[BOLT] Change base class of ExecutableFileMemoryManager

When we derive EFMM from SectionMemoryManager, it brings into EFMM extra
functionality, such as the registry of exception handling sections,
page permission management, etc. Such functionality is of no use to
llvm-bolt and can even be detrimental (see
https://github.com/llvm/llvm-project/issues/56726).

Change the base class of ExecutableFileMemoryManager to MemoryManager,
avoid registering EH sections, and skip memory finalization.

Fixes #56726

Reviewed By: yota9

Differential Revision: https://reviews.llvm.org/D133994

1 files changed, 14 insertions, 26 deletions

diff --git a/bolt/lib/Rewrite/ExecutableFileMemoryManager.cpp b/bolt/lib/Rewrite/ExecutableFileMemoryManager.cpp
index b186e80..68695d1 100644
--- a/bolt/lib/Rewrite/ExecutableFileMemoryManager.cpp
+++ b/bolt/lib/Rewrite/ExecutableFileMemoryManager.cpp
@@ -8,6 +8,7 @@
 
 #include "bolt/Rewrite/ExecutableFileMemoryManager.h"
 #include "bolt/Rewrite/RewriteInstance.h"
+#include "llvm/Support/MemAlloc.h"
 
 #undef  DEBUG_TYPE
 #define DEBUG_TYPE "efmm"
@@ -20,34 +21,24 @@ namespace llvm {
 
 namespace bolt {
 
-uint8_t *ExecutableFileMemoryManager::allocateSection(intptr_t Size,
-                                                      unsigned Alignment,
-                                                      unsigned SectionID,
-                                                      StringRef SectionName,
-                                                      bool IsCode,
-                                                      bool IsReadOnly) {
+uint8_t *ExecutableFileMemoryManager::allocateSection(
+    uintptr_t Size, unsigned Alignment, unsigned SectionID,
+    StringRef SectionName, bool IsCode, bool IsReadOnly) {
+  uint8_t *Ret = static_cast<uint8_t *>(llvm::allocate_buffer(Size, Alignment));
+  AllocatedSections.push_back(AllocInfo{Ret, Size, Alignment});
+
   // Register a debug section as a note section.
   if (!ObjectsLoaded && RewriteInstance::isDebugSection(SectionName)) {
-    uint8_t *DataCopy = new uint8_t[Size];
     BinarySection &Section =
-        BC.registerOrUpdateNoteSection(SectionName, DataCopy, Size, Alignment);
+        BC.registerOrUpdateNoteSection(SectionName, Ret, Size, Alignment);
     Section.setSectionID(SectionID);
     assert(!Section.isAllocatable() && "note sections cannot be allocatable");
-    return DataCopy;
+    return Ret;
   }
 
   if (!IsCode && (SectionName == ".strtab" || SectionName == ".symtab" ||
                   SectionName == "" || SectionName.startswith(".rela.")))
-    return SectionMemoryManager::allocateDataSection(Size, Alignment, SectionID,
-                                                     SectionName, IsReadOnly);
-
-  uint8_t *Ret;
-  if (IsCode)
-    Ret = SectionMemoryManager::allocateCodeSection(Size, Alignment, SectionID,
-                                                    SectionName);
-  else
-    Ret = SectionMemoryManager::allocateDataSection(Size, Alignment, SectionID,
-                                                    SectionName, IsReadOnly);
+    return Ret;
 
   SmallVector<char, 256> Buf;
   if (ObjectsLoaded > 0) {
@@ -75,19 +66,16 @@ uint8_t *ExecutableFileMemoryManager::allocateSection(intptr_t Size,
       dbgs() << "BOLT: allocating "
              << (IsCode ? "code" : (IsReadOnly ? "read-only data" : "data"))
              << " section : " << SectionName << " with size " << Size
-             << ", alignment " << Alignment << " at 0x" << Ret
+             << ", alignment " << Alignment << " at " << Ret
              << ", ID = " << SectionID << "\n");
   return Ret;
 }
 
-bool ExecutableFileMemoryManager::finalizeMemory(std::string *ErrMsg) {
-  LLVM_DEBUG(dbgs() << "BOLT: finalizeMemory()\n");
-  ++ObjectsLoaded;
-  return SectionMemoryManager::finalizeMemory(ErrMsg);
+ExecutableFileMemoryManager::~ExecutableFileMemoryManager() {
+  for (const AllocInfo &AI : AllocatedSections)
+    llvm::deallocate_buffer(AI.Address, AI.Size, AI.Alignment);
 }
 
-ExecutableFileMemoryManager::~ExecutableFileMemoryManager() {}
-
 } // namespace bolt
 
 } // namespace llvm