blob: 1f5ce959f5965b0249f70786e44f472581625955 [file] [log] [blame]
Josh Poimboeuf67326662016-09-19 10:52:14 -05001#!/bin/bash
Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01002# SPDX-License-Identifier: GPL-2.0
Josh Poimboeuf67326662016-09-19 10:52:14 -05003#
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
47command -v awk >/dev/null 2>&1 || die "awk isn't installed"
48command -v readelf >/dev/null 2>&1 || die "readelf isn't installed"
49command -v addr2line >/dev/null 2>&1 || die "addr2line isn't installed"
50
51usage() {
52 echo "usage: faddr2line <object file> <func+offset> <func+offset>..." >&2
53 exit 1
54}
55
56warn() {
57 echo "$1" >&2
58}
59
60die() {
61 echo "ERROR: $1" >&2
62 exit 1
63}
64
65# Try to figure out the source directory prefix so we can remove it from the
66# addr2line output. HACK ALERT: This assumes that start_kernel() is in
67# kernel/init.c! This only works for vmlinux. Otherwise it falls back to
68# printing the absolute path.
69find_dir_prefix() {
70 local objfile=$1
71
72 local start_kernel_addr=$(readelf -sW $objfile | awk '$8 == "start_kernel" {printf "0x%s", $2}')
73 [[ -z $start_kernel_addr ]] && return
74
75 local file_line=$(addr2line -e $objfile $start_kernel_addr)
76 [[ -z $file_line ]] && return
77
78 local prefix=${file_line%init/main.c:*}
79 if [[ -z $prefix ]] || [[ $prefix = $file_line ]]; then
80 return
81 fi
82
83 DIR_PREFIX=$prefix
84 return 0
85}
86
87__faddr2line() {
88 local objfile=$1
89 local func_addr=$2
90 local dir_prefix=$3
91 local print_warnings=$4
92
93 local func=${func_addr%+*}
94 local offset=${func_addr#*+}
95 offset=${offset%/*}
96 local size=
97 [[ $func_addr =~ "/" ]] && size=${func_addr#*/}
98
99 if [[ -z $func ]] || [[ -z $offset ]] || [[ $func = $func_addr ]]; then
100 warn "bad func+offset $func_addr"
101 DONE=1
102 return
103 fi
104
105 # Go through each of the object's symbols which match the func name.
106 # In rare cases there might be duplicates.
NeilBrown2aab9c32017-10-12 14:22:04 +1100107 file_end=$(size -Ax $objfile | awk '$1 == ".text" {print $2}')
Josh Poimboeuf67326662016-09-19 10:52:14 -0500108 while read symbol; do
109 local fields=($symbol)
Josh Poimboeufefdb4162016-10-25 09:51:11 -0500110 local sym_base=0x${fields[0]}
111 local sym_type=${fields[1]}
NeilBrown2aab9c32017-10-12 14:22:04 +1100112 local sym_end=${fields[3]}
Josh Poimboeufefdb4162016-10-25 09:51:11 -0500113
114 # calculate the size
115 local sym_size=$(($sym_end - $sym_base))
116 if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then
117 warn "bad symbol size: base: $sym_base end: $sym_end"
118 DONE=1
119 return
120 fi
121 sym_size=0x$(printf %x $sym_size)
Josh Poimboeuf67326662016-09-19 10:52:14 -0500122
123 # calculate the address
124 local addr=$(($sym_base + $offset))
125 if [[ -z $addr ]] || [[ $addr = 0 ]]; then
126 warn "bad address: $sym_base + $offset"
127 DONE=1
128 return
129 fi
Josh Poimboeufefdb4162016-10-25 09:51:11 -0500130 addr=0x$(printf %x $addr)
Josh Poimboeuf67326662016-09-19 10:52:14 -0500131
132 # weed out non-function symbols
Josh Poimboeufefdb4162016-10-25 09:51:11 -0500133 if [[ $sym_type != t ]] && [[ $sym_type != T ]]; then
Josh Poimboeuf67326662016-09-19 10:52:14 -0500134 [[ $print_warnings = 1 ]] &&
Josh Poimboeufefdb4162016-10-25 09:51:11 -0500135 echo "skipping $func address at $addr due to non-function symbol of type '$sym_type'"
Josh Poimboeuf67326662016-09-19 10:52:14 -0500136 continue
137 fi
138
139 # if the user provided a size, make sure it matches the symbol's size
140 if [[ -n $size ]] && [[ $size -ne $sym_size ]]; then
141 [[ $print_warnings = 1 ]] &&
Josh Poimboeufefdb4162016-10-25 09:51:11 -0500142 echo "skipping $func address at $addr due to size mismatch ($size != $sym_size)"
Josh Poimboeuf67326662016-09-19 10:52:14 -0500143 continue;
144 fi
145
146 # make sure the provided offset is within the symbol's range
147 if [[ $offset -gt $sym_size ]]; then
148 [[ $print_warnings = 1 ]] &&
Josh Poimboeufefdb4162016-10-25 09:51:11 -0500149 echo "skipping $func address at $addr due to size mismatch ($offset > $sym_size)"
Josh Poimboeuf67326662016-09-19 10:52:14 -0500150 continue
151 fi
152
153 # separate multiple entries with a blank line
154 [[ $FIRST = 0 ]] && echo
155 FIRST=0
156
Josh Poimboeufefdb4162016-10-25 09:51:11 -0500157 # pass real address to addr2line
158 echo "$func+$offset/$sym_size:"
159 addr2line -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;"
Josh Poimboeuf67326662016-09-19 10:52:14 -0500160 DONE=1
161
NeilBrown2aab9c32017-10-12 14:22:04 +1100162 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; }')
Josh Poimboeuf67326662016-09-19 10:52:14 -0500163}
164
165[[ $# -lt 2 ]] && usage
166
167objfile=$1
168[[ ! -f $objfile ]] && die "can't find objfile $objfile"
169shift
170
171DIR_PREFIX=supercalifragilisticexpialidocious
172find_dir_prefix $objfile
173
174FIRST=1
175while [[ $# -gt 0 ]]; do
176 func_addr=$1
177 shift
178
179 # print any matches found
180 DONE=0
181 __faddr2line $objfile $func_addr $DIR_PREFIX 0
182
183 # if no match was found, print warnings
184 if [[ $DONE = 0 ]]; then
185 __faddr2line $objfile $func_addr $DIR_PREFIX 1
186 warn "no match for $func_addr"
187 fi
188done