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//===-- 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
#include "asan_internal.h"
#include "asan_interceptors.h"
namespace __asan {
static const uptr kNumberOfSizeClasses = 255;
struct AsanChunk;
class AsanChunkFifoList {
explicit AsanChunkFifoList(LinkerInitialized) { }
AsanChunkFifoList() { clear(); }
void Push(AsanChunk *n);
void PushList(AsanChunkFifoList *q);
AsanChunk *Pop();
uptr size() { return size_; }
void clear() {
first_ = last_ = 0;
size_ = 0;
AsanChunk *first_;
AsanChunk *last_;
uptr size_;
struct AsanThreadLocalMallocStorage {
explicit AsanThreadLocalMallocStorage(LinkerInitialized x)
: quarantine_(x) { }
AsanThreadLocalMallocStorage() {
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 {
uptr magic; // Modified by the instrumented code.
uptr descr; // Modified by the instrumented code.
FakeFrame *next;
u64 real_stack : 48;
u64 size_minus_one : 16;
struct FakeFrameFifo {
void FifoPush(FakeFrame *node);
FakeFrame *FifoPop();
FakeFrame *first_, *last_;
class FakeFrameLifo {
void LifoPush(FakeFrame *node) {
node->next = top_;
top_ = node;
void LifoPop() {
top_ = top_->next;
FakeFrame *top() { return top_; }
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 {
explicit FakeStack(LinkerInitialized) {}
void Init(uptr stack_size);
void StopUsingFakeStack() { alive_ = false; }
void Cleanup();
uptr AllocateStack(uptr size, uptr real_stack);
static void OnFree(uptr ptr, uptr size, uptr real_stack);
// Return the bottom of the maped region.
uptr AddrIsInFakeStack(uptr addr);
bool StackSize() { return stack_size_; }
static const uptr kMinStackFrameSizeLog = 9; // Min frame is 512B.
static const uptr kMaxStackFrameSizeLog = 16; // Max stack frame is 64K.
static const uptr kMaxStackMallocSize = 1 << kMaxStackFrameSizeLog;
static const uptr kNumberOfSizeClasses =
kMaxStackFrameSizeLog - kMinStackFrameSizeLog + 1;
bool AddrIsInSizeClass(uptr addr, uptr size_class);
// Each size class should be large enough to hold all frames.
uptr ClassMmapSize(uptr size_class);
uptr ClassSize(uptr size_class) {
return 1UL << (size_class + kMinStackFrameSizeLog);
void DeallocateFrame(FakeFrame *fake_frame);
uptr ComputeSizeClass(uptr alloc_size);
void AllocateOneSizeClass(uptr size_class);
uptr stack_size_;
bool alive_;
uptr allocated_size_classes_[kNumberOfSizeClasses];
FakeFrameFifo size_classes_[kNumberOfSizeClasses];
FakeFrameLifo call_stack_;
void *asan_memalign(uptr alignment, uptr size, AsanStackTrace *stack);
void asan_free(void *ptr, AsanStackTrace *stack);
void *asan_malloc(uptr size, AsanStackTrace *stack);
void *asan_calloc(uptr nmemb, uptr size, AsanStackTrace *stack);
void *asan_realloc(void *p, uptr size, AsanStackTrace *stack);
void *asan_valloc(uptr size, AsanStackTrace *stack);
void *asan_pvalloc(uptr size, AsanStackTrace *stack);
int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
AsanStackTrace *stack);
uptr asan_malloc_usable_size(void *ptr, AsanStackTrace *stack);
uptr asan_mz_size(const void *ptr);
void asan_mz_force_lock();
void asan_mz_force_unlock();
void DescribeHeapAddress(uptr addr, uptr access_size);
} // namespace __asan