[src/trunk]: src/lib/libkvm distinguish between partial and failed read, so t...

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

details:   https://anonhg.NetBSD.org/src/rev/fa21167e26e4
branches:  trunk
changeset: 344438:fa21167e26e4
user:      mrg <mrg%NetBSD.org@localhost>
date:      Tue Mar 29 06:51:40 2016 +0000

description:
distinguish between partial and failed read, so that "read 0xffffffff bytes failed"
is not output..

diffstat:

 lib/libkvm/kvm.c |  15 ++++++++++-----
 1 files changed, 10 insertions(+), 5 deletions(-)

diffs (36 lines):

diff -r 4839b4331e1d -r fa21167e26e4 lib/libkvm/kvm.c
--- a/lib/libkvm/kvm.c  Tue Mar 29 06:36:12 2016 +0000
+++ b/lib/libkvm/kvm.c  Tue Mar 29 06:51:40 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kvm.c,v 1.101 2014/02/19 20:21:22 dsl Exp $    */
+/*     $NetBSD: kvm.c,v 1.102 2016/03/29 06:51:40 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 1.101 2014/02/19 20:21:22 dsl Exp $");
+__RCSID("$NetBSD: kvm.c,v 1.102 2016/03/29 06:51:40 mrg Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -515,9 +515,14 @@
         */
        sz = Pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), dump_off);
        if (sz != sizeof(cpu_hdr)) {
-               _kvm_err(kd, 0, "read %zx bytes at offset %"PRIx64
-                   " for cpu_hdr instead of requested %zu",
-                   sz, dump_off, sizeof(cpu_hdr));
+               if (sz == -1)
+                       _kvm_err(kd, 0, "read %zx bytes at offset %"PRIx64
+                           " for cpu_hdr failed: %s", sizeof(cpu_hdr),
+                           dump_off, strerror(errno));
+               else
+                       _kvm_err(kd, 0, "read %zx bytes at offset %"PRIx64
+                           " for cpu_hdr instead of requested %zu",
+                           sz, dump_off, sizeof(cpu_hdr));
                return (-1);
        }
        if ((CORE_GETMAGIC(cpu_hdr) != KCORE_MAGIC)