xref: /freebsd/sys/tools/amd64_vdso.sh (revision 5036d9652a5701d00e9e40ea942c278e9f77d33d)
1#!/bin/sh
2# SPDX-License-Identifier: BSD-2-Clause
3#
4# Copyright (c) 2021 The FreeBSD Foundation
5# All rights reserved.
6#
7# This software was developed by Konstantin Belousov <kib@FreeBSD.org>
8# under sponsorship from the FreeBSD Foundation.
9#
10# Redistribution and use in source and binary forms, with or without
11# modification, are permitted provided that the following conditions
12# are met:
13# 1. Redistributions of source code must retain the above copyright
14#    notice, this list of conditions and the following disclaimer.
15# 2. Redistributions in binary form must reproduce the above copyright
16#    notice, this list of conditions and the following disclaimer in the
17#    documentation and/or other materials provided with the distribution.
18#
19# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29# SUCH DAMAGE.
30
31set -e
32
33${CC} -x assembler-with-cpp -DLOCORE -fPIC -nostdinc -c \
34   -o sigtramp.pico -I. -I"${S}" -include opt_global.h \
35   "${S}"/amd64/amd64/sigtramp.S
36
37# We need to make vdso as compact as possible, for it to leave space
38# for other things in the shared page.  For this, we pack everything
39# into single loadable segment.
40#
41# -z rodynamic is undocumented lld-specific option, seemingly required
42# for lld to avoid putting dynamic into dedicated writeable segment,
43# despite ldscript placement.  It is omitted for ld.bfd, but ldscript
44# alone is enough there.
45#
46if ${LD} --version | ${AWK} '/^GNU ld/{exit 1}' ; then
47    RODYNAMIC="-z rodynamic"
48else
49    RODYNAMIC=""
50fi
51${LD} --shared -Bsymbolic -soname="elf-vdso.so.1" \
52   -T "${S}"/conf/vdso_amd64.ldscript \
53   --eh-frame-hdr --no-undefined ${RODYNAMIC} -z norelro -nmagic \
54   --hash-style=sysv --fatal-warnings --strip-all \
55   -o elf-vdso.so.1 sigtramp.pico
56
57if [ "$(wc -c elf-vdso.so.1 | ${AWK} '{print $1}')" -gt 2048 ]
58then
59    echo "elf-vdso.so.1 too large" 1>&2
60    exit 1
61fi
62
63if [ -n "$(${ELFDUMP} -d elf-vdso.so.1 | \
64  ${AWK} '/DT_REL.*SZ/{print "RELOCS"}')" ]
65then
66    echo "elf-vdso.so.1 contains runtime relocations" 1>&2
67    exit 1
68fi
69
70${CC} ${DEBUG} -x assembler-with-cpp -DLOCORE -fPIC -nostdinc -c \
71   -o elf-vdso.so.o -I. -I"${S}" -include opt_global.h \
72   -DVDSO_NAME=elf_vdso_so_1 -DVDSO_FILE=\"elf-vdso.so.1\" \
73   "${S}"/tools/vdso_wrap.S
74
75${NM} -D elf-vdso.so.1 | \
76   ${AWK} '/__vdso_sigcode/{printf "#define VDSO_SIGCODE_OFFSET 0x%s\n",$1}' \
77   >vdso_offsets.h
78