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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
43set -o errexit
44set -o nounset
45
46command -v awk >/dev/null 2>&1 || die "awk isn't installed"
47command -v readelf >/dev/null 2>&1 || die "readelf isn't installed"
48command -v addr2line >/dev/null 2>&1 || die "addr2line isn't installed"
49
50usage() {
51 echo "usage: faddr2line <object file> <func+offset> <func+offset>..." >&2
52 exit 1
53}
54
55warn() {
56 echo "$1" >&2
57}
58
59die() {
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.
68find_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${fields[0]}
109 local sym_type=${fields[1]}
110 local sym_end=0x${fields[3]}
111
112 # calculate the size
113 local sym_size=$(($sym_end - $sym_base))
114 if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then
115 warn "bad symbol size: base: $sym_base end: $sym_end"
116 DONE=1
117 return
118 fi
119 sym_size=0x$(printf %x $sym_size)
120
121 # calculate the address
122 local addr=$(($sym_base + $offset))
123 if [[ -z $addr ]] || [[ $addr = 0 ]]; then
124 warn "bad address: $sym_base + $offset"
125 DONE=1
126 return
127 fi
128 addr=0x$(printf %x $addr)
129
130 # weed out non-function symbols
131 if [[ $sym_type != t ]] && [[ $sym_type != T ]]; then
132 [[ $print_warnings = 1 ]] &&
133 echo "skipping $func address at $addr due to non-function symbol of type '$sym_type'"
134 continue
135 fi
136
137 # if the user provided a size, make sure it matches the symbol's size
138 if [[ -n $size ]] && [[ $size -ne $sym_size ]]; then
139 [[ $print_warnings = 1 ]] &&
140 echo "skipping $func address at $addr due to size mismatch ($size != $sym_size)"
141 continue;
142 fi
143
144 # make sure the provided offset is within the symbol's range
145 if [[ $offset -gt $sym_size ]]; then
146 [[ $print_warnings = 1 ]] &&
147 echo "skipping $func address at $addr due to size mismatch ($offset > $sym_size)"
148 continue
149 fi
150
151 # separate multiple entries with a blank line
152 [[ $FIRST = 0 ]] && echo
153 FIRST=0
154
155 # pass real address to addr2line
156 echo "$func+$offset/$sym_size:"
157 addr2line -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;"
158 DONE=1
159
160 done < <(nm -n $objfile | awk -v fn=$func '$3 == fn { found=1; line=$0; start=$1; next } found == 1 { found=0; print line, $1 }')
161}
162
163[[ $# -lt 2 ]] && usage
164
165objfile=$1
166[[ ! -f $objfile ]] && die "can't find objfile $objfile"
167shift
168
169DIR_PREFIX=supercalifragilisticexpialidocious
170find_dir_prefix $objfile
171
172FIRST=1
173while [[ $# -gt 0 ]]; do
174 func_addr=$1
175 shift
176
177 # print any matches found
178 DONE=0
179 __faddr2line $objfile $func_addr $DIR_PREFIX 0
180
181 # if no match was found, print warnings
182 if [[ $DONE = 0 ]]; then
183 __faddr2line $objfile $func_addr $DIR_PREFIX 1
184 warn "no match for $func_addr"
185 fi
186done
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
47READELF="${CROSS_COMPILE:-}readelf"
48ADDR2LINE="${CROSS_COMPILE:-}addr2line"
49SIZE="${CROSS_COMPILE:-}size"
50NM="${CROSS_COMPILE:-}nm"
51
52command -v awk >/dev/null 2>&1 || die "awk isn't installed"
53command -v ${READELF} >/dev/null 2>&1 || die "readelf isn't installed"
54command -v ${ADDR2LINE} >/dev/null 2>&1 || die "addr2line isn't installed"
55command -v ${SIZE} >/dev/null 2>&1 || die "size isn't installed"
56command -v ${NM} >/dev/null 2>&1 || die "nm isn't installed"
57
58usage() {
59 echo "usage: faddr2line <object file> <func+offset> <func+offset>..." >&2
60 exit 1
61}
62
63warn() {
64 echo "$1" >&2
65}
66
67die() {
68 echo "ERROR: $1" >&2
69 exit 1
70}
71
72# Try to figure out the source directory prefix so we can remove it from the
73# addr2line output. HACK ALERT: This assumes that start_kernel() is in
74# kernel/init.c! This only works for vmlinux. Otherwise it falls back to
75# printing the absolute path.
