From 28a765542c7a57821fc4c06454c1326e2f66a1d9 Mon Sep 17 00:00:00 2001 From: Andrew Kaylor Date: Wed, 16 Oct 2013 00:32:24 +0000 Subject: Adding padding to the .eh_frame section in RuntimeDyld git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192754 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'lib/ExecutionEngine/RuntimeDyld') diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp index 49f8dc378e..febc81cde0 100644 --- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp +++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp @@ -258,6 +258,7 @@ unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj, bool IsZeroInit; bool IsReadOnly; uint64_t DataSize; + unsigned PaddingSize = 0; StringRef Name; Check(Section.isRequiredForExecution(IsRequired)); Check(Section.isVirtual(IsVirtual)); @@ -272,6 +273,12 @@ unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj, StubBufSize += StubAlignment - EndAlignment; } + // The .eh_frame section (at least on Linux) needs an extra four bytes padded + // with zeroes added at the end. For MachO objects, this section has a + // slightly different name, so this won't have any effect for MachO objects. + if (Name == ".eh_frame") + PaddingSize = 4; + unsigned Allocate; unsigned SectionID = Sections.size(); uint8_t *Addr; @@ -280,7 +287,7 @@ unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj, // Some sections, such as debug info, don't need to be loaded for execution. // Leave those where they are. if (IsRequired) { - Allocate = DataSize + StubBufSize; + Allocate = DataSize + PaddingSize + StubBufSize; Addr = IsCode ? MemMgr->allocateCodeSection(Allocate, Alignment, SectionID, Name) : MemMgr->allocateDataSection(Allocate, Alignment, SectionID, Name, @@ -298,6 +305,13 @@ unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj, else memcpy(Addr, pData, DataSize); + // Fill in any extra bytes we allocated for padding + if (PaddingSize != 0) { + memset(Addr + DataSize, 0, PaddingSize); + // Update the DataSize variable so that the stub offset is set correctly. + DataSize += PaddingSize; + } + DEBUG(dbgs() << "emitSection SectionID: " << SectionID << " Name: " << Name << " obj addr: " << format("%p", pData) -- cgit v1.2.3