blob: 450b332573397ee16ba343673f014ef954b37193
1 | #!/bin/bash |
2 | # |
3 | # Translate stack dump function offsets. |
4 | # |
5 | # addr2line doesn't work with KASLR addresses. This works similarly to |
6 | # addr2line, but instead takes the 'func+0x123' format as input: |
7 | # |
8 | # $ ./scripts/faddr2line ~/k/vmlinux meminfo_proc_show+0x5/0x568 |
9 | # meminfo_proc_show+0x5/0x568: |
10 | # meminfo_proc_show at fs/proc/meminfo.c:27 |
11 | # |
12 | # If the address is part of an inlined function, the full inline call chain is |
13 | # printed: |
14 | # |
15 | # $ ./scripts/faddr2line ~/k/vmlinux native_write_msr+0x6/0x27 |
16 | # native_write_msr+0x6/0x27: |
17 | # arch_static_branch at arch/x86/include/asm/msr.h:121 |
18 | # (inlined by) static_key_false at include/linux/jump_label.h:125 |
19 | # (inlined by) native_write_msr at arch/x86/include/asm/msr.h:125 |
20 | # |
21 | # The function size after the '/' in the input is optional, but recommended. |
22 | # It's used to help disambiguate any duplicate symbol names, which can occur |
23 | # rarely. If the size is omitted for a duplicate symbol then it's possible for |
24 | # multiple code sites to be printed: |
25 | # |
26 | # $ ./scripts/faddr2line ~/k/vmlinux raw_ioctl+0x5 |
27 | # raw_ioctl+0x5/0x20: |
28 | # raw_ioctl at drivers/char/raw.c:122 |
29 | # |
30 | # raw_ioctl+0x5/0xb1: |
31 | # raw_ioctl at net/ipv4/raw.c:876 |
32 | # |
33 | # Multiple addresses can be specified on a single command line: |
34 | # |
35 | # $ ./scripts/faddr2line ~/k/vmlinux type_show+0x10/45 free_reserved_area+0x90 |
36 | # type_show+0x10/0x2d: |
37 | # type_show at drivers/video/backlight/backlight.c:213 |
38 | # |
39 | # free_reserved_area+0x90/0x123: |
40 | # free_reserved_area at mm/page_alloc.c:6429 (discriminator 2) |
41 | |
42 | |
43 | set -o errexit |
44 | set -o nounset |
45 | |
46 | command -v awk >/dev/null 2>&1 || die "awk isn't installed" |
47 | command -v readelf >/dev/null 2>&1 || die "readelf isn't installed" |
48 | command -v addr2line >/dev/null 2>&1 || die "addr2line isn't installed" |
49 | |
50 | usage() { |
51 | echo "usage: faddr2line <object file> <func+offset> <func+offset>..." >&2 |
52 | exit 1 |
53 | } |
54 | |
55 | warn() { |
56 | echo "$1" >&2 |
57 | } |
58 | |
59 | die() { |
60 | echo "ERROR: $1" >&2 |
61 | exit 1 |
62 | } |
63 | |
64 | # Try to figure out the source directory prefix so we can remove it from the |
65 | # addr2line output. HACK ALERT: This assumes that start_kernel() is in |
66 | # kernel/init.c! This only works for vmlinux. Otherwise it falls back to |
67 | # printing the absolute path. |
68 | find_dir_prefix() { |
69 | local objfile=$1 |
70 | |
71 | local start_kernel_addr=$(readelf -sW $objfile | awk '$8 == "start_kernel" {printf "0x%s", $2}') |
72 | [[ -z $start_kernel_addr ]] && return |
73 | |
74 | local file_line=$(addr2line -e $objfile $start_kernel_addr) |
75 | [[ -z $file_line ]] && return |
76 | |
77 | local prefix=${file_line%init/main.c:*} |
78 | if [[ -z $prefix ]] || [[ $prefix = $file_line ]]; then |
