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 cont=
  25
  26 while read i ; do
  27
  28 case "$i" in
  29 *Code:*)
  30         code=$i
  31         cont=yes
  32         ;;
  33 *)
  34         [ -n "$cont" ] && {
  35                 xdump="$(echo $i | grep '^[[:xdigit:]<>[:space:]]\+$')"
  36                 if [ -n "$xdump" ]; then
  37                         code="$code $xdump"
  38                 else
  39                         cont=
  40                 fi
  41         }
  42         ;;
  43 esac
  44
  45 done
  46
  47 if [ -z "$code" ]; then
  48         rm $T
  49         exit
  50 fi
  51
  52 echo $code
  53 code=`echo $code | sed -e 's/.*Code: //'`
  54
  55 width=`expr index "$code" ' '`
  56 width=$((($width-1)/2))
  57 case $width in
  58 1) type=byte ;;
  59 2) type=2byte ;;
  60 4) type=4byte ;;
  61 esac
  62
  63 if [ -z "$ARCH" ]; then
  64     case `uname -m` in
  65         aarch64*) ARCH=arm64 ;;
  66         arm*) ARCH=arm ;;
  67     esac
  68 fi
  69
  70 disas() {
  71         ${CROSS_COMPILE}as $AFLAGS -o $1.o $1.s > /dev/null 2>&1
  72
  73         if [ "$ARCH" = "arm" ]; then
  74                 if [ $width -eq 2 ]; then
  75                         OBJDUMPFLAGS="-M force-thumb"
  76                 fi
  77
  78                 ${CROSS_COMPILE}strip $1.o
  79         fi
  80
  81         if [ "$ARCH" = "arm64" ]; then
  82                 if [ $width -eq 4 ]; then
  83                         type=inst
  84                 fi
  85
  86                 ${CROSS_COMPILE}strip $1.o
  87         fi
  88
  89         ${CROSS_COMPILE}objdump $OBJDUMPFLAGS -S $1.o | \
  90                 grep -v "/tmp\|Disassembly\|\.text\|^$" > $1.dis 2>&1
  91 }
  92
  93 marker=`expr index "$code" "\<"`
  94 if [ $marker -eq 0 ]; then
  95         marker=`expr index "$code" "\("`
  96 fi
  97
  98 touch $T.oo
  99 if [ $marker -ne 0 ]; then
 100         echo All code >> $T.oo
 101         echo ======== >> $T.oo
 102         beforemark=`echo "$code"`
 103         echo -n "       .$type 0x" > $T.s
 104         echo $beforemark | sed -e 's/ /,0x/g; s/[<>()]//g' >> $T.s
 105         disas $T
 106         cat $T.dis >> $T.oo
 107         rm -f $T.o $T.s $T.dis
 108
 109 # and fix code at-and-after marker
 110         code=`echo "$code" | cut -c$((${marker} + 1))-`
 111 fi
 112 echo Code starting with the faulting instruction  > $T.aa
 113 echo =========================================== >> $T.aa
 114 code=`echo $code | sed -e 's/ [<(]/ /;s/[>)] / /;s/ /,0x/g; s/[>)]$//'`
 115 echo -n "       .$type 0x" > $T.s
 116 echo $code >> $T.s
 117 disas $T
 118 cat $T.dis >> $T.aa
 119
 120 # (lines of whole $T.oo) - (lines of $T.aa, i.e. "Code starting") + 3,
 121 # i.e. the title + the "===..=" line (sed is counting from 1, 0 address is
 122 # special)
 123 faultlinenum=$(( $(wc -l $T.oo  | cut -d" " -f1) - \
 124                  $(wc -l $T.aa  | cut -d" " -f1) + 3))
 125
 126 faultline=`cat $T.dis | head -1 | cut -d":" -f2-`
 127 faultline=`echo "$faultline" | sed -e 's/\[/\\\[/g; s/\]/\\\]/g'`
 128
 129 cat $T.oo | sed -e "${faultlinenum}s/^\([^:]*:\)\(.*\)/\1\*\2\t\t<-- trapping instruction/"
 130 echo
 131 cat $T.aa
 132 cleanup