1#!/bin/sh 2# SPDX-License-Identifier: GPL-2.0-or-later 3 4# Copyright © 2015 IBM Corporation 5 6 7# This script checks the relocations of a vmlinux for "suspicious" 8# relocations. 9 10# based on relocs_check.pl 11# Copyright © 2009 IBM Corporation 12 13if [ $# -lt 3 ]; then 14 echo "$0 [path to objdump] [path to nm] [path to vmlinux]" 1>&2 15 exit 1 16fi 17 18# Have Kbuild supply the path to objdump and nm so we handle cross compilation. 19objdump="$1" 20nm="$2" 21vmlinux="$3" 22 23# Remove from the bad relocations those that match an undefined weak symbol 24# which will result in an absolute relocation to 0. 25# Weak unresolved symbols are of that form in nm output: 26# " w _binary__btf_vmlinux_bin_end" 27undef_weak_symbols=$($nm "$vmlinux" | awk '$1 ~ /w/ { print $2 }') 28 29bad_relocs=$( 30$objdump -R "$vmlinux" | 31 # Only look at relocation lines. 32 grep -E '\<R_' | 33 # These relocations are okay 34 # On PPC64: 35 # R_PPC64_RELATIVE, R_PPC64_NONE 36 # On PPC: 37 # R_PPC_RELATIVE, R_PPC_ADDR16_HI, 38 # R_PPC_ADDR16_HA,R_PPC_ADDR16_LO, 39 # R_PPC_NONE 40 grep -F -w -v 'R_PPC64_RELATIVE 41R_PPC64_NONE 42R_PPC_ADDR16_LO 43R_PPC_ADDR16_HI 44R_PPC_ADDR16_HA 45R_PPC_RELATIVE 46R_PPC_NONE' | 47 ([ "$undef_weak_symbols" ] && grep -F -w -v "$undef_weak_symbols" || cat) 48) 49 50if [ -z "$bad_relocs" ]; then 51 exit 0 52fi 53 54num_bad=$(echo "$bad_relocs" | wc -l) 55echo "WARNING: $num_bad bad relocations" 56echo "$bad_relocs" 57 58# If we see this type of relocation it's an idication that 59# we /may/ be using an old version of binutils. 60if echo "$bad_relocs" | grep -q -F -w R_PPC64_UADDR64; then 61 echo "WARNING: You need at least binutils >= 2.19 to build a CONFIG_RELOCATABLE kernel" 62fi 63