From 676abde78705d4a8c7a7ecc22e57a5d7e0d65d0d Mon Sep 17 00:00:00 2001
From: christos <christos@NetBSD.org>
Date: Sun, 7 Dec 2003 07:27:09 +0000
Subject: [PATCH] be more descriptive about what failed by printing the errno
 and the variable we were trying to fetch.

---
 usr.bin/systat/extern.h |  4 ++--
 usr.bin/systat/fetch.c  | 11 ++++++-----
 usr.bin/systat/systat.h |  4 ++--
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/usr.bin/systat/extern.h b/usr.bin/systat/extern.h
index 0f5d049d2da4..102aef2e5ffb 100644
--- a/usr.bin/systat/extern.h
+++ b/usr.bin/systat/extern.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: extern.h,v 1.32 2003/09/12 17:32:31 mycroft Exp $	*/
+/*	$NetBSD: extern.h,v 1.33 2003/12/07 07:27:09 christos Exp $	*/
 
 /*-
  * Copyright (c) 1991, 1993
@@ -129,7 +129,7 @@ void	 ip_run(char *);
 void	 ip_time(char *);
 void	 ip_zero(char *);
 int	 keyboard(void) __attribute__((__noreturn__));
-ssize_t	 kvm_ckread(const void *, void *, size_t);
+ssize_t	 kvm_ckread(const void *, void *, size_t, const char *);
 void	 labelbufcache(void);
 void	 labelicmp(void);
 void	 labeliostat(void);
diff --git a/usr.bin/systat/fetch.c b/usr.bin/systat/fetch.c
index db65a184acda..51d8b3992cef 100644
--- a/usr.bin/systat/fetch.c
+++ b/usr.bin/systat/fetch.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: fetch.c,v 1.11 2003/08/07 11:15:58 agc Exp $	*/
+/*	$NetBSD: fetch.c,v 1.12 2003/12/07 07:27:09 christos Exp $	*/
 
 /*-
  * Copyright (c) 1980, 1992, 1993
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)fetch.c	8.1 (Berkeley) 6/6/93";
 #endif
-__RCSID("$NetBSD: fetch.c,v 1.11 2003/08/07 11:15:58 agc Exp $");
+__RCSID("$NetBSD: fetch.c,v 1.12 2003/12/07 07:27:09 christos Exp $");
 #endif /* not lint */
 
 #include <sys/param.h>
@@ -42,17 +42,18 @@ __RCSID("$NetBSD: fetch.c,v 1.11 2003/08/07 11:15:58 agc Exp $");
 #include <sys/sysctl.h>
 
 #include <string.h>
+#include <errno.h>
 
 #include "systat.h"
 #include "extern.h"
 
 ssize_t
-kvm_ckread(const void *a, void *b, size_t l)
+kvm_ckread(const void *a, void *b, size_t l, const char *name)
 {
 	if (kvm_read(kd, (u_long)a, b, l) != l) {
 		if (verbose)
-			error("error reading kmem at %lx\n",
-			   (u_long) a);
+			error("error reading kmem for %s at %p (%s)\n", name,
+			    a, strerror(errno));
 		return (0);
 	} else
 		return (1);
diff --git a/usr.bin/systat/systat.h b/usr.bin/systat/systat.h
index 0960b23713e0..13ee514705aa 100644
--- a/usr.bin/systat/systat.h
+++ b/usr.bin/systat/systat.h
@@ -57,8 +57,8 @@ struct	command {
 #define	TCP	0x1
 #define	UDP	0x2
 
-#define KREAD(addr, buf, len)  kvm_ckread((addr), (buf), (len))
+#define KREAD(addr, buf, len)  kvm_ckread((addr), (buf), (len), # addr)
 #define NVAL(indx)  namelist[(indx)].n_value
 #define NPTR(indx)  (void *)NVAL((indx))
-#define NREAD(indx, buf, len) kvm_ckread(NPTR((indx)), (buf), (len))
+#define NREAD(indx, buf, len) kvm_ckread(NPTR((indx)), (buf), (len), # indx)
 #define LONG	(sizeof (long))