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" 64GREP="grep" 65 66command -v ${AWK} >/dev/null 2>&1 || die "${AWK} isn't installed" 67command -v ${READELF} >/dev/null 2>&1 || die "${READELF} isn't installed" 68command -v ${ADDR2LINE} >/dev/null 2>&1 || die "${ADDR2LINE} isn't installed" 69 70# Try to figure out the source directory prefix so we can remove it from the 71# addr2line output. HACK ALERT: This assumes that start_kernel() is in 72# init/main.c! This only works for vmlinux. Otherwise it falls back to 73# printing the absolute path. 74find_dir_prefix() { 75 local objfile=$1 76 77 local start_kernel_addr=$(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | 78 ${AWK} '$8 == "start_kernel" {printf "0x%s", $2}') 79 [[ -z $start_kernel_addr ]] && return 80 81 local file_line=$(${ADDR2LINE} -e $objfile $start_kernel_addr) 82 [[ -z $file_line ]] && return 83 84 local prefix=${file_line%init/main.c:*} 85 if [[ -z $prefix ]] || [[ $prefix = $file_line ]]; then 86 return 87 fi 88 89 DIR_PREFIX=$prefix 90 return 0 91} 92 93__faddr2line() { 94 local objfile=$1 95 local func_addr=$2 96 local dir_prefix=$3 97 local print_warnings=$4 98 99 local sym_name=${func_addr%+*} 100 local func_offset=${func_addr#*+} 101 func_offset=${func_offset%/*} 102 local user_size= 103 local file_type 104 local is_vmlinux=0 105 [[ $func_addr =~ "/" ]] && user_size=${func_addr#*/} 106 107 if [[ -z $sym_name ]] || [[ -z $func_offset ]] || [[ $sym_name = $func_addr ]]; then 108 warn "bad func+offset $func_addr" 109 DONE=1 110 return 111 fi 112 113 # vmlinux uses absolute addresses in the section table rather than 114 # section offsets. 115 local file_type=$(${READELF} --file-header $objfile | 116 ${AWK} '$1 == "Type:" { print $2; exit }') 117 if [[ $file_type = "EXEC" ]] || [[ $file_type == "DYN" ]]; then 118 is_vmlinux=1 119 fi 120 121 # Go through each of the object's symbols which match the func name. 122 # In rare cases there might be duplicates, in which case we print all 123 # matches. 124 while read line; do 125 local fields=($line) 126 local sym_addr=0x${fields[1]} 127 local sym_elf_size=${fields[2]} 128 local sym_sec=${fields[6]} 129 local sec_size 130 local sec_name 131 132 # Get the section size: 133 sec_size=$(${READELF} --section-headers --wide $objfile | 134 sed 's/\[ /\[/' | 135 ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }') 136 137 if [[ -z $sec_size ]]; then 138 warn "bad section size: section: $sym_sec" 139 DONE=1 140 return 141 fi 142 143 # Get the section name: 144 sec_name=$(${READELF} --section-headers --wide $objfile | 145 sed 's/\[ /\[/' | 146 ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print $2; exit }') 147 148 if [[ -z $sec_name ]]; then 149 warn "bad section name: section: $sym_sec" 150 DONE=1 151 return 152 fi 153 154 # Calculate the symbol size. 155 # 156 # Unfortunately we can't use the ELF size, because kallsyms 157 # also includes the padding bytes in its size calculation. For 158 # kallsyms, the size calculation is the distance between the 159 # symbol and the next symbol in a sorted list. 160 local sym_size 161 local cur_sym_addr 162 local found=0 163 while read line; do 164 local fields=($line) 165 cur_sym_addr=0x${fields[1]} 166 local cur_sym_elf_size=${fields[2]} 167 local cur_sym_name=${fields[7]:-} 168 169 if [[ $cur_sym_addr = $sym_addr ]] && 170 [[ $cur_sym_elf_size = $sym_elf_size ]] && 171 [[ $cur_sym_name = $sym_name ]]; then 172 found=1 173 continue 174 fi 175 176 if [[ $found = 1 ]]; then 177 sym_size=$(($cur_sym_addr - $sym_addr)) 178 [[ $sym_size -lt $sym_elf_size ]] && continue; 179 found=2 180 break 181 fi 182 done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2) 183 184 if [[ $found = 0 ]]; then 185 warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size" 186 DONE=1 187 return 188 fi 189 190 # If nothing was found after the symbol, assume it's the last 191 # symbol in the section. 