1#!/bin/sh
2# SPDX-License-Identifier: GPL-2.0
3
4if [ $# -ne 2 ]
5then
6	echo "Usage: headers_install.sh INFILE OUTFILE"
7	echo
8	echo "Prepares kernel header files for use by user space, by removing"
9	echo "all compiler.h definitions and #includes, removing any"
10	echo "#ifdef __KERNEL__ sections, and putting __underscores__ around"
11	echo "asm/inline/volatile keywords."
12	echo
13	echo "INFILE: header file to operate on"
14	echo "OUTFILE: output file which the processed header is written to"
15
16	exit 1
17fi
18
19# Grab arguments
20INFILE=$1
21OUTFILE=$2
22TMPFILE=$OUTFILE.tmp
23
24trap 'rm -f $OUTFILE $TMPFILE' EXIT
25
26# SPDX-License-Identifier with GPL variants must have "WITH Linux-syscall-note"
27if [ -n "$(sed -n -e "/SPDX-License-Identifier:.*GPL-/{/WITH Linux-syscall-note/!p}" $INFILE)" ]; then
28	echo "error: $INFILE: missing \"WITH Linux-syscall-note\" for SPDX-License-Identifier" >&2
29	exit 1
30fi
31
32sed -E -e '
33	s/([[:space:](])(__user|__force|__iomem)[[:space:]]/\1/g
34	s/__attribute_const__([[:space:]]|$)/\1/g
35	s@^#include <linux/compiler(|_types).h>@@
36	s/(^|[^a-zA-Z0-9])__packed([^a-zA-Z0-9_]|$)/\1__attribute__((packed))\2/g
37	s/(^|[[:space:](])(inline|asm|volatile)([[:space:](]|$)/\1__\2__\3/g
38	s@#(ifndef|define|endif[[:space:]]*/[*])[[:space:]]*_UAPI@#\1 @
39' $INFILE > $TMPFILE || exit 1
40
41scripts/unifdef -U__KERNEL__ -D__EXPORTED_HEADERS__ $TMPFILE > $OUTFILE
42[ $? -gt 1 ] && exit 1
43
44# Remove /* ... */ style comments, and find CONFIG_ references in code
45configs=$(sed -e '
46:comment
47	s:/\*[^*][^*]*:/*:
48	s:/\*\*\**\([^/]\):/*\1:
49	t comment
50	s:/\*\*/: :
51	t comment
52	/\/\*/! b check
53	N
54	b comment
55:print
56	P
57	D
58:check
59	s:^\(CONFIG_[[:alnum:]_]*\):\1\n:
60	t print
61	s:^[[:alnum:]_][[:alnum:]_]*::
62	s:^[^[:alnum:]_][^[:alnum:]_]*::
63	t check
64	d
65' $OUTFILE)
66
67# The entries in the following list do not result in an error.
68# Please do not add a new entry. This list is only for existing ones.
69# The list will be reduced gradually, and deleted eventually. (hopefully)
70#
71# The format is <file-name>:<CONFIG-option> in each line.
72config_leak_ignores="
73arch/arc/include/uapi/asm/page.h:CONFIG_ARC_PAGE_SIZE_16K
74arch/arc/include/uapi/asm/page.h:CONFIG_ARC_PAGE_SIZE_4K
75arch/arc/include/uapi/asm/swab.h:CONFIG_ARC_HAS_SWAPE
76arch/arm/include/uapi/asm/ptrace.h:CONFIG_CPU_ENDIAN_BE8
77arch/nios2/include/uapi/asm/swab.h:CONFIG_NIOS2_CI_SWAB_NO
78arch/nios2/include/uapi/asm/swab.h:CONFIG_NIOS2_CI_SWAB_SUPPORT
79arch/x86/include/uapi/asm/auxvec.h:CONFIG_IA32_EMULATION
80arch/x86/include/uapi/asm/auxvec.h:CONFIG_X86_64
81"
82
83for c in $configs
84do
85	leak_error=1
86
87	for ignore in $config_leak_ignores
88	do
89		if echo "$INFILE:$c" | grep -q "$ignore$"; then
90			leak_error=
91			break
92		fi
93	done
94
95	if [ "$leak_error" = 1 ]; then
96		echo "error: $INFILE: leak $c to user-space" >&2
97		exit 1
98	fi
99done
100
101rm -f $TMPFILE
102trap - EXIT
103