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: $1" >&2 58 exit 1 59} 60 61UTIL_SUFFIX="" 62if [[ "${LLVM:-}" == "" ]]; then 63 UTIL_PREFIX=${CROSS_COMPILE:-} 64else 65 UTIL_PREFIX=llvm- 66 67 if [[ "${LLVM}" == *"/" ]]; then 68 UTIL_PREFIX=${LLVM}${UTIL_PREFIX} 69 elif [[ "${LLVM}" == "-"* ]]; then 70 UTIL_SUFFIX=${LLVM} 71 fi 72fi 73 74READELF="${UTIL_PREFIX}readelf${UTIL_SUFFIX}" 75ADDR2LINE="${UTIL_PREFIX}addr2line${UTIL_SUFFIX}" 76AWK="awk" 77GREP="grep" 78 79# Enforce ASCII-only output from tools like readelf 80# ensuring sed processes strings correctly. 81export LANG=C 82 83command -v ${AWK} >/dev/null 2>&1 || die "${AWK} isn't installed" 84command -v ${READELF} >/dev/null 2>&1 || die "${READELF} isn't installed" 85command -v ${ADDR2LINE} >/dev/null 2>&1 || die "${ADDR2LINE} isn't installed" 86 87# Try to figure out the source directory prefix so we can remove it from the 88# addr2line output. HACK ALERT: This assumes that start_kernel() is in 89# init/main.c! This only works for vmlinux. Otherwise it falls back to 90# printing the absolute path. 91find_dir_prefix() { 92 local start_kernel_addr=$(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | 93 ${AWK} '$8 == "start_kernel" {printf "0x%s", $2}') 94 [[ -z $start_kernel_addr ]] && return 95 96 run_addr2line ${start_kernel_addr} "" 97 [[ -z $ADDR2LINE_OUT ]] && return 98 99 local file_line=${ADDR2LINE_OUT#* at } 100 if [[ -z $file_line ]] || [[ $file_line = $ADDR2LINE_OUT ]]; then 101 return 102 fi 103 local prefix=${file_line%init/main.c:*} 104 if [[ -z $prefix ]] || [[ $prefix = $file_line ]]; then 105 return 106 fi 107 108 DIR_PREFIX=$prefix 109 return 0 110} 111 112run_readelf() { 113 local objfile=$1 114 local out=$(${READELF} --file-header --section-headers --symbols --wide $objfile) 115 116 # This assumes that readelf first prints the file header, then the section headers, then the symbols. 117 # Note: It seems that GNU readelf does not prefix section headers with the "There are X section headers" 118 # line when multiple options are given, so let's also match with the "Section Headers:" line. 119 ELF_FILEHEADER=$(echo "${out}" | sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/q;p') 120 ELF_SECHEADERS=$(echo "${out}" | sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/,$p' | sed -n '/Symbol table .* contains [0-9]* entries:/q;p') 121 ELF_SYMS=$(echo "${out}" | sed -n '/Symbol table .* contains [0-9]* entries:/,$p') 122} 123 124check_vmlinux() { 125 # vmlinux uses absolute addresses in the section table rather than 126 # section offsets. 127 IS_VMLINUX=0 128 local file_type=$(echo "${ELF_FILEHEADER}" | 129 ${AWK} '$1 == "Type:" { print $2; exit }') 130 if [[ $file_type = "EXEC" ]] || [[ $file_type == "DYN" ]]; then 131 IS_VMLINUX=1 132 fi 133} 134 135init_addr2line() { 136 local objfile=$1 137 138 check_vmlinux 139 140 ADDR2LINE_ARGS="--functions --pretty-print --inlines --addresses --exe=$objfile" 141 if [[ $IS_VMLINUX = 1 ]]; then 142 # If the executable file is vmlinux, we don't pass section names to 143 # addr2line, so we can launch it now as a single long-running process. 