79 | return |
80 | fi |
81 | |
82 | DIR_PREFIX=$prefix |
83 | return 0 |
84 | } |
85 | |
86 | __faddr2line() { |
87 | local objfile=$1 |
88 | local func_addr=$2 |
89 | local dir_prefix=$3 |
90 | local print_warnings=$4 |
91 | |
92 | local func=${func_addr%+*} |
93 | local offset=${func_addr#*+} |
94 | offset=${offset%/*} |
95 | local size= |
96 | [[ $func_addr =~ "/" ]] && size=${func_addr#*/} |
97 | |
98 | if [[ -z $func ]] || [[ -z $offset ]] || [[ $func = $func_addr ]]; then |
99 | warn "bad func+offset $func_addr" |
100 | DONE=1 |
101 | return |
102 | fi |
103 | |
104 | # Go through each of the object's symbols which match the func name. |
105 | # In rare cases there might be duplicates. |
106 | while read symbol; do |
107 | local fields=($symbol) |
108 | local sym_base=0x${fields[1]} |
109 | local sym_size=${fields[2]} |
110 | local sym_type=${fields[3]} |
111 | |
112 | # calculate the address |
113 | local addr=$(($sym_base + $offset)) |
114 | if [[ -z $addr ]] || [[ $addr = 0 ]]; then |
115 | warn "bad address: $sym_base + $offset" |
116 | DONE=1 |
117 | return |
118 | fi |
119 | local hexaddr=0x$(printf %x $addr) |
120 | |
121 | # weed out non-function symbols |
122 | if [[ $sym_type != "FUNC" ]]; then |
123 | [[ $print_warnings = 1 ]] && |
124 | echo "skipping $func address at $hexaddr due to non-function symbol" |
125 | continue |
126 | fi |
127 | |
128 | # if the user provided a size, make sure it matches the symbol's size |
129 | if [[ -n $size ]] && [[ $size -ne $sym_size ]]; then |
130 | [[ $print_warnings = 1 ]] && |
131 | echo "skipping $func address at $hexaddr due to size mismatch ($size != $sym_size)" |
132 | continue; |
133 | fi |
134 | |
135 | # make sure the provided offset is within the symbol's range |
136 | if [[ $offset -gt $sym_size ]]; then |
137 | [[ $print_warnings = 1 ]] && |
138 | echo "skipping $func address at $hexaddr due to size mismatch ($offset > $sym_size)" |
139 | continue |
140 | fi |
141 | |
142 | # separate multiple entries with a blank line |
143 | [[ $FIRST = 0 ]] && echo |
144 | FIRST=0 |
145 | |
146 | local hexsize=0x$(printf %x $sym_size) |
147 | echo "$func+$offset/$hexsize:" |
148 | addr2line -fpie $objfile $hexaddr | sed "s; $dir_prefix\(\./\)*; ;" |
149 | DONE=1 |
150 | |
151 | done < <(readelf -sW $objfile | awk -v f=$func '$8 == f {print}') |
152 | } |
153 | |
154 | [[ $# -lt 2 ]] && usage |
155 | |
156 | objfile=$1 |
157 | [[ ! -f $objfile ]] && die "can't find objfile $objfile" |
158 | shift |
159 | |
160 | DIR_PREFIX=supercalifragilisticexpialidocious |
161 | find_dir_prefix $objfile |
162 | |
163 | FIRST=1 |
164 | while [[ $# -gt 0 ]]; do |
165 | func_addr=$1 |
166 | shift |
167 | |
168 | # print any matches found |
169 | DONE=0 |
170 | __faddr2line $objfile $func_addr $DIR_PREFIX 0 |
171 | |
172 | # if no match was found, print warnings |
173 | if [[ $DONE = 0 ]]; then |
174 | __faddr2line $objfile $func_addr $DIR_PREFIX 1 |
175 | warn "no match for $func_addr" |
176 | fi |
177 | done |
178 |