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 kstrtobool 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

 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