On Darwin ARM, memory needs special handling to do JIT. This patch expands
this handling to work properly for modifying stub functions, relocations
back to entry points after JIT compilation, etc..
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57013 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp
index ffaeb1c..a90a6a5 100644
--- a/lib/ExecutionEngine/JIT/JITEmitter.cpp
+++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -560,6 +560,10 @@
if (ExceptionHandling) DE->setModuleInfo(Info);
}
+ void setMemoryExecutable(void) {
+ MemMgr->setMemoryExecutable();
+ }
+
private:
void *getPointerToGlobal(GlobalValue *GV, void *Reference, bool NoNeedStub);
void *getPointerToGVLazyPtr(GlobalValue *V, void *Reference,
@@ -791,6 +795,8 @@
void JITEmitter::startFunction(MachineFunction &F) {
uintptr_t ActualSize = 0;
+ // Set the memory writable, if it's not already
+ MemMgr->setMemoryWritable();
if (MemMgr->NeedsExactSize()) {
DOUT << "ExactSize\n";
const TargetInstrInfo* TII = F.getTarget().getInstrInfo();
@@ -938,7 +944,7 @@
Relocations.clear();
// Mark code region readable and executable if it's not so already.
- sys::Memory::SetRXPrivilege(FnStart, FnEnd-FnStart);
+ MemMgr->setMemoryExecutable();
#ifndef NDEBUG
{
@@ -1086,6 +1092,10 @@
void *JITEmitter::finishFunctionStub(const GlobalValue* F) {
NumBytes += getCurrentPCOffset();
+
+ // Invalidate the icache if necessary.
+ sys::Memory::InvalidateInstructionCache(BufferBegin, NumBytes);
+
std::swap(SavedBufferBegin, BufferBegin);
BufferEnd = SavedBufferEnd;
CurBufferPtr = SavedCurBufferPtr;
diff --git a/lib/ExecutionEngine/JIT/JITMemoryManager.cpp b/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
index 804e88d..0ffc779 100644
--- a/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
+++ b/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
@@ -365,6 +365,21 @@
// Finally, remove this entry from TableBlocks.
TableBlocks.erase(I);
}
+
+ /// setMemoryWritable - When code generation is in progress,
+ /// the code pages may need permissions changed.
+ void setMemoryWritable(void)
+ {
+ for (unsigned i = 0, e = Blocks.size(); i != e; ++i)
+ sys::Memory::setWritable(Blocks[i]);
+ }
+ /// setMemoryExecutable - When code generation is done and we're ready to
+ /// start execution, the code pages may need permissions changed.
+ void setMemoryExecutable(void)
+ {
+ for (unsigned i = 0, e = Blocks.size(); i != e; ++i)
+ sys::Memory::setExecutable(Blocks[i]);
+ }
};
}