upx/src/linker.h
Markus F.X.J. Oberhumer 3495d1affd all: minor cleanups
2024-05-28 10:26:39 +02:00

247 lines
8.5 KiB
C++

/* linker.h --
This file is part of the UPX executable compressor.
Copyright (C) 1996-2024 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 1996-2024 Laszlo Molnar
All Rights Reserved.
UPX and the UCL library are free software; you can redistribute them
and/or modify them under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING.
If not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
Markus F.X.J. Oberhumer Laszlo Molnar
<markus@oberhumer.com> <ezerotven+github@gmail.com>
*/
#pragma once
/*************************************************************************
// ElfLinker
**************************************************************************/
class ElfLinker : private upx::noncopyable {
friend class Packer;
public:
const N_BELE_RTP::AbstractPolicy *const bele; // target endianness
protected:
struct Section;
struct Symbol;
struct Relocation;
byte *input = nullptr;
int inputlen = 0;
byte *output = nullptr;
int outputlen = 0;
unsigned output_capacity = 0;
Section *head = nullptr;
Section *tail = nullptr;
Section **sections = nullptr;
Symbol **symbols = nullptr;
Relocation **relocations = nullptr;
unsigned nsections = 0;
unsigned nsections_capacity = 0;
unsigned nsymbols = 0;
unsigned nsymbols_capacity = 0;
unsigned nrelocations = 0;
unsigned nrelocations_capacity = 0;
bool reloc_done = false;
protected:
void preprocessSections(char *start, char const *end);
void preprocessSymbols(char *start, char const *end);
void preprocessRelocations(char *start, char const *end);
Section *findSection(const char *name, bool fatal = true) const;
Symbol *addSymbol(const char *name, const char *section, upx_uint64_t offset);
Relocation *addRelocation(const char *section, unsigned off, const char *type,
const char *symbol, upx_uint64_t add);
public:
explicit ElfLinker(const N_BELE_RTP::AbstractPolicy *b = &N_BELE_RTP::le_policy) noexcept;
virtual ~ElfLinker() noexcept;
void init(const void *pdata, int plen, unsigned pxtra = 0);
// virtual void setLoaderAlignOffset(int phase);
int addLoader(const char *sname);
void addLoader(const char *s, va_list ap);
#if (ACC_CC_CLANG || ACC_CC_GNUC)
void addLoaderVA(const char *s, ...) __attribute__((__sentinel__));
#else
void addLoaderVA(const char *s, ...);
#endif
Section *addSection(const char *sname, const void *sdata, int slen, unsigned p2align);
int getSection(const char *sname, int *slen = nullptr) const;
int getSectionSize(const char *sname) const;
byte *getLoader(int *llen = nullptr) const;
void defineSymbol(const char *name, upx_uint64_t value);
Symbol *findSymbol(const char *name, bool fatal = true) const;
upx_uint64_t getSymbolOffset(const char *) const;
void dumpSymbol(const Symbol *, unsigned flags, FILE *fp) const;
void dumpSymbols(unsigned flags = 0, FILE *fp = nullptr) const;
void alignWithByte(unsigned len, byte b);
virtual void alignCode(unsigned len) { alignWithByte(len, 0); }
virtual void alignData(unsigned len) { alignWithByte(len, 0); }
// provide overloads to pacify GitHub CodeQL
void defineSymbol(const char *name, int value) { defineSymbol(name, upx_uint64_t(value)); }
void defineSymbol(const char *name, unsigned value) { defineSymbol(name, upx_uint64_t(value)); }
void defineSymbol(const char *name, unsigned long value) {
defineSymbol(name, upx_uint64_t(value));
}
protected:
void relocate();
virtual void relocate1(const Relocation *, byte *location, upx_uint64_t value,
const char *type);
};
struct ElfLinker::Section : private upx::noncopyable {
char *name = nullptr;
void *input = nullptr;
byte *output = nullptr;
unsigned size = 0;
unsigned sort_id = 0; // for qsort()
