#!/bin/bash

  # SPDX-License-Identifier: GPL-2.0

  # (c) 2014, Sasha Levin <sasha.levin@oracle.com>
  #set -x

  if [[ $# < 1 ]]; then

  	echo "Usage:"

  	echo "	$0 -r <release> | <vmlinux> [base path] [modules path]"

  	exit 1
  fi

  if [[ $1 == "-r" ]] ; then
  	vmlinux=""
  	basepath="auto"
  	modpath=""
  	release=$2
  
  	for fn in {,/usr/lib/debug}/boot/vmlinux-$release{,.debug} /lib/modules/$release{,/build}/vmlinux ; do
  		if [ -e "$fn" ] ; then
  			vmlinux=$fn
  			break
  		fi
  	done
  
  	if [[ $vmlinux == "" ]] ; then
  		echo "ERROR! vmlinux image for release $release is not found" >&2
  		exit 2
  	fi
  else
  	vmlinux=$1
  	basepath=${2-auto}
  	modpath=$3
  	release=""
  fi

  declare -A cache

  declare -A modcache

  find_module() {
  	if [[ "$modpath" != "" ]] ; then
  		for fn in $(find "$modpath" -name "${module//_/[-_]}.ko*") ; do
  			if readelf -WS "$fn" | grep -qwF .debug_line ; then
  				echo $fn
  				return
  			fi
  		done
  		return 1
  	fi
  
  	modpath=$(dirname "$vmlinux")
  	find_module && return
  
  	if [[ $release == "" ]] ; then
  		release=$(gdb -ex 'print init_uts_ns.name.release' -ex 'quit' -quiet -batch "$vmlinux" | sed -n 's/\$1 = "\(.*\)".*/\1/p')
  	fi
  
  	for dn in {/usr/lib/debug,}/lib/modules/$release ; do
  		if [ -e "$dn" ] ; then
  			modpath="$dn"
  			find_module && return
  		fi
  	done
  
  	modpath=""
  	return 1
  }

  parse_symbol() {
  	# The structure of symbol at this point is:

  	#   ([name]+[offset]/[total length])

  	#
  	# For example:
  	#   do_basic_setup+0x9c/0xbf

  	if [[ $module == "" ]] ; then
  		local objfile=$vmlinux
  	elif [[ "${modcache[$module]+isset}" == "isset" ]]; then
  		local objfile=${modcache[$module]}
  	else

  		local objfile=$(find_module)
  		if [[ $objfile == "" ]] ; then

  			echo "WARNING! Modules path isn't set, but is needed to parse this symbol" >&2
  			return
  		fi

  		modcache[$module]=$objfile
  	fi

  	# Remove the englobing parenthesis
  	symbol=${symbol#\(}
  	symbol=${symbol%\)}

  	# Strip segment
  	local segment
  	if [[ $symbol == *:* ]] ; then
  		segment=${symbol%%:*}:
  		symbol=${symbol#*:}
  	fi

  	# Strip the symbol name so that we could look it up
  	local name=${symbol%+*}
  
  	# Use 'nm vmlinux' to figure out the base address of said symbol.
  	# It's actually faster to call it every time than to load it
  	# all into bash.

  	if [[ "${cache[$module,$name]+isset}" == "isset" ]]; then
  		local base_addr=${cache[$module,$name]}

  	else

  		local base_addr=$(nm "$objfile" | awk '$3 == "'$name'" && ($2 == "t" || $2 == "T") {print $1; exit}')
  		if [[ $base_addr == "" ]] ; then
  			# address not found
  			return
  		fi

  		cache[$module,$name]="$base_addr"

  	fi
  	# Let's start doing the math to get the exact address into the
  	# symbol. First, strip out the symbol total length.
  	local expr=${symbol%/*}
  
  	# Now, replace the symbol name with the base address we found
  	# before.
  	expr=${expr/$name/0x$base_addr}
  
  	# Evaluate it to find the actual address
  	expr=$((expr))
  	local address=$(printf "%x
  " "$expr")
  
  	# Pass it to addr2line to get filename and line number

  	# Could get more than one result
  	if [[ "${cache[$module,$address]+isset}" == "isset" ]]; then
  		local code=${cache[$module,$address]}

  	else

  		local code=$(${CROSS_COMPILE}addr2line -i -e "$objfile" "$address")

  		cache[$module,$address]=$code

  	fi
  
  	# addr2line doesn't return a proper error code if it fails, so
  	# we detect it using the value it prints so that we could preserve
  	# the offset/size into the function and bail out
  	if [[ $code == "??:0" ]]; then
  		return
  	fi

  	# Strip out the base of the path on each line
  	code=$(while read -r line; do echo "${line#$basepath/}"; done <<< "$code")

  
  	# In the case of inlines, move everything to same line
  	code=${code//$'
  '/' '}
  
  	# Replace old address with pretty line numbers

  	symbol="$segment$name ($code)"

  }
  
  decode_code() {
  	local scripts=`dirname "${BASH_SOURCE[0]}"`
  
  	echo "$1" | $scripts/decodecode
  }
  
  handle_line() {
  	local words
  
  	# Tokenize
  	read -a words <<<"$1"
  
  	# Remove hex numbers. Do it ourselves until it happens in the
  	# kernel
  
  	# We need to know the index of the last element before we
  	# remove elements because arrays are sparse
  	local last=$(( ${#words[@]} - 1 ))
  
  	for i in "${!words[@]}"; do
  		# Remove the address
  		if [[ ${words[$i]} =~ \[\<([^]]+)\>\] ]]; then
  			unset words[$i]
  		fi
  
  		# Format timestamps with tabs
  		if [[ ${words[$i]} == \[ && ${words[$i+1]} == *\] ]]; then
  			unset words[$i]
  			words[$i+1]=$(printf "[%13s
  " "${words[$i+1]}")
  		fi
  	done

  	if [[ ${words[$last]} =~ \[([^]]+)\] ]]; then
  		module=${words[$last]}
  		module=${module#\[}
  		module=${module%\]}
  		symbol=${words[$last-1]}
  		unset words[$last-1]
  	else
  		# The symbol is the last element, process it
  		symbol=${words[$last]}
  		module=
  	fi

  	unset words[$last]
  	parse_symbol # modifies $symbol
  
  	# Add up the line number to the symbol

  	echo "${words[@]}" "$symbol $module"

  }

  if [[ $basepath == "auto" ]] ; then
  	module=""
  	symbol="kernel_init+0x0/0x0"
  	parse_symbol
  	basepath=${symbol#kernel_init (}
  	basepath=${basepath%/init/main.c:*)}
  fi

  while read line; do
  	# Let's see if we have an address in the line

  	if [[ $line =~ \[\<([^]]+)\>\] ]] ||
  	   [[ $line =~ [^+\ ]+\+0x[0-9a-f]+/0x[0-9a-f]+ ]]; then

  		# Translate address to line numbers
  		handle_line "$line"
  	# Is it a code line?
  	elif [[ $line == *Code:* ]]; then

  		decode_code "$line"
  	else

  		# Nothing special in this line, show it as is
  		echo "$line"
  	fi
  done