diff options
Diffstat (limited to 'scripts/faddr2line')
| -rwxr-xr-x | scripts/faddr2line | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/scripts/faddr2line b/scripts/faddr2line new file mode 100755 index 000000000..9e730b805 --- /dev/null +++ b/scripts/faddr2line @@ -0,0 +1,292 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Translate stack dump function offsets. +# +# addr2line doesn't work with KASLR addresses. This works similarly to +# addr2line, but instead takes the 'func+0x123' format as input: +# +# $ ./scripts/faddr2line ~/k/vmlinux meminfo_proc_show+0x5/0x568 +# meminfo_proc_show+0x5/0x568: +# meminfo_proc_show at fs/proc/meminfo.c:27 +# +# If the address is part of an inlined function, the full inline call chain is +# printed: +# +# $ ./scripts/faddr2line ~/k/vmlinux native_write_msr+0x6/0x27 +# native_write_msr+0x6/0x27: +# arch_static_branch at arch/x86/include/asm/msr.h:121 +# (inlined by) static_key_false at include/linux/jump_label.h:125 +# (inlined by) native_write_msr at arch/x86/include/asm/msr.h:125 +# +# The function size after the '/' in the input is optional, but recommended. +# It's used to help disambiguate any duplicate symbol names, which can occur +# rarely. If the size is omitted for a duplicate symbol then it's possible for +# multiple code sites to be printed: +# +# $ ./scripts/faddr2line ~/k/vmlinux raw_ioctl+0x5 +# raw_ioctl+0x5/0x20: +# raw_ioctl at drivers/char/raw.c:122 +# +# raw_ioctl+0x5/0xb1: +# raw_ioctl at net/ipv4/raw.c:876 +# +# Multiple addresses can be specified on a single command line: +# +# $ ./scripts/faddr2line ~/k/vmlinux type_show+0x10/45 free_reserved_area+0x90 +# type_show+0x10/0x2d: +# type_show at drivers/video/backlight/backlight.c:213 +# +# free_reserved_area+0x90/0x123: +# free_reserved_area at mm/page_alloc.c:6429 (discriminator 2) + + +set -o errexit +set -o nounset + +usage() { + echo "usage: faddr2line [--list] <object file> <func+offset> <func+offset>..." >&2 + exit 1 +} + +warn() { + echo "$1" >&2 +} + +die() { + echo "ERROR: $1" >&2 + exit 1 +} + +READELF="${CROSS_COMPILE:-}readelf" +ADDR2LINE="${CROSS_COMPILE:-}addr2line" +AWK="awk" + +command -v ${AWK} >/dev/null 2>&1 || die "${AWK} isn't installed" +command -v ${READELF} >/dev/null 2>&1 || die "${READELF} isn't installed" +command -v ${ADDR2LINE} >/dev/null 2>&1 || die "${ADDR2LINE} isn't installed" + +# Try to figure out the source directory prefix so we can remove it from the +# addr2line output. HACK ALERT: This assumes that start_kernel() is in +# init/main.c! This only works for vmlinux. Otherwise it falls back to +# printing the absolute path. +find_dir_prefix() { + local objfile=$1 + + local start_kernel_addr=$(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | + ${AWK} '$8 == "start_kernel" {printf "0x%s", $2}') + [[ -z $start_kernel_addr ]] && return + + local file_line=$(${ADDR2LINE} -e $objfile $start_kernel_addr) + [[ -z $file_line ]] && return + + local prefix=${file_line%init/main.c:*} + if [[ -z $prefix ]] || [[ $prefix = $file_line ]]; then + return + fi + + DIR_PREFIX=$prefix + return 0 +} + +__faddr2line() { + local objfile=$1 + local func_addr=$2 + local dir_prefix=$3 + local print_warnings=$4 + + local sym_name=${func_addr%+*} + local func_offset=${func_addr#*+} + func_offset=${func_offset%/*} + local user_size= + local file_type + local is_vmlinux=0 + [[ $func_addr =~ "/" ]] && user_size=${func_addr#*/} + + if [[ -z $sym_name ]] || [[ -z $func_offset ]] || [[ $sym_name = $func_addr ]]; then + warn "bad func+offset $func_addr" + DONE=1 + return + fi + + # vmlinux uses absolute addresses in the section table rather than + # section offsets. + local file_type=$(${READELF} --file-header $objfile | + ${AWK} '$1 == "Type:" { print $2; exit }') + if [[ $file_type = "EXEC" ]] || [[ $file_type == "DYN" ]]; then + is_vmlinux=1 + fi + + # Go through each of the object's symbols which match the func name. + # In rare cases there might be duplicates, in which case we print all + # matches. + while read line; do + local fields=($line) + local sym_addr=0x${fields[1]} + local sym_elf_size=${fields[2]} + local sym_sec=${fields[6]} + local sec_size + local sec_name + + # Get the section size: + sec_size=$(${READELF} --section-headers --wide $objfile | + sed 's/\[ /\[/' | + ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }') + + if [[ -z $sec_size ]]; then + warn "bad section size: section: $sym_sec" + DONE=1 + return + fi + + # Get the section name: + sec_name=$(${READELF} --section-headers --wide $objfile | + sed 's/\[ /\[/' | + ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print $2; exit }') + + if [[ -z $sec_name ]]; then + warn "bad section name: section: $sym_sec" + DONE=1 + return + fi + + # Calculate the symbol size. + # + # Unfortunately we can't use the ELF size, because kallsyms + # also includes the padding bytes in its size calculation. For + # kallsyms, the size calculation is the distance between the + # symbol and the next symbol in a sorted list. + local sym_size + local cur_sym_addr + local found=0 + while read line; do + local fields=($line) + cur_sym_addr=0x${fields[1]} + local cur_sym_elf_size=${fields[2]} + local cur_sym_name=${fields[7]:-} + + if [[ $cur_sym_addr = $sym_addr ]] && + [[ $cur_sym_elf_size = $sym_elf_size ]] && + [[ $cur_sym_name = $sym_name ]]; then + found=1 + continue + fi + + if [[ $found = 1 ]]; then + sym_size=$(($cur_sym_addr - $sym_addr)) + [[ $sym_size -lt $sym_elf_size ]] && continue; + found=2 + break + fi + done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2) + + if [[ $found = 0 ]]; then + warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size" + DONE=1 + return + fi + + # If nothing was found after the symbol, assume it's the last + # symbol in the section. + [[ $found = 1 ]] && sym_size=$(($sec_size - $sym_addr)) + + if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then + warn "bad symbol size: sym_addr: $sym_addr cur_sym_addr: $cur_sym_addr" + DONE=1 + return + fi + + sym_size=0x$(printf %x $sym_size) + + # Calculate the address from user-supplied offset: + local addr=$(($sym_addr + $func_offset)) + if [[ -z $addr ]] || [[ $addr = 0 ]]; then + warn "bad address: $sym_addr + $func_offset" + DONE=1 + return + fi + addr=0x$(printf %x $addr) + + # If the user provided a size, make sure it matches the symbol's size: + if [[ -n $user_size ]] && [[ $user_size -ne $sym_size ]]; then + [[ $print_warnings = 1 ]] && + echo "skipping $sym_name address at $addr due to size mismatch ($user_size != $sym_size)" + continue; + fi + + # Make sure the provided offset is within the symbol's range: + if [[ $func_offset -gt $sym_size ]]; then + [[ $print_warnings = 1 ]] && + echo "skipping $sym_name address at $addr due to size mismatch ($func_offset > $sym_size)" + continue + fi + + # In case of duplicates or multiple addresses specified on the + # cmdline, separate multiple entries with a blank line: + [[ $FIRST = 0 ]] && echo + FIRST=0 + + echo "$sym_name+$func_offset/$sym_size:" + + # Pass section address to addr2line and strip absolute paths + # from the output: + local args="--functions --pretty-print --inlines --exe=$objfile" + [[ $is_vmlinux = 0 ]] && args="$args --section=$sec_name" + local output=$(${ADDR2LINE} $args $addr | sed "s; $dir_prefix\(\./\)*; ;") + [[ -z $output ]] && continue + + # Default output (non --list): + if [[ $LIST = 0 ]]; then + echo "$output" | while read -r line + do + echo $line + done + DONE=1; + continue + fi + + # For --list, show each line with its corresponding source code: + echo "$output" | while read -r line + do + echo + echo $line + n=$(echo $line | sed 's/.*:\([0-9]\+\).*/\1/g') + n1=$[$n-5] + n2=$[$n+5] + f=$(echo $line | sed 's/.*at \(.\+\):.*/\1/g') + ${AWK} 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f + done + + DONE=1 + + done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn') +} + +[[ $# -lt 2 ]] && usage + +objfile=$1 + +LIST=0 +[[ "$objfile" == "--list" ]] && LIST=1 && shift && objfile=$1 + +[[ ! -f $objfile ]] && die "can't find objfile $objfile" +shift + +DIR_PREFIX=supercalifragilisticexpialidocious +find_dir_prefix $objfile + +FIRST=1 +while [[ $# -gt 0 ]]; do + func_addr=$1 + shift + + # print any matches found + DONE=0 + __faddr2line $objfile $func_addr $DIR_PREFIX 0 + + # if no match was found, print warnings + if [[ $DONE = 0 ]]; then + __faddr2line $objfile $func_addr $DIR_PREFIX 1 + warn "no match for $func_addr" + fi +done |