1#!/bin/bash
2# SPDX-License-Identifier: GPL-2.0
3# (c) 2014, Sasha Levin <sasha.levin@oracle.com>
4#set -x
5
6usage() {
7	echo "Usage:"
8	echo "	$0 -r <release> | <vmlinux> [<base path>|auto] [<modules path>]"
9}
10
11# Try to find a Rust demangler
12if type llvm-cxxfilt >/dev/null 2>&1 ; then
13	cppfilt=llvm-cxxfilt
14elif type c++filt >/dev/null 2>&1 ; then
15	cppfilt=c++filt
16	cppfilt_opts=-i
17fi
18
19if [[ $1 == "-r" ]] ; then
20	vmlinux=""
21	basepath="auto"
22	modpath=""
23	release=$2
24
25	for fn in {,/usr/lib/debug}/boot/vmlinux-$release{,.debug} /lib/modules/$release{,/build}/vmlinux ; do
26		if [ -e "$fn" ] ; then
27			vmlinux=$fn
28			break
29		fi
30	done
31
32	if [[ $vmlinux == "" ]] ; then
33		echo "ERROR! vmlinux image for release $release is not found" >&2
34		usage
35		exit 2
36	fi
37else
38	vmlinux=$1
39	basepath=${2-auto}
40	modpath=$3
41	release=""
42	debuginfod=
43
44	# Can we use debuginfod-find?
45	if type debuginfod-find >/dev/null 2>&1 ; then
46		debuginfod=${1-only}
47	fi
48
49	if [[ $vmlinux == "" && -z $debuginfod ]] ; then
50		echo "ERROR! vmlinux image must be specified" >&2
51		usage
52		exit 1
53	fi
54fi
55
56declare aarray_support=true
57declare -A cache 2>/dev/null
58if [[ $? != 0 ]]; then
59	aarray_support=false
60else
61	declare -A modcache
62fi
63
64find_module() {
65	if [[ -n $debuginfod ]] ; then
66		if [[ -n $modbuildid ]] ; then
67			debuginfod-find debuginfo $modbuildid && return
68		fi
69
70		# Only using debuginfod so don't try to find vmlinux module path
71		if [[ $debuginfod == "only" ]] ; then
72			return
73		fi
74	fi
75
76	if [[ "$modpath" != "" ]] ; then
77		for fn in $(find "$modpath" -name "${module//_/[-_]}.ko*") ; do
78			if readelf -WS "$fn" | grep -qwF .debug_line ; then
79				echo $fn
80				return
81			fi
82		done
83		return 1
84	fi
85
86	modpath=$(dirname "$vmlinux")
87	find_module && return
88
89	if [[ $release == "" ]] ; then
90		release=$(gdb -ex 'print init_uts_ns.name.release' -ex 'quit' -quiet -batch "$vmlinux" 2>/dev/null | sed -n 's/\$1 = "\(.*\)".*/\1/p')
91	fi
92
93	for dn in {/usr/lib/debug,}/lib/modules/$release ; do
94		if [ -e "$dn" ] ; then
95			modpath="$dn"
96			find_module && return
97		fi
98	done
99
100	modpath=""
101	return 1
102}
103
104parse_symbol() {
105	# The structure of symbol at this point is:
106	#   ([name]+[offset]/[total length])
107	#
108	# For example:
109	#   do_basic_setup+0x9c/0xbf
110
111	if [[ $module == "" ]] ; then
112		local objfile=$vmlinux
113	elif [[ $aarray_support == true && "${modcache[$module]+isset}" == "isset" ]]; then
114		local objfile=${modcache[$module]}
115	else
116		local objfile=$(find_module)
117		if [[ $objfile == "" ]] ; then
118			echo "WARNING! Modules path isn't set, but is needed to parse this symbol" >&2
119			return
120		fi
121		if [[ $aarray_support == true ]]; then
122			modcache[$module]=$objfile
123		fi
124	fi
125
126	# Remove the englobing parenthesis
127	symbol=${symbol#\(}
128	symbol=${symbol%\)}
129
130	# Strip segment
131	local segment
132	if [[ $symbol == *:* ]] ; then
133		segment=${symbol%%:*}:
134		symbol=${symbol#*:}
135	fi
136
137	# Strip the symbol name so that we could look it up
138	local name=${symbol%+*}
139
140	# Use 'nm vmlinux' to figure out the base address of said symbol.
141	# It's actually faster to call it every time than to load it
142	# all into bash.
143	if [[ $aarray_support == true && "${cache[$module,$name]+isset}" == "isset" ]]; then
144		local base_addr=${cache[$module,$name]}
145	else
146		local base_addr=$(nm "$objfile" 2>/dev/null | awk '$3 == "'$name'" && ($2 == "t" || $2 == "T") {print $1; exit}')
147		if [[ $base_addr == "" ]] ; then
148			# address not found
149			return
150		fi
151		if [[ $aarray_support == true ]]; then
152			cache[$module,$name]="$base_addr"
153		fi
154	fi
155	# Let's start doing the math to get the exact address into the
156	# symbol. First, strip out the symbol total length.
