From 28cbcb99d84b82c21c1bb457ed783f5a20f8b2b7 Mon Sep 17 00:00:00 2001
From: Frank Mori Hess <fmhess@speakeasy.net>
Date: Tue, 26 Nov 2002 20:06:22 +0000
Subject: [PATCH] added error check for mmap() call

---
 demo/mmap.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/demo/mmap.c b/demo/mmap.c
index 25b9b85..9cbe778 100644
--- a/demo/mmap.c
+++ b/demo/mmap.c
@@ -54,6 +54,10 @@ int main(int argc, char *argv[])
 
 	map=mmap(NULL,size,PROT_READ,MAP_SHARED,comedi_fileno(dev),0);
 	fprintf(stderr,"map=%p\n",map);
+	if( map == MAP_FAILED ){
+		perror( "mmap" );
+		exit(1);
+	}
 
 	for(i=0;i<n_chan;i++){
 		chanlist[i]=CR_PACK(channel+i,range,aref);