diff options
| -rw-r--r-- | include/llvm/MC/MCObjectDisassembler.h | 16 | ||||
| -rw-r--r-- | lib/MC/MCObjectDisassembler.cpp | 12 |
2 files changed, 27 insertions, 1 deletions
diff --git a/include/llvm/MC/MCObjectDisassembler.h b/include/llvm/MC/MCObjectDisassembler.h index de2aae7c6a..edaf7dca5a 100644 --- a/include/llvm/MC/MCObjectDisassembler.h +++ b/include/llvm/MC/MCObjectDisassembler.h @@ -65,6 +65,22 @@ public: virtual ArrayRef<uint64_t> getStaticExitFunctions(); /// @} + /// \name Translation between effective and objectfile load address. + /// @{ + /// \brief Compute the effective load address, from an objectfile virtual + /// address. This is implemented in a format-specific way, to take into + /// account things like PIE/ASLR when doing dynamic disassembly. + /// For example, on Mach-O this would be done by adding the VM addr slide, + /// on glibc ELF by keeping a map between segment load addresses, filled + /// using dl_iterate_phdr, etc.. + /// In most static situations and in the default impl., this returns \p Addr. + virtual uint64_t getEffectiveLoadAddr(uint64_t Addr); + + /// \brief Compute the original load address, as specified in the objectfile. + /// This is the inverse of getEffectiveLoadAddr. + virtual uint64_t getOriginalLoadAddr(uint64_t EffectiveAddr); + /// @} + protected: const object::ObjectFile &Obj; const MCDisassembler &Dis; diff --git a/lib/MC/MCObjectDisassembler.cpp b/lib/MC/MCObjectDisassembler.cpp index 8cb9a8abdf..4ce8e92793 100644 --- a/lib/MC/MCObjectDisassembler.cpp +++ b/lib/MC/MCObjectDisassembler.cpp @@ -44,7 +44,7 @@ uint64_t MCObjectDisassembler::getEntrypoint() { if (Name == "main" || Name == "_main") { uint64_t Entrypoint; SI->getAddress(Entrypoint); - return Entrypoint; + return getEffectiveLoadAddr(Entrypoint); } } return 0; @@ -58,6 +58,14 @@ ArrayRef<uint64_t> MCObjectDisassembler::getStaticExitFunctions() { return ArrayRef<uint64_t>(); } +uint64_t MCObjectDisassembler::getEffectiveLoadAddr(uint64_t Addr) { + return Addr; +} + +uint64_t MCObjectDisassembler::getOriginalLoadAddr(uint64_t Addr) { + return Addr; +} + MCModule *MCObjectDisassembler::buildEmptyModule() { MCModule *Module = new MCModule; Module->Entrypoint = getEntrypoint(); @@ -90,6 +98,7 @@ void MCObjectDisassembler::buildSectionAtoms(MCModule *Module) { uint64_t SecSize; SI->getSize(SecSize); if (StartAddr == UnknownAddressOrSize || SecSize == UnknownAddressOrSize) continue; + StartAddr = getEffectiveLoadAddr(StartAddr); StringRef Contents; SI->getContents(Contents); StringRefMemoryObject memoryObject(Contents, StartAddr); @@ -170,6 +179,7 @@ void MCObjectDisassembler::buildCFG(MCModule *Module) { if (SymType == SymbolRef::ST_Function) { uint64_t SymAddr; SI->getAddress(SymAddr); + SymAddr = getEffectiveLoadAddr(SymAddr); Calls.insert(SymAddr); Splits.insert(SymAddr); } |