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, 136 insertions, 0 deletions

diff --git a/libutils/String8_fuzz.cpp b/libutils/String8_fuzz.cpp
new file mode 100644
index 000000000..2adfe98b0
--- /dev/null
+++ b/libutils/String8_fuzz.cpp
@@ -0,0 +1,136 @@
+/*
+ * 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 <iostream>
+
+#include "fuzzer/FuzzedDataProvider.h"
+#include "utils/String8.h"
+
+static constexpr int MAX_STRING_BYTES = 256;
+static constexpr uint8_t MAX_OPERATIONS = 50;
+
+std::vector<std::function<void(FuzzedDataProvider&, android::String8, android::String8)>>
+        operations = {
+
+                // Bytes and size
+                [](FuzzedDataProvider&, android::String8 str1, android::String8) -> void {
+                    str1.bytes();
+                },
+                [](FuzzedDataProvider&, android::String8 str1, android::String8) -> void {
+                    str1.isEmpty();
+                },
+                [](FuzzedDataProvider&, android::String8 str1, android::String8) -> void {
+                    str1.length();
+                },
+                [](FuzzedDataProvider&, android::String8 str1, android::String8) -> void {
+                    str1.size();
+                },
+
+                // Casing
+                [](FuzzedDataProvider&, android::String8 str1, android::String8) -> void {
+                    str1.toUpper();
+                },
+                [](FuzzedDataProvider&, android::String8 str1, android::String8) -> void {
+                    str1.toLower();
+                },
+
+                [](FuzzedDataProvider&, android::String8 str1, android::String8 str2) -> void {
+                    str1.removeAll(str2.c_str());
+                },
+                [](FuzzedDataProvider&, android::String8 str1, android::String8 str2) -> void {
+                    str1.compare(str2);
+                },
+
+                // Append and format
+                [](FuzzedDataProvider&, android::String8 str1, android::String8 str2) -> void {
+                    str1.append(str2);
+                },
+                [](FuzzedDataProvider&, android::String8 str1, android::String8 str2) -> void {
+                    str1.appendFormat(str1.c_str(), str2.c_str());
+                },
+                [](FuzzedDataProvider&, android::String8 str1, android::String8 str2) -> void {
+                    str1.format(str1.c_str(), str2.c_str());
+                },
+
+                // Find operation
+                [](FuzzedDataProvider& dataProvider, android::String8 str1,
+                   android::String8) -> void {
+                    // We need to get a value from our fuzzer here.
+                    int start_index = dataProvider.ConsumeIntegralInRange<int>(0, str1.size());
+                    str1.find(str1.c_str(), start_index);
+                },
+
+                // Path handling
+                [](FuzzedDataProvider&, android::String8 str1, android::String8) -> void {
+                    str1.getBasePath();
+                },
+                [](FuzzedDataProvider&, android::String8 str1, android::String8) -> void {
+                    str1.getPathExtension();
+                },
+                [](FuzzedDataProvider&, android::String8 str1, android::String8) -> void {
+                    str1.getPathLeaf();
+                },
+                [](FuzzedDataProvider&, android::String8 str1, android::String8) -> void {
+                    str1.getPathDir();
+                },
+                [](FuzzedDataProvider&, android::String8 str1, android::String8) -> void {
+                    str1.convertToResPath();
+                },
+                [](FuzzedDataProvider&, android::String8 str1, android::String8) -> void {
+                    android::String8 path_out_str = android::String8();
+                    str1.walkPath(&path_out_str);
+                    path_out_str.clear();
+                },
+                [](FuzzedDataProvider& dataProvider, android::String8 str1,
+                   android::String8) -> void {
+                    str1.setPathName(dataProvider.ConsumeBytesWithTerminator<char>(5).data());
+                },
+                [](FuzzedDataProvider& dataProvider, android::String8 str1,
+                   android::String8) -> void {
+                    str1.appendPath(dataProvider.ConsumeBytesWithTerminator<char>(5).data());
+                },
+};
+
+void callFunc(uint8_t index, FuzzedDataProvider& dataProvider, android::String8 str1,
+              android::String8 str2) {
+    operations[index](dataProvider, str1, str2);
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    FuzzedDataProvider dataProvider(data, size);
+    // Generate vector lengths
+    const size_t kVecOneLen = dataProvider.ConsumeIntegralInRange<size_t>(1, MAX_STRING_BYTES);
+    const size_t kVecTwoLen = dataProvider.ConsumeIntegralInRange<size_t>(1, MAX_STRING_BYTES);
+    // Populate vectors
+    std::vector<char> vec = dataProvider.ConsumeBytesWithTerminator<char>(kVecOneLen);
+    std::vector<char> vec_two = dataProvider.ConsumeBytesWithTerminator<char>(kVecTwoLen);
+    // Create UTF-8 pointers
+    android::String8 str_one_utf8 = android::String8(vec.data());
+    android::String8 str_two_utf8 = android::String8(vec_two.data());
+
+    // Run operations against strings
+    int opsRun = 0;
+    while (dataProvider.remaining_bytes() > 0 && opsRun++ < MAX_OPERATIONS) {
+        uint8_t op = dataProvider.ConsumeIntegralInRange<uint8_t>(0, operations.size() - 1);
+        callFunc(op, dataProvider, str_one_utf8, str_two_utf8);
+    }
+
+    // Just to be extra sure these can be freed, we're going to explicitly clear
+    // them
+    str_one_utf8.clear();
+    str_two_utf8.clear();
+    return 0;
+}