Moving SectionMemoryManager into RuntimeDyld and adding unit tests for it.
The SectionMemoryManager now supports (and requires) applying section-specific page permissions. Clients using this memory manager must call either MCJIT::finalizeObject() or SectionMemoryManager::applyPermissions() before executing JITed code.
See r168718 for changes from the previous implementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168721 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ExecutionEngine/RuntimeDyld/SectionMemoryManager.cpp b/lib/ExecutionEngine/RuntimeDyld/SectionMemoryManager.cpp
new file mode 100644
index 0000000..fa35acd
--- /dev/null
+++ b/lib/ExecutionEngine/RuntimeDyld/SectionMemoryManager.cpp
@@ -0,0 +1,226 @@
+//===- SectionMemoryManager.cpp - Memory manager for MCJIT/RtDyld *- C++ -*-==//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the section-based memory manager used by the MCJIT
+// execution engine and RuntimeDyld
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Config/config.h"
+#include "llvm/ExecutionEngine/SectionMemoryManager.h"
+#include "llvm/Support/DynamicLibrary.h"
+#include "llvm/Support/MathExtras.h"
+
+#ifdef __linux__
+ // These includes used by SectionMemoryManager::getPointerToNamedFunction()
+ // for Glibc trickery. See comments in this function for more information.
+ #ifdef HAVE_SYS_STAT_H
+ #include <sys/stat.h>
+ #endif
+ #include <fcntl.h>
+ #include <unistd.h>
+#endif
+
+namespace llvm {
+
+uint8_t *SectionMemoryManager::allocateDataSection(uintptr_t Size,
+ unsigned Alignment,
+ unsigned SectionID,
+ bool IsReadOnly) {
+ if (IsReadOnly)
+ return allocateSection(RODataMem, Size, Alignment);
+ return allocateSection(RWDataMem, Size, Alignment);
+}
+
+uint8_t *SectionMemoryManager::allocateCodeSection(uintptr_t Size,
+ unsigned Alignment,
+ unsigned SectionID) {
+ return allocateSection(CodeMem, Size, Alignment);
+}
+
+uint8_t *SectionMemoryManager::allocateSection(MemoryGroup &MemGroup,
+ uintptr_t Size,
+ unsigned Alignment) {
+ if (!Alignment)
+ Alignment = 16;
+
+ assert(!(Alignment & (Alignment - 1)) && "Alignment must be a power of two.");
+
+ uintptr_t RequiredSize = Alignment * ((Size + Alignment - 1)/Alignment + 1);
+ uintptr_t Addr = 0;
+
+ // Look in the list of free memory regions and use a block there if one
+ // is available.
+ for (int i = 0, e = MemGroup.FreeMem.size(); i != e; ++i) {
+ sys::MemoryBlock &MB = MemGroup.FreeMem[i];
+ if (MB.size() >= RequiredSize) {
+ Addr = (uintptr_t)MB.base();
+ uintptr_t EndOfBlock = Addr + MB.size();
+ // Align the address.
+ Addr = (Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1);
+ // Store cutted free memory block.
+ MemGroup.FreeMem[i] = sys::MemoryBlock((void*)(Addr + Size),
+ EndOfBlock - Addr - Size);
+ return (uint8_t*)Addr;
+ }
+ }
+
+ // No pre-allocated free block was large enough. Allocate a new memory region.
+ // Note that all sections get allocated as read-write. The permissions will
+ // be updated later based on memory group.
+ //
+ // FIXME: It would be useful to define a default allocation size (or add
+ // it as a constructor parameter) to minimize the number of allocations.
+ //
+ // FIXME: Initialize the Near member for each memory group to avoid
+ // interleaving.
+ error_code ec;
+ sys::MemoryBlock MB = sys::Memory::allocateMappedMemory(RequiredSize,
+ &MemGroup.Near,
+ sys::Memory::MF_READ |
+ sys::Memory::MF_WRITE,
+ ec);
+ if (ec) {
+ // FIXME: Add error propogation to the interface.
+ return NULL;
+ }
+
+ // Save this address as the basis for our next request
+ MemGroup.Near = MB;
+
+ MemGroup.AllocatedMem.push_back(MB);
+ Addr = (uintptr_t)MB.base();
+ uintptr_t EndOfBlock = Addr + MB.size();
+
+ // Align the address.
+ Addr = (Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1);
+
+ // The allocateMappedMemory may allocate much more memory than we need. In
+ // this case, we store the unused memory as a free memory block.
