diff options
author | Dimitry Andric <dim@FreeBSD.org> | 2015-03-24 21:31:36 +0000 |
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committer | Dimitry Andric <dim@FreeBSD.org> | 2015-03-24 21:31:36 +0000 |
commit | fb911942f1434f3d1750f83f25f5e42c80e60638 (patch) | |
tree | 1678c4a4f0182e4029a86d135aa4a1b7d09e3c41 /lib/ReaderWriter/ELF/ARM/ARMRelocationHandler.cpp |
Notes
Diffstat (limited to 'lib/ReaderWriter/ELF/ARM/ARMRelocationHandler.cpp')
-rw-r--r-- | lib/ReaderWriter/ELF/ARM/ARMRelocationHandler.cpp | 500 |
1 files changed, 500 insertions, 0 deletions
diff --git a/lib/ReaderWriter/ELF/ARM/ARMRelocationHandler.cpp b/lib/ReaderWriter/ELF/ARM/ARMRelocationHandler.cpp new file mode 100644 index 000000000000..d24fdf0fa410 --- /dev/null +++ b/lib/ReaderWriter/ELF/ARM/ARMRelocationHandler.cpp @@ -0,0 +1,500 @@ +//===--------- lib/ReaderWriter/ELF/ARM/ARMRelocationHandler.cpp ----------===// +// +// The LLVM Linker +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "ARMTargetHandler.h" +#include "ARMLinkingContext.h" + +#include "llvm/Support/Debug.h" +#include "llvm/Support/Endian.h" +#include "llvm/Support/MathExtras.h" + +using namespace lld; +using namespace lld::elf; +using namespace llvm::support::endian; + +static Reference::Addend readAddend_THM_MOV(const uint8_t *location) { + const uint16_t halfHi = read16le(location); + const uint16_t halfLo = read16le(location + 2); + + const uint16_t imm8 = halfLo & 0xFF; + const uint16_t imm3 = (halfLo >> 12) & 0x7; + + const uint16_t imm4 = halfHi & 0xF; + const uint16_t bitI = (halfHi >> 10) & 0x1; + + const auto result = int16_t((imm4 << 12) | (bitI << 11) | (imm3 << 8) | imm8); + return result; +} + +static Reference::Addend readAddend_ARM_MOV(const uint8_t *location) { + const uint32_t value = read32le(location); + + const uint32_t imm12 = value & 0xFFF; + const uint32_t imm4 = (value >> 16) & 0xF; + + const auto result = int32_t((imm4 << 12) | imm12); + return result; +} + +static Reference::Addend readAddend_THM_CALL(const uint8_t *location) { + const uint16_t halfHi = read16le(location); + const uint16_t halfLo = read16le(location + 2); + + const uint16_t imm10 = halfHi & 0x3FF; + const uint16_t bitS = (halfHi >> 10) & 0x1; + + const uint16_t imm11 = halfLo & 0x7FF; + const uint16_t bitJ2 = (halfLo >> 11) & 0x1; + const uint16_t bitI2 = (~(bitJ2 ^ bitS)) & 0x1; + const uint16_t bitJ1 = (halfLo >> 13) & 0x1; + const uint16_t bitI1 = (~(bitJ1 ^ bitS)) & 0x1; + + const auto result = int32_t((bitS << 24) | (bitI1 << 23) | (bitI2 << 22) | + (imm10 << 12) | (imm11 << 1)); + return llvm::SignExtend64<25>(result); +} + +static Reference::Addend readAddend_ARM_CALL(const uint8_t *location) { + const uint32_t value = read32le(location); + + const bool isBLX = (value & 0xF0000000) == 0xF0000000; + const uint32_t bitH = isBLX ? ((value & 0x1000000) >> 24) : 0; + + const auto result = int32_t(((value & 0xFFFFFF) << 2) | (bitH << 1)); + return llvm::SignExtend64<26>(result); +} + +static Reference::Addend readAddend_THM_JUMP11(const uint8_t *location) { + const auto value = read16le(location); + const uint16_t imm11 = value & 0x7FF; + + return llvm::SignExtend32<12>(imm11 << 1); +} + +static Reference::Addend readAddend(const uint8_t *location, + Reference::KindValue kindValue) { + switch (kindValue) { + case R_ARM_ABS32: + case R_ARM_REL32: + case R_ARM_TLS_IE32: + case R_ARM_TLS_LE32: + return (int32_t)read32le(location); + case R_ARM_PREL31: + return (int32_t)(read32le(location) & 0x7FFFFFFF); + case R_ARM_THM_CALL: + case R_ARM_THM_JUMP24: + return readAddend_THM_CALL(location); + case R_ARM_THM_JUMP11: + return readAddend_THM_JUMP11(location); + case R_ARM_CALL: + case R_ARM_JUMP24: + return readAddend_ARM_CALL(location); + case R_ARM_MOVW_ABS_NC: + case R_ARM_MOVT_ABS: + return readAddend_ARM_MOV(location); + case R_ARM_THM_MOVW_ABS_NC: + case R_ARM_THM_MOVT_ABS: + return readAddend_THM_MOV(location); + default: + return 0; + } +} + +static inline void applyArmReloc(uint8_t *location, uint32_t result, + uint32_t mask = 0xFFFFFFFF) { + assert(!