зеркало из https://github.com/mozilla/gecko-dev.git
142 строки
3.4 KiB
C++
142 строки
3.4 KiB
C++
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
|
|
* You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#ifndef BaseElf_h
|
|
#define BaseElf_h
|
|
|
|
#include "ElfLoader.h"
|
|
#include "Elfxx.h"
|
|
|
|
|
|
/**
|
|
* Base class for ELF libraries. This class includes things that will be
|
|
* common between SystemElfs and CustomElfs.
|
|
*/
|
|
class BaseElf: public LibHandle
|
|
{
|
|
public:
|
|
/**
|
|
* Hash function for symbol lookup, as defined in ELF standard for System V.
|
|
*/
|
|
static unsigned long Hash(const char *symbol);
|
|
|
|
/**
|
|
* Returns the address corresponding to the given symbol name (with a
|
|
* pre-computed hash).
|
|
*/
|
|
void *GetSymbolPtr(const char *symbol, unsigned long hash) const;
|
|
|
|
/**
|
|
* Returns a pointer to the Elf Symbol in the Dynamic Symbol table
|
|
* corresponding to the given symbol name (with a pre-computed hash).
|
|
*/
|
|
const Elf::Sym *GetSymbol(const char *symbol, unsigned long hash) const;
|
|
|
|
BaseElf(const char *path, Mappable *mappable = nullptr)
|
|
: LibHandle(path)
|
|
, mappable(mappable)
|
|
{
|
|
}
|
|
|
|
protected:
|
|
/**
|
|
* Inherited from LibHandle. Those are temporary and are not supposed to
|
|
* be used.
|
|
*/
|
|
virtual void *GetSymbolPtr(const char *symbol) const;
|
|
virtual bool Contains(void *addr) const;
|
|
virtual void *GetBase() const { return GetPtr(0); }
|
|
|
|
#ifdef __ARM_EABI__
|
|
virtual const void *FindExidx(int *pcount) const;
|
|
#endif
|
|
|
|
virtual Mappable *GetMappable() const { return NULL; };
|
|
|
|
public:
|
|
/* private: */
|
|
/**
|
|
* Returns a pointer relative to the base address where the library is
|
|
* loaded.
|
|
*/
|
|
void *GetPtr(const Elf::Addr offset) const
|
|
{
|
|
if (reinterpret_cast<void *>(offset) > base)
|
|
return reinterpret_cast<void *>(offset);
|
|
return base + offset;
|
|
}
|
|
|
|
/**
|
|
* Like the above, but returns a typed (const) pointer
|
|
*/
|
|
template <typename T>
|
|
const T *GetPtr(const Elf::Addr offset) const
|
|
{
|
|
if (reinterpret_cast<void *>(offset) > base)
|
|
return reinterpret_cast<const T *>(offset);
|
|
return reinterpret_cast<const T *>(base + offset);
|
|
}
|
|
|
|
/* Appropriated Mappable */
|
|
/* /!\ we rely on this being nullptr for BaseElf instances, but not
|
|
* CustomElf instances. */
|
|
RefPtr<Mappable> mappable;
|
|
|
|
/* Base address where the library is loaded */
|
|
MappedPtr base;
|
|
|
|
/* Buckets and chains for the System V symbol hash table */
|
|
Array<Elf::Word> buckets;
|
|
UnsizedArray<Elf::Word> chains;
|
|
|
|
/* protected: */
|
|
/* String table */
|
|
Elf::Strtab strtab;
|
|
|
|
/* Symbol table */
|
|
UnsizedArray<Elf::Sym> symtab;
|
|
|
|
#ifdef __ARM_EABI__
|
|
/* ARM.exidx information used by FindExidx */
|
|
Array<uint32_t[2]> arm_exidx;
|
|
#endif
|
|
};
|
|
|
|
|
|
/**
|
|
* Class for ELF libraries that already loaded in memory.
|
|
*/
|
|
class LoadedElf: public BaseElf
|
|
{
|
|
public:
|
|
/**
|
|
* Returns a LoadedElf corresponding to the already loaded ELF
|
|
* at the given base address.
|
|
*/
|
|
static already_AddRefed<LibHandle> Create(const char *path,
|
|
void *base_addr);
|
|
|
|
private:
|
|
LoadedElf(const char *path)
|
|
: BaseElf(path) { }
|
|
|
|
~LoadedElf()
|
|
{
|
|
/* Avoid base's destructor unmapping something that doesn't actually
|
|
* belong to it. */
|
|
base.release();
|
|
ElfLoader::Singleton.Forget(this);
|
|
}
|
|
|
|
/**
|
|
* Initializes the library according to information found in the given
|
|
* PT_DYNAMIC header.
|
|
* Returns whether this succeeded or failed.
|
|
*/
|
|
bool InitDyn(const Elf::Phdr *pt_dyn);
|
|
};
|
|
|
|
|
|
#endif /* BaseElf_h */
|