1#!/usr/bin/env 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=$1 114 local tmpfile 115 tmpfile=$(mktemp) 116 117 ${READELF} --file-header --section-headers --symbols --wide "$objfile" > "$tmpfile" 118 119 # This assumes that readelf first prints the file header, then the section headers, then the symbols. 120 # Note: It seems that GNU readelf does not prefix section headers with the "There are X section headers" 121 # line when multiple options are given, so let's also match with the "Section Headers:" line. 122 ELF_FILEHEADER=$(sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/q;p' "$tmpfile") 123 ELF_SECHEADERS=$(sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/,$p' "$tmpfile" | sed -n '/Symbol table .* contains [0-9]* entries:/q;p') 124 ELF_SYMS=$(sed -n '/Symbol table .* contains [0-9]* entries:/,$p' "$tmpfile") 125 126 rm -f -- "$tmpfile" 127} 128 129check_vmlinux() { 130 # vmlinux uses absolute addresses in the section table rather than 131 # section offsets. 132 IS_VMLINUX=0 133 local file_type=$(echo "${ELF_FILEHEADER}" | 134 ${AWK} '$1 == "Type:" { print $2; exit }') 135 if [[ $file_type = "EXEC" ]] || [[ $file_type == "DYN" ]]; then 136 IS_VMLINUX=1 137 fi 138} 139 140init_addr2line() { 141 local objfile=$1 142 143 check_vmlinux 144 145 ADDR2LINE_ARGS="--functions --pretty-print --inlines --addresses --exe=$objfile" 146 if [[ $IS_VMLINUX = 1 ]]; then 147 # If the executable file is vmlinux, we don't pass section names to 148 # addr2line, so we can launch it now as a single long-running process. 149 coproc ADDR2LINE_PROC (${ADDR2LINE} ${ADDR2LINE_ARGS}) 150 fi 151} 152 153run_addr2line() { 154 local addr=$1 155 local sec_name=$2 156 157 if [[ $IS_VMLINUX = 1 ]]; then 158 # We send to the addr2line process: (1) the address, then (2) a sentinel 159 # value, i.e., something that can't be interpreted as a valid address 160 # (i.e., ","). This causes addr2line to write out: (1) the answer for 161 # our address, then (2) either "?? ??:0" or "0x0...0: ..." (if 162 # using binutils' addr2line), or "," (if using LLVM's addr2line). 163 echo ${addr} >& "${ADDR2LINE_PROC[1]}" 164 echo "," >& "${ADDR2LINE_PROC[1]}" 165 local first_line 166 read -r first_line <& "${ADDR2LINE_PROC[0]}" 167 ADDR2LINE_OUT=$(echo "${first_line}" | sed 's/^0x[0-9a-fA-F]*: //') 168 while read -r line <& "${ADDR2LINE_PROC[0]}"; do 169 if [[ "$line" == "?? ??:0" ]] || [[ "$line" == "," ]] || [[ $(echo "$line" | ${GREP} "^0x00*: ") ]]; then 170 break 171 fi 172 ADDR2LINE_OUT+=$'\n'$(echo "$line" | sed 's/^0x[0-9a-fA-F]*: //') 173 done 174 else 175 # Run addr2line as a single invocation. 176 local sec_arg 177 [[ -z $sec_name ]] && sec_arg="" || sec_arg="--section=${sec_name}" 178 ADDR2LINE_OUT=$(${ADDR2LINE} ${ADDR2LINE_ARGS} ${sec_arg} ${addr} | sed 's/^0x[0-9a-fA-F]*: //') 179 fi 180} 181 182__faddr2line() { 183 local objfile=$1 184 local func_addr=$2 185 local dir_prefix=$3 186 local print_warnings=$4 187 188 local sym_name=${func_addr%+*} 189 local func_offset=${func_addr#*+} 190 func_offset=${func_offset%/*} 191 local user_size= 192 [[ $func_addr =~ "/" ]] && user_size=${func_addr#*/} 193 194 if [[ -z $sym_name ]] || [[ -z $func_offset ]] || [[ $sym_name = $func_addr ]]; then 195 warn "bad func+offset $func_addr" 196 DONE=1 197 return 198 fi 199 200 # Go through each of the object's symbols which match the func name. 201 # In rare cases there might be duplicates, in which case we print all 202 # matches. 203 while read line; do 204 local fields=($line) 205 local sym_addr=0x${fields[1]} 206 local sym_elf_size=${fields[2]} 207 local sym_sec=${fields[6]} 208 local sec_size 209 local sec_name 210 211 # Get the section size: 212 sec_size=$(echo "${ELF_SECHEADERS}" | sed 's/\[ /\[/' | 213 ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }') 214 215 if [[ -z $sec_size ]]; then 216 warn "bad section size: section: $sym_sec" 217 DONE=1 218 return 219 fi 220 221 # Get the section name: 222 sec_name=$(echo "${ELF_SECHEADERS}" | sed 's/\[ /\[/' | 223 ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print $2; exit }') 224 225 if [[ -z $sec_name ]]; then 226 warn "bad section name: section: $sym_sec" 227 DONE=1 228 return 229 fi 230 