Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#!/bin/bash
2# SPDX-License-Identifier: GPL-2.0
3#
4# Translate stack dump function offsets.
5#
6# addr2line doesn't work with KASLR addresses. This works similarly to
7# addr2line, but instead takes the 'func+0x123' format as input:
8#
9# $ ./scripts/faddr2line ~/k/vmlinux meminfo_proc_show+0x5/0x568
10# meminfo_proc_show+0x5/0x568:
11# meminfo_proc_show at fs/proc/meminfo.c:27
12#
13# If the address is part of an inlined function, the full inline call chain is
14# printed:
15#
16# $ ./scripts/faddr2line ~/k/vmlinux native_write_msr+0x6/0x27
17# native_write_msr+0x6/0x27:
18# arch_static_branch at arch/x86/include/asm/msr.h:121
19# (inlined by) static_key_false at include/linux/jump_label.h:125
20# (inlined by) native_write_msr at arch/x86/include/asm/msr.h:125
21#
22# The function size after the '/' in the input is optional, but recommended.
23# It's used to help disambiguate any duplicate symbol names, which can occur
24# rarely. If the size is omitted for a duplicate symbol then it's possible for
25# multiple code sites to be printed:
26#
27# $ ./scripts/faddr2line ~/k/vmlinux raw_ioctl+0x5
28# raw_ioctl+0x5/0x20:
29# raw_ioctl at drivers/char/raw.c:122
30#
31# raw_ioctl+0x5/0xb1:
32# raw_ioctl at net/ipv4/raw.c:876
33#
34# Multiple addresses can be specified on a single command line:
35#
36# $ ./scripts/faddr2line ~/k/vmlinux type_show+0x10/45 free_reserved_area+0x90
37# type_show+0x10/0x2d:
38# type_show at drivers/video/backlight/backlight.c:213
39#
40# free_reserved_area+0x90/0x123:
41# free_reserved_area at mm/page_alloc.c:6429 (discriminator 2)
42
43
44set -o errexit
45set -o nounset
46
47usage() {
48 echo "usage: faddr2line [--list] <object file> <func+offset> <func+offset>..." >&2
49 exit 1
50}
51
52warn() {
53 echo "$1" >&2
54}
55
56die() {
57 echo "ERROR: $1" >&2
58 exit 1
59}
60
61READELF="${CROSS_COMPILE:-}readelf"
62ADDR2LINE="${CROSS_COMPILE:-}addr2line"
63AWK="awk"
64
65command -v ${AWK} >/dev/null 2>&1 || die "${AWK} isn't installed"
66command -v ${READELF} >/dev/null 2>&1 || die "${READELF} isn't installed"
67command -v ${ADDR2LINE} >/dev/null 2>&1 || die "${ADDR2LINE} isn't installed"
68
69# Try to figure out the source directory prefix so we can remove it from the
70# addr2line output. HACK ALERT: This assumes that start_kernel() is in
71# init/main.c! This only works for vmlinux. Otherwise it falls back to
72# printing the absolute path.
73find_dir_prefix() {
74 local objfile=$1
75
76 local start_kernel_addr=$(${READELF} --symbols --wide $objfile | ${AWK} '$8 == "start_kernel" {printf "0x%s", $2}')
77 [[ -z $start_kernel_addr ]] && return
78
79 local file_line=$(${ADDR2LINE} -e $objfile $start_kernel_addr)
80 [[ -z $file_line ]] && return
81
82 local prefix=${file_line%init/main.c:*}
83 if [[ -z $prefix ]] || [[ $prefix = $file_line ]]; then
84 return
85 fi
86
87 DIR_PREFIX=$prefix
88 return 0
89}
90
91__faddr2line() {
92 local objfile=$1
93 local func_addr=$2
94 local dir_prefix=$3
95 local print_warnings=$4
96
97 local sym_name=${func_addr%+*}
98 local offset=${func_addr#*+}
99 offset=${offset%/*}
100 local user_size=
101 [[ $func_addr =~ "/" ]] && user_size=${func_addr#*/}
102
103 if [[ -z $sym_name ]] || [[ -z $offset ]] || [[ $sym_name = $func_addr ]]; then
104 warn "bad func+offset $func_addr"
105 DONE=1
106 return
107 fi
108
109 # Go through each of the object's symbols which match the func name.
110 # In rare cases there might be duplicates, in which case we print all
111 # matches.
112 while read line; do
113 local fields=($line)
114 local sym_addr=0x${fields[1]}
115 local sym_elf_size=${fields[2]}
116 local sym_sec=${fields[6]}
117
118 # Get the section size:
119 local sec_size=$(${READELF} --section-headers --wide $objfile |
120 sed 's/\[ /\[/' |
121 ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }')
122
123 if [[ -z $sec_size ]]; then
124 warn "bad section size: section: $sym_sec"
125 DONE=1
126 return
127 fi
128
129 # Calculate the symbol size.
