aosp12/bionic/linker/linker_note_gnu_property.h

94 lines
3.0 KiB
C++

/*
* Copyright (C) 2020 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#pragma once
#include <elf.h>
#include <link.h>
#include "linker_soinfo.h"
// The Elf* structures below are derived from the document
// Linux Extensions to gABI (https://github.com/hjl-tools/linux-abi/wiki).
// Essentially, these types would be defined in <elf.h>, but this is not
// the case at the moment.
struct Elf32_Prop {
Elf32_Word pr_type;
Elf32_Word pr_datasz;
char pr_data[0];
};
// On 32-bit machines this should be 4-byte aligned.
struct Elf32_NhdrGNUProperty {
Elf32_Nhdr nhdr;
char n_name[4];
char n_desc[0];
};
struct Elf64_Prop {
Elf64_Word pr_type;
Elf64_Word pr_datasz;
char pr_data[0];
};
// On 64-bit machines this should be 8-byte aligned.
struct Elf64_NhdrGNUProperty {
Elf64_Nhdr nhdr;
char n_name[4];
char n_desc[0];
};
struct ElfProgramProperty {
#if defined(__aarch64__)
bool bti_compatible = false;
#endif
};
// Representation of the .note.gnu.property section found in the segment
// with p_type = PT_GNU_PROPERTY.
class GnuPropertySection {
public:
GnuPropertySection(){};
explicit GnuPropertySection(const soinfo* si);
GnuPropertySection(const ElfW(Phdr)* phdr, size_t phdr_count, const ElfW(Addr) load_bias,
const char* name);
#if defined(__aarch64__)
bool IsBTICompatible() const;
#endif
private:
const ElfW(NhdrGNUProperty)* FindSegment(const ElfW(Phdr)* phdr, size_t phdr_count,
const ElfW(Addr) load_bias, const char* name) const;
bool SanityCheck(const ElfW(NhdrGNUProperty)* note_nhdr, const char* name) const;
bool Parse(const ElfW(NhdrGNUProperty)* note_nhdr, const char* name);
ElfProgramProperty properties_ __unused;
};