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 ${ADDR2LINE} -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;" 167 DONE=1 168 169 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; }') 170} 171 172[[ $# -lt 2 ]] && usage 173 174objfile=$1 175[[ ! -f $objfile ]] && die "can't find objfile $objfile" 176shift 177 178DIR_PREFIX=supercalifragilisticexpialidocious 179find_dir_prefix $objfile 180 181FIRST=1 182while [[ $# -gt 0 ]]; do 183 func_addr=$1 184 shift 185 186 # print any matches found 187 DONE=0 188 __faddr2line $objfile $func_addr $DIR_PREFIX 0 189 190 # if no match was found, print warnings 191 if [[ $DONE = 0 ]]; then 192 __faddr2line $objfile $func_addr $DIR_PREFIX 1 193 warn "no match for $func_addr" 194 fi 195done 196