52 lines
1.6 KiB
C++
52 lines
1.6 KiB
C++
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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// Tests whether scaling the Entropic scheduling weight based on input execution
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// time is effective or not. Inputs of size less than 7 will take at least 100
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// microseconds more than inputs of size greater than or equal to 7. Inputs of
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// size greater than 7 in the corpus should be favored by the exec-time-scaled
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// Entropic scheduling policy than the input of size less than 7 in the corpus,
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// eventually finding the crashing input with less executions.
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#include <chrono>
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#include <cstdint>
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#include <thread>
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static volatile int Sink;
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static volatile int *Nil = nullptr;
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extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
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if (Size > 10)
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return 0; // To make the test quicker.
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if (Size < 7) {
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// execute a lot slower than the crashing input below.
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size_t ExecTimeUSec = 100;
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std::this_thread::sleep_for(std::chrono::microseconds(ExecTimeUSec));
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Sink = 7;
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if (Size > 0 && Data[0] == 0xaa && Size > 1 && Data[1] == 0xbb &&
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Size > 2 && Data[2] == 0xcc && Size > 3 && Data[3] == 0xdd &&
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Size > 4 && Data[4] == 0xee && Size > 5 && Data[5] == 0xff)
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Sink += 7;
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}
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// Give unique coverage for each input of size (7, 8, 9, 10)
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if (Size == 7)
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Sink = -7;
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if (Size == 8)
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Sink = -8;
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if (Size == 9)
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Sink = -9;
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if (Size == 10)
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Sink = -10;
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if (Sink < 0 && Data[0] == 0xab && Data[1] == 0xcd)
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*Nil = 42; // crash.
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return 0;
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}
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