144 coproc ADDR2LINE_PROC (${ADDR2LINE} ${ADDR2LINE_ARGS}) 145 fi 146} 147 148run_addr2line() { 149 local addr=$1 150 local sec_name=$2 151 152 if [[ $IS_VMLINUX = 1 ]]; then 153 # We send to the addr2line process: (1) the address, then (2) a sentinel 154 # value, i.e., something that can't be interpreted as a valid address 155 # (i.e., ","). This causes addr2line to write out: (1) the answer for 156 # our address, then (2) either "?? ??:0" or "0x0...0: ..." (if 157 # using binutils' addr2line), or "," (if using LLVM's addr2line). 158 echo ${addr} >& "${ADDR2LINE_PROC[1]}" 159 echo "," >& "${ADDR2LINE_PROC[1]}" 160 local first_line 161 read -r first_line <& "${ADDR2LINE_PROC[0]}" 162 ADDR2LINE_OUT=$(echo "${first_line}" | sed 's/^0x[0-9a-fA-F]*: //') 163 while read -r line <& "${ADDR2LINE_PROC[0]}"; do 164 if [[ "$line" == "?? ??:0" ]] || [[ "$line" == "," ]] || [[ $(echo "$line" | ${GREP} "^0x00*: ") ]]; then 165 break 166 fi 167 ADDR2LINE_OUT+=$'\n'$(echo "$line" | sed 's/^0x[0-9a-fA-F]*: //') 168 done 169 else 170 # Run addr2line as a single invocation. 171 local sec_arg 172 [[ -z $sec_name ]] && sec_arg="" || sec_arg="--section=${sec_name}" 173 ADDR2LINE_OUT=$(${ADDR2LINE} ${ADDR2LINE_ARGS} ${sec_arg} ${addr} | sed 's/^0x[0-9a-fA-F]*: //') 174 fi 175} 176 177__faddr2line() { 178 local objfile=$1 179 local func_addr=$2 180 local dir_prefix=$3 181 local print_warnings=$4 182 183 local sym_name=${func_addr%+*} 184 local func_offset=${func_addr#*+} 185 func_offset=${func_offset%/*} 186 local user_size= 187 [[ $func_addr =~ "/" ]] && user_size=${func_addr#*/} 188 189 if [[ -z $sym_name ]] || [[ -z $func_offset ]] || [[ $sym_name = $func_addr ]]; then 190 warn "bad func+offset $func_addr" 191 DONE=1 192 return 193 fi 194 195 # Go through each of the object's symbols which match the func name. 196 # In rare cases there might be duplicates, in which case we print all 197 # matches. 198 while read line; do 199 local fields=($line) 200 local sym_addr=0x${fields[1]} 201 local sym_elf_size=${fields[2]} 202 local sym_sec=${fields[6]} 203 local sec_size 204 local sec_name 205 206 # Get the section size: 207 sec_size=$(echo "${ELF_SECHEADERS}" | sed 's/\[ /\[/' | 208 ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }') 209 210 if [[ -z $sec_size ]]; then 211 warn "bad section size: section: $sym_sec" 212 DONE=1 213 return 214 fi 215 216 # Get the section name: 217 sec_name=$(echo "${ELF_SECHEADERS}" | sed 's/\[ /\[/' | 218 ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print $2; exit }') 219 220 if [[ -z $sec_name ]]; then 221 warn "bad section name: section: $sym_sec" 222 DONE=1 223 return 224 fi 225 226 # Calculate the symbol size. 227 # 228 # Unfortunately we can't use the ELF size, because kallsyms 229 # also includes the padding bytes in its size calculation. For 230 # kallsyms, the size calculation is the distance between the 231 # symbol and the next symbol in a sorted list. 232 local sym_size 233 local cur_sym_addr 234 local found=0 235 while read line; do 236 local fields=($line) 237 cur_sym_addr=0x${fields[1]} 238 local cur_sym_elf_size=${fields[2]} 239 local cur_sym_name=${fields[7]:-} 240 241 # is_mapping_symbol(cur_sym_name) 242 if [[ ${cur_sym_name} =~ ^(\.L|L0|\$) ]]; then 243 continue 244 fi 245 246 if [[ $cur_sym_addr = $sym_addr ]] && 247 [[ $cur_sym_elf_size = $sym_elf_size ]] && 248 [[ $cur_sym_name = $sym_name ]]; then 249 found=1 250 continue 251 fi 252 253 if [[ $found = 1 ]]; then 254 sym_size=$(($cur_sym_addr - $sym_addr)) 255 [[ $sym_size -lt $sym_elf_size ]] && continue; 256 found=2 257 break 258 fi 259 done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2) 260 261 if [[ $found = 0 ]]; then 262 warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size" 263 DONE=1 264 return 265 fi 266 267 # If nothing was found after the symbol, assume it's the last 268 # symbol in the section. 