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096612ff46
If the length was set longer than the backing store, on a call to `Set(index, false)`, and subsequently a call `Set(index-1, true)` was done, it would try to write outside the backing store. Closes: https://github.com/dart-lang/sdk/issues/44946 TEST=runtime/vm/bitmap_test.cc TEST=tests/ffi_2/function_structs_by_value_generated_test.dart/0 Change-Id: Ib636e90b0f6acace9ec8b71557370c281e9e4a99 Cq-Include-Trybots: luci.dart.try:app-kernel-linux-debug-x64-try Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/184423 Commit-Queue: Daco Harkes <dacoharkes@google.com> Reviewed-by: Aske Simon Christensen <askesc@google.com>
85 lines
2.5 KiB
C++
85 lines
2.5 KiB
C++
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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#ifndef RUNTIME_VM_BITMAP_H_
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#define RUNTIME_VM_BITMAP_H_
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#include "vm/allocation.h"
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#include "vm/datastream.h"
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#include "vm/thread_state.h"
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#include "vm/zone.h"
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namespace dart {
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// BitmapBuilder is used to build a bitmap. The implementation is optimized
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// for a dense set of small bit maps without a fixed upper bound (e.g: a
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// pointer map description of a stack).
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class BitmapBuilder : public ZoneAllocated {
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public:
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BitmapBuilder()
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: length_(0),
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data_size_in_bytes_(kInitialSizeInBytes),
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data_(ThreadState::Current()->zone()->Alloc<uint8_t>(
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kInitialSizeInBytes)) {
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memset(data_, 0, kInitialSizeInBytes);
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}
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intptr_t Length() const { return length_; }
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void SetLength(intptr_t length);
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// Get/Set individual bits in the bitmap, setting bits beyond the bitmap's
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// length increases the length and expands the underlying bitmap if
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// needed.
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bool Get(intptr_t bit_offset) const;
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void Set(intptr_t bit_offset, bool value);
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// Return the bit offset of the highest bit set.
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intptr_t Maximum() const;
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// Return the bit offset of the lowest bit set.
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intptr_t Minimum() const;
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// Sets min..max (inclusive) to value.
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void SetRange(intptr_t min, intptr_t max, bool value);
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void Print() const;
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void AppendAsBytesTo(BaseWriteStream* stream) const;
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private:
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static const intptr_t kInitialSizeInBytes = 16;
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static const intptr_t kIncrementSizeInBytes = 16;
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bool InRange(intptr_t offset) const {
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if (offset < 0) {
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FATAL1(
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"Fatal error in BitmapBuilder::InRange :"
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" invalid bit_offset, %" Pd "\n",
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offset);
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}
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return (offset < length_);
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}
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bool InBackingStore(intptr_t bit_offset) {
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intptr_t byte_offset = bit_offset >> kBitsPerByteLog2;
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return byte_offset < data_size_in_bytes_;
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}
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// Get/Set a bit that is known to be covered by the backing store.
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bool GetBit(intptr_t bit_offset) const;
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void SetBit(intptr_t bit_offset, bool value);
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intptr_t length_;
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// Backing store for the bitmap. Reading bits beyond the backing store
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// (up to length_) is allowed and they are assumed to be false.
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intptr_t data_size_in_bytes_;
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uint8_t* data_;
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DISALLOW_COPY_AND_ASSIGN(BitmapBuilder);
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};
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} // namespace dart
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#endif // RUNTIME_VM_BITMAP_H_
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