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 <rdun...@infradead.org>

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#