+ unsigned FreeSize = EndOfBlock-Addr-Size;
+ if (FreeSize > 16)
+ MemGroup.FreeMem.push_back(sys::MemoryBlock((void*)(Addr + Size), FreeSize));
+
+ // Return aligned address
+ return (uint8_t*)Addr;
+}
+
+bool SectionMemoryManager::applyPermissions(std::string *ErrMsg)
+{
+ // FIXME: Should in-progress permissions be reverted if an error occurs?
+ error_code ec;
+
+ // Make code memory executable.
+ ec = applyMemoryGroupPermissions(CodeMem,
+ sys::Memory::MF_READ | sys::Memory::MF_EXEC);
+ if (ec) {
+ if (ErrMsg) {
+ *ErrMsg = ec.message();
+ }
+ return true;
+ }
+
+ // Make read-only data memory read-only.
+ ec = applyMemoryGroupPermissions(RODataMem,
+ sys::Memory::MF_READ | sys::Memory::MF_EXEC);
+ if (ec) {
+ if (ErrMsg) {
+ *ErrMsg = ec.message();
+ }
+ return true;
+ }
+
+ // Read-write data memory already has the correct permissions
+
+ return false;
+}
+
+error_code SectionMemoryManager::applyMemoryGroupPermissions(MemoryGroup &MemGroup,
+ unsigned Permissions) {
+
+ for (int i = 0, e = MemGroup.AllocatedMem.size(); i != e; ++i) {
+ error_code ec;
+ ec = sys::Memory::protectMappedMemory(MemGroup.AllocatedMem[i],
+ Permissions);
+ if (ec) {
+ return ec;
+ }
+ }
+
+ return error_code::success();
+}
+
+void SectionMemoryManager::invalidateInstructionCache() {
+ for (int i = 0, e = CodeMem.AllocatedMem.size(); i != e; ++i)
+ sys::Memory::InvalidateInstructionCache(CodeMem.AllocatedMem[i].base(),
+ CodeMem.AllocatedMem[i].size());
+}
+
+static int jit_noop() {
+ return 0;
+}
+
+void *SectionMemoryManager::getPointerToNamedFunction(const std::string &Name,
+ bool AbortOnFailure) {
+#if defined(__linux__)
+ //===--------------------------------------------------------------------===//
+ // Function stubs that are invoked instead of certain library calls
+ //
+ // Force the following functions to be linked in to anything that uses the
+ // JIT. This is a hack designed to work around the all-too-clever Glibc
+ // strategy of making these functions work differently when inlined vs. when
+ // not inlined, and hiding their real definitions in a separate archive file
+ // that the dynamic linker can't see. For more info, search for
+ // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
+ if (Name == "stat") return (void*)(intptr_t)&stat;
+ if (Name == "fstat") return (void*)(intptr_t)&fstat;
+ if (Name == "lstat") return (void*)(intptr_t)&lstat;
+ if (Name == "stat64") return (void*)(intptr_t)&stat64;
+ if (Name == "fstat64") return (void*)(intptr_t)&fstat64;
+ if (Name == "lstat64") return (void*)(intptr_t)&lstat64;
+ if (Name == "atexit") return (void*)(intptr_t)&atexit;
+ if (Name == "mknod") return (void*)(intptr_t)&mknod;
+#endif // __linux__
+
+ // We should not invoke parent's ctors/dtors from generated main()!
+ // On Mingw and Cygwin, the symbol __main is resolved to
+ // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
+ // (and register wrong callee's dtors with atexit(3)).
+ // We expect ExecutionEngine::runStaticConstructorsDestructors()
+ // is called before ExecutionEngine::runFunctionAsMain() is called.
+ if (Name == "__main") return (void*)(intptr_t)&jit_noop;
+
+ const char *NameStr = Name.c_str();
+ void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
+ if (Ptr) return Ptr;
+
+ // If it wasn't found and if it starts with an underscore ('_') character,
+ // try again without the underscore.
+ if (NameStr[0] == '_') {
+ Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
+ if (Ptr) return Ptr;
+ }
+
+ if (AbortOnFailure)
+ report_fatal_error("Program used external function '" + Name +
+ "' which could not be resolved!");
+ return 0;
+}
+
+SectionMemoryManager::~SectionMemoryManager() {
+ for (unsigned i = 0, e = CodeMem.AllocatedMem.size(); i != e; ++i)
+ sys::Memory::releaseMappedMemory(CodeMem.AllocatedMem[i]);
+ for (unsigned i = 0, e = RWDataMem.AllocatedMem.size(); i != e; ++i)
+ sys::Memory::releaseMappedMemory(RWDataMem.AllocatedMem[i]);
+ for (unsigned i = 0, e = RODataMem.AllocatedMem.size(); i != e; ++i)
+ sys::Memory::releaseMappedMemory(RODataMem.AllocatedMem[i]);
+}
+
+} // namespace llvm
+