summaryrefslogtreecommitdiffstats
path: root/scripts/decode_stacktrace.sh
blob: fa5be6f57b0090317e503f5a7ab8e4094e2e9890 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
# (c) 2014, Sasha Levin <sasha.levin@oracle.com>
#set -x

usage() {
	echo "Usage:"
	echo "	$0 -r <release> | <vmlinux> [<base path>|auto] [<modules path>]"
}

# Try to find a Rust demangler
if type llvm-cxxfilt >/dev/null 2>&1 ; then
	cppfilt=llvm-cxxfilt
elif type c++filt >/dev/null 2>&1 ; then
	cppfilt=c++filt
	cppfilt_opts=-i
fi

UTIL_SUFFIX=
if [[ -z ${LLVM:-} ]]; then
	UTIL_PREFIX=${CROSS_COMPILE:-}
else
	UTIL_PREFIX=llvm-
	if [[ ${LLVM} == */ ]]; then
		UTIL_PREFIX=${LLVM}${UTIL_PREFIX}
	elif [[ ${LLVM} == -* ]]; then
		UTIL_SUFFIX=${LLVM}
	fi
fi

READELF=${UTIL_PREFIX}readelf${UTIL_SUFFIX}
ADDR2LINE=${UTIL_PREFIX}addr2line${UTIL_SUFFIX}

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
		usage
		exit 2
	fi
else
	vmlinux=$1
	basepath=${2-auto}
	modpath=$3
	release=""
	debuginfod=

	# Can we use debuginfod-find?
	if type debuginfod-find >/dev/null 2>&1 ; then
		debuginfod=${1-only}
	fi

	if [[ $vmlinux == "" && -z $debuginfod ]] ; then
		echo "ERROR! vmlinux image must be specified" >&2
		usage
		exit 1
	fi
fi

declare aarray_support=true
declare -A cache 2>/dev/null
if [[ $? != 0 ]]; then
	aarray_support=false
else
	declare -A modcache
fi

find_module() {
	if [[ -n $debuginfod ]] ; then
		if [[ -n $modbuildid ]] ; then
			debuginfod-find debuginfo $modbuildid && return
		fi

		# Only using debuginfod so don't try to find vmlinux module path
		if [[ $debuginfod == "only" ]] ; then
			return
		fi
	fi

	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" 2>/dev/null | 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 [[ $aarray_support == true && "${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
		if [[ $aarray_support == true ]]; then
			modcache[$module]=$objfile
		fi
	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 [[ $aarray_support == true && "${cache[$module,$name]+isset}" == "isset" ]]; then
		local base_addr=${cache[$module,$name]}
	else
		local base_addr=$(nm "$objfile" 2>/dev/null | awk '$3 == "'$name'" && ($2 == "t" || $2 == "T") {print $1; exit}')
		if [[ $base_addr == "" ]] ; then
			# address not found
			return
		fi
		if [[ $aarray_support == true ]]; then
			cache[$module,$name]="$base_addr"
		fi
	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\n" "$expr")

	# Pass it to addr2line to get filename and line number
	# Could get more than one result
	if [[ $aarray_support == true && "${cache[$module,$address]+isset}" == "isset" ]]; then
		local code=${cache[$module,$address]}
	else
		local code=$(${ADDR2LINE} -i -e "$objfile" "$address" 2>/dev/null)
		if [[ $aarray_support == true ]]; then
			cache[$module,$address]=$code
		fi
	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=${code//$'\n'/' '}

	# Demangle if the name looks like a Rust symbol and if
	# we got a Rust demangler
	if [[ $name =~ ^_R && $cppfilt != "" ]] ; then
		name=$("$cppfilt" "$cppfilt_opts" "$name")
	fi

	# Replace old address with pretty line numbers
	symbol="$segment$name ($code)"
}

debuginfod_get_vmlinux() {
	local vmlinux_buildid=${1##* }

	if [[ $vmlinux != "" ]]; then
		return
	fi

	if [[ $vmlinux_buildid =~ ^[0-9a-f]+ ]]; then
		vmlinux=$(debuginfod-find debuginfo $vmlinux_buildid)
		if [[ $? -ne 0 ]] ; then
			echo "ERROR! vmlinux image not found via debuginfod-find" >&2
			usage
			exit 2
		fi
		return
	fi
	echo "ERROR! Build ID for vmlinux not found. Try passing -r or specifying vmlinux" >&2
	usage
	exit 2
}

decode_code() {
	local scripts=`dirname "${BASH_SOURCE[0]}"`

	echo "$1" | $scripts/decodecode
}

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

	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]=$(printf "[%13s\n" "${words[$i+1]}")
		fi
	done

	if [[ ${words[$last]} =~ ^[0-9a-f]+\] ]]; then
		words[$last-1]="${words[$last-1]} ${words[$last]}"
		unset words[$last]
		last=$(( $last - 1 ))
	fi

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

	unset words[$last]
	parse_symbol # modifies $symbol

	# Add up the line number to the symbol
	echo "${words[@]}" "$symbol $module"
}

while read line; do
	# Strip unexpected carriage return at end of line
	line=${line%$'\r'}

	# 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"
	# Is it a version line?
	elif [[ -n $debuginfod && $line =~ PID:\ [0-9]+\ Comm: ]]; then
		debuginfod_get_vmlinux "$line"
	else
		# Nothing special in this line, show it as is
		echo "$line"
	fi
done