From d116a7a066ded40f839b9d24d181c6e6cc933fad Mon Sep 17 00:00:00 2001
From: Michael Prokop <mika@grml.org>
Date: Fri, 9 Jun 2017 22:08:03 +0200
Subject: [PATCH] sysdump: ignore files inside /sys/kernel/debug to avoid
 hanging

There are several files inside /sys/kernel/debug which aren't
safe for cat-ing, like for example
/sys/kernel/debug/hid/0003:80EE:0021.0001/events So ignore all
files inside /sys/kernel/debug to avoid a hanging sysdump
process.

While at it avoid read on already closed file-handle and redirect
error message to stderr if a file can't be opened/read.

Closes grml/grml#55
---
 sysdump | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/sysdump b/sysdump
index 17c2b9f..177424c 100755
--- a/sysdump
+++ b/sysdump
@@ -62,7 +62,15 @@ sub dump_value($$)
 	my $level = shift;
 	my $file = shift;
 
-	open (FILE, "<$file") || print "can't open $file: $!";
+	if ($file =~ "/sys/kernel/debug/.*") {
+		print("ignoring file $file\n");
+		return 0;
+	}
+
+	if (!open (FILE, "<$file")) {
+		print STDERR "can't open $file: '$!'\n";
+		return 0;
+	}
 
 	my $value;
 	{	local $/;
-- 
2.1.4