intelchecker.sh - A script to identify that hyperthreading bug in intel processors

intelchecker.sh

#!/bin/bash
# Copyright 2017 Uwe Kleine-König
# Converted to bash for chromebooks (ie, read-only filesystem w/o perl) by fattire
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License version 2 as published by the
# Free Software Foundation.
#
# Note:  You can also check your Skylake processors here: http://ark.intel.com/products/codename/37572/Skylake
#        And Kaby Lake here:  http://ark.intel.com/products/codename/82879/Kaby-Lake

FILE=/proc/cpuinfo
if [ ! -f $FILE ]; then
   echo "failed to open $FILE\n"
   exit 0
fi

function checkcpu {
if [ ! -z ${cpunum} ]; then
  echo "cpu $cpunum: "
  if [[ $vendor -eq "GenuineIntel" && $family -eq "6" ]]; then
    echo "  It's an Intel.  Checking model & stepping..."
    if [[ $model -eq "78" || $model -eq "94" ]] ; then
      if [[ $stepping -eq "3" ]]; then 
        echo -n "  Your CPU is affected by the issue. ";
        if [[ $[microcoderev] -ge $((0xb9)) ]]; then
          echo "   BUT your microcode is new enough";
        elif [[ $hyperthreading -ne "on" ]]; then
          echo "   BUT hyper threading is off, which works around the problem";
        else
          echo "You should install the latest intel-microcode."
          echo "  Yours is version $microcoderev ($[microcoderev]), but you should have at least 0xb9 ($((0xb9))).";
        fi
      else
        echo "  You may need a BIOS/UEFI update (unknown Skylake-Y/H/U/S stepping:  $stepping)";
      fi
    elif [[ $model -eq  "85" || $model -eq  "142" || $model -eq  "158" ]]; then
      echo "  You may need a BIOS/UEFI update (Kaby Lake, or Skylake-X processor)";
    else
      echo "   But you're likely not affected";
    fi
  else 
    echo "No.  Not the right kind of Intel chip.  You're not affected.";
  fi
fi
# clear everything for the next cpu
cpunum=
vendor=
vamily=
model=
stepping=
microcoderv=
hyperthreading=
}

clear
echo "Checking your CPUs...."
while read -r line
do
  # remove the colon because it's breaking the regex for some POSIXTIVELY dumb reason
  if [[ ${line//:} =~ ^processor\s*(.*) ]]; then
      cpunum=`echo ${BASH_REMATCH[1]} | sed -E 's,\\t|\\r|\\n,,g'`
  fi
  if [[ ${line//:} =~ ^vendor_id\s*(.*) ]]; then
      vendor=`echo ${BASH_REMATCH[1]} | sed -E 's,\\t|\\r|\\n,,g'`
  fi
  if [[ ${line//:} =~ ^cpu.*family\s*(.*) ]]; then
      family=`echo ${BASH_REMATCH[1]} | sed -E 's,\\t|\\r|\\n,,g'`
  fi
  if [[ ${line//:} =~ ^model\s*(.*) ]]; then
      x="`echo ${BASH_REMATCH[1]} | sed -E 's,\\t|\\r|\\n,,g'`"
      if [[ ${BASH_REMATCH[1]} =~ [:space:0-9]+$ ]]; then
         model=$x
      fi
  fi
  if [[ ${line//:} =~ ^stepping\s*(.*) ]]; then
      stepping=`echo ${BASH_REMATCH[1]} | sed -E 's,\\t|\\r|\\n,,g'`
  fi
  if [[ ${line//:} =~ ^microcode\s*(.*) ]]; then
      microcoderev=`echo ${BASH_REMATCH[1]} | sed -E 's,\\t|\\r|\\n,,g'`
  fi
  if [[ ${line//:} =~ ^flags\s* ]]; then
    if [[ ${line//:} == *" ht "* ]]; then
      hyperthreading="on"
    else
      hyperthreading="off"
    fi
  fi
  # assume blank lines between chips
  if [[ ! -n ${line} ]]; then
     checkcpu
  fi
done < $FILE