Add fuzzers for libutils classes

Adds fuzzers for BitSet, FileMap, String8, String16, and Vector.
Test: Ran fuzzers on Android Pixel 3a. Aggregate coverage was 1.2% (this is far lower than true coverage due to shared libraries being counted)

Change-Id: I739216fe88afa51dc2f73b857da91116853382f0

Removed unneeded cflags, moved libbase to defaults

Test: Built Android.bp successfully

Signed-off-by: Dylan Katz <dylan.katz@leviathansecurity.com>
Change-Id: I739216fe88afa51dc2f73b857da91116853382f0

1 files changed, 70 insertions, 0 deletions

diff --git a/libutils/BitSet_fuzz.cpp b/libutils/BitSet_fuzz.cpp
new file mode 100644
index 000000000..2e6043cf0
--- /dev/null
+++ b/libutils/BitSet_fuzz.cpp
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <functional>
+
+#include "fuzzer/FuzzedDataProvider.h"
+#include "utils/BitSet.h"
+static constexpr uint8_t MAX_OPERATIONS = 50;
+
+// We need to handle both 32 and 64 bit bitsets, so we use a function template
+// here. Sadly, std::function can't be generic, so we generate a vector of
+// std::functions using this function.
+template <typename T>
+std::vector<std::function<void(T, uint32_t)>> getOperationsForType() {
+    return {
+            [](T bs, uint32_t val) -> void { bs.markBit(val); },
+            [](T bs, uint32_t val) -> void { bs.valueForBit(val); },
+            [](T bs, uint32_t val) -> void { bs.hasBit(val); },
+            [](T bs, uint32_t val) -> void { bs.clearBit(val); },
+            [](T bs, uint32_t val) -> void { bs.getIndexOfBit(val); },
+            [](T bs, uint32_t) -> void { bs.clearFirstMarkedBit(); },
+            [](T bs, uint32_t) -> void { bs.markFirstUnmarkedBit(); },
+            [](T bs, uint32_t) -> void { bs.clearLastMarkedBit(); },
+            [](T bs, uint32_t) -> void { bs.clear(); },
+            [](T bs, uint32_t) -> void { bs.count(); },
+            [](T bs, uint32_t) -> void { bs.isEmpty(); },
+            [](T bs, uint32_t) -> void { bs.isFull(); },
+            [](T bs, uint32_t) -> void { bs.firstMarkedBit(); },
+            [](T bs, uint32_t) -> void { bs.lastMarkedBit(); },
+    };
+}
+
+// Our operations for 32 and 64 bit bitsets
+static const std::vector<std::function<void(android::BitSet32, uint32_t)>> thirtyTwoBitOps =
+        getOperationsForType<android::BitSet32>();
+static const std::vector<std::function<void(android::BitSet64, uint32_t)>> sixtyFourBitOps =
+        getOperationsForType<android::BitSet64>();
+
+void runOperationFor32Bit(android::BitSet32 bs, uint32_t bit, uint8_t operation) {
+    thirtyTwoBitOps[operation](bs, bit);
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    FuzzedDataProvider dataProvider(data, size);
+    uint32_t thirty_two_base = dataProvider.ConsumeIntegral<uint32_t>();
+    uint64_t sixty_four_base = dataProvider.ConsumeIntegral<uint64_t>();
+    android::BitSet32 b1 = android::BitSet32(thirty_two_base);
+    android::BitSet64 b2 = android::BitSet64(sixty_four_base);
+
+    size_t opsRun = 0;
+    while (dataProvider.remaining_bytes() > 0 && opsRun++ < MAX_OPERATIONS) {
+        uint32_t bit = dataProvider.ConsumeIntegral<uint32_t>();
+        uint8_t op = dataProvider.ConsumeIntegral<uint8_t>();
+        thirtyTwoBitOps[op % thirtyTwoBitOps.size()](b1, bit);
+        sixtyFourBitOps[op % sixtyFourBitOps.size()](b2, bit);
+    }
+    return 0;
+}