/*
* Copyright (C) 2016 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 <errno.h>
#include <linux/fs.h>
#include <stdint.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <unistd.h>
#include <android-base/macros.h>
#include <android-base/unique_fd.h>
#include <cutils/ashmem.h>
#include <gtest/gtest.h>
using android::base::unique_fd;
void TestCreateRegion(size_t size, unique_fd &fd, int prot) {
fd = unique_fd(ashmem_create_region(nullptr, size));
ASSERT_TRUE(fd >= 0);
ASSERT_TRUE(ashmem_valid(fd));
ASSERT_EQ(size, static_cast<size_t>(ashmem_get_size_region(fd)));
ASSERT_EQ(0, ashmem_set_prot_region(fd, prot));
}
void TestMmap(const unique_fd& fd, size_t size, int prot, void** region, off_t off = 0) {
ASSERT_TRUE(fd >= 0);
ASSERT_TRUE(ashmem_valid(fd));
*region = mmap(nullptr, size, prot, MAP_SHARED, fd, off);
ASSERT_NE(MAP_FAILED, *region);
}
void TestProtDenied(const unique_fd &fd, size_t size, int prot) {
ASSERT_TRUE(fd >= 0);
ASSERT_TRUE(ashmem_valid(fd));
EXPECT_EQ(MAP_FAILED, mmap(nullptr, size, prot, MAP_SHARED, fd, 0));
}
void TestProtIs(const unique_fd& fd, int prot) {
ASSERT_TRUE(fd >= 0);
ASSERT_TRUE(ashmem_valid(fd));
EXPECT_EQ(prot, ioctl(fd, ASHMEM_GET_PROT_MASK));
}
void FillData(uint8_t* data, size_t dataLen) {
for (size_t i = 0; i < dataLen; i++) {
data[i] = i & 0xFF;
}
}
TEST(AshmemTest, BasicTest) {
constexpr size_t size = PAGE_SIZE;
uint8_t data[size];
FillData(data, size);
unique_fd fd;
ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ | PROT_WRITE));
void *region1;
ASSERT_NO_FATAL_FAILURE(TestMmap(fd, size, PROT_READ | PROT_WRITE, ®ion1));
memcpy(region1, &data, size);
ASSERT_EQ(0, memcmp(region1, &data, size));
EXPECT_EQ(0, munmap(region1, size));
void *region2;
ASSERT_NO_FATAL_FAILURE(TestMmap(fd, size, PROT_READ, ®ion2));
ASSERT_EQ(0, memcmp(region2, &data, size));
EXPECT_EQ(0, munmap(region2, size));
}
TEST(AshmemTest, ForkTest) {
constexpr size_t size = PAGE_SIZE;
uint8_t data[size];
FillData(data, size);
unique_fd fd;
ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ | PROT_WRITE));
void *region1;
ASSERT_NO_FATAL_FAILURE(TestMmap(fd, size, PROT_READ | PROT_WRITE, ®ion1));
memcpy(region1, &data, size);
ASSERT_EQ(0, memcmp(region1, &data, size));
EXPECT_EQ(0, munmap(region1, size));
ASSERT_EXIT(
{
if (!ashmem_valid(fd)) {
_exit(3);
}
void* region2 = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (region2 == MAP_FAILED) {
_exit(1);
}
if (memcmp(region2, &data, size) != 0) {
_exit(2);
}
memset(region2, 0, size);
munmap(region2, size);
_exit(0);
},
::testing::ExitedWithCode(0), "");
memset(&data, 0, size);
void *region2;
ASSERT_NO_FATAL_FAILURE(TestMmap(fd, size, PROT_READ | PROT_WRITE, ®ion2));
ASSERT_EQ(0, memcmp(region2, &data, size));
EXPECT_EQ(0, munmap(region2, size));
}
TEST(AshmemTest, FileOperationsTest) {
unique_fd fd;
void* region;
// Allocate a 4-page buffer, but leave page-sized holes on either side
constexpr size_t size = PAGE_SIZE * 4;
constexpr size_t dataSize = PAGE_SIZE * 2;
constexpr size_t holeSize = PAGE_SIZE;
ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ | PROT_WRITE));
ASSERT_NO_FATAL_FAILURE(TestMmap(fd, dataSize, PROT_READ | PROT_WRITE, ®ion, holeSize));
uint8_t data[dataSize];
FillData(data, dataSize);
memcpy(region, data, dataSize);
constexpr off_t dataStart = holeSize;
constexpr off_t dataEnd = dataStart + dataSize;
// The sequence of seeks below looks something like this:
//
// [ ][data][data][ ]
// --^ lseek(99, SEEK_SET)
// ------^ lseek(dataStart, SEEK_CUR)
// ------^ lseek(0, SEEK_DATA)
