1 files changed, 157 insertions, 0 deletions
diff --git a/lib/asan/asan_allocator.h b/lib/asan/asan_allocator.h
new file mode 100644
index 000000000000..9b691e04ff40
--- /dev/null
+++ b/lib/asan/asan_allocator.h
@@ -0,0 +1,157 @@
+//===-- asan_allocator.h ----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// ASan-private header for asan_allocator.cc.
+//===----------------------------------------------------------------------===//
+
+#ifndef ASAN_ALLOCATOR_H
+#define ASAN_ALLOCATOR_H
+
+#include "asan_internal.h"
+#include "asan_interceptors.h"
+
+namespace __asan {
+
+static const size_t kNumberOfSizeClasses = 255;
+struct AsanChunk;
+
+class AsanChunkFifoList {
+ public:
+  explicit AsanChunkFifoList(LinkerInitialized) { }
+  AsanChunkFifoList() { clear(); }
+  void Push(AsanChunk *n);
+  void PushList(AsanChunkFifoList *q);
+  AsanChunk *Pop();
+  size_t size() { return size_; }
+  void clear() {
+    first_ = last_ = NULL;
+    size_ = 0;
+  }
+ private:
+  AsanChunk *first_;
+  AsanChunk *last_;
+  size_t size_;
+};
+
+struct AsanThreadLocalMallocStorage {
+  explicit AsanThreadLocalMallocStorage(LinkerInitialized x)
+      : quarantine_(x) { }
+  AsanThreadLocalMallocStorage() {
+    CHECK(real_memset);
+    real_memset(this, 0, sizeof(AsanThreadLocalMallocStorage));
+  }
+
+  AsanChunkFifoList quarantine_;
+  AsanChunk *free_lists_[kNumberOfSizeClasses];
+  void CommitBack();
+};
+
+// Fake stack frame contains local variables of one function.
+// This struct should fit into a stack redzone (32 bytes).
+struct FakeFrame {
+  uintptr_t magic;  // Modified by the instrumented code.
+  uintptr_t descr;  // Modified by the instrumented code.
+  FakeFrame *next;
+  uint64_t real_stack     : 48;
+  uint64_t size_minus_one : 16;
+};
+
+struct FakeFrameFifo {
+ public:
+  void FifoPush(FakeFrame *node);
+  FakeFrame *FifoPop();
+ private:
+  FakeFrame *first_, *last_;
+};
+
+class FakeFrameLifo {
+ public:
+  void LifoPush(FakeFrame *node) {
+    node->next = top_;
+    top_ = node;
+  }
+  void LifoPop() {
+    CHECK(top_);
+    top_ = top_->next;
+  }
+  FakeFrame *top() { return top_; }
+ private:
+  FakeFrame *top_;
+};
+
+// For each thread we create a fake stack and place stack objects on this fake
+// stack instead of the real stack. The fake stack is not really a stack but
+// a fast malloc-like allocator so that when a function exits the fake stack
+// is not poped but remains there for quite some time until gets used again.
+// So, we poison the objects on the fake stack when function returns.
+// It helps us find use-after-return bugs.
+// We can not rely on __asan_stack_free being called on every function exit,
+// so we maintain a lifo list of all current fake frames and update it on every
+// call to __asan_stack_malloc.
+class FakeStack {
+ public:
+  FakeStack();
+  explicit FakeStack(LinkerInitialized) {}
+  void Init(size_t stack_size);
+  void StopUsingFakeStack() { alive_ = false; }
+  void Cleanup();
+  uintptr_t AllocateStack(size_t size, size_t real_stack);
+  static void OnFree(size_t ptr, size_t size, size_t real_stack);
+  // Return the bottom of the maped region.
+  uintptr_t AddrIsInFakeStack(uintptr_t addr);
+ private:
+  static const size_t kMinStackFrameSizeLog = 9;  // Min frame is 512B.
+  static const size_t kMaxStackFrameSizeLog = 16;  // Max stack frame is 64K.
+  static const size_t kMaxStackMallocSize = 1 << kMaxStackFrameSizeLog;
+  static const size_t kNumberOfSizeClasses =
+      kMaxStackFrameSizeLog - kMinStackFrameSizeLog + 1;
+
+  bool AddrIsInSizeClass(uintptr_t addr, size_t size_class);
+
+  // Each size class should be large enough to hold all frames.
+  size_t ClassMmapSize(size_t size_class);
+
+  size_t ClassSize(size_t size_class) {
+    return 1UL << (size_class + kMinStackFrameSizeLog);
+  }
+
+  void DeallocateFrame(FakeFrame *fake_frame);
+
+  size_t ComputeSizeClass(size_t alloc_size);
+  void AllocateOneSizeClass(size_t size_class);
+
+  size_t stack_size_;
+  bool   alive_;
+
+  uintptr_t allocated_size_classes_[kNumberOfSizeClasses];
+  FakeFrameFifo size_classes_[kNumberOfSizeClasses];
+  FakeFrameLifo call_stack_;
+};
+
+void *asan_memalign(size_t alignment, size_t size, AsanStackTrace *stack);
+void asan_free(void *ptr, AsanStackTrace *stack);
+
+void *asan_malloc(size_t size, AsanStackTrace *stack);
+void *asan_calloc(size_t nmemb, size_t size, AsanStackTrace *stack);
+void *asan_realloc(void *p, size_t size, AsanStackTrace *stack);
+void *asan_valloc(size_t size, AsanStackTrace *stack);
+void *asan_pvalloc(size_t size, AsanStackTrace *stack);
+
+int asan_posix_memalign(void **memptr, size_t alignment, size_t size,
+                          AsanStackTrace *stack);
+
+size_t __asan_mz_size(const void *ptr);
+void __asan_mz_force_lock();
+void __asan_mz_force_unlock();
+void DescribeHeapAddress(uintptr_t addr, size_t access_size);
+
+}  // namespace __asan
+#endif  // ASAN_ALLOCATOR_H