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