xref: /linux/scripts/decode_stacktrace.sh (revision 722ecdbce68a87de2d9296f91308f44ea900a039)
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
11if [[ $1 == "-r" ]] ; then
12	vmlinux=""
13	basepath="auto"
14	modpath=""
15	release=$2
16
17	for fn in {,/usr/lib/debug}/boot/vmlinux-$release{,.debug} /lib/modules/$release{,/build}/vmlinux ; do
18		if [ -e "$fn" ] ; then
19			vmlinux=$fn
20			break
21		fi
22	done
23
24	if [[ $vmlinux == "" ]] ; then
25		echo "ERROR! vmlinux image for release $release is not found" >&2
26		usage
27		exit 2
28	fi
29else
30	vmlinux=$1
31	basepath=${2-auto}
32	modpath=$3
33	release=""
34	debuginfod=
35
36	# Can we use debuginfod-find?
37	if type debuginfod-find >/dev/null 2>&1 ; then
38		debuginfod=${1-only}
39	fi
40
41	if [[ $vmlinux == "" && -z $debuginfod ]] ; then
42		echo "ERROR! vmlinux image must be specified" >&2
43		usage
44		exit 1
45	fi
46fi
47
48declare aarray_support=true
49declare -A cache 2>/dev/null
50if [[ $? != 0 ]]; then
51	aarray_support=false
52else
53	declare -A modcache
54fi
55
56find_module() {
57	if [[ -n $debuginfod ]] ; then
58		if [[ -n $modbuildid ]] ; then
59			debuginfod-find debuginfo $modbuildid && return
60		fi
61
62		# Only using debuginfod so don't try to find vmlinux module path
63		if [[ $debuginfod == "only" ]] ; then
64			return
65		fi
66	fi
67
68	if [[ "$modpath" != "" ]] ; then
69		for fn in $(find "$modpath" -name "${module//_/[-_]}.ko*") ; do
70			if readelf -WS "$fn" | grep -qwF .debug_line ; then
71				echo $fn
72				return
73			fi
74		done
75		return 1
76	fi
77
78	modpath=$(dirname "$vmlinux")
79	find_module && return
80
81	if [[ $release == "" ]] ; then
82		release=$(gdb -ex 'print init_uts_ns.name.release' -ex 'quit' -quiet -batch "$vmlinux" 2>/dev/null | sed -n 's/\$1 = "\(.*\)".*/\1/p')
83	fi
84
85	for dn in {/usr/lib/debug,}/lib/modules/$release ; do
86		if [ -e "$dn" ] ; then
87			modpath="$dn"
88			find_module && return
89		fi
90	done
91
92	modpath=""
93	return 1
94}
95
96parse_symbol() {
97	# The structure of symbol at this point is:
98	#   ([name]+[offset]/[total length])
99	#
100	# For example:
101	#   do_basic_setup+0x9c/0xbf
102
103	if [[ $module == "" ]] ; then
104		local objfile=$vmlinux
105	elif [[ $aarray_support == true && "${modcache[$module]+isset}" == "isset" ]]; then
106		local objfile=${modcache[$module]}
107	else
108		local objfile=$(find_module)
109		if [[ $objfile == "" ]] ; then
110			echo "WARNING! Modules path isn't set, but is needed to parse this symbol" >&2
111			return
112		fi
113		if [[ $aarray_support == true ]]; then
114			modcache[$module]=$objfile
115		fi
116	fi
117
118	# Remove the englobing parenthesis
119	symbol=${symbol#\(}
120	symbol=${symbol%\)}
121
122	# Strip segment
123	local segment
124	if [[ $symbol == *:* ]] ; then
125		segment=${symbol%%:*}:
126		symbol=${symbol#*:}
127	fi
128
129	# Strip the symbol name so that we could look it up
130	local name=${symbol%+*}
131
132	# Use 'nm vmlinux' to figure out the base address of said symbol.
133	# It's actually faster to call it every time than to load it
134	# all into bash.
135	if [[ $aarray_support == true && "${cache[$module,$name]+isset}" == "isset" ]]; then
136		local base_addr=${cache[$module,$name]}
137	else
138		local base_addr=$(nm "$objfile" 2>/dev/null | awk '$3 == "'$name'" && ($2 == "t" || $2 == "T") {print $1; exit}')
139		if [[ $base_addr == "" ]] ; then
140			# address not found
141			return
142		fi
143		if [[ $aarray_support == true ]]; then
144			cache[$module,$name]="$base_addr"
145		fi
146	fi
147	# Let's start doing the math to get the exact address into the
148	# symbol. First, strip out the symbol total length.
149	local expr=${symbol%/*}
150
151	# Now, replace the symbol name with the base address we found
152	# before.
