blob: 12640f7e726b29ce5ac9d256c589ce758a2521e8 [file] [log] [blame]
Michael Ellerman5c02cd22008-04-24 12:08:22 +10001#!/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
Benjamin Herrenschmidt27f448882011-09-19 18:27:58 +000023reloc_got2 kernstart_addr memstart_addr linux_banner _stext
Michael Ellermane2500be2014-06-24 17:17:47 +100024__prom_init_toc_start __prom_init_toc_end btext_setup_display TOC."
Michael Ellerman5c02cd22008-04-24 12:08:22 +100025
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
Kumar Galada3de6d2008-06-13 07:20:58 +100052 # ignore register save/restore funcitons
Andreas Schwabfe921c82014-09-13 10:20:17 +020053 case $UNDEF in
54 _restgpr_*|_restgpr0_*|_rest32gpr_*)
Kumar Galada3de6d2008-06-13 07:20:58 +100055 OK=1
Andreas Schwabfe921c82014-09-13 10:20:17 +020056 ;;
57 _savegpr_*|_savegpr0_*|_save32gpr_*)
Stephen Rothwell5afd8782010-06-29 20:04:22 +000058 OK=1
Andreas Schwabfe921c82014-09-13 10:20:17 +020059 ;;
60 esac
Kumar Galada3de6d2008-06-13 07:20:58 +100061
Michael Ellerman5c02cd22008-04-24 12:08:22 +100062 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