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llvm-mirror/lib/Object/RelocationResolver.cpp
Fangrui Song 72e7abe0f8 [DWARF] Refactor RelocVisitor and fix computation of SHT_RELA-typed relocation entries
Summary:
getRelocatedValue may compute incorrect value for SHT_RELA-typed relocation entries.

// DWARFDataExtractor.cpp
uint64_t DWARFDataExtractor::getRelocatedValue(uint32_t Size, uint32_t *Off,
...
  // This formula is correct for REL, but may be incorrect for RELA if the value
  // stored in the location (getUnsigned(Off, Size)) is not zero.
  return getUnsigned(Off, Size) + Rel->Value;

In this patch, we

* refactor these visit* functions to include a new parameter `uint64_t A`.
  Since these visit* functions are no longer used as visitors, rename them to resolve*.
  + REL: A is used as the addend. A is the value stored in the location where the
    relocation applies: getUnsigned(Off, Size)
  + RELA: The addend encoded in RelocationRef is used, e.g. getELFAddend(R)
* and add another set of supports* functions to check if a given relocation type is handled.
  DWARFObjInMemory uses them to fail early.

Reviewers: echristo, dblaikie

Reviewed By: echristo

Subscribers: mgorny, aprantl, aheejin, fedor.sergeev, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57939

llvm-svn: 356729
2019-03-22 02:43:11 +00:00

498 lines
12 KiB
C++

//===- RelocationResolver.cpp ------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines utilities to resolve relocations in object files.
//
//===----------------------------------------------------------------------===//
#include "llvm/Object/RelocationResolver.h"
namespace llvm {
namespace object {
static int64_t getELFAddend(RelocationRef R) {
Expected<int64_t> AddendOrErr = ELFRelocationRef(R).getAddend();
handleAllErrors(AddendOrErr.takeError(), [](const ErrorInfoBase &EI) {
report_fatal_error(EI.message());
});
return *AddendOrErr;
}
static bool supportsX86_64(uint64_t Type) {
switch (Type) {
case ELF::R_X86_64_NONE:
case ELF::R_X86_64_64:
case ELF::R_X86_64_DTPOFF32:
case ELF::R_X86_64_DTPOFF64:
case ELF::R_X86_64_PC32:
case ELF::R_X86_64_32:
case ELF::R_X86_64_32S:
return true;
default:
return false;
}
}
static uint64_t resolveX86_64(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case ELF::R_X86_64_NONE:
return A;
case ELF::R_X86_64_64:
case ELF::R_X86_64_DTPOFF32:
case ELF::R_X86_64_DTPOFF64:
return S + getELFAddend(R);
case ELF::R_X86_64_PC32:
return S + getELFAddend(R) - R.getOffset();
case ELF::R_X86_64_32:
case ELF::R_X86_64_32S:
return (S + getELFAddend(R)) & 0xFFFFFFFF;
default:
llvm_unreachable("Invalid relocation type");
}
}
static bool supportsAArch64(uint64_t Type) {
switch (Type) {
case ELF::R_AARCH64_ABS32:
case ELF::R_AARCH64_ABS64:
return true;
default:
return false;
}
}
static uint64_t resolveAArch64(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case ELF::R_AARCH64_ABS32:
return (S + getELFAddend(R)) & 0xFFFFFFFF;
case ELF::R_AARCH64_ABS64:
return S + getELFAddend(R);
default:
llvm_unreachable("Invalid relocation type");
}
}
static bool supportsBPF(uint64_t Type) {
switch (Type) {
case ELF::R_BPF_64_32:
case ELF::R_BPF_64_64:
return true;
default:
return false;
}
}
static uint64_t resolveBPF(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case ELF::R_BPF_64_32:
return S & 0xFFFFFFFF;
case ELF::R_BPF_64_64:
return S;
default:
llvm_unreachable("Invalid relocation type");
}
}
static bool supportsMips64(uint64_t Type) {
switch (Type) {
case ELF::R_MIPS_32:
case ELF::R_MIPS_64:
case ELF::R_MIPS_TLS_DTPREL64:
return true;
default:
return false;
}
}
static uint64_t resolveMips64(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case ELF::R_MIPS_32:
return (S + getELFAddend(R)) & 0xFFFFFFFF;
case ELF::R_MIPS_64:
return S + getELFAddend(R);
case ELF::R_MIPS_TLS_DTPREL64:
return S + getELFAddend(R) - 0x8000;
default:
llvm_unreachable("Invalid relocation type");
}
}
static bool supportsPPC64(uint64_t Type) {
switch (Type) {
case ELF::R_PPC64_ADDR32:
case ELF::R_PPC64_ADDR64:
return true;
default:
return false;
}
}
static uint64_t resolvePPC64(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case ELF::R_PPC64_ADDR32:
return (S + getELFAddend(R)) & 0xFFFFFFFF;
case ELF::R_PPC64_ADDR64:
return S + getELFAddend(R);
default:
llvm_unreachable("Invalid relocation type");
}
}
static bool supportsSystemZ(uint64_t Type) {
switch (Type) {
case ELF::R_390_32:
case ELF::R_390_64:
return true;
default:
return false;
}
}
static uint64_t resolveSystemZ(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case ELF::R_390_32:
return (S + getELFAddend(R)) & 0xFFFFFFFF;
case ELF::R_390_64:
return S + getELFAddend(R);
default:
llvm_unreachable("Invalid relocation type");
}
}
static bool supportsSparc64(uint64_t Type) {
switch (Type) {
case ELF::R_SPARC_32:
case ELF::R_SPARC_64:
case ELF::R_SPARC_UA32:
case ELF::R_SPARC_UA64:
return true;
default:
return false;
}
}
static uint64_t resolveSparc64(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case ELF::R_SPARC_32:
