scripts/decodecode

   1 #!/bin/sh
   2 # SPDX-License-Identifier: GPL-2.0
   3 # Disassemble the Code: line in Linux oopses
   4 # usage: decodecode < oops.file
   5 #
   6 # options: set env. variable AFLAGS=options to pass options to "as";
   7 # e.g., to decode an i386 oops on an x86_64 system, use:
   8 # AFLAGS=--32 decodecode < 386.oops
   9
  10 cleanup() {
  11         rm -f $T $T.s $T.o $T.oo $T.aa $T.dis
  12         exit 1
  13 }
  14
  15 die() {
  16         echo "$@"
  17         exit 1
  18 }
  19
  20 trap cleanup EXIT
  21
  22 T=`mktemp` || die "cannot create temp file"
  23 code=
  24
  25 while read i ; do
  26
  27 case "$i" in
  28 *Code:*)
  29         code=$i
  30         ;;
  31 esac
  32
  33 done
  34
  35 if [ -z "$code" ]; then
  36         rm $T
  37         exit
  38 fi
  39
  40 echo $code
  41 code=`echo $code | sed -e 's/.*Code: //'`
  42
  43 width=`expr index "$code" ' '`
  44 width=$((($width-1)/2))
  45 case $width in
  46 1) type=byte ;;
  47 2) type=2byte ;;
  48 4) type=4byte ;;
  49 esac
  50
  51 disas() {
  52         ${CROSS_COMPILE}as $AFLAGS -o $1.o $1.s > /dev/null 2>&1
  53
  54         if [ "$ARCH" = "arm" ]; then
  55                 if [ $width -eq 2 ]; then
  56                         OBJDUMPFLAGS="-M force-thumb"
  57                 fi
  58
  59                 ${CROSS_COMPILE}strip $1.o
  60         fi
  61
  62         if [ "$ARCH" = "arm64" ]; then
  63                 if [ $width -eq 4 ]; then
  64                         type=inst
  65                 fi
  66
  67                 ${CROSS_COMPILE}strip $1.o
  68         fi
  69
  70         ${CROSS_COMPILE}objdump $OBJDUMPFLAGS -S $1.o | \
  71                 grep -v "/tmp\|Disassembly\|\.text\|^$" > $1.dis 2>&1
  72 }
  73
  74 marker=`expr index "$code" "\<"`
  75 if [ $marker -eq 0 ]; then
  76         marker=`expr index "$code" "\("`
  77 fi
  78
  79 touch $T.oo
  80 if [ $marker -ne 0 ]; then
  81         echo All code >> $T.oo
  82         echo ======== >> $T.oo
  83         beforemark=`echo "$code"`
  84         echo -n "       .$type 0x" > $T.s
  85         echo $beforemark | sed -e 's/ /,0x/g; s/[<>()]//g' >> $T.s
  86         disas $T
  87         cat $T.dis >> $T.oo
  88         rm -f $T.o $T.s $T.dis
  89
  90 # and fix code at-and-after marker
  91         code=`echo "$code" | cut -c$((${marker} + 1))-`
  92 fi
  93 echo Code starting with the faulting instruction  > $T.aa
  94 echo =========================================== >> $T.aa
  95 code=`echo $code | sed -e 's/ [<(]/ /;s/[>)] / /;s/ /,0x/g; s/[>)]$//'`
  96 echo -n "       .$type 0x" > $T.s
  97 echo $code >> $T.s
  98 disas $T
  99 cat $T.dis >> $T.aa
 100
 101 # (lines of whole $T.oo) - (lines of $T.aa, i.e. "Code starting") + 3,
 102 # i.e. the title + the "===..=" line (sed is counting from 1, 0 address is
 103 # special)
 104 faultlinenum=$(( $(wc -l $T.oo  | cut -d" " -f1) - \
 105                  $(wc -l $T.aa  | cut -d" " -f1) + 3))
 106
 107 faultline=`cat $T.dis | head -1 | cut -d":" -f2-`
 108 faultline=`echo "$faultline" | sed -e 's/\[/\\\[/g; s/\]/\\\]/g'`
 109
 110 cat $T.oo | sed -e "${faultlinenum}s/^\(.*:\)\(.*\)/\1\*\2\t\t<-- trapping instruction/"
 111 echo
 112 cat $T.aa
 113 cleanup