130 #
131 # Unfortunately we can't use the ELF size, because kallsyms
132 # also includes the padding bytes in its size calculation. For
133 # kallsyms, the size calculation is the distance between the
134 # symbol and the next symbol in a sorted list.
135 local sym_size
136 local cur_sym_addr
137 local found=0
138 while read line; do
139 local fields=($line)
140 cur_sym_addr=0x${fields[1]}
141 local cur_sym_elf_size=${fields[2]}
142 local cur_sym_name=${fields[7]:-}
143
144 if [[ $cur_sym_addr = $sym_addr ]] &&
145 [[ $cur_sym_elf_size = $sym_elf_size ]] &&
146 [[ $cur_sym_name = $sym_name ]]; then
147 found=1
148 continue
149 fi
150
151 if [[ $found = 1 ]]; then
152 sym_size=$(($cur_sym_addr - $sym_addr))
153 [[ $sym_size -lt $sym_elf_size ]] && continue;
154 found=2
155 break
156 fi
157 done < <(${READELF} --symbols --wide $objfile | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2)
158
159 if [[ $found = 0 ]]; then
160 warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size"
161 DONE=1
162 return
163 fi
164
165 # If nothing was found after the symbol, assume it's the last
166 # symbol in the section.
167 [[ $found = 1 ]] && sym_size=$(($sec_size - $sym_addr))
168
169 if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then
170 warn "bad symbol size: sym_addr: $sym_addr cur_sym_addr: $cur_sym_addr"
171 DONE=1
172 return
173 fi
174
175 sym_size=0x$(printf %x $sym_size)
176
177 # Calculate the section address from user-supplied offset:
178 local addr=$(($sym_addr + $offset))
179 if [[ -z $addr ]] || [[ $addr = 0 ]]; then
180 warn "bad address: $sym_addr + $offset"
181 DONE=1
182 return
183 fi
184 addr=0x$(printf %x $addr)
185
186 # If the user provided a size, make sure it matches the symbol's size:
187 if [[ -n $user_size ]] && [[ $user_size -ne $sym_size ]]; then
188 [[ $print_warnings = 1 ]] &&
189 echo "skipping $sym_name address at $addr due to size mismatch ($user_size != $sym_size)"
190 continue;
191 fi
192
193 # Make sure the provided offset is within the symbol's range:
194 if [[ $offset -gt $sym_size ]]; then
195 [[ $print_warnings = 1 ]] &&
196 echo "skipping $sym_name address at $addr due to size mismatch ($offset > $sym_size)"
197 continue
198 fi
199
200 # In case of duplicates or multiple addresses specified on the
201 # cmdline, separate multiple entries with a blank line:
202 [[ $FIRST = 0 ]] && echo
203 FIRST=0
204
205 echo "$sym_name+$offset/$sym_size:"
206
207 # Pass section address to addr2line and strip absolute paths
208 # from the output:
209 local output=$(${ADDR2LINE} -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;")
210 [[ -z $output ]] && continue
211
212 # Default output (non --list):
213 if [[ $LIST = 0 ]]; then
214 echo "$output" | while read -r line
215 do
216 echo $line
217 done
218 DONE=1;
219 continue
220 fi
221
222 # For --list, show each line with its corresponding source code:
223 echo "$output" | while read -r line
224 do
225 echo
226 echo $line
227 n=$(echo $line | sed 's/.*:\([0-9]\+\).*/\1/g')
228 n1=$[$n-5]
229 n2=$[$n+5]
230 f=$(echo $line | sed 's/.*at \(.\+\):.*/\1/g')
231 ${AWK} 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f
232 done
233
234 DONE=1
235
236 done < <(${READELF} --symbols --wide $objfile | ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn')
237}
238
239[[ $# -lt 2 ]] && usage
240
241objfile=$1
242
243LIST=0
244[[ "$objfile" == "--list" ]] && LIST=1 && shift && objfile=$1
245
246[[ ! -f $objfile ]] && die "can't find objfile $objfile"
247shift
248
249DIR_PREFIX=supercalifragilisticexpialidocious
250find_dir_prefix $objfile
251
252FIRST=1
253while [[ $# -gt 0 ]]; do
254 func_addr=$1
255 shift
256
257 # print any matches found
258 DONE=0
259 __faddr2line $objfile $func_addr $DIR_PREFIX 0
260
261 # if no match was found, print warnings
262 if [[ $DONE = 0 ]]; then
263 __faddr2line $objfile $func_addr $DIR_PREFIX 1
264 warn "no match for $func_addr"
265 fi
266done