[src/trunk]: src/lib/libkvm initialise the kvm errbuf so that if an error occ...

[mrg <mrg%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/498f78dbcc68
branches:  trunk
changeset: 445594:498f78dbcc68
user:      mrg <mrg%NetBSD.org@localhost>
date:      Mon Nov 05 00:43:30 2018 +0000

description:
initialise the kvm errbuf so that if an error occurs, but the
internal _kvm_*err() functions aren't called, stack garbage is
not reported as an error string.

call _kvm_err() if _kvm_kvatop() fails.  now the above is not
triggered anymore :-)

diffstat:

 lib/libkvm/kvm.c |  9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)

diffs (38 lines):

diff -r 361099922697 -r 498f78dbcc68 lib/libkvm/kvm.c
--- a/lib/libkvm/kvm.c  Sun Nov 04 21:41:12 2018 +0000
+++ b/lib/libkvm/kvm.c  Mon Nov 05 00:43:30 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kvm.c,v 1.103 2018/02/07 14:03:18 maxv Exp $   */
+/*     $NetBSD: kvm.c,v 1.104 2018/11/05 00:43:30 mrg Exp $    */
 
 /*-
  * Copyright (c) 1989, 1992, 1993
@@ -38,7 +38,7 @@
 #if 0
 static char sccsid[] = "@(#)kvm.c      8.2 (Berkeley) 2/13/94";
 #else
-__RCSID("$NetBSD: kvm.c,v 1.103 2018/02/07 14:03:18 maxv Exp $");
+__RCSID("$NetBSD: kvm.c,v 1.104 2018/11/05 00:43:30 mrg Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -255,6 +255,7 @@
        kd->fdalign = 1;
        kd->iobuf = NULL;
        kd->iobufsz = 0;
+       kd->errbuf[0] = '\0';
 
        if (flag & KVM_NO_FILES) {
                kd->alive = KVM_ALIVE_SYSCTL;
@@ -851,8 +852,10 @@
                        off_t   foff;
 
                        cc = _kvm_kvatop(kd, (vaddr_t)kva, &pa);
-                       if (cc == 0)
+                       if (cc == 0) {
+                               _kvm_err(kd, kd->program, "_kvm_kvatop(%lx)", kva);
                                return (-1);
+                       }
                        if (cc > len)
                                cc = len;
                        foff = _kvm_pa2off(kd, pa);