linux/tools/debugging/kernel-chktaint
Mathieu Chouquet-Stringer 547f574fd9 docs: Update documentation to reflect what TAINT_CPU_OUT_OF_SPEC means
Here's a patch updating the meaning of TAINT_CPU_OUT_OF_SPEC after
Borislav introduced changes in a7e1f67ed2 and upcoming patches in tip.

TAINT_CPU_OUT_OF_SPEC now means a bit more what it implies as the
flag isn't set just because of a CPU misconfiguration or mismatch.
Historically it was for SMP kernel oops on an officially SMP incapable
processor but now it also covers CPUs whose MSRs have been incorrectly
poked at from userspace, drivers being used on non supported
architectures, broken firmware, mismatched CPUs, ...

Update documentation and script to reflect that.

Signed-off-by: Mathieu Chouquet-Stringer <me@mathieu.digital>
Link: https://lore.kernel.org/r/20201202153244.709752-1-me@mathieu.digital
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-12-08 10:53:58 -07:00

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#! /bin/sh
# SPDX-License-Identifier: GPL-2.0
#
# Randy Dunlap <rdunlap@infradead.org>, 2018
# Thorsten Leemhuis <linux@leemhuis.info>, 2018
usage()
{
cat <<EOF
usage: ${0##*/}
${0##*/} <int>
Call without parameters to decode /proc/sys/kernel/tainted.
Call with a positive integer as parameter to decode a value you
retrieved from /proc/sys/kernel/tainted on another system.
EOF
}
if [ "$1"x != "x" ]; then
if [ "$1"x == "--helpx" ] || [ "$1"x == "-hx" ] ; then
usage
exit 1
elif [ $1 -ge 0 ] 2>/dev/null ; then
taint=$1
else
echo "Error: Parameter '$1' not a positive interger. Aborting." >&2
exit 1
fi
else
TAINTFILE="/proc/sys/kernel/tainted"
if [ ! -r $TAINTFILE ]; then
echo "No file: $TAINTFILE"
exit
fi
taint=`cat $TAINTFILE`
fi
if [ $taint -eq 0 ]; then
echo "Kernel not Tainted"
exit
else
echo "Kernel is \"tainted\" for the following reasons:"
fi
T=$taint
out=
addout() {
out=$out$1
}
if [ `expr $T % 2` -eq 0 ]; then
addout "G"
else
addout "P"
echo " * proprietary module was loaded (#0)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "F"
echo " * module was force loaded (#1)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "S"
echo " * kernel running on an out of specification system (#2)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "R"
echo " * module was force unloaded (#3)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "M"
echo " * processor reported a Machine Check Exception (MCE) (#4)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "B"
echo " * bad page referenced or some unexpected page flags (#5)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "U"
echo " * taint requested by userspace application (#6)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "D"
echo " * kernel died recently, i.e. there was an OOPS or BUG (#7)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "A"
echo " * an ACPI table was overridden by user (#8)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "W"
echo " * kernel issued warning (#9)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "C"
echo " * staging driver was loaded (#10)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "I"
echo " * workaround for bug in platform firmware applied (#11)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "O"
echo " * externally-built ('out-of-tree') module was loaded (#12)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "E"
echo " * unsigned module was loaded (#13)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "L"
echo " * soft lockup occurred (#14)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "K"
echo " * kernel has been live patched (#15)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "X"
echo " * auxiliary taint, defined for and used by distros (#16)"
fi
T=`expr $T / 2`
if [ `expr $T % 2` -eq 0 ]; then
addout " "
else
addout "T"
echo " * kernel was built with the struct randomization plugin (#17)"
fi
echo "For a more detailed explanation of the various taint flags see"
echo " Documentation/admin-guide/tainted-kernels.rst in the the Linux kernel sources"
echo " or https://kernel.org/doc/html/latest/admin-guide/tainted-kernels.html"
echo "Raw taint value as int/string: $taint/'$out'"
#EOF#