Current File : //usr/lib/modules/6.8.0-45-generic/build/scripts/decodecode
#!/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 ;;
loongarch*) ARCH=loongarch ;;
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 $t.o
fi
if [ "$ARCH" = "riscv" ]; then
OBJDUMPFLAGS="-M no-aliases --section=.text -D"
${CROSS_COMPILE}strip $t.o
fi
if [ "$ARCH" = "loongarch" ]; then
${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"
opcode="$substr"
if [ "$ARCH" = "riscv" ]; then
opcode=$(echo $opcode | tr ' ' '\n' | tac | tr -d '\n')
fi
# return if opcode bytes do not match @opline anymore
if ! echo $opline | grep -q "$opcode";
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
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