linux-kernel - [PATCH v3] scripts: add extract-vmlinux

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1313484365-22129-1-git-send-email-corentincj@iksaif.net>
Date:	Tue, 16 Aug 2011 10:46:05 +0200
From:	Corentin Chary <corentincj@...aif.net>
To:	linux-kernel@...r.kernel.org
Cc:	Michal Marek <mmarek@...e.cz>,
	Dick Streefland <dick@...eefland.net>,
	WANG Cong <xiyou.wangcong@...il.com>,
	Corentin Chary <corentincj@...aif.net>
Subject: [PATCH v3] scripts: add extract-vmlinux

This script can be used to extract vmlinux from a compressed
kernel image (bzImage, etc..). It's inspired from (a subset of)
extract-ikconfig.

It's something a lot of people have been looking for (mainly
people with xen < 4 that doesn't support bzImages at all).

Signed-off-by: Corentin Chary <corentincj@...aif.net>
---

Since v1:
* update license

Since v2:
* add some comments

 scripts/extract-vmlinux |   62 +++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 62 insertions(+), 0 deletions(-)
 create mode 100755 scripts/extract-vmlinux

diff --git a/scripts/extract-vmlinux b/scripts/extract-vmlinux
new file mode 100755
index 0000000..4ab8517
--- /dev/null
+++ b/scripts/extract-vmlinux
@@ -0,0 +1,62 @@
+#!/bin/sh
+# ----------------------------------------------------------------------
+# extract-vmlinux - Extract uncompressed vmlinux from a kernel image
+#
+# Inspired from extract-ikconfig
+# (c) 2009,2010 Dick Streefland <dick@...eefland.net>
+#
+# (c) 2011      Corentin Chary <corentin.chary@...il.com>
+#
+# Licensed under the GNU General Public License, version 2 (GPLv2).
+# ----------------------------------------------------------------------
+
+check_vmlinux()
+{
+	# Use readelf to check if it's a valid ELF
+	# TODO: find a better to way to check that it's really vmlinux
+	#       and not just an elf
+	readelf -h $1 > /dev/null 2>&1 || return 1
+
+	cat $1
+	exit 0
+}
+
+try_decompress()
+{
+	# The obscure use of the "tr" filter is to work around older versions of
+	# "grep" that report the byte offset of the line instead of the pattern.
+
+	# Try to find the header ($1) and decompress from here
+	for	pos in `tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2"`
+	do
+		pos=${pos%%:*}
+		tail -c+$pos "$img" | $3 > $tmp 2> /dev/null
+		check_vmlinux $tmp
+	done
+}
+
+# Check invocation:
+me=${0##*/}
+img=$1
+if	[ $# -ne 1 -o ! -s "$img" ]
+then
+	echo "Usage: $me <kernel-image>" >&2
+	exit 2
+fi
+
+# Prepare temp files:
+tmp=$(mktemp /tmp/vmlinux-XXX)
+trap "rm -f $tmp" 0
+
+# Initial attempt for uncompressed images or objects:
+check_vmlinux $img
+
+# That didn't work, so retry after decompression.
+try_decompress '\037\213\010' xy    gunzip
+try_decompress '\3757zXZ\000' abcde unxz
+try_decompress 'BZh'          xy    bunzip2
+try_decompress '\135\0\0\0'   xxx   unlzma
+try_decompress '\211\114\132' xy    'lzop -d'
+
+# Bail out:
+echo "$me: Cannot find vmlinux." >&2
-- 
1.7.3.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/