From b5eb8f3030df216b67f2c5d59ad92649ce35a6c8 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sun, 21 Jan 1996 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1996-01-21

---
 port/devproc.c | 5 ++++-
 port/proc.c    | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/port/devproc.c b/port/devproc.c
index e5e454c7d18568418eeacaa6bb657119a58d2ed0..26400667207596d87f3bb8f7f7dc4bd78a9b2beb 100644
--- a/port/devproc.c
+++ b/port/devproc.c
@@ -270,9 +270,9 @@ procread(Chan *c, void *va, long n, ulong offset)
 	Ureg kur;
 	uchar *rptr;
 	Mntwalk *mw;
-	int i, j, rsize;
 	Segment *sg, *s;
 	char *a = va, *sps;
+	int i, j, rsize, pid;
 	char statbuf[NSEG*32];
 
 	if(c->qid.path & CHDIR)
@@ -440,9 +440,12 @@ procread(Chan *c, void *va, long n, ulong offset)
 			unlock(&p->exl);
 			error(Enochild);
 		}
+		pid = p->pid;
 		while(p->waitq == 0) {
 			unlock(&p->exl);
 			sleep(&p->waitr, haswaitq, p);
+			if(p->pid != pid)
+				error(Eprocdied);
 			lock(&p->exl);
 		}
 		wq = p->waitq;
diff --git a/port/proc.c b/port/proc.c
index 328868fc6b84264171bb79e633584d8ac740c43c..c345f717fd918e43abeabeed53a5ca49d4304677 100644
--- a/port/proc.c
+++ b/port/proc.c
@@ -708,6 +708,7 @@ pexit(char *exitstr, int freemem)
 
 	lock(&up->exl);		/* Prevent my children from leaving waits */
 	up->pid = 0;
+	wakeup(&up->waitr);
 	unlock(&up->exl);
 
 	for(f = up->waitq; f; f = next) {