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-rwxr-xr-xscripts/decodecode237
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