diff options
author | Kostya Serebryany <kcc@google.com> | 2013-04-11 11:39:19 +0000 |
---|---|---|
committer | Kostya Serebryany <kcc@google.com> | 2013-04-11 11:39:19 +0000 |
commit | 244384d1a8a518c0b1ceaa5809333a91db1104b6 (patch) | |
tree | 47d90ddc0a1a619a7af1334f5765d6348af037bc /lib/asan/asan_fake_stack.h | |
parent | 2c02f6327f51243fc0ba17992cecb2857fa8bdf8 (diff) |
[asan] move fake stack into a separate .h file; actually disable a failing test
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@179273 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/asan/asan_fake_stack.h')
-rw-r--r-- | lib/asan/asan_fake_stack.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/lib/asan/asan_fake_stack.h b/lib/asan/asan_fake_stack.h new file mode 100644 index 000000000..63bcbdc1e --- /dev/null +++ b/lib/asan/asan_fake_stack.h @@ -0,0 +1,106 @@ +//===-- asan_fake_stack.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_fake_stack.cc +//===----------------------------------------------------------------------===// + +#ifndef ASAN_FAKE_STACK_H +#define ASAN_FAKE_STACK_H + +namespace __asan { + +// 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 { + 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(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_; } + + private: + 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_; +}; + +} // namespace __asan + +#endif // ASAN_FAKE_STACK_H |