153	expr=${expr/$name/0x$base_addr}
154
155	# Evaluate it to find the actual address
156	expr=$((expr))
157	local address=$(printf "%x\n" "$expr")
158
159	# Pass it to addr2line to get filename and line number
160	# Could get more than one result
161	if [[ $aarray_support == true && "${cache[$module,$address]+isset}" == "isset" ]]; then
162		local code=${cache[$module,$address]}
163	else
164		local code=$(${CROSS_COMPILE}addr2line -i -e "$objfile" "$address" 2>/dev/null)
165		if [[ $aarray_support == true ]]; then
166			cache[$module,$address]=$code
167		fi
168	fi
169
170	# addr2line doesn't return a proper error code if it fails, so
171	# we detect it using the value it prints so that we could preserve
172	# the offset/size into the function and bail out
173	if [[ $code == "??:0" ]]; then
174		return
175	fi
176
177	# Strip out the base of the path on each line
178	code=$(while read -r line; do echo "${line#$basepath/}"; done <<< "$code")
179
180	# In the case of inlines, move everything to same line
181	code=${code//$'\n'/' '}
182
183	# Replace old address with pretty line numbers
184	symbol="$segment$name ($code)"
185}
186
187debuginfod_get_vmlinux() {
188	local vmlinux_buildid=${1##* }
189
190	if [[ $vmlinux != "" ]]; then
191		return
192	fi
193
194	if [[ $vmlinux_buildid =~ ^[0-9a-f]+ ]]; then
195		vmlinux=$(debuginfod-find debuginfo $vmlinux_buildid)
196		if [[ $? -ne 0 ]] ; then
197			echo "ERROR! vmlinux image not found via debuginfod-find" >&2
198			usage
199			exit 2
200		fi
201		return
202	fi
203	echo "ERROR! Build ID for vmlinux not found. Try passing -r or specifying vmlinux" >&2
204	usage
205	exit 2
206}
207
208decode_code() {
209	local scripts=`dirname "${BASH_SOURCE[0]}"`
210
211	echo "$1" | $scripts/decodecode
212}
213
214handle_line() {
215	if [[ $basepath == "auto" && $vmlinux != "" ]] ; then
216		module=""
217		symbol="kernel_init+0x0/0x0"
218		parse_symbol
219		basepath=${symbol#kernel_init (}
220		basepath=${basepath%/init/main.c:*)}
221	fi
222
223	local words
224
225	# Tokenize
226	read -a words <<<"$1"
227
228	# Remove hex numbers. Do it ourselves until it happens in the
229	# kernel
230
231	# We need to know the index of the last element before we
232	# remove elements because arrays are sparse
233	local last=$(( ${#words[@]} - 1 ))
234
235	for i in "${!words[@]}"; do
236		# Remove the address
237		if [[ ${words[$i]} =~ \[\<([^]]+)\>\] ]]; then
238			unset words[$i]
239		fi
240
241		# Format timestamps with tabs
242		if [[ ${words[$i]} == \[ && ${words[$i+1]} == *\] ]]; then
243			unset words[$i]
244			words[$i+1]=$(printf "[%13s\n" "${words[$i+1]}")
245		fi
246	done
247
248	if [[ ${words[$last]} =~ ^[0-9a-f]+\] ]]; then
249		words[$last-1]="${words[$last-1]} ${words[$last]}"
250		unset words[$last]
251		last=$(( $last - 1 ))
252	fi
253
254	if [[ ${words[$last]} =~ \[([^]]+)\] ]]; then
255		module=${words[$last]}
256		module=${module#\[}
257		module=${module%\]}
258		modbuildid=${module#* }
259		module=${module% *}
260		if [[ $modbuildid == $module ]]; then
261			modbuildid=
262		fi
263		symbol=${words[$last-1]}
264		unset words[$last-1]
265	else
266		# The symbol is the last element, process it
267		symbol=${words[$last]}
268		module=
269		modbuildid=
270	fi
271
272	unset words[$last]
273	parse_symbol # modifies $symbol
274
275	# Add up the line number to the symbol
276	echo "${words[@]}" "$symbol $module"
277}
278
279while read line; do
280	# Let's see if we have an address in the line
281	if [[ $line =~ \[\<([^]]+)\>\] ]] ||
282	   [[ $line =~ [^+\ ]+\+0x[0-9a-f]+/0x[0-9a-f]+ ]]; then
283		# Translate address to line numbers
284		handle_line "$line"
285	# Is it a code line?
286	elif [[ $line == *Code:* ]]; then
287		decode_code "$line"
288	# Is it a version line?
289	elif [[ -n $debuginfod && $line =~ PID:\ [0-9]+\ Comm: ]]; then
290		debuginfod_get_vmlinux "$line"
291	else
292		# Nothing special in this line, show it as is
293		echo "$line"
294	fi
295done
296