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1e150869ca
When extract-vmlinux succeeds, it doesn't output which decompression method was found at which offset. Adding this additional output in check_vmlinux() helps troubleshooting and reverse-engineering images. The last check_vmlinux() call was also quoted to accept spaces. Signed-off-by: Maxime Thiebaut <maxime+kernel@thiebaut.dev> Reviewed-by: Nicolas Schier <nsc@kernel.org> Link: https://lore.kernel.org/r/X6OQ4pHdpreJtlTnf0tFEb4Uxz8T8gFv_7Yw6tpBK4ZBgHYjJr_URwUwCVynpkb-H8Yjk7DdBF01zY-sfqu_7N5trZQfcd6s_4PtdGlHtlA=@thiebaut.dev Signed-off-by: Nathan Chancellor <nathan@kernel.org>
65 lines
1.7 KiB
Bash
Executable file
65 lines
1.7 KiB
Bash
Executable file
#!/bin/sh
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# SPDX-License-Identifier: GPL-2.0-only
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# ----------------------------------------------------------------------
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# extract-vmlinux - Extract uncompressed vmlinux from a kernel image
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#
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# Inspired from extract-ikconfig
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# (c) 2009,2010 Dick Streefland <dick@streefland.net>
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#
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# (c) 2011 Corentin Chary <corentin.chary@gmail.com>
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#
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# ----------------------------------------------------------------------
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me=${0##*/}
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check_vmlinux()
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{
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if file "$1" | grep -q 'Linux kernel.*boot executable' ||
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readelf -h "$1" > /dev/null 2>&1
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then
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cat "$1"
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echo "$me: Extracted vmlinux using '$2' from offset $3" >&2
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exit 0
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fi
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}
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try_decompress()
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{
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# The obscure use of the "tr" filter is to work around older versions of
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# "grep" that report the byte offset of the line instead of the pattern.
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# Try to find the header ($1) and decompress from here
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for pos in `tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2"`
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do
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pos=${pos%%:*}
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tail -c+$pos "$img" | $3 > $tmp 2> /dev/null
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check_vmlinux $tmp "$3" $pos
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done
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}
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# Check invocation:
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img=$1
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if [ $# -ne 1 -o ! -s "$img" ]
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then
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echo "Usage: $me <kernel-image>" >&2
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exit 2
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fi
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# Prepare temp files:
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tmp=$(mktemp /tmp/vmlinux-XXX)
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trap "rm -f $tmp" 0
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# That didn't work, so retry after decompression.
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try_decompress '\037\213\010' xy gunzip
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try_decompress '\3757zXZ\000' abcde unxz
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try_decompress 'BZh' xy bunzip2
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try_decompress '\135\0\0\0' xxx unlzma
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try_decompress '\211\114\132' xy 'lzop -d'
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try_decompress '\002!L\030' xxx 'lz4 -d'
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try_decompress '(\265/\375' xxx unzstd
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# Finally check for uncompressed images or objects:
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check_vmlinux "$img" cat 0
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# Bail out:
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echo "$me: Cannot find vmlinux." >&2
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