case ELF::R_SPARC_64:
case ELF::R_SPARC_UA32:
case ELF::R_SPARC_UA64:
return S + getELFAddend(R);
default:
llvm_unreachable("Invalid relocation type");
}
}
static bool supportsAmdgpu(uint64_t Type) {
switch (Type) {
case ELF::R_AMDGPU_ABS32:
case ELF::R_AMDGPU_ABS64:
return true;
default:
return false;
}
}
static uint64_t resolveAmdgpu(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case ELF::R_AMDGPU_ABS32:
case ELF::R_AMDGPU_ABS64:
return S + getELFAddend(R);
default:
llvm_unreachable("Invalid relocation type");
}
}
static bool supportsX86(uint64_t Type) {
switch (Type) {
case ELF::R_386_NONE:
case ELF::R_386_32:
case ELF::R_386_PC32:
return true;
default:
return false;
}
}
static uint64_t resolveX86(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case ELF::R_386_NONE:
return A;
case ELF::R_386_32:
return S + A;
case ELF::R_386_PC32:
return S - R.getOffset() + A;
default:
llvm_unreachable("Invalid relocation type");
}
}
static bool supportsPPC32(uint64_t Type) {
return Type == ELF::R_PPC_ADDR32;
}
static uint64_t resolvePPC32(RelocationRef R, uint64_t S, uint64_t A) {
if (R.getType() == ELF::R_PPC_ADDR32)
return (S + getELFAddend(R)) & 0xFFFFFFFF;
llvm_unreachable("Invalid relocation type");
}
static bool supportsARM(uint64_t Type) {
return Type == ELF::R_ARM_ABS32;
}
static uint64_t resolveARM(RelocationRef R, uint64_t S, uint64_t A) {
if (R.getType() == ELF::R_ARM_ABS32)
return (S + A) & 0xFFFFFFFF;
llvm_unreachable("Invalid relocation type");
}
static bool supportsAVR(uint64_t Type) {
switch (Type) {
case ELF::R_AVR_16:
case ELF::R_AVR_32:
return true;
default:
return false;
}
}
static uint64_t resolveAVR(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case ELF::R_AVR_16:
return (S + getELFAddend(R)) & 0xFFFF;
case ELF::R_AVR_32:
return (S + getELFAddend(R)) & 0xFFFFFFFF;
default:
llvm_unreachable("Invalid relocation type");
}
}
static bool supportsLanai(uint64_t Type) {
return Type == ELF::R_LANAI_32;
}
static uint64_t resolveLanai(RelocationRef R, uint64_t S, uint64_t A) {
if (R.getType() == ELF::R_LANAI_32)
return (S + getELFAddend(R)) & 0xFFFFFFFF;
llvm_unreachable("Invalid relocation type");
}
static bool supportsMips32(uint64_t Type) {
switch (Type) {
case ELF::R_MIPS_32:
case ELF::R_MIPS_TLS_DTPREL32:
return true;
default:
return false;
}
}
static uint64_t resolveMips32(RelocationRef R, uint64_t S, uint64_t A) {
// FIXME: Take in account implicit addends to get correct results.
uint32_t Rel = R.getType();
if (Rel == ELF::R_MIPS_32)
return (S + A) & 0xFFFFFFFF;
if (Rel == ELF::R_MIPS_TLS_DTPREL32)
return (S + A) & 0xFFFFFFFF;
llvm_unreachable("Invalid relocation type");
}
static bool supportsSparc32(uint64_t Type) {
switch (Type) {
case ELF::R_SPARC_32:
case ELF::R_SPARC_UA32:
return true;
default:
return false;
}
}
static uint64_t resolveSparc32(RelocationRef R, uint64_t S, uint64_t A) {
uint32_t Rel = R.getType();
if (Rel == ELF::R_SPARC_32 || Rel == ELF::R_SPARC_UA32)
return S + getELFAddend(R);
return A;
}
static bool supportsHexagon(uint64_t Type) {
return Type == ELF::R_HEX_32;
}
static uint64_t resolveHexagon(RelocationRef R, uint64_t S, uint64_t A) {
if (R.getType() == ELF::R_HEX_32)
return S + getELFAddend(R);
llvm_unreachable("Invalid relocation type");
}
static bool supportsCOFFX86(uint64_t Type) {
switch (Type) {
case COFF::IMAGE_REL_I386_SECREL:
case COFF::IMAGE_REL_I386_DIR32:
return true;
default:
return false;
}
}
static uint64_t resolveCOFFX86(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case COFF::IMAGE_REL_I386_SECREL:
case COFF::IMAGE_REL_I386_DIR32:
return (S + A) & 0xFFFFFFFF;
default:
llvm_unreachable("Invalid relocation type");
}
}
static bool supportsCOFFX86_64(uint64_t Type) {
switch (Type) {