269 [[ $found = 1 ]] && sym_size=$(($sec_size - $sym_addr)) 270 271 if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then 272 warn "bad symbol size: sym_addr: $sym_addr cur_sym_addr: $cur_sym_addr" 273 DONE=1 274 return 275 fi 276 277 sym_size=0x$(printf %x $sym_size) 278 279 # Calculate the address from user-supplied offset: 280 local addr=$(($sym_addr + $func_offset)) 281 if [[ -z $addr ]] || [[ $addr = 0 ]]; then 282 warn "bad address: $sym_addr + $func_offset" 283 DONE=1 284 return 285 fi 286 addr=0x$(printf %x $addr) 287 288 # If the user provided a size, make sure it matches the symbol's size: 289 if [[ -n $user_size ]] && [[ $user_size -ne $sym_size ]]; then 290 [[ $print_warnings = 1 ]] && 291 echo "skipping $sym_name address at $addr due to size mismatch ($user_size != $sym_size)" 292 continue; 293 fi 294 295 # Make sure the provided offset is within the symbol's range: 296 if [[ $func_offset -gt $sym_size ]]; then 297 [[ $print_warnings = 1 ]] && 298 echo "skipping $sym_name address at $addr due to size mismatch ($func_offset > $sym_size)" 299 continue 300 fi 301 302 # In case of duplicates or multiple addresses specified on the 303 # cmdline, separate multiple entries with a blank line: 304 [[ $FIRST = 0 ]] && echo 305 FIRST=0 306 307 echo "$sym_name+$func_offset/$sym_size:" 308 309 # Pass section address to addr2line and strip absolute paths 310 # from the output: 311 run_addr2line $addr $sec_name 312 local output=$(echo "${ADDR2LINE_OUT}" | sed "s; $dir_prefix\(\./\)*; ;") 313 [[ -z $output ]] && continue 314 315 # Default output (non --list): 316 if [[ $LIST = 0 ]]; then 317 echo "$output" | while read -r line 318 do 319 echo $line 320 done 321 DONE=1; 322 continue 323 fi 324 325 # For --list, show each line with its corresponding source code: 326 echo "$output" | while read -r line 327 do 328 echo 329 echo $line 330 n=$(echo $line | sed 's/.*:\([0-9]\+\).*/\1/g') 331 n1=$[$n-5] 332 n2=$[$n+5] 333 f=$(echo $line | sed 's/.*at \(.\+\):.*/\1/g') 334 ${AWK} 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f 335 done 336 337 DONE=1 338 339 done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v fn=$sym_name '$8 == fn') 340} 341 342[[ $# -lt 2 ]] && usage 343 344objfile=$1 345 346LIST=0 347[[ "$objfile" == "--list" ]] && LIST=1 && shift && objfile=$1 348 349[[ ! -f $objfile ]] && die "can't find objfile $objfile" 350shift 351 352run_readelf $objfile 353 354echo "${ELF_SECHEADERS}" | ${GREP} -q '\.debug_info' || die "CONFIG_DEBUG_INFO not enabled" 355 356init_addr2line $objfile 357 358DIR_PREFIX=supercalifragilisticexpialidocious 359find_dir_prefix 360 361FIRST=1 362while [[ $# -gt 0 ]]; do 363 func_addr=$1 364 shift 365 366 # print any matches found 367 DONE=0 368 __faddr2line $objfile $func_addr $DIR_PREFIX 0 369 370 # if no match was found, print warnings 371 if [[ $DONE = 0 ]]; then 372 __faddr2line $objfile $func_addr $DIR_PREFIX 1 373 warn "no match for $func_addr" 374 fi 375done 376