231 # Calculate the symbol size. 232 # 233 # Unfortunately we can't use the ELF size, because kallsyms 234 # also includes the padding bytes in its size calculation. For 235 # kallsyms, the size calculation is the distance between the 236 # symbol and the next symbol in a sorted list. 237 local sym_size 238 local cur_sym_addr 239 local found=0 240 while read line; do 241 local fields=($line) 242 cur_sym_addr=0x${fields[1]} 243 local cur_sym_elf_size=${fields[2]} 244 local cur_sym_name=${fields[7]:-} 245 246 # is_mapping_symbol(cur_sym_name) 247 if [[ ${cur_sym_name} =~ ^(\.L|L0|\$) ]]; then 248 continue 249 fi 250 251 if [[ $cur_sym_addr = $sym_addr ]] && 252 [[ $cur_sym_elf_size = $sym_elf_size ]] && 253 [[ $cur_sym_name = $sym_name ]]; then 254 found=1 255 continue 256 fi 257 258 if [[ $found = 1 ]]; then 259 sym_size=$(($cur_sym_addr - $sym_addr)) 260 [[ $sym_size -lt $sym_elf_size ]] && continue; 261 found=2 262 break 263 fi 264 done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2) 265 266 if [[ $found = 0 ]]; then 267 warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size" 268 DONE=1 269 return 270 fi 271 272 # If nothing was found after the symbol, assume it's the last 273 # symbol in the section. 274 [[ $found = 1 ]] && sym_size=$(($sec_size - $sym_addr)) 275 276 if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then 277 warn "bad symbol size: sym_addr: $sym_addr cur_sym_addr: $cur_sym_addr" 278 DONE=1 279 return 280 fi 281 282 sym_size=0x$(printf %x $sym_size) 283 284 # Calculate the address from user-supplied offset: 285 local addr=$(($sym_addr + $func_offset)) 286 if [[ -z $addr ]] || [[ $addr = 0 ]]; then 287 warn "bad address: $sym_addr + $func_offset" 288 DONE=1 289 return 290 fi 291 addr=0x$(printf %x $addr) 292 293 # If the user provided a size, make sure it matches the symbol's size: 294 if [[ -n $user_size ]] && [[ $user_size -ne $sym_size ]]; then 295 [[ $print_warnings = 1 ]] && 296 echo "skipping $sym_name address at $addr due to size mismatch ($user_size != $sym_size)" 297 continue; 298 fi 299 300 # Make sure the provided offset is within the symbol's range: 301 if [[ $func_offset -gt $sym_size ]]; then 302 [[ $print_warnings = 1 ]] && 303 echo "skipping $sym_name address at $addr due to size mismatch ($func_offset > $sym_size)" 304 continue 305 fi 306 307 # In case of duplicates or multiple addresses specified on the 308 # cmdline, separate multiple entries with a blank line: 309 [[ $FIRST = 0 ]] && echo 310 FIRST=0 311 312 echo "$sym_name+$func_offset/$sym_size:" 313 314 # Pass section address to addr2line and strip absolute paths 315 # from the output: 316 run_addr2line $addr $sec_name 317 local output=$(echo "${ADDR2LINE_OUT}" | sed "s; $dir_prefix\(\./\)*; ;") 318 [[ -z $output ]] && continue 319 320 # Default output (non --list): 321 if [[ $LIST = 0 ]]; then 322 echo "$output" | while read -r line 323 do 324 echo $line 325 done 326 DONE=1; 327 continue 328 fi 329 330 # For --list, show each line with its corresponding source code: 331 echo "$output" | while read -r line 332 do 333 echo 334 echo $line 335 n=$(echo $line | sed 's/.*:\([0-9]\+\).*/\1/g') 336 n1=$[$n-5] 337 n2=$[$n+5] 338 f=$(echo $line | sed 's/.*at \(.\+\):.*/\1/g') 339 ${AWK} 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f 340 done 341 342 DONE=1 343 344 done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v fn=$sym_name '$8 == fn') 345} 346 347[[ $# -lt 2 ]] && usage 348 349objfile=$1 350 351LIST=0 352[[ "$objfile" == "--list" ]] && LIST=1 && shift && objfile=$1 353 354[[ ! -f $objfile ]] && die "can't find objfile $objfile" 355shift 356 357run_readelf $objfile 358 359echo "${ELF_SECHEADERS}" | ${GREP} -q '\.debug_info' || die "CONFIG_DEBUG_INFO not enabled" 360 361init_addr2line $objfile 362 363DIR_PREFIX=supercalifragilisticexpialidocious 364find_dir_prefix 365 366FIRST=1 367while [[ $# -gt 0 ]]; do 368 func_addr=$1 369 shift 370 371 # print any matches found 372 DONE=0 373 __faddr2line $objfile $func_addr $DIR_PREFIX 0 374 375 # if no match was found, print warnings 376 if [[ $DONE = 0 ]]; then 377 __faddr2line $objfile $func_addr $DIR_PREFIX 1 378 warn "no match for $func_addr" 379 fi 380done 381