From a8d2f819ad8c3137e67ff2c1b23fc3281b92c156 Mon Sep 17 00:00:00 2001 From: Alexey Samsonov Date: Wed, 27 Aug 2014 23:06:08 +0000 Subject: Fix unaligned reads/writes in X86JIT and RuntimeDyldELF. Summary: Introduce support::ulittleX_t::ref type to Support/Endian.h and use it in x86 JIT to enforce correct endianness and fix unaligned accesses. Test Plan: regression test suite Reviewers: lhames Subscribers: ributzka, llvm-commits Differential Revision: http://reviews.llvm.org/D5011 llvm-svn: 216631 --- .../ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp | 48 ++++++++++------------ 1 file changed, 22 insertions(+), 26 deletions(-) (limited to 'llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp') diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp index 9aa04119724..adea5ad2241 100644 --- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp +++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp @@ -23,6 +23,7 @@ #include "llvm/Object/ELFObjectFile.h" #include "llvm/Object/ObjectFile.h" #include "llvm/Support/ELF.h" +#include "llvm/Support/Endian.h" #include "llvm/Support/MemoryBuffer.h" using namespace llvm; @@ -260,10 +261,9 @@ void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section, llvm_unreachable("Relocation type not implemented yet!"); break; case ELF::R_X86_64_64: { - uint64_t *Target = reinterpret_cast(Section.Address + Offset); - *Target = Value + Addend; + support::ulittle64_t::ref(Section.Address + Offset) = Value + Addend; DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at " - << format("%p\n", Target)); + << format("%p\n", Section.Address + Offset)); break; } case ELF::R_X86_64_32: @@ -273,17 +273,15 @@ void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section, (Type == ELF::R_X86_64_32S && ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN))); uint32_t TruncatedAddr = (Value & 0xFFFFFFFF); - uint32_t *Target = reinterpret_cast(Section.Address + Offset); - *Target = TruncatedAddr; + support::ulittle32_t::ref(Section.Address + Offset) = TruncatedAddr; DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at " - << format("%p\n", Target)); + << format("%p\n", Section.Address + Offset)); break; } case ELF::R_X86_64_GOTPCREL: { // findGOTEntry returns the 'G + GOT' part of the relocation calculation // based on the load/target address of the GOT (not the current/local addr). uint64_t GOTAddr = findGOTEntry(Value, SymOffset); - uint32_t *Target = reinterpret_cast(Section.Address + Offset); uint64_t FinalAddress = Section.LoadAddress + Offset; // The processRelocationRef method combines the symbol offset and the addend // and in most cases that's what we want. For this relocation type, we need @@ -291,30 +289,29 @@ void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section, int64_t RealOffset = GOTAddr + Addend - SymOffset - FinalAddress; assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN); int32_t TruncOffset = (RealOffset & 0xFFFFFFFF); - *Target = TruncOffset; + support::ulittle32_t::ref(Section.Address + Offset) = TruncOffset; break; } case ELF::R_X86_64_PC32: { // Get the placeholder value from the generated object since // a previous relocation attempt may have overwritten the loaded version - uint32_t *Placeholder = - reinterpret_cast(Section.ObjAddress + Offset); - uint32_t *Target = reinterpret_cast(Section.Address + Offset); + support::ulittle32_t::ref Placeholder( + (void *)(Section.ObjAddress + Offset)); uint64_t FinalAddress = Section.LoadAddress + Offset; - int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress; + int64_t RealOffset = Placeholder + Value + Addend - FinalAddress; assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN); int32_t TruncOffset = (RealOffset & 0xFFFFFFFF); - *Target = TruncOffset; + support::ulittle32_t::ref(Section.Address + Offset) = TruncOffset; break; } case ELF::R_X86_64_PC64: { // Get the placeholder value from the generated object since // a previous relocation attempt may have overwritten the loaded version - uint64_t *Placeholder = - reinterpret_cast(Section.ObjAddress + Offset); - uint64_t *Target = reinterpret_cast(Section.Address + Offset); + support::ulittle64_t::ref Placeholder( + (void *)(Section.ObjAddress + Offset)); uint64_t FinalAddress = Section.LoadAddress + Offset; - *Target = *Placeholder + Value + Addend - FinalAddress; + support::ulittle64_t::ref(Section.Address + Offset) = + Placeholder + Value + Addend - FinalAddress; break; } } @@ -327,21 +324,20 @@ void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section, case ELF::R_386_32: { // Get the placeholder value from the generated object since // a previous relocation attempt may have overwritten the loaded version - uint32_t *Placeholder = - reinterpret_cast(Section.ObjAddress + Offset); - uint32_t *Target = reinterpret_cast(Section.Address + Offset); - *Target = *Placeholder + Value + Addend; + support::ulittle32_t::ref Placeholder( + (void *)(Section.ObjAddress + Offset)); + support::ulittle32_t::ref(Section.Address + Offset) = + Placeholder + Value + Addend; break; } case ELF::R_386_PC32: { // Get the placeholder value from the generated object since // a previous relocation attempt may have overwritten the loaded version - uint32_t *Placeholder = - reinterpret_cast(Section.ObjAddress + Offset); - uint32_t *Target = reinterpret_cast(Section.Address + Offset); + support::ulittle32_t::ref Placeholder( + (void *)(Section.ObjAddress + Offset)); uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF); - uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress; - *Target = RealOffset; + uint32_t RealOffset = Placeholder + Value + Addend - FinalAddress; + support::ulittle32_t::ref(Section.Address + Offset) = RealOffset; break; } default: -- cgit v1.2.3