1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
// Copyright 2018 The gVisor Authors.
//
// 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 <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
#include <vector>
#include "gtest/gtest.h"
#include "absl/base/macros.h"
#include "test/util/cleanup.h"
#include "test/util/file_descriptor.h"
#include "test/util/temp_path.h"
#include "test/util/test_util.h"
namespace gvisor {
namespace testing {
namespace {
class ReadTest : public ::testing::Test {
void SetUp() override {
name_ = NewTempAbsPath();
int fd;
ASSERT_THAT(fd = open(name_.c_str(), O_CREAT, 0644), SyscallSucceeds());
ASSERT_THAT(close(fd), SyscallSucceeds());
}
void TearDown() override { unlink(name_.c_str()); }
public:
std::string name_;
};
TEST_F(ReadTest, ZeroBuffer) {
int fd;
ASSERT_THAT(fd = open(name_.c_str(), O_RDWR), SyscallSucceeds());
char msg[] = "hello world";
EXPECT_THAT(PwriteFd(fd, msg, strlen(msg), 0),
SyscallSucceedsWithValue(strlen(msg)));
char buf[10];
EXPECT_THAT(ReadFd(fd, buf, 0), SyscallSucceedsWithValue(0));
EXPECT_THAT(close(fd), SyscallSucceeds());
}
TEST_F(ReadTest, EmptyFileReturnsZeroAtEOF) {
int fd;
ASSERT_THAT(fd = open(name_.c_str(), O_RDWR), SyscallSucceeds());
char eof_buf[10];
EXPECT_THAT(ReadFd(fd, eof_buf, 10), SyscallSucceedsWithValue(0));
EXPECT_THAT(close(fd), SyscallSucceeds());
}
TEST_F(ReadTest, EofAfterRead) {
int fd;
ASSERT_THAT(fd = open(name_.c_str(), O_RDWR), SyscallSucceeds());
// Write some bytes to be read.
constexpr char kMessage[] = "hello world";
EXPECT_THAT(PwriteFd(fd, kMessage, sizeof(kMessage), 0),
SyscallSucceedsWithValue(sizeof(kMessage)));
// Read all of the bytes at once.
char buf[sizeof(kMessage)];
EXPECT_THAT(ReadFd(fd, buf, sizeof(kMessage)),
SyscallSucceedsWithValue(sizeof(kMessage)));
// Read again with a non-zero buffer and expect EOF.
char eof_buf[10];
EXPECT_THAT(ReadFd(fd, eof_buf, 10), SyscallSucceedsWithValue(0));
EXPECT_THAT(close(fd), SyscallSucceeds());
}
TEST_F(ReadTest, DevNullReturnsEof) {
int fd;
ASSERT_THAT(fd = open("/dev/null", O_RDONLY), SyscallSucceeds());
std::vector<char> buf(1);
EXPECT_THAT(ReadFd(fd, buf.data(), 1), SyscallSucceedsWithValue(0));
EXPECT_THAT(close(fd), SyscallSucceeds());
}
const int kReadSize = 128 * 1024;
// Do not allow random save as it could lead to partial reads.
TEST_F(ReadTest, CanReadFullyFromDevZero) {
int fd;
ASