From: kn <kn@openbsd.org>
Date: Mon, 7 Nov 2022 11:03:14 +0000 (+0000)
Subject: Set up logger(1) traps earlier to catch logfile setup failures
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=44e1f38769613700cf6d7ee3779e7f8af5df97e8;p=openbsd

Set up logger(1) traps earlier to catch logfile setup failures

If /usr is mounted read-only, kernel relinking fails silently without any
log trace:

	# /usr/libexec/reorder_kernel
	/usr/libexec/reorder_kernel[35]: cannot create /usr/share/relink/kernel/GENERIC.MP/relink.log: Read-only file system

This stderr line does not show up anywhere because init(8) redirects stdout
and stderr to /dev/null, executes rc(8) which inherits it and thus executes
reorder_kernel with both streams discarded.

So install the error handler first, then try to set up a log file.

Introduce ERRMSG to provide error messages to users, i.e. not say
"see .../relink.log" when creating this file is what failed:

	# ksh ./reorder_kernel.sh
	./reorder_kernel.sh[40]: cannot create /usr/share/relink/kernel/GENERIC.MP/relink.log: Read-only file system
	# tail -n1 /var/log/message	# or xconsole(1)
	Nov  7 10:51:00 eru reorder_kernel.sh: failed

OK tb
---

diff --git a/libexec/reorder_kernel/reorder_kernel.sh b/libexec/reorder_kernel/reorder_kernel.sh
index 957c85b9102..4d89b40ead6 100644
--- a/libexec/reorder_kernel/reorder_kernel.sh
+++ b/libexec/reorder_kernel/reorder_kernel.sh
@@ -1,6 +1,6 @@
 #!/bin/ksh
 #
-# $OpenBSD: reorder_kernel.sh,v 1.11 2022/05/13 13:20:16 sthen Exp $
+# $OpenBSD: reorder_kernel.sh,v 1.12 2022/11/07 11:03:14 kn Exp $
 #
 # Copyright (c) 2017 Robert Peichaer <rpe@openbsd.org>
 #
@@ -30,15 +30,17 @@ LOGFILE=$KERNEL_DIR/$KERNEL/relink.log
 PROGNAME=${0##*/}
 SHA256=/var/db/kernel.SHA256
 
+# Install trap handlers to inform about success or failure via syslog.
+ERRMSG='failed'
+trap 'trap - EXIT; logger -st $PROGNAME "$ERRMSG" >/dev/console 2>&1' ERR
+trap 'logger -t $PROGNAME "kernel relinking done"' EXIT
+
 # Create kernel compile dir and redirect stdout/stderr to a logfile.
 mkdir -m 700 -p $KERNEL_DIR/$KERNEL
 exec 1>$LOGFILE
 exec 2>&1
 
-# Install trap handlers to inform about success or failure via syslog.
-trap 'trap - EXIT; logger -st $PROGNAME \
-	"failed -- see $LOGFILE" >>/dev/console 2>&1' ERR
-trap 'logger -t $PROGNAME "kernel relinking done"' EXIT
+ERRMSG="failed -- see $LOGFILE"
 
 if [[ -f $KERNEL_DIR.tgz ]]; then
 	rm -rf $KERNEL_DIR/$KERNEL/*