From f306361695318725efb627300753fe67d4a6629b Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Wed, 22 May 1991 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1991-05-22

---
 port/stfcall.c | 2 +-
 port/sysproc.c | 9 ++++++---
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/port/stfcall.c b/port/stfcall.c
index 80e90d72e1a5a74d81b4dd14505d49cfe325c8f2..79a338ccc22203ac28e05b9b6f47cb96ff51a549 100644
--- a/port/stfcall.c
+++ b/port/stfcall.c
@@ -7,7 +7,7 @@
 
 #include	"fcall.h"
 
-#define DPRINT 	if(fcalldebug)kprint
+#define DPRINT 	if(fcalldebug)print
 
 int fcalldebug = 0;
 
diff --git a/port/sysproc.c b/port/sysproc.c
index f1a281066dd4bf68743dfc681a77ae8315f08ceb..39a8b4e69be895a2b074d33c5b5d060e6233d8e4 100644
--- a/port/sysproc.c
+++ b/port/sysproc.c
@@ -152,7 +152,7 @@ sysexec(ulong *arg)
 	char **argv, **argp;
 	char *a, *charp, *file;
 	char *progarg[sizeof(Exec)/2+1], elem[NAMELEN];
-	ulong ssize, spage, nargs, nbytes, n, bssend;
+	ulong sbase, ssize, spage, nargs, nbytes, n, bssend;
 	ulong *sp;
 	int indir;
 	Exec exec;
@@ -239,13 +239,16 @@ sysexec(ulong *arg)
 	}
 	ssize = BY2WD*(nargs+1) + ((nbytes+(BY2WD-1)) & ~(BY2WD-1));
 	spage = (ssize+(BY2PG-1)) >> PGSHIFT;
-
+	sbase = TSTKTOP-(spage<<PGSHIFT);
 	/*
 	 * Build the stack segment, putting it in kernel virtual for the moment
 	 */
+	if(sbase <= USERADDR)
+		errors("not enough argument stack space");
+
 	s = &p->seg[ESEG];
 	s->proc = p;
-	s->o = neworig(TSTKTOP-(spage<<PGSHIFT), spage, OWRPERM, 0);
+	s->o = neworig(sbase, spage, OWRPERM, 0);
 	s->minva = s->o->va;
 	s->maxva = TSTKTOP;