summaryrefslogtreecommitdiff
path: root/scripts/decode_stacktrace.sh
blob: 98a7d63a723e3bf49b8d4542ea5d5da090ca64c3 (plain) (blame)
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
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
# (c) 2014, Sasha Levin <sasha.levin@oracle.com>
#set -x

if [[ $# < 2 ]]; then
	echo "Usage:"
	echo "	$0 [vmlinux] [base path] [modules path]"
	exit 1
fi

vmlinux=$1
basepath=$2
modpath=$3
declare -A cache
declare -A modcache

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
		[[ $modpath == "" ]] && return
		local objfile=$(find "$modpath" -name $module.ko -print -quit)
		[[ $objfile == "" ]] && return
		modcache[$module]=$objfile
	fi

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

	# 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" | grep -i ' t ' | awk "/ $name\$/ {print \$1}" | head -n1)
		cache[$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\n" "$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=$(addr2line -i -e "$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
	code=${code//^$basepath/""}

	# In the case of inlines, move everything to same line
	code=${code//$'\n'/' '}

	# Replace old address with pretty line numbers
	symbol="$name ($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]=$(printf "[%13s\n" "${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"
}

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