76find_dir_prefix() {
77 local objfile=$1
78
79 local start_kernel_addr=$(${READELF} -sW $objfile | awk '$8 == "start_kernel" {printf "0x%s", $2}')
80 [[ -z $start_kernel_addr ]] && return
81
82 local file_line=$(${ADDR2LINE} -e $objfile $start_kernel_addr)
83 [[ -z $file_line ]] && return
84
85 local prefix=${file_line%init/main.c:*}
86 if [[ -z $prefix ]] || [[ $prefix = $file_line ]]; then
87 return
88 fi
89
90 DIR_PREFIX=$prefix
91 return 0
92}
93
94__faddr2line() {
95 local objfile=$1
96 local func_addr=$2
97 local dir_prefix=$3
98 local print_warnings=$4
99
100 local func=${func_addr%+*}
101 local offset=${func_addr#*+}
102 offset=${offset%/*}
103 local size=
104 [[ $func_addr =~ "/" ]] && size=${func_addr#*/}
105
106 if [[ -z $func ]] || [[ -z $offset ]] || [[ $func = $func_addr ]]; then
107 warn "bad func+offset $func_addr"
108 DONE=1
109 return
110 fi
111
112 # Go through each of the object's symbols which match the func name.
113 # In rare cases there might be duplicates.
114 file_end=$(${SIZE} -Ax $objfile | awk '$1 == ".text" {print $2}')
115 while read symbol; do
116 local fields=($symbol)
117 local sym_base=0x${fields[0]}
118 local sym_type=${fields[1]}
119 local sym_end=${fields[3]}
120
121 # calculate the size
122 local sym_size=$(($sym_end - $sym_base))
123 if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then
124 warn "bad symbol size: base: $sym_base end: $sym_end"
125 DONE=1
126 return
127 fi
128 sym_size=0x$(printf %x $sym_size)
129
130 # calculate the address
131 local addr=$(($sym_base + $offset))
132 if [[ -z $addr ]] || [[ $addr = 0 ]]; then
133 warn "bad address: $sym_base + $offset"
134 DONE=1
135 return
136 fi
137 addr=0x$(printf %x $addr)
138
139 # weed out non-function symbols
140 if [[ $sym_type != t ]] && [[ $sym_type != T ]]; then
141 [[ $print_warnings = 1 ]] &&
142 echo "skipping $func address at $addr due to non-function symbol of type '$sym_type'"
143 continue
144 fi
145
146 # if the user provided a size, make sure it matches the symbol's size
147 if [[ -n $size ]] && [[ $size -ne $sym_size ]]; then
148 [[ $print_warnings = 1 ]] &&
149 echo "skipping $func address at $addr due to size mismatch ($size != $sym_size)"
150 continue;
151 fi
152
153 # make sure the provided offset is within the symbol's range
154 if [[ $offset -gt $sym_size ]]; then
155 [[ $print_warnings = 1 ]] &&
156 echo "skipping $func address at $addr due to size mismatch ($offset > $sym_size)"
157 continue
158 fi
159
160 # separate multiple entries with a blank line
161 [[ $FIRST = 0 ]] && echo
162 FIRST=0
163
164 # pass real address to addr2line
165 echo "$func+$offset/$sym_size:"
166 local file_lines=$(${ADDR2LINE} -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;")
167 [[ -z $file_lines ]] && return
168
169 # show each line with context
170 echo "$file_lines" | while read -r line
171 do
172 echo $line
173 n=$(echo $line | sed 's/.*:\([0-9]\+\).*/\1/g')
174 n1=$[$n-5]
175 n2=$[$n+5]
176 f=$(echo $line | sed 's/.*at \(.\+\):.*/\1/g')
177 awk 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") {printf("%d\t%s\n", NR, $0)}' $f
178 done
179
180 DONE=1
181
182 done < <(${NM} -n $objfile | awk -v fn=$func -v end=$file_end '$3 == fn { found=1; line=$0; start=$1; next } found == 1 { found=0; print line, "0x"$1 } END {if (found == 1) print line, end; }')
183}
184
185[[ $# -lt 2 ]] && usage
186
187objfile=$1
188[[ ! -f $objfile ]] && die "can't find objfile $objfile"
189shift
190
191DIR_PREFIX=supercalifragilisticexpialidocious
192find_dir_prefix $objfile
193
194FIRST=1
195while [[ $# -gt 0 ]]; do
196 func_addr=$1
197 shift
198
199 # print any matches found
200 DONE=0
201 __faddr2line $objfile $func_addr $DIR_PREFIX 0
202
203 # if no match was found, print warnings
204 if [[ $DONE = 0 ]]; then
205 __faddr2line $objfile $func_addr $DIR_PREFIX 1
206 warn "no match for $func_addr"
207 fi
208done