(result & ~mask)); + write32le(location, (read32le(location) & ~mask) | (result & mask)); +} + +static inline void applyThmReloc(uint8_t *location, uint16_t resHi, + uint16_t resLo, uint16_t maskHi, + uint16_t maskLo = 0xFFFF) { + assert(!(resHi & ~maskHi) && !(resLo & ~maskLo)); + write16le(location, (read16le(location) & ~maskHi) | (resHi & maskHi)); + location += 2; + write16le(location, (read16le(location) & ~maskLo) | (resLo & maskLo)); +} + +static inline void applyThumb16Reloc(uint8_t *location, uint16_t result, + uint16_t mask = 0xFFFF) { + assert(!(result & ~mask)); + write16le(location, (read16le(location) & ~mask) | (result & mask)); +} + +/// \brief R_ARM_ABS32 - (S + A) | T +static void relocR_ARM_ABS32(uint8_t *location, uint64_t P, uint64_t S, + int64_t A, bool addressesThumb) { + uint64_t T = addressesThumb; + uint32_t result = (uint32_t)((S + A) | T); + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " T: 0x" << Twine::utohexstr(T); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + applyArmReloc(location, result); +} + +/// \brief R_ARM_REL32 - ((S + A) | T) - P +static void relocR_ARM_REL32(uint8_t *location, uint64_t P, uint64_t S, + int64_t A, bool addressesThumb) { + uint64_t T = addressesThumb; + uint32_t result = (uint32_t)(((S + A) | T) - P); + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " T: 0x" << Twine::utohexstr(T); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + applyArmReloc(location, result); +} + +/// \brief R_ARM_PREL31 - ((S + A) | T) - P +static void relocR_ARM_PREL31(uint8_t *location, uint64_t P, uint64_t S, + int64_t A, bool addressesThumb) { + uint64_t T = addressesThumb; + uint32_t result = (uint32_t)(((S + A) | T) - P); + const uint32_t mask = 0x7FFFFFFF; + uint32_t rel31 = result & mask; + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " T: 0x" << Twine::utohexstr(T); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result); + llvm::dbgs() << " rel31: 0x" << Twine::utohexstr(rel31) << "\n"); + + applyArmReloc(location, rel31, mask); +} + +/// \brief Relocate B/BL instructions. useJs defines whether J1 & J2 are used +static void relocR_ARM_THM_B_L(uint8_t *location, uint32_t result, bool useJs) { + result = (result & 0x01FFFFFE) >> 1; + + const uint16_t imm10 = (result >> 11) & 0x3FF; + const uint16_t bitS = (result >> 23) & 0x1; + const uint16_t resHi = (bitS << 10) | imm10; + + const uint16_t imm11 = result & 0x7FF; + const uint16_t bitJ2 = useJs ? ((result >> 21) & 0x1) : bitS; + const uint16_t bitI2 = (~(bitJ2 ^ bitS)) & 0x1; + const uint16_t bitJ1 = useJs ? ((result >> 22) & 0x1) : bitS; + const uint16_t bitI1 = (~(bitJ1 ^ bitS)) & 0x1; + const uint16_t resLo = (bitI1 << 13) | (bitI2 << 11) | imm11; + + applyThmReloc(location, resHi, resLo, 0x7FF, 0x2FFF); +} + +/// \brief R_ARM_THM_CALL - ((S + A) | T) - P +static void relocR_ARM_THM_CALL(uint8_t *location, uint64_t P, uint64_t S, + int64_t A, bool useJs, bool addressesThumb) { + uint64_t T = addressesThumb; + const bool switchMode = !addressesThumb; + + if (switchMode) { + P &= ~0x3; // Align(P, 4) by rounding down + } + + uint32_t result = (uint32_t)(((S + A) | T) - P); + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " T: 0x" << Twine::utohexstr(T); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + relocR_ARM_THM_B_L(location, result, useJs); + + if (switchMode) { + applyThmReloc(location, 0, 0, 0, 0x1001); + } +} + +/// \brief R_ARM_THM_JUMP24 - ((S + A) | T) - P +static void relocR_ARM_THM_JUMP24(uint8_t *location, uint64_t P, uint64_t S, + int64_t A, bool addressesThumb) { + uint64_t T = addressesThumb; + uint32_t result = (uint32_t)(((S + A) | T) - P); + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " T: 0x" << Twine::utohexstr(T); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + relocR_ARM_THM_B_L(location, result, true); +} + +/// \brief R_ARM_THM_JUMP11 - S + A - P +static void relocR_ARM_THM_JUMP11(uint8_t *location, uint64_t P, uint64_t S, + int64_t A) { + uint32_t result = (uint32_t)(S + A - P); + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + + //we cut off first bit because it is always 1 according to p. 4.5.3 + result = (result & 0x0FFE) >> 1; + + applyThumb16Reloc(location, result, 0x7FF); +} + +/// \brief R_ARM_CALL - ((S + A) | T) - P +static void relocR_ARM_CALL(uint8_t *location, uint64_t P, uint64_t S, + int64_t A, bool addressesThumb) { + uint64_t T = addressesThumb; + const bool switchMode = addressesThumb; + + uint32_t result = (uint32_t)(((S + A) | T) - P); + const uint32_t imm24 = (result & 0x03FFFFFC) >> 2; + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " T: 0x" << Twine::utohexstr(T); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + applyArmReloc(location, imm24, 0xFFFFFF); + + if (switchMode) { + const uint32_t bitH = (result & 0x2) >> 1; + applyArmReloc(location, (0xFA | bitH) << 24, 0xFF000000); + } +} + +/// \brief R_ARM_JUMP24 - ((S + A) | T) - P +static void relocR_ARM_JUMP24(uint8_t *location, uint64_t P, uint64_t S, + int64_t A, bool addressesThumb) { + uint64_t T = addressesThumb; + uint32_t result = (uint32_t)(((S + A) | T) - P); + const uint32_t imm24 = (result & 0x03FFFFFC) >> 2; + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " T: 0x" << Twine::utohexstr(T); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + applyArmReloc(location, imm24, 0xFFFFFF); +} + +/// \brief Relocate ARM MOVW/MOVT instructions +static void relocR_ARM_MOV(uint8_t *location, uint32_t result) { + const uint32_t imm12 = result & 0xFFF; + const uint32_t imm4 = (result >> 12) & 0xF; + + applyArmReloc(location, (imm4 << 16) | imm12, 0xF0FFF); +} + +/// \brief R_ARM_MOVW_ABS_NC - (S + A) | T +static void relocR_ARM_MOVW_ABS_NC(uint8_t *location, uint64_t P, uint64_t S, + int64_t A, bool addressesThumb) { + uint64_t T = addressesThumb; + uint32_t result = (uint32_t)((S + A) | T); + const uint32_t arg = result & 0x0000FFFF; + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " T: 0x" << Twine::utohexstr(T); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + return relocR_ARM_MOV(location, arg); +} + +/// \brief R_ARM_MOVT_ABS - S + A +static void relocR_ARM_MOVT_ABS(uint8_t *location, uint64_t P, uint64_t S, + int64_t A) { + uint32_t result = (uint32_t)(S + A); + const uint32_t arg = (result & 0xFFFF0000) >> 16; + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + return relocR_ARM_MOV(location, arg); +} + +/// \brief Relocate Thumb MOVW/MOVT instructions +static void relocR_ARM_THM_MOV(uint8_t *location, uint32_t result) { + const uint16_t imm8 = result & 0xFF; + const uint16_t imm3 = (result >> 8) & 0x7; + const uint16_t resLo = (imm3 << 12) | imm8; + + const uint16_t imm4 = (result >> 12) & 0xF; + const uint16_t bitI = (result >> 11) & 0x1; + const uint16_t resHi = (bitI << 10) | imm4; + + applyThmReloc(location, resHi, resLo, 0x40F, 0x70FF); +} + +/// \brief R_ARM_THM_MOVW_ABS_NC - (S + A) | T +static void relocR_ARM_THM_MOVW_ABS_NC(uint8_t *location, uint64_t P, + uint64_t S, int64_t A, + bool addressesThumb) { + uint64_t T = addressesThumb; + uint32_t result = (uint32_t)((S + A) | T); + const uint32_t arg = result & 0x0000FFFF; + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " T: 0x" << Twine::utohexstr(T); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + return relocR_ARM_THM_MOV(location, arg); +} + +/// \brief R_ARM_THM_MOVT_ABS - S + A +static void relocR_ARM_THM_MOVT_ABS(uint8_t *location, uint64_t P, uint64_t S, + int64_t A) { + uint32_t result = (uint32_t)(S + A); + const uint32_t arg = (result & 0xFFFF0000) >> 16; + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + return relocR_ARM_THM_MOV(location, arg); +} + +/// \brief R_ARM_TLS_IE32 - GOT(S) + A - P => S + A - P +static void relocR_ARM_TLS_IE32(uint8_t *location, uint64_t P, uint64_t S, + int64_t A) { + uint32_t result = (uint32_t)(S + A - P); + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + applyArmReloc(location, result); +} + +/// \brief R_ARM_TLS_LE32 - S + A - tp => S + A + tpoff +static void relocR_ARM_TLS_LE32(uint8_t *location, uint64_t P, uint64_t S, + int64_t A, uint64_t tpoff) { + uint32_t result = (uint32_t)(S + A + tpoff); + + DEBUG_WITH_TYPE( + "ARM", llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -"; + llvm::dbgs() << " S: 0x" << Twine::utohexstr(S); + llvm::dbgs() << " A: 0x" << Twine::utohexstr(A); + llvm::dbgs() << " P: 0x" << Twine::utohexstr(P); + llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n"); + applyArmReloc(location, result); +} + +std::error_code ARMTargetRelocationHandler::applyRelocation( + ELFWriter &writer, llvm::FileOutputBuffer &buf, const lld::AtomLayout &atom, + const Reference &ref) const { + uint8_t *atomContent = buf.getBufferStart() + atom._fileOffset; + uint8_t *location = atomContent + ref.offsetInAtom(); + uint64_t targetVAddress = writer.addressOfAtom(ref.target()); + uint64_t relocVAddress = atom._virtualAddr + ref.offsetInAtom(); + + if (ref.kindNamespace() != Reference::KindNamespace::ELF) + return std::error_code(); + assert(ref.kindArch() == Reference::KindArch::ARM); + + // Calculate proper initial addend for the relocation + const Reference::Addend addend = + readAddend(location, ref.kindValue()); + + // Flags that the relocation addresses Thumb instruction + bool addressesThumb = false; + + if (const auto *definedAtom = dyn_cast<DefinedAtom>(ref.target())) { + addressesThumb = (DefinedAtom::codeARMThumb == definedAtom->codeModel()); + } + + switch (ref.kindValue()) { + case R_ARM_NONE: + break; + case R_ARM_ABS32: + relocR_ARM_ABS32(location, relocVAddress, targetVAddress, addend, + addressesThumb); + break; + case R_ARM_REL32: + relocR_ARM_REL32(location, relocVAddress, targetVAddress, addend, + addressesThumb); + break; + case R_ARM_THM_CALL: + // TODO: consider adding bool variable to disable J1 & J2 for archs + // before ARMv6 + relocR_ARM_THM_CALL(location, relocVAddress, targetVAddress, addend, true, + addressesThumb); + break; + case R_ARM_CALL: + relocR_ARM_CALL(location, relocVAddress, targetVAddress, addend, + addressesThumb); + break; + case R_ARM_JUMP24: + relocR_ARM_JUMP24(location, relocVAddress, targetVAddress, addend, + addressesThumb); + break; + case R_ARM_THM_JUMP24: + relocR_ARM_THM_JUMP24(location, relocVAddress, targetVAddress, addend, + addressesThumb); + break; + case R_ARM_THM_JUMP11: + relocR_ARM_THM_JUMP11(location, relocVAddress, targetVAddress, addend); + break; + case R_ARM_MOVW_ABS_NC: + relocR_ARM_MOVW_ABS_NC(location, relocVAddress, targetVAddress, addend, + addressesThumb); + break; + case R_ARM_MOVT_ABS: + relocR_ARM_MOVT_ABS(location, relocVAddress, targetVAddress, addend); + break; + case R_ARM_THM_MOVW_ABS_NC: + relocR_ARM_THM_MOVW_ABS_NC(location, relocVAddress, targetVAddress, addend, + addressesThumb); + break; + case R_ARM_THM_MOVT_ABS: + relocR_ARM_THM_MOVT_ABS(location, relocVAddress, targetVAddress, addend); + break; + case R_ARM_PREL31: + relocR_ARM_PREL31(location, relocVAddress, targetVAddress, addend, + addressesThumb); + break; + case R_ARM_TLS_IE32: + relocR_ARM_TLS_IE32(location, relocVAddress, targetVAddress, addend); + break; + case R_ARM_TLS_LE32: + relocR_ARM_TLS_LE32(location, relocVAddress, targetVAddress, addend, + _armLayout.getTPOffset()); + break; + default: + return make_unhandled_reloc_error(); + } + + return std::error_code(); +} |