You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

143 lines
4.1 KiB

//===- MipsPLT.cpp --------------------------------------------------------===//
//
// The MCLinker Project
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include <llvm/Support/Casting.h>
#include <llvm/Support/ELF.h>
#include "mcld/Support/MsgHandling.h"
#include "MipsGOTPLT.h"
#include "MipsPLT.h"
namespace {
const uint32_t PLT0[] = {
0x3c1c0000, // lui $28, %hi(&GOTPLT[0])
0x8f990000, // lw $25, %lo(&GOTPLT[0])($28)
0x279c0000, // addiu $28, $28, %lo(&GOTPLT[0])
0x031cc023, // subu $24, $24, $28
0x03e07821, // move $15, $31
0x0018c082, // srl $24, $24, 2
0x0320f809, // jalr $25
0x2718fffe // subu $24, $24, 2
};
const uint32_t PLTA[] = {
0x3c0f0000, // lui $15, %hi(.got.plt entry)
0x8df90000, // l[wd] $25, %lo(.got.plt entry)($15)
0x03200008, // jr $25
0x25f80000 // addiu $24, $15, %lo(.got.plt entry)
};
} // anonymous namespace
namespace mcld {
//===----------------------------------------------------------------------===//
// MipsPLT0 Entry
//===----------------------------------------------------------------------===//
class MipsPLT0 : public PLT::Entry<sizeof(PLT0)> {
public:
MipsPLT0(SectionData& pParent) : PLT::Entry<sizeof(PLT0)>(pParent) {}
};
//===----------------------------------------------------------------------===//
// MipsPLTA Entry
//===----------------------------------------------------------------------===//
class MipsPLTA : public PLT::Entry<sizeof(PLTA)> {
public:
MipsPLTA(SectionData& pParent) : PLT::Entry<sizeof(PLTA)>(pParent) {}
};
//===----------------------------------------------------------------------===//
// MipsPLT
//===----------------------------------------------------------------------===//
MipsPLT::MipsPLT(LDSection& pSection) : PLT(pSection) {
new MipsPLT0(*m_pSectionData);
}
void MipsPLT::finalizeSectionSize() {
uint64_t size = sizeof(PLT0) + (m_pSectionData->size() - 1) * sizeof(PLTA);
m_Section.setSize(size);
uint32_t offset = 0;
SectionData::iterator frag, fragEnd = m_pSectionData->end();
for (frag = m_pSectionData->begin(); frag != fragEnd; ++frag) {
frag->setOffset(offset);
offset += frag->size();
}
}
bool MipsPLT::hasPLT1() const {
return m_pSectionData->size() > 1;
}
uint64_t MipsPLT::emit(MemoryRegion& pRegion) {
uint64_t result = 0x0;
iterator it = begin();
unsigned char* buffer = pRegion.begin();
memcpy(buffer, llvm::cast<MipsPLT0>((*it)).getValue(), MipsPLT0::EntrySize);
result += MipsPLT0::EntrySize;
++it;
MipsPLTA* plta = 0;
for (iterator ie = end(); it != ie; ++it) {
plta = &(llvm::cast<MipsPLTA>(*it));
memcpy(buffer + result, plta->getValue(), MipsPLTA::EntrySize);
result += MipsPLTA::EntrySize;
}
return result;
}
PLTEntryBase* MipsPLT::create() {
return new MipsPLTA(*m_pSectionData);
}
void MipsPLT::applyAllPLT(MipsGOTPLT& pGOTPLT) {
assert(m_Section.addr() && ".plt base address is NULL!");
size_t count = 0;
for (iterator it = m_pSectionData->begin(); it != m_pSectionData->end();
++it) {
PLTEntryBase* plt = &(llvm::cast<PLTEntryBase>(*it));
if (it == m_pSectionData->begin()) {
uint32_t* data = static_cast<uint32_t*>(malloc(plt->size()));
if (!data)
fatal(diag::fail_allocate_memory_plt);
memcpy(data, PLT0, plt->size());
uint64_t gotAddr = pGOTPLT.addr();
data[0] |= ((gotAddr + 0x8000) >> 16) & 0xffff;
data[1] |= gotAddr & 0xffff;
data[2] |= gotAddr & 0xffff;
plt->setValue(reinterpret_cast<unsigned char*>(data));
} else {
uint32_t* data = static_cast<uint32_t*>(malloc(plt->size()));
if (!data)
fatal(diag::fail_allocate_memory_plt);
memcpy(data, PLTA, plt->size());
uint64_t gotEntryAddr = pGOTPLT.getEntryAddr(count++);
data[0] |= ((gotEntryAddr + 0x8000) >> 16) & 0xffff;
data[1] |= gotEntryAddr & 0xffff;
data[3] |= gotEntryAddr & 0xffff;
plt->setValue(reinterpret_cast<unsigned char*>(data));
}
}
}
} // namespace mcld