platform_system_core/libutils/FileMap_test.cpp

/*
 * Copyright (C) 2019 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 "utils/FileMap.h"

#include <gtest/gtest.h>

#include "android-base/file.h"

TEST(FileMap, zero_length_mapping) {
    // http://b/119818070 "app crashes when reading asset of zero length".
    // mmap fails with EINVAL for a zero length region.
    TemporaryFile tf;
    ASSERT_TRUE(tf.fd != -1);

    android::FileMap m;
    ASSERT_TRUE(m.create("test", tf.fd, 4096, 0, true));
    ASSERT_STREQ("test", m.getFileName());
    ASSERT_EQ(0u, m.getDataLength());
    ASSERT_EQ(4096, m.getDataOffset());
}

TEST(FileMap, large_offset) {
    // Make sure that an offset > INT32_MAX will not fail the create
    // function. See http://b/155662887.
    TemporaryFile tf;
    ASSERT_TRUE(tf.fd != -1);

    off64_t offset = INT32_MAX + 1024LL;

    // Make the temporary file large enough to pass the mmap.
    ASSERT_EQ(offset, lseek64(tf.fd, offset, SEEK_SET));
    char value = 0;
    ASSERT_EQ(1, write(tf.fd, &value, 1));

    android::FileMap m;
    ASSERT_TRUE(m.create("test", tf.fd, offset, 0, true));
    ASSERT_STREQ("test", m.getFileName());
    ASSERT_EQ(0u, m.getDataLength());
    ASSERT_EQ(offset, m.getDataOffset());
}

TEST(FileMap, offset_overflow) {
    // Make sure that an end that overflows SIZE_MAX will not abort.
    // See http://b/156997193.
    TemporaryFile tf;
    ASSERT_TRUE(tf.fd != -1);

    off64_t offset = 200;
    size_t length = SIZE_MAX;

    android::FileMap m;
    ASSERT_FALSE(m.create("test", tf.fd, offset, length, true));
}