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 24opal_query_takeover opal_do_takeover opal_enter_rtas opal_secondary_entry 25boot_command_line __prom_init_toc_start __prom_init_toc_end 26btext_setup_display" 27 28NM="$1" 29OBJ="$2" 30 31ERROR=0 32 33for UNDEF in $($NM -u $OBJ | awk '{print $2}') 34do 35 # On 64-bit nm gives us the function descriptors, which have 36 # a leading . on the name, so strip it off here. 37 UNDEF="${UNDEF#.}" 38 39 if [ $KBUILD_VERBOSE ]; then 40 if [ $KBUILD_VERBOSE -ne 0 ]; then 41 echo "Checking prom_init.o symbol '$UNDEF'" 42 fi 43 fi 44 45 OK=0 46 for WHITE in $WHITELIST 47 do 48 if [ "$UNDEF" = "$WHITE" ]; then 49 OK=1 50 break 51 fi 52 done 53 54 # ignore register save/restore funcitons 55 if [ "${UNDEF:0:9}" = "_restgpr_" ]; then 56 OK=1 57 fi 58 if [ "${UNDEF:0:10}" = "_restgpr0_" ]; then 59 OK=1 60 fi 61 if [ "${UNDEF:0:11}" = "_rest32gpr_" ]; then 62 OK=1 63 fi 64 if [ "${UNDEF:0:9}" = "_savegpr_" ]; then 65 OK=1 66 fi 67 if [ "${UNDEF:0:10}" = "_savegpr0_" ]; then 68 OK=1 69 fi 70 if [ "${UNDEF:0:11}" = "_save32gpr_" ]; then 71 OK=1 72 fi 73 74 if [ $OK -eq 0 ]; then 75 ERROR=1 76 echo "Error: External symbol '$UNDEF' referenced" \ 77 "from prom_init.c" >&2 78 fi 79done 80 81exit $ERROR 82