// ------------^ lseek(dataStart, SEEK_HOLE)
// ^-- lseek(-99, SEEK_END)
// ^------ lseek(-dataStart, SEEK_CUR)
const struct {
// lseek() parameters
off_t offset;
int whence;
// Expected lseek() return value
off_t ret;
} seeks[] = {
{99, SEEK_SET, 99}, {dataStart, SEEK_CUR, dataStart + 99},
{0, SEEK_DATA, dataStart}, {dataStart, SEEK_HOLE, dataEnd},
{-99, SEEK_END, size - 99}, {-dataStart, SEEK_CUR, dataEnd - 99},
};
for (const auto& cfg : seeks) {
errno = 0;
ASSERT_TRUE(ashmem_valid(fd));
auto off = lseek(fd, cfg.offset, cfg.whence);
ASSERT_EQ(cfg.ret, off) << "lseek(" << cfg.offset << ", " << cfg.whence << ") failed"
<< (errno ? ": " : "") << (errno ? strerror(errno) : "");
if (off >= dataStart && off < dataEnd) {
off_t dataOff = off - dataStart;
ssize_t readSize = dataSize - dataOff;
uint8_t buf[readSize];
ASSERT_EQ(readSize, TEMP_FAILURE_RETRY(read(fd, buf, readSize)));
EXPECT_EQ(0, memcmp(buf, data + dataOff, readSize));
}
}
EXPECT_EQ(0, munmap(region, dataSize));
}
TEST(AshmemTest, ProtTest) {
unique_fd fd;
constexpr size_t size = PAGE_SIZE;
void *region;
ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ));
TestProtDenied(fd, size, PROT_WRITE);
TestProtIs(fd, PROT_READ);
ASSERT_NO_FATAL_FAILURE(TestMmap(fd, size, PROT_READ, ®ion));
EXPECT_EQ(0, munmap(region, size));
ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_WRITE));
TestProtDenied(fd, size, PROT_READ);
TestProtIs(fd, PROT_WRITE);
ASSERT_NO_FATAL_FAILURE(TestMmap(fd, size, PROT_WRITE, ®ion));
EXPECT_EQ(0, munmap(region, size));
ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ | PROT_WRITE));
TestProtIs(fd, PROT_READ | PROT_WRITE);
ASSERT_EQ(0, ashmem_set_prot_region(fd, PROT_READ));
errno = 0;
ASSERT_EQ(-1, ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE))
<< "kernel shouldn't allow adding protection bits";
EXPECT_EQ(EINVAL, errno);
TestProtIs(fd, PROT_READ);
TestProtDenied(fd, size, PROT_WRITE);
}
TEST(AshmemTest, ForkProtTest) {
unique_fd fd;
constexpr size_t size = PAGE_SIZE;
int protFlags[] = { PROT_READ, PROT_WRITE };
for (size_t i = 0; i < arraysize(protFlags); i++) {
ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ | PROT_WRITE));
ASSERT_EXIT(
{
if (!ashmem_valid(fd)) {
_exit(3);
} else if (ashmem_set_prot_region(fd, protFlags[i]) >= 0) {
_exit(0);
} else {
_exit(1);
}
},
::testing::ExitedWithCode(0), "");
ASSERT_NO_FATAL_FAILURE(TestProtDenied(fd, size, protFlags[1-i]));
}
}
TEST(AshmemTest, ForkMultiRegionTest) {
constexpr size_t size = PAGE_SIZE;
uint8_t data[size];
FillData(data, size);
constexpr int nRegions = 16;
unique_fd fd[nRegions];
for (int i = 0; i < nRegions; i++) {
ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd[i], PROT_READ | PROT_WRITE));
void *region;
ASSERT_NO_FATAL_FAILURE(TestMmap(fd[i], size, PROT_READ | PROT_WRITE, ®ion));
memcpy(region, &data, size);
ASSERT_EQ(0, memcmp(region, &data, size));
EXPECT_EQ(0, munmap(region, size));
}
ASSERT_EXIT({
for (int i = 0; i < nRegions; i++) {
if (!ashmem_valid(fd[i])) {
_exit(3);
}
void *region = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd[i], 0);
if (region == MAP_FAILED) {
_exit(1);
}
if (memcmp(region, &data, size) != 0) {
munmap(region, size);
_exit(2);
}
memset(region, 0, size);
munmap(region, size);
}
_exit(0);
}, ::testing::ExitedWithCode(0), "");
memset(&data, 0, size);
for (int i = 0; i < nRegions; i++) {
void *region;
ASSERT_NO_FATAL_FAILURE(TestMmap(fd[i], size, PROT_READ | PROT_WRITE, ®ion));
ASSERT_EQ(0, memcmp(region, &data, size));
EXPECT_EQ(0, munmap(region, size));
}
}