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 func_offset=${func_addr#*+} 99 func_offset=${func_offset%/*} 100 local user_size= 101 local file_type 102 local is_vmlinux=0 103 [[ $func_addr =~ "/" ]] && user_size=${func_addr#*/} 104 105 if [[ -z $sym_name ]] || [[ -z $func_offset ]] || [[ $sym_name = $func_addr ]]; then 106 warn "bad func+offset $func_addr" 107 DONE=1 108 return 109 fi 110 111 # vmlinux uses absolute addresses in the section table rather than 112 # section offsets. 113 local file_type=$(${READELF} --file-header $objfile | 114 ${AWK} '$1 == "Type:" { print $2; exit }') 115 [[ $file_type = "EXEC" ]] && is_vmlinux=1 116 117 # Go through each of the object's symbols which match the func name. 118 # In rare cases there might be duplicates, in which case we print all 119 # matches. 120 while read line; do 121 local fields=($line) 122 local sym_addr=0x${fields[1]} 123 local sym_elf_size=${fields[2]} 124 local sym_sec=${fields[6]} 125 local sec_size 126 local sec_name 127 128 # Get the section size: 129 sec_size=$(${READELF} --section-headers --wide $objfile | 130 sed 's/\[ /\[/' | 131 ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }') 132 133 if [[ -z $sec_size ]]; then 134 warn "bad section size: section: $sym_sec" 135 DONE=1 136 return 137 fi 138 139 # Get the section name: 140 sec_name=$(${READELF} --section-headers --wide $objfile | 141 sed 's/\[ /\[/' | 142 ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print $2; exit }') 143 144 if [[ -z $sec_name ]]; then 145 warn "bad section name: section: $sym_sec" 146 DONE=1 147 return 148 fi 149 150 # Calculate the symbol size. 151 # 152 # Unfortunately we can't use the ELF size, because kallsyms 153 # also includes the padding bytes in its size calculation. For 154 # kallsyms, the size calculation is the distance between the 155 # symbol and the next symbol in a sorted list. 156 local sym_size 157 local cur_sym_addr 158 local found=0 159 while read line; do 160 local fields=($line) 161 cur_sym_addr=0x${fields[1]} 162 local cur_sym_elf_size=${fields[2]} 163 local cur_sym_name=${fields[7]:-} 164 165 if [[ $cur_sym_addr = $sym_addr ]] && 166 [[ $cur_sym_elf_size = $sym_elf_size ]] && 167 [[ $cur_sym_name = $sym_name ]]; then 168 found=1 169 continue 170 fi 171 172 if [[ $found = 1 ]]; then 173 sym_size=$(($cur_sym_addr - $sym_addr)) 174 [[ $sym_size -lt $sym_elf_size ]] && continue; 175 found=2 176 break 177 fi 178 done < <(${READELF} --symbols --wide $objfile | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2) 179 180 if [[ $found = 0 ]]; then 181 warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size" 182 DONE=1 183 return 184 fi 185 186 # If nothing was found after the symbol, assume it's the last 187 # symbol in the section. 188 [[ $found = 1 ]] && sym_size=$(($sec_size - $sym_addr)) 189 190 if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then 191 warn "bad symbol size: sym_addr: $sym_addr cur_sym_addr: $cur_sym_addr" 192 DONE=1 193 return 194 fi 195 196 sym_size=0x$(printf %x $sym_size) 197 198 # Calculate the address from user-supplied offset: 199 local addr=$(($sym_addr + $func_offset)) 200 if [[ -z $addr ]] || [[ $addr = 0 ]]; then 201 warn "bad address: $sym_addr + $func_offset" 202 DONE=1 203 return 204 fi 205 addr=0x$(printf %x $addr) 206 207 # If the user provided a size, make sure it matches the symbol's size: 208 if [[ -n $user_size ]] && [[ $user_size -ne $sym_size ]]; then 209 [[ $print_warnings = 1 ]] && 210 echo "skipping $sym_name address at $addr due to size mismatch ($user_size != $sym_size)" 211 continue; 212 fi 213 214 # Make sure the provided offset is within the symbol's range: 215 if [[ $func_offset -gt $sym_size ]]; then 216 [[ $print_warnings = 1 ]] && 217 echo "skipping $sym_name address at $addr due to size mismatch ($func_offset > $sym_size)" 218 continue 219 fi 220 221 # In case of duplicates or multiple addresses specified on the 222 # cmdline, separate multiple entries with a blank line: 223 [[ $FIRST = 0 ]] && echo 224 FIRST=0 225 226 echo "$sym_name+$func_offset/$sym_size:" 227 228 # Pass section address to addr2line and strip absolute paths 229 # from the output: 230 local args="--functions --pretty-print --inlines --exe=$objfile" 231 [[ $is_vmlinux = 0 ]] && args="$args --section=$sec_name" 232 local output=$(${ADDR2LINE} $args $addr | sed "s; $dir_prefix\(\./\)*; ;") 233 [[ -z $output ]] && continue 234 235 # Default output (non --list): 236 if [[ $LIST = 0 ]]; then 237 echo "$output" | while read -r line 238 do 239 echo $line 240 done 241 DONE=1; 242 continue 243 fi 244 245 # For --list, show each line with its corresponding source code: 246 echo "$output" | while read -r line 247 do 248 echo 249 echo $line 250 n=$(echo $line | sed 's/.*:\([0-9]\+\).*/\1/g') 251 n1=$[$n-5] 252 n2=$[$n+5] 253 f=$(echo $line | sed 's/.*at \(.\+\):.*/\1/g') 254 ${AWK} 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f 255 done 256 257 DONE=1 258 259 done < <(${READELF} --symbols --wide $objfile | ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn') 260} 261 262[[ $# -lt 2 ]] && usage 263 264objfile=$1 265 266LIST=0 267[[ "$objfile" == "--list" ]] && LIST=1 && shift && objfile=$1 268 269[[ ! -f $objfile ]] && die "can't find objfile $objfile" 270shift 271 272DIR_PREFIX=supercalifragilisticexpialidocious 273find_dir_prefix $objfile 274 275FIRST=1 276while [[ $# -gt 0 ]]; do 277 func_addr=$1 278 shift 279 280 # print any matches found 281 DONE=0 282 __faddr2line $objfile $func_addr $DIR_PREFIX 0 283 284 # if no match was found, print warnings 285 if [[ $DONE = 0 ]]; then 286 __faddr2line $objfile $func_addr $DIR_PREFIX 1 287 warn "no match for $func_addr" 288 fi 289done 290