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 # PC=hex - the PC (program counter) the oops points to
  10
  11 cleanup() {
  12         rm -f $T $T.s $T.o $T.oo $T.aa $T.dis
  13         exit 1
  14 }
  15
  16 die() {
  17         echo "$@"
  18         exit 1
  19 }
  20
  21 trap cleanup EXIT
  22
  23 T=`mktemp` || die "cannot create temp file"
  24 code=
  25 cont=
  26
  27 while read i ; do
  28
  29 case "$i" in
  30 *Code:*)
  31         code=$i
  32         cont=yes
  33         ;;
  34 *)
  35         [ -n "$cont" ] && {
  36                 xdump="$(echo $i | grep '^[[:xdigit:]<>[:space:]]\+$')"
  37                 if [ -n "$xdump" ]; then
  38                         code="$code $xdump"
  39                 else
  40                         cont=
  41                 fi
  42         }
  43         ;;
  44 esac
  45
  46 done
  47
  48 if [ -z "$code" ]; then
  49         rm $T
  50         exit
  51 fi
  52
  53 echo $code
  54 code=`echo $code | sed -e 's/.*Code: //'`
  55
  56 width=`expr index "$code" ' '`
  57 width=$((($width-1)/2))
  58 case $width in
  59 1) type=byte ;;
  60 2) type=2byte ;;
  61 4) type=4byte ;;
  62 esac
  63
  64 if [ -z "$ARCH" ]; then
  65     case `uname -m` in
  66         aarch64*) ARCH=arm64 ;;
  67         arm*) ARCH=arm ;;
  68     esac
  69 fi
  70
  71 # Params: (tmp_file, pc_sub)
  72 disas() {
  73         t=$1
  74         pc_sub=$2
  75
  76         ${CROSS_COMPILE}as $AFLAGS -o $t.o $t.s > /dev/null 2>&1
  77
  78         if [ "$ARCH" = "arm" ]; then
  79                 if [ $width -eq 2 ]; then
  80                         OBJDUMPFLAGS="-M force-thumb"
  81                 fi
  82
  83                 ${CROSS_COMPILE}strip $t.o
  84         fi
  85
  86         if [ "$ARCH" = "arm64" ]; then
  87                 if [ $width -eq 4 ]; then
  88                         type=inst
  89                 fi
  90
  91                 ${CROSS_COMPILE}strip $t.o
  92         fi
  93
  94         if [ $pc_sub -ne 0 ]; then
  95                 if [ $PC ]; then
  96                         adj_vma=$(( $PC - $pc_sub ))
  97                         OBJDUMPFLAGS="$OBJDUMPFLAGS --adjust-vma=$adj_vma"
  98                 fi
  99         fi
 100
 101         ${CROSS_COMPILE}objdump $OBJDUMPFLAGS -S $t.o | \
 102                 grep -v "/tmp\|Disassembly\|\.text\|^$" > $t.dis 2>&1
 103 }
 104
 105 marker=`expr index "$code" "\<"`
 106 if [ $marker -eq 0 ]; then
 107         marker=`expr index "$code" "\("`
 108 fi
 109
 110
 111 touch $T.oo
 112 if [ $marker -ne 0 ]; then
 113         # 2 opcode bytes and a single space
 114         pc_sub=$(( $marker / 3 ))
 115         echo All code >> $T.oo
 116         echo ======== >> $T.oo
 117         beforemark=`echo "$code"`
 118         echo -n "       .$type 0x" > $T.s
 119         echo $beforemark | sed -e 's/ /,0x/g; s/[<>()]//g' >> $T.s
 120         disas $T $pc_sub
 121         cat $T.dis >> $T.oo
 122         rm -f $T.o $T.s $T.dis
 123
 124 # and fix code at-and-after marker
 125         code=`echo "$code" | cut -c$((${marker} + 1))-`
 126 fi
 127 echo Code starting with the faulting instruction  > $T.aa
 128 echo =========================================== >> $T.aa
 129 code=`echo $code | sed -e 's/ [<(]/ /;s/[>)] / /;s/ /,0x/g; s/[>)]$//'`
 130 echo -n "       .$type 0x" > $T.s
 131 echo $code >> $T.s
 132 disas $T 0
 133 cat $T.dis >> $T.aa
 134
 135 # (lines of whole $T.oo) - (lines of $T.aa, i.e. "Code starting") + 3,
 136 # i.e. the title + the "===..=" line (sed is counting from 1, 0 address is
 137 # special)
 138 faultlinenum=$(( $(wc -l $T.oo  | cut -d" " -f1) - \
 139                  $(wc -l $T.aa  | cut -d" " -f1) + 3))
 140
 141 faultline=`cat $T.dis | head -1 | cut -d":" -f2-`
 142 faultline=`echo "$faultline" | sed -e 's/\[/\\\[/g; s/\]/\\\]/g'`
 143
 144 cat $T.oo | sed -e "${faultlinenum}s/^\([^:]*:\)\(.*\)/\1\*\2\t\t<-- trapping instruction/"
 145 echo
 146 cat $T.aa
 147 cleanup