diff options
Diffstat (limited to 'scripts/decodecode')
| -rwxr-xr-x | scripts/decodecode | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/scripts/decodecode b/scripts/decodecode new file mode 100755 index 000000000..b28fd2686 --- /dev/null +++ b/scripts/decodecode @@ -0,0 +1,237 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Disassemble the Code: line in Linux oopses +# usage: decodecode < oops.file +# +# options: set env. variable AFLAGS=options to pass options to "as"; +# e.g., to decode an i386 oops on an x86_64 system, use: +# AFLAGS=--32 decodecode < 386.oops +# PC=hex - the PC (program counter) the oops points to + +faultlinenum=1 + +cleanup() { + rm -f $T $T.s $T.o $T.oo $T.aa $T.dis + exit 1 +} + +die() { + echo "$@" + exit 1 +} + +trap cleanup EXIT + +T=`mktemp` || die "cannot create temp file" +code= +cont= + +while read i ; do + +case "$i" in +*Code:*) + code=$i + cont=yes + ;; +*) + [ -n "$cont" ] && { + xdump="$(echo $i | grep '^[[:xdigit:]<>[:space:]]\+$')" + if [ -n "$xdump" ]; then + code="$code $xdump" + else + cont= + fi + } + ;; +esac + +done + +if [ -z "$code" ]; then + rm $T + exit +fi + +echo $code +code=`echo $code | sed -e 's/.*Code: //'` + +width=`expr index "$code" ' '` +width=$((($width-1)/2)) +case $width in +1) type=byte ;; +2) type=2byte ;; +4) type=4byte ;; +esac + +if [ -z "$ARCH" ]; then + case `uname -m` in + aarch64*) ARCH=arm64 ;; + arm*) ARCH=arm ;; + esac +fi + +# Params: (tmp_file, pc_sub) +disas() { + t=$1 + pc_sub=$2 + + ${CROSS_COMPILE}as $AFLAGS -o $t.o $t.s > /dev/null 2>&1 + + if [ "$ARCH" = "arm" ]; then + if [ $width -eq 2 ]; then + OBJDUMPFLAGS="-M force-thumb" + fi + + ${CROSS_COMPILE}strip $t.o + fi + + if [ "$ARCH" = "arm64" ]; then + if [ $width -eq 4 ]; then + type=inst + fi + + ${CROSS_COMPILE}strip $t.o + fi + + if [ $pc_sub -ne 0 ]; then + if [ $PC ]; then + adj_vma=$(( $PC - $pc_sub )) + OBJDUMPFLAGS="$OBJDUMPFLAGS --adjust-vma=$adj_vma" + fi + fi + + ${CROSS_COMPILE}objdump $OBJDUMPFLAGS -S $t.o | \ + grep -v "/tmp\|Disassembly\|\.text\|^$" > $t.dis 2>&1 +} + +# Match the maximum number of opcode bytes from @op_bytes contained within +# @opline +# +# Params: +# @op_bytes: The string of bytes from the Code: line +# @opline: The disassembled line coming from objdump +# +# Returns: +# The max number of opcode bytes from the beginning of @op_bytes which match +# the opcode bytes in the objdump line. +get_substr_opcode_bytes_num() +{ + local op_bytes=$1 + local opline=$2 + + local retval=0 + substr="" + + for opc in $op_bytes; + do + substr+="$opc" + + # return if opcode bytes do not match @opline anymore + if ! echo $opline | grep -q "$substr"; + then + break + fi + + # add trailing space + substr+=" " + retval=$((retval+1)) + done + + return $retval +} + +# Return the line number in objdump output to where the IP marker in the Code: +# line points to +# +# Params: +# @all_code: code in bytes without the marker +# @dis_file: disassembled file +# @ip_byte: The byte to which the IP points to +get_faultlinenum() +{ + local all_code="$1" + local dis_file="$2" + + # num bytes including IP byte + local num_bytes_ip=$(( $3 + 1 * $width )) + + # Add the two header lines (we're counting from 1). + local retval=3 + + # remove marker + all_code=$(echo $all_code | sed -e 's/[<>()]//g') + + while read line + do + get_substr_opcode_bytes_num "$all_code" "$line" + ate_opcodes=$? + + if ! (( $ate_opcodes )); then + continue + fi + + num_bytes_ip=$((num_bytes_ip - ($ate_opcodes * $width) )) + if (( $num_bytes_ip <= 0 )); then + break + fi + + # Delete matched opcode bytes from all_code. For that, compute + # how many chars those opcodes are represented by and include + # trailing space. + # + # a byte is 2 chars, ate_opcodes is also the number of trailing + # spaces + del_chars=$(( ($ate_opcodes * $width * 2) + $ate_opcodes )) + + all_code=$(echo $all_code | sed -e "s!^.\{$del_chars\}!!") + + let "retval+=1" + + done < $dis_file + + return $retval +} + +marker=`expr index "$code" "\<"` +if [ $marker -eq 0 ]; then + marker=`expr index "$code" "\("` +fi + +touch $T.oo +if [ $marker -ne 0 ]; then + # How many bytes to subtract from the program counter + # in order to get to the beginning virtual address of the + # Code: + pc_sub=$(( (($marker - 1) / (2 * $width + 1)) * $width )) + echo All code >> $T.oo + echo ======== >> $T.oo + beforemark=`echo "$code"` + echo -n " .$type 0x" > $T.s + + echo $beforemark | sed -e 's/ /,0x/g; s/[<>()]//g' >> $T.s + + disas $T $pc_sub + + cat $T.dis >> $T.oo + + get_faultlinenum "$code" "$T.dis" $pc_sub + faultlinenum=$? + + # and fix code at-and-after marker + code=`echo "$code" | cut -c$((${marker} + 1))-` + + rm -f $T.o $T.s $T.dis +fi + +echo Code starting with the faulting instruction > $T.aa +echo =========================================== >> $T.aa +code=`echo $code | sed -e 's/\r//;s/ [<(]/ /;s/[>)] / /;s/ /,0x/g; s/[>)]$//'` +echo -n " .$type 0x" > $T.s +echo $code >> $T.s +disas $T 0 +cat $T.dis >> $T.aa + +cat $T.oo | sed -e "${faultlinenum}s/^\([^:]*:\)\(.*\)/\1\*\2\t\t<-- trapping instruction/" +echo +cat $T.aa +cleanup |