1#!/bin/bash
  2# SPDX-License-Identifier: GPL-2.0
  3# (c) 2014, Sasha Levin <sasha.levin@oracle.com>
  4#set -x
  5
  6if [[ $# < 1 ]]; then
  7	echo "Usage:"
  8	echo "	$0 -r <release> | <vmlinux> [base path] [modules path]"
  9	exit 1
 10fi
 11
 12if [[ $1 == "-r" ]] ; then
 13	vmlinux=""
 14	basepath="auto"
 15	modpath=""
 16	release=$2
 17
 18	for fn in {,/usr/lib/debug}/boot/vmlinux-$release{,.debug} /lib/modules/$release{,/build}/vmlinux ; do
 19		if [ -e "$fn" ] ; then
 20			vmlinux=$fn
 21			break
 22		fi
 23	done
 24
 25	if [[ $vmlinux == "" ]] ; then
 26		echo "ERROR! vmlinux image for release $release is not found" >&2
 27		exit 2
 28	fi
 29else
 30	vmlinux=$1
 31	basepath=${2-auto}
 32	modpath=$3
 33	release=""
 34fi
 35
 36declare -A cache
 37declare -A modcache
 38
 39find_module() {
 40	if [[ "$modpath" != "" ]] ; then
 41		for fn in $(find "$modpath" -name "${module//_/[-_]}.ko*") ; do
 42			if readelf -WS "$fn" | grep -qwF .debug_line ; then
 43				echo $fn
 44				return
 45			fi
 46		done
 47		return 1
 48	fi
 49
 50	modpath=$(dirname "$vmlinux")
 51	find_module && return
 52
 53	if [[ $release == "" ]] ; then
 54		release=$(gdb -ex 'print init_uts_ns.name.release' -ex 'quit' -quiet -batch "$vmlinux" | sed -n 's/\$1 = "\(.*\)".*/\1/p')
 55	fi
 56
 57	for dn in {/usr/lib/debug,}/lib/modules/$release ; do
 58		if [ -e "$dn" ] ; then
 59			modpath="$dn"
 60			find_module && return
 61		fi
 62	done
 63
 64	modpath=""
 65	return 1
 66}
 67
 68parse_symbol() {
 69	# The structure of symbol at this point is:
 70	#   ([name]+[offset]/[total length])
 71	#
 72	# For example:
 73	#   do_basic_setup+0x9c/0xbf
 74
 75	if [[ $module == "" ]] ; then
 76		local objfile=$vmlinux
 77	elif [[ "${modcache[$module]+isset}" == "isset" ]]; then
 78		local objfile=${modcache[$module]}
 79	else
 80		local objfile=$(find_module)
 81		if [[ $objfile == "" ]] ; then
 82			echo "WARNING! Modules path isn't set, but is needed to parse this symbol" >&2
 83			return
 84		fi
 85		modcache[$module]=$objfile
 86	fi
 87
 88	# Remove the englobing parenthesis
 89	symbol=${symbol#\(}
 90	symbol=${symbol%\)}
 91
 92	# Strip segment
 93	local segment
 94	if [[ $symbol == *:* ]] ; then
 95		segment=${symbol%%:*}:
 96		symbol=${symbol#*:}
 97	fi
 98
 99	# Strip the symbol name so that we could look it up
100	local name=${symbol%+*}
101
102	# Use 'nm vmlinux' to figure out the base address of said symbol.
103	# It's actually faster to call it every time than to load it
104	# all into bash.
105	if [[ "${cache[$module,$name]+isset}" == "isset" ]]; then
106		local base_addr=${cache[$module,$name]}
107	else
108		local base_addr=$(nm "$objfile" | awk '$3 == "'$name'" && ($2 == "t" || $2 == "T") {print $1; exit}')
109		if [[ $base_addr == "" ]] ; then
110			# address not found
111			return
112		fi
113		cache[$module,$name]="$base_addr"
114	fi
115	# Let's start doing the math to get the exact address into the
116	# symbol. First, strip out the symbol total length.
117	local expr=${symbol%/*}
118
119	# Now, replace the symbol name with the base address we found
120	# before.
121	expr=${expr/$name/0x$base_addr}
122
123	# Evaluate it to find the actual address
124	expr=$((expr))
125	local address=$(printf "%x\n" "$expr")
126
127	# Pass it to addr2line to get filename and line number
128	# Could get more than one result
129	if [[ "${cache[$module,$address]+isset}" == "isset" ]]; then
130		local code=${cache[$module,$address]}
131	else
132		local code=$(${CROSS_COMPILE}addr2line -i -e "$objfile" "$address")
133		cache[$module,$address]=$code
134	fi
135
136	# addr2line doesn't return a proper error code if it fails, so
137	# we detect it using the value it prints so that we could preserve
138	# the offset/size into the function and bail out
139	if [[ $code == "??:0" ]]; then
140		return
141	fi
142
143	# Strip out the base of the path on each line
144	code=$(while read -r line; do echo "${line#$basepath/}"; done <<< "$code")
145
146	# In the case of inlines, move everything to same line
147	code=${code//$'\n'/' '}
148
149	# Replace old address with pretty line numbers
150	symbol="$segment$name ($code)"
151}
152
153decode_code() {
154	local scripts=`dirname "${BASH_SOURCE[0]}"`
155
156	echo "$1" | $scripts/decodecode
157}
158
159handle_line() {
160	local words
161
162	# Tokenize
163	read -a words <<<"$1"
164
165	# Remove hex numbers. Do it ourselves until it happens in the
166	# kernel
167
168	# We need to know the index of the last element before we
169	# remove elements because arrays are sparse
170	local last=$(( ${#words[@]} - 1 ))
171
172	for i in "${!words[@]}"; do
173		# Remove the address
174		if [[ ${words[$i]} =~ \[\<([^]]+)\>\] ]]; then
175			unset words[$i]
176		fi
177
178		# Format timestamps with tabs
179		if [[ ${words[$i]} == \[ && ${words[$i+1]} == *\] ]]; then
180			unset words[$i]
181			words[$i+1]=$(printf "[%13s\n" "${words[$i+1]}")
182		fi
183	done
184
185	if [[ ${words[$last]} =~ \[([^]]+)\] ]]; then
186		module=${words[$last]}
187		module=${module#\[}
188		module=${module%\]}
189		symbol=${words[$last-1]}
190		unset words[$last-1]
191	else
192		# The symbol is the last element, process it
193		symbol=${words[$last]}
194		module=
195	fi
196
197	unset words[$last]
198	parse_symbol # modifies $symbol
199
200	# Add up the line number to the symbol
201	echo "${words[@]}" "$symbol $module"
202}
203
204if [[ $basepath == "auto" ]] ; then
205	module=""
206	symbol="kernel_init+0x0/0x0"
207	parse_symbol
208	basepath=${symbol#kernel_init (}
209	basepath=${basepath%/init/main.c:*)}
210fi
211
212while read line; do
213	# Let's see if we have an address in the line
214	if [[ $line =~ \[\<([^]]+)\>\] ]] ||
215	   [[ $line =~ [^+\ ]+\+0x[0-9a-f]+/0x[0-9a-f]+ ]]; then
216		# Translate address to line numbers
217		handle_line "$line"
218	# Is it a code line?
219	elif [[ $line == *Code:* ]]; then
220		decode_code "$line"
221	else
222		# Nothing special in this line, show it as is
223		echo "$line"
224	fi
225done