1#!/bin/sh 2# 3# Copyright © 2008 IBM Corporation 4# 5# This program is free software; you can redistribute it and/or 6# modify it under the terms of the GNU General Public License 7# as published by the Free Software Foundation; either version 8# 2 of the License, or (at your option) any later version. 9 10# This script checks prom_init.o to see what external symbols it 11# is using, if it finds symbols not in the whitelist it returns 12# an error. The point of this is to discourage people from 13# intentionally or accidentally adding new code to prom_init.c 14# which has side effects on other parts of the kernel. 15 16# If you really need to reference something from prom_init.o add 17# it to the list below: 18 19WHITELIST="add_reloc_offset __bss_start __bss_stop copy_and_flush 20_end enter_prom memcpy memset reloc_offset __secondary_hold 21__secondary_hold_acknowledge __secondary_hold_spinloop __start 22strcmp strcpy strlcpy strlen strncmp strstr logo_linux_clut224 23reloc_got2 kernstart_addr memstart_addr linux_banner _stext 24__prom_init_toc_start __prom_init_toc_end btext_setup_display TOC." 25 26NM="$1" 27OBJ="$2" 28 29ERROR=0 30 31for UNDEF in $($NM -u $OBJ | awk '{print $2}') 32do 33 # On 64-bit nm gives us the function descriptors, which have 34 # a leading . on the name, so strip it off here. 35 UNDEF="${UNDEF#.}" 36 37 if [ $KBUILD_VERBOSE ]; then 38 if [ $KBUILD_VERBOSE -ne 0 ]; then 39 echo "Checking prom_init.o symbol '$UNDEF'" 40 fi 41 fi 42 43 OK=0 44 for WHITE in $WHITELIST 45 do 46 if [ "$UNDEF" = "$WHITE" ]; then 47 OK=1 48 break 49 fi 50 done 51 52 # ignore register save/restore funcitons 53 case $UNDEF in 54 _restgpr_*|_restgpr0_*|_rest32gpr_*) 55 OK=1 56 ;; 57 _savegpr_*|_savegpr0_*|_save32gpr_*) 58 OK=1 59 ;; 60 esac 61 62 if [ $OK -eq 0 ]; then 63 ERROR=1 64 echo "Error: External symbol '$UNDEF' referenced" \ 65 "from prom_init.c" >&2 66 fi 67done 68 69exit $ERROR 70