case COFF::IMAGE_REL_AMD64_SECREL:
case COFF::IMAGE_REL_AMD64_ADDR64:
return true;
default:
return false;
}
}
static uint64_t resolveCOFFX86_64(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case COFF::IMAGE_REL_AMD64_SECREL:
return (S + A) & 0xFFFFFFFF;
case COFF::IMAGE_REL_AMD64_ADDR64:
return S + A;
default:
llvm_unreachable("Invalid relocation type");
}
}
static bool supportsMachOX86_64(uint64_t Type) {
return Type == MachO::X86_64_RELOC_UNSIGNED;
}
static uint64_t resolveMachOX86_64(RelocationRef R, uint64_t S, uint64_t A) {
if (R.getType() == MachO::X86_64_RELOC_UNSIGNED)
return S;
llvm_unreachable("Invalid relocation type");
}
static bool supportsWasm32(uint64_t Type) {
switch (Type) {
case wasm::R_WASM_FUNCTION_INDEX_LEB:
case wasm::R_WASM_TABLE_INDEX_SLEB:
case wasm::R_WASM_TABLE_INDEX_I32:
case wasm::R_WASM_MEMORY_ADDR_LEB:
case wasm::R_WASM_MEMORY_ADDR_SLEB:
case wasm::R_WASM_MEMORY_ADDR_I32:
case wasm::R_WASM_TYPE_INDEX_LEB:
case wasm::R_WASM_GLOBAL_INDEX_LEB:
case wasm::R_WASM_FUNCTION_OFFSET_I32:
case wasm::R_WASM_SECTION_OFFSET_I32:
case wasm::R_WASM_EVENT_INDEX_LEB:
return true;
default:
return false;
}
}
static uint64_t resolveWasm32(RelocationRef R, uint64_t S, uint64_t A) {
switch (R.getType()) {
case wasm::R_WASM_FUNCTION_INDEX_LEB:
case wasm::R_WASM_TABLE_INDEX_SLEB:
case wasm::R_WASM_TABLE_INDEX_I32:
case wasm::R_WASM_MEMORY_ADDR_LEB:
case wasm::R_WASM_MEMORY_ADDR_SLEB:
case wasm::R_WASM_MEMORY_ADDR_I32:
case wasm::R_WASM_TYPE_INDEX_LEB:
case wasm::R_WASM_GLOBAL_INDEX_LEB:
case wasm::R_WASM_FUNCTION_OFFSET_I32:
case wasm::R_WASM_SECTION_OFFSET_I32:
case wasm::R_WASM_EVENT_INDEX_LEB:
// For wasm section, its offset at 0 -- ignoring Value
return A;
default:
llvm_unreachable("Invalid relocation type");
}
}
std::pair<bool (*)(uint64_t), RelocationResolver>
getRelocationResolver(const ObjectFile &Obj) {
if (Obj.isCOFF()) {
if (Obj.getBytesInAddress() == 8)
return {supportsCOFFX86_64, resolveCOFFX86_64};
return {supportsCOFFX86, resolveCOFFX86};
} else if (Obj.isELF()) {
if (Obj.getBytesInAddress() == 8) {
switch (Obj.getArch()) {
case Triple::x86_64:
return {supportsX86_64, resolveX86_64};
case Triple::aarch64:
case Triple::aarch64_be:
return {supportsAArch64, resolveAArch64};
case Triple::bpfel:
case Triple::bpfeb:
return {supportsBPF, resolveBPF};
case Triple::mips64el:
case Triple::mips64:
return {supportsMips64, resolveMips64};
case Triple::ppc64le:
case Triple::ppc64:
return {supportsPPC64, resolvePPC64};
case Triple::systemz:
return {supportsSystemZ, resolveSystemZ};
case Triple::sparcv9:
return {supportsSparc64, resolveSparc64};
case Triple::amdgcn:
return {supportsAmdgpu, resolveAmdgpu};
default:
return {nullptr, nullptr};
}
}
// 32-bit object file
assert(Obj.getBytesInAddress() == 4 &&
"Invalid word size in object file");
switch (Obj.getArch()) {
case Triple::x86:
return {supportsX86, resolveX86};
case Triple::ppc:
return {supportsPPC32, resolvePPC32};
case Triple::arm:
case Triple::armeb:
return {supportsARM, resolveARM};
case Triple::avr:
return {supportsAVR, resolveAVR};
case Triple::lanai:
return {supportsLanai, resolveLanai};
case Triple::mipsel:
case Triple::mips:
return {supportsMips32, resolveMips32};
case Triple::sparc:
return {supportsSparc32, resolveSparc32};
case Triple::hexagon:
return {supportsHexagon, resolveHexagon};
default:
return {nullptr, nullptr};
}
} else if (Obj.isMachO()) {
if (Obj.getArch() == Triple::x86_64)
return {supportsMachOX86_64, resolveMachOX86_64};
return {nullptr, nullptr};
} else if (Obj.isWasm()) {
if (Obj.getArch() == Triple::wasm32)
return {supportsWasm32, resolveWasm32};
return {nullptr, nullptr};
}
llvm_unreachable("Invalid object file");
}
} // namespace object
} // namespace llvm