upx_uint64_t offset = 0;
unsigned p2align = 0; // log2
Section *next = nullptr;
explicit Section(const char *n, const void *i, unsigned s, unsigned a = 0);
~Section() noexcept;
};
struct ElfLinker::Symbol : private upx::noncopyable {
char *name = nullptr;
Section *section = nullptr;
upx_uint64_t offset = 0;
explicit Symbol(const char *n, Section *s, upx_uint64_t o);
~Symbol() noexcept;
};
struct ElfLinker::Relocation : private upx::noncopyable {
const Section *section = nullptr;
unsigned offset = 0;
const char *type = nullptr;
const Symbol *value = nullptr;
upx_uint64_t add = 0; // used in .rela relocations
explicit Relocation(const Section *s, unsigned o, const char *t, const Symbol *v,
upx_uint64_t a);
~Relocation() noexcept {}
};
/*************************************************************************
// ElfLinker arch subclasses
**************************************************************************/
class ElfLinkerAMD64 /*not_final*/ : public ElfLinker {
typedef ElfLinker super;
protected:
virtual void alignCode(unsigned len) override { alignWithByte(len, 0x90); }
virtual void relocate1(const Relocation *, byte *location, upx_uint64_t value,
const char *type) override;
};
class ElfLinkerArm64LE final : public ElfLinker {
typedef ElfLinker super;
protected:
virtual void relocate1(const Relocation *, byte *location, upx_uint64_t value,
const char *type) override;
};
class ElfLinkerArmBE final : public ElfLinker {
typedef ElfLinker super;
public:
explicit ElfLinkerArmBE() noexcept : super(&N_BELE_RTP::be_policy) {}
protected:
virtual void relocate1(const Relocation *, byte *location, upx_uint64_t value,
const char *type) override;
};
class ElfLinkerArmLE final : public ElfLinker {
typedef ElfLinker super;
protected:
virtual void relocate1(const Relocation *, byte *location, upx_uint64_t value,
const char *type) override;
};
class ElfLinkerM68k final : public ElfLinker {
typedef ElfLinker super;
public:
explicit ElfLinkerM68k() noexcept : super(&N_BELE_RTP::be_policy) {}
protected:
virtual void alignCode(unsigned len) override;
virtual void relocate1(const Relocation *, byte *location, upx_uint64_t value,
const char *type) override;
};
class ElfLinkerMipsBE final : public ElfLinker {
typedef ElfLinker super;
public:
explicit ElfLinkerMipsBE() noexcept : super(&N_BELE_RTP::be_policy) {}
protected:
virtual void relocate1(const Relocation *, byte *location, upx_uint64_t value,
const char *type) override;
};
class ElfLinkerMipsLE final : public ElfLinker {
typedef ElfLinker super;
protected:
virtual void relocate1(const Relocation *, byte *location, upx_uint64_t value,
const char *type) override;
};
class ElfLinkerPpc32 final : public ElfLinker {
typedef ElfLinker super;
public:
explicit ElfLinkerPpc32() noexcept : super(&N_BELE_RTP::be_policy) {}
protected:
virtual void relocate1(const Relocation *, byte *location, upx_uint64_t value,
const char *type) override;
};
class ElfLinkerPpc64 final : public ElfLinker {
typedef ElfLinker super;
public:
explicit ElfLinkerPpc64() noexcept : super(&N_BELE_RTP::be_policy) {}
protected:
virtual void relocate1(const Relocation *, byte *location, upx_uint64_t value,
const char *type) override;
};
class ElfLinkerPpc64le final : public ElfLinker {
typedef ElfLinker super;
protected:
virtual void relocate1(const Relocation *, byte *location, upx_uint64_t value,
const char *type) override;
};
class ElfLinkerX86 final : public ElfLinker {
typedef ElfLinker super;
protected:
virtual void alignCode(unsigned len) override { alignWithByte(len, 0x90); }
virtual void relocate1(const Relocation *, byte *location, upx_uint64_t value,
const char *type) override;
};
/* vim:set ts=4 sw=4 et: */