1#!/bin/sh
 2# SPDX-License-Identifier: GPL-2.0-or-later
 3#
 4# Copyright © 2008 IBM Corporation
 5#
 
 
 
 
 6
 7# This script checks prom_init.o to see what external symbols it
 8# is using, if it finds symbols not in the whitelist it returns
 9# an error. The point of this is to discourage people from
10# intentionally or accidentally adding new code to prom_init.c
11# which has side effects on other parts of the kernel.
12
13# If you really need to reference something from prom_init.o add
14# it to the list below:
15
16has_renamed_memintrinsics()
17{
18	grep -q "^CONFIG_KASAN=y$" ${KCONFIG_CONFIG} && \
19		! grep -q "^CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX=y" ${KCONFIG_CONFIG}
20}
21
22if has_renamed_memintrinsics
23then
24	MEM_FUNCS="__memcpy __memset"
25else
26	MEM_FUNCS="memcpy memset"
27fi
28
29WHITELIST="add_reloc_offset __bss_start __bss_stop copy_and_flush
30_end enter_prom $MEM_FUNCS reloc_offset __secondary_hold
31__secondary_hold_acknowledge __secondary_hold_spinloop __start
32logo_linux_clut224 btext_prepare_BAT
33reloc_got2 kernstart_addr memstart_addr linux_banner _stext
34btext_setup_display TOC. relocate"
 
 
35
36NM="$1"
37OBJ="$2"
38
39ERROR=0
40
41check_section()
42{
43    file=$1
44    section=$2
45    size=$(objdump -h -j $section $file 2>/dev/null | awk "\$2 == \"$section\" {print \$3}")
46    size=${size:-0}
47    if [ $size -ne 0 ]; then
48	ERROR=1
49	echo "Error: Section $section not empty in prom_init.c" >&2
50    fi
51}
52
53for UNDEF in $($NM -u $OBJ | awk '{print $2}')
54do
55	# On 64-bit nm gives us the function descriptors, which have
56	# a leading . on the name, so strip it off here.
57	UNDEF="${UNDEF#.}"
58
59	case "$KBUILD_VERBOSE" in
60	*1*)
61		echo "Checking prom_init.o symbol '$UNDEF'" ;;
62	esac
 
63
64	OK=0
65	for WHITE in $WHITELIST
66	do
67		if [ "$UNDEF" = "$WHITE" ]; then
68			OK=1
69			break
70		fi
71	done
72
73	# ignore register save/restore funcitons
74	case $UNDEF in
75	_restgpr_*|_restgpr0_*|_rest32gpr_*)
76		OK=1
77		;;
78	_savegpr_*|_savegpr0_*|_save32gpr_*)
 
 
 
79		OK=1
80		;;
81	esac
 
 
 
 
 
 
 
 
82
83	if [ $OK -eq 0 ]; then
84		ERROR=1
85		echo "Error: External symbol '$UNDEF' referenced" \
86		     "from prom_init.c" >&2
87	fi
88done
89
90check_section $OBJ .data
91check_section $OBJ .bss
92check_section $OBJ .init.data
93
94exit $ERROR

 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