192 [[ $found = 1 ]] && sym_size=$(($sec_size - $sym_addr)) 193 194 if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then 195 warn "bad symbol size: sym_addr: $sym_addr cur_sym_addr: $cur_sym_addr" 196 DONE=1 197 return 198 fi 199 200 sym_size=0x$(printf %x $sym_size) 201 202 # Calculate the address from user-supplied offset: 203 local addr=$(($sym_addr + $func_offset)) 204 if [[ -z $addr ]] || [[ $addr = 0 ]]; then 205 warn "bad address: $sym_addr + $func_offset" 206 DONE=1 207 return 208 fi 209 addr=0x$(printf %x $addr) 210 211 # If the user provided a size, make sure it matches the symbol's size: 212 if [[ -n $user_size ]] && [[ $user_size -ne $sym_size ]]; then 213 [[ $print_warnings = 1 ]] && 214 echo "skipping $sym_name address at $addr due to size mismatch ($user_size != $sym_size)" 215 continue; 216 fi 217 218 # Make sure the provided offset is within the symbol's range: 219 if [[ $func_offset -gt $sym_size ]]; then 220 [[ $print_warnings = 1 ]] && 221 echo "skipping $sym_name address at $addr due to size mismatch ($func_offset > $sym_size)" 222 continue 223 fi 224 225 # In case of duplicates or multiple addresses specified on the 226 # cmdline, separate multiple entries with a blank line: 227 [[ $FIRST = 0 ]] && echo 228 FIRST=0 229 230 echo "$sym_name+$func_offset/$sym_size:" 231 232 # Pass section address to addr2line and strip absolute paths 233 # from the output: 234 local args="--functions --pretty-print --inlines --exe=$objfile" 235 [[ $is_vmlinux = 0 ]] && args="$args --section=$sec_name" 236 local output=$(${ADDR2LINE} $args $addr | sed "s; $dir_prefix\(\./\)*; ;") 237 [[ -z $output ]] && continue 238 239 # Default output (non --list): 240 if [[ $LIST = 0 ]]; then 241 echo "$output" | while read -r line 242 do 243 echo $line 244 done 245 DONE=1; 246 continue 247 fi 248 249 # For --list, show each line with its corresponding source code: 250 echo "$output" | while read -r line 251 do 252 echo 253 echo $line 254 n=$(echo $line | sed 's/.*:\([0-9]\+\).*/\1/g') 255 n1=$[$n-5] 256 n2=$[$n+5] 257 f=$(echo $line | sed 's/.*at \(.\+\):.*/\1/g') 258 ${AWK} 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f 259 done 260 261 DONE=1 262 263 done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn') 264} 265 266[[ $# -lt 2 ]] && usage 267 268objfile=$1 269 270LIST=0 271[[ "$objfile" == "--list" ]] && LIST=1 && shift && objfile=$1 272 273[[ ! -f $objfile ]] && die "can't find objfile $objfile" 274shift 275 276${READELF} --section-headers --wide $objfile | ${GREP} -q '\.debug_info' || die "CONFIG_DEBUG_INFO not enabled" 277 278DIR_PREFIX=supercalifragilisticexpialidocious 279find_dir_prefix $objfile 280 281FIRST=1 282while [[ $# -gt 0 ]]; do 283 func_addr=$1 284 shift 285 286 # print any matches found 287 DONE=0 288 __faddr2line $objfile $func_addr $DIR_PREFIX 0 289 290 # if no match was found, print warnings 291 if [[ $DONE = 0 ]]; then 292 __faddr2line $objfile $func_addr $DIR_PREFIX 1 293 warn "no match for $func_addr" 294 fi 295done 296