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Adding padding to the .eh_frame section in RuntimeDyld 

llvm-svn: 192754
This commit is contained in:
Andrew Kaylor 2013-10-16 00:32:24 +00:00
parent c442a76c60
commit 877b931a41
1 changed files with 15 additions and 1 deletions
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16
llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
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@ -258,6 +258,7 @@ unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj,
bool IsZeroInit; bool IsZeroInit;
bool IsReadOnly; bool IsReadOnly;
uint64_t DataSize; uint64_t DataSize;
unsigned PaddingSize = 0;
StringRef Name; StringRef Name;
Check(Section.isRequiredForExecution(IsRequired)); Check(Section.isRequiredForExecution(IsRequired));
Check(Section.isVirtual(IsVirtual)); Check(Section.isVirtual(IsVirtual));
@ -272,6 +273,12 @@ unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj,
StubBufSize += StubAlignment - EndAlignment; 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 Allocate;
unsigned SectionID = Sections.size(); unsigned SectionID = Sections.size();
uint8_t *Addr; 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. // Some sections, such as debug info, don't need to be loaded for execution.
// Leave those where they are. // Leave those where they are.
if (IsRequired) { if (IsRequired) {
Allocate = DataSize + StubBufSize; Allocate = DataSize + PaddingSize + StubBufSize;
Addr = IsCode Addr = IsCode
? MemMgr->allocateCodeSection(Allocate, Alignment, SectionID, Name) ? MemMgr->allocateCodeSection(Allocate, Alignment, SectionID, Name)
: MemMgr->allocateDataSection(Allocate, Alignment, SectionID, Name, : MemMgr->allocateDataSection(Allocate, Alignment, SectionID, Name,
@ -298,6 +305,13 @@ unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj,
else else
memcpy(Addr, pData, DataSize); 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 DEBUG(dbgs() << "emitSection SectionID: " << SectionID
<< " Name: " << Name << " Name: " << Name
<< " obj addr: " << format("%p", pData) << " obj addr: " << format("%p", pData)