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

2 files changed, 227 insertions, 0 deletions

diff --git a/lib/ExecutionEngine/RuntimeDyld/CMakeLists.txt b/lib/ExecutionEngine/RuntimeDyld/CMakeLists.txt
index cbf7cf14d4..728303ac4e 100644
--- a/lib/ExecutionEngine/RuntimeDyld/CMakeLists.txt
+++ b/lib/ExecutionEngine/RuntimeDyld/CMakeLists.txt
@@ -3,4 +3,5 @@ add_llvm_library(LLVMRuntimeDyld
   RuntimeDyld.cpp
   RuntimeDyldELF.cpp
   RuntimeDyldMachO.cpp
+  SectionMemoryManager.cpp
   )
diff --git a/lib/ExecutionEngine/RuntimeDyld/SectionMemoryManager.cpp b/lib/ExecutionEngine/RuntimeDyld/SectionMemoryManager.cpp
new file mode 100644
index 0000000000..fa35acd389
--- /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
+