee99d1c8ac8f..5f176eefa77e53927663a31eafb88ab5476379ff 100644
--- a/power/trap.c
+++ b/power/trap.c
@@ -364,7 +364,7 @@ dumpregs(Ureg *ur)
 /*
  * Call user, if necessary, with note
  */
-void
+int
 notify(Ureg *ur)
 {
 	int l;
@@ -374,7 +374,7 @@ notify(Ureg *ur)
 	if(u->p->procctl)
 		procctl(u->p);
 	if(u->nnote == 0)
-		return;
+		return 0;
 
 	s = spllo();
 	qlock(&u->p->debug);
@@ -424,6 +424,7 @@ notify(Ureg *ur)
 	}
 	qunlock(&u->p->debug);
 	splx(s);
+	return 1;
 }
 
 /*
@@ -544,8 +545,8 @@ syscall(Ureg *aur)
 	splhi();
 	if(r1!=FORK && (u->p->procctl || u->nnote)){
 		u->svr1 = ret;
-		notify(ur);
-		return ur->r1;
+		if(notify(ur))
+			return ur->r1;
 	}
 
 	return ret;
diff --git a/ss/trap.c b/ss/trap.c
index 677b424b0edf31528df1ecdb514e1795e8dcb727..d2f501eed188f6dcb7520b234e557f5cf3b57cc8 100644
--- a/ss/trap.c
+++ b/ss/trap.c
@@ -7,7 +7,6 @@
 #include	"io.h"
 #include	"errno.h"
 
-void	notify(Ureg*);
 void	noted(Ureg**, ulong);
 void	rfnote(Ureg**);
 
@@ -226,7 +225,7 @@ dumpregs(Ureg *ur)
 	dumpstack();
 }
 
-void
+int
 notify(Ureg *ur)
 {
 	int l;
@@ -235,8 +234,8 @@ notify(Ureg *ur)
 
 	if(u->p->procctl)
 		procctl(u->p);
-	if(u->nnote==0)
-		return;
+	if(u->nnote == 0)
+		return 0;
 
 	s = spllo();
 	qlock(&u->p->debug);
@@ -288,6 +287,7 @@ notify(Ureg *ur)
 	}
 	qunlock(&u->p->debug);
 	splx(s);
+	return 1;
 }
 
 /*
@@ -408,8 +408,8 @@ syscall(Ureg *aur)
 	splhi();
 	if(r7!=FORK && (u->p->procctl || u->nnote)){
 		u->svr7 = ret;
-		notify(ur);
-		return ur->r7;
+		if(notify(ur))
+			return ur->r7;
 	}
 	return ret;
 }