bbce18b8d1
This note will be used to allow binaries to opt out of, or in to, upcoming vulnerability mitigation and other features. It is not yet connected but being added now to facilitate testing and ensure compatibility with existing kernels and tools. Reviewed by: brooks, jhb, kib, markj Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17438
85 lines
3.1 KiB
C
85 lines
3.1 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright 2000 David E. O'Brien, John D. Polstra.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/elf_common.h>
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#include "notes.h"
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/*
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* Special ".note" entry specifying the ABI version. See
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* http://www.netbsd.org/Documentation/kernel/elf-notes.html
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* for more information.
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*
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* For all arches except sparc, gcc emits the section directive for the
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* following struct with a PROGBITS type. However, newer versions of binutils
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* (after 2.16.90) require the section to be of NOTE type, to guarantee that the
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* .note.ABI-tag section correctly ends up in the first page of the final
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* executable.
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*
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* Unfortunately, there is no clean way to tell gcc to use another section type,
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* so this C file (or the C file that includes it) must be compiled in multiple
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* steps:
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*
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* - Compile the .c file to a .s file.
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* - Edit the .s file to change the 'progbits' type to 'note', for the section
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* directive that defines the .note.ABI-tag section.
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* - Compile the .s file to an object file.
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*
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* These steps are done in the invididual Makefiles for each applicable arch.
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*/
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static const struct {
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int32_t namesz;
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int32_t descsz;
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int32_t type;
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char name[sizeof(NOTE_FREEBSD_VENDOR)];
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int32_t desc;
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} abitag __attribute__ ((section (NOTE_SECTION), aligned(4))) __used = {
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.namesz = sizeof(NOTE_FREEBSD_VENDOR),
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.descsz = sizeof(int32_t),
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.type = NT_FREEBSD_ABI_TAG,
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.name = NOTE_FREEBSD_VENDOR,
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.desc = __FreeBSD_version
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};
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static const struct {
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int32_t namesz;
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int32_t descsz;
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int32_t type;
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char name[sizeof(NOTE_FREEBSD_VENDOR)];
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uint32_t desc[1];
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} crt_feature_ctl __attribute__ ((section (NOTE_SECTION),
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aligned(4))) __used = {
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.namesz = sizeof(NOTE_FREEBSD_VENDOR),
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.descsz = sizeof(uint32_t),
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.type = NT_FREEBSD_FEATURE_CTL,
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.name = NOTE_FREEBSD_VENDOR,
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.desc = { 0 }
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};
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