Re: [PATCH 0/1] RFC: Revamp admin-guide/tainted-kernels.rst to make it more comprehensible

[Randy Dunlap]

On 12/17/18 10:24 AM, Jonathan Corbet wrote:
> Here's an idea if you feel like improving this: rather than putting an
> inscrutable program inline, add a taint_status script to scripts/ that
> prints out the status in fully human-readable form, with the explanation
> for every set bit.


And some people prefer not adding tools that use python, perl, etc.

E.g., I use this shell script (named 'chktaint', which could probably
be done better):

(see attachment)

-- 
~Randy
#! /bin/sh
# GPL v2.
# Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

TAINTFILE="/proc/sys/kernel/tainted"

if [ ! -r $TAINTFILE ]; then
	echo "No file: $TAINTFILE"
	exit
fi

taint=`cat $TAINTFILE`
if [ $taint -eq 0 ]; then
	echo "Kernel not Tainted"
	exit
fi

echo "Raw Taint value: $taint"
T=$taint
out=

addout() {
	out=$out$1
}

if [ `expr $T % 2` -eq 0 ]; then
	addout "G"
else
	addout "P"	# Proprietary module was loaded
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "F"	# module was force loaded
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "S"	# oops on non-supported SMP hardware
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "R"	# module was force unloaded
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "M"	# Machine Check exception
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "B"	# Bad Page reference
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "U"	# User taint requested
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "D"	# kernel Died, Oops, or Bug
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "A"	# ACPI table overridden
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "W"	# previous Warning was issued
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "C"	# Staging (Crap) module was loaded
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "I"	# firmware bug workaround
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "O"	# out-of-tree module loaded
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "E"	# unsigned module loaded in kernel with signing
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "L"	# soft lockup reported
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "K"	# kernel has been live-patched
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "X"	# auxiliary taint, used by distros
fi

T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
	addout " "
else
	addout "T"	# struct randomization plugin was used
fi

echo "Kernel Taint: $out"
#EOF#