157	local expr=${symbol%/*}
158
159	# Now, replace the symbol name with the base address we found
160	# before.
161	expr=${expr/$name/0x$base_addr}
162
163	# Evaluate it to find the actual address
164	expr=$((expr))
165	local address=$(printf "%x\n" "$expr")
166
167	# Pass it to addr2line to get filename and line number
168	# Could get more than one result
169	if [[ $aarray_support == true && "${cache[$module,$address]+isset}" == "isset" ]]; then
170		local code=${cache[$module,$address]}
171	else
172		local code=$(${CROSS_COMPILE}addr2line -i -e "$objfile" "$address" 2>/dev/null)
173		if [[ $aarray_support == true ]]; then
174			cache[$module,$address]=$code
175		fi
176	fi
177
178	# addr2line doesn't return a proper error code if it fails, so
179	# we detect it using the value it prints so that we could preserve
180	# the offset/size into the function and bail out
181	if [[ $code == "??:0" ]]; then
182		return
183	fi
184
185	# Strip out the base of the path on each line
186	code=$(while read -r line; do echo "${line#$basepath/}"; done <<< "$code")
187
188	# In the case of inlines, move everything to same line
189	code=${code//$'\n'/' '}
190
191	# Demangle if the name looks like a Rust symbol and if
192	# we got a Rust demangler
193	if [[ $name =~ ^_R && $cppfilt != "" ]] ; then
194		name=$("$cppfilt" "$cppfilt_opts" "$name")
195	fi
196
197	# Replace old address with pretty line numbers
198	symbol="$segment$name ($code)"
199}
200
201debuginfod_get_vmlinux() {
202	local vmlinux_buildid=${1##* }
203
204	if [[ $vmlinux != "" ]]; then
205		return
206	fi
207
208	if [[ $vmlinux_buildid =~ ^[0-9a-f]+ ]]; then
209		vmlinux=$(debuginfod-find debuginfo $vmlinux_buildid)
210		if [[ $? -ne 0 ]] ; then
211			echo "ERROR! vmlinux image not found via debuginfod-find" >&2
212			usage
213			exit 2
214		fi
215		return
216	fi
217	echo "ERROR! Build ID for vmlinux not found. Try passing -r or specifying vmlinux" >&2
218	usage
219	exit 2
220}
221
222decode_code() {
223	local scripts=`dirname "${BASH_SOURCE[0]}"`
224
225	echo "$1" | $scripts/decodecode
226}
227
228handle_line() {
229	if [[ $basepath == "auto" && $vmlinux != "" ]] ; then
230		module=""
231		symbol="kernel_init+0x0/0x0"
232		parse_symbol
233		basepath=${symbol#kernel_init (}
234		basepath=${basepath%/init/main.c:*)}
235	fi
236
237	local words
238
239	# Tokenize
240	read -a words <<<"$1"
241
242	# Remove hex numbers. Do it ourselves until it happens in the
243	# kernel
244
245	# We need to know the index of the last element before we
246	# remove elements because arrays are sparse
247	local last=$(( ${#words[@]} - 1 ))
248
249	for i in "${!words[@]}"; do
250		# Remove the address
251		if [[ ${words[$i]} =~ \[\<([^]]+)\>\] ]]; then
252			unset words[$i]
253		fi
254
255		# Format timestamps with tabs
256		if [[ ${words[$i]} == \[ && ${words[$i+1]} == *\] ]]; then
257			unset words[$i]
258			words[$i+1]=$(printf "[%13s\n" "${words[$i+1]}")
259		fi
260	done
261
262	if [[ ${words[$last]} =~ ^[0-9a-f]+\] ]]; then
263		words[$last-1]="${words[$last-1]} ${words[$last]}"
264		unset words[$last]
265		last=$(( $last - 1 ))
266	fi
267
268	if [[ ${words[$last]} =~ \[([^]]+)\] ]]; then
269		module=${words[$last]}
270		module=${module#\[}
271		module=${module%\]}
272		modbuildid=${module#* }
273		module=${module% *}
274		if [[ $modbuildid == $module ]]; then
275			modbuildid=
276		fi
277		symbol=${words[$last-1]}
278		unset words[$last-1]
279	else
280		# The symbol is the last element, process it
281		symbol=${words[$last]}
282		module=
283		modbuildid=
284	fi
285
286	unset words[$last]
287	parse_symbol # modifies $symbol
288
289	# Add up the line number to the symbol
290	echo "${words[@]}" "$symbol $module"
291}
292
293while read line; do
294	# Let's see if we have an address in the line
295	if [[ $line =~ \[\<([^]]+)\>\] ]] ||
296	   [[ $line =~ [^+\ ]+\+0x[0-9a-f]+/0x[0-9a-f]+ ]]; then
297		# Translate address to line numbers
298		handle_line "$line"
299	# Is it a code line?
300	elif [[ $line == *Code:* ]]; then
301		decode_code "$line"
302	# Is it a version line?
303	elif [[ -n $debuginfod && $line =~ PID:\ [0-9]+\ Comm: ]]; then
304		debuginfod_get_vmlinux "$line"
305	else
306		# Nothing special in this line, show it as is
307		echo "$line"
308	fi
309done
310