diff options
| -rwxr-xr-x | scripts/faddr2line | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/scripts/faddr2line b/scripts/faddr2line new file mode 100755 index 000000000000..4fbfe8305fe3 --- /dev/null +++ b/scripts/faddr2line @@ -0,0 +1,177 @@ +#!/bin/bash +# +# 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 + +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" + +usage() { + echo "usage: faddr2line <object file> <func+offset> <func+offset>..." >&2 + exit 1 +} + +warn() { + echo "$1" >&2 +} + +die() { + echo "ERROR: $1" >&2 + exit 1 +} + +# 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 +# kernel/init.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 -sW $objfile | 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=$4 + + local func=${func_addr%+*} + local offset=${func_addr#*+} + offset=${offset%/*} + local size= + [[ $func_addr =~ "/" ]] && size=${func_addr#*/} + + if [[ -z $func ]] || [[ -z $offset ]] || [[ $func = $func_addr ]]; then + warn "bad func+offset $func_addr" + DONE=1 + return + fi + + # Go through each of the object's symbols which match the func name. + # In rare cases there might be duplicates. + while read symbol; do + local fields=($symbol) + local sym_base=0x${fields[1]} + local sym_size=${fields[2]} + local sym_type=${fields[3]} + + # calculate the address + local addr=$(($sym_base + $offset)) + if [[ -z $addr ]] || [[ $addr = 0 ]]; then + warn "bad address: $sym_base + $offset" + DONE=1 + return + fi + local hexaddr=0x$(printf %x $addr) + + # weed out non-function symbols + if [[ $sym_type != "FUNC" ]]; then + [[ $print_warnings = 1 ]] && + echo "skipping $func address at $hexaddr due to non-function symbol" + continue + fi + + # if the user provided a size, make sure it matches the symbol's size + if [[ -n $size ]] && [[ $size -ne $sym_size ]]; then + [[ $print_warnings = 1 ]] && + echo "skipping $func address at $hexaddr due to size mismatch ($size != $sym_size)" + continue; + fi + + # make sure the provided offset is within the symbol's range + if [[ $offset -gt $sym_size ]]; then + [[ $print_warnings = 1 ]] && + echo "skipping $func address at $hexaddr due to size mismatch ($offset > $sym_size)" + continue + fi + + # separate multiple entries with a blank line + [[ $FIRST = 0 ]] && echo + FIRST=0 + + local hexsize=0x$(printf %x $sym_size) + echo "$func+$offset/$hexsize:" + addr2line -fpie $objfile $hexaddr | sed "s;$dir_prefix;;" + DONE=1 + + done < <(readelf -sW $objfile | awk -v f=$func '$8 == f {print}') +} + +[[ $# -lt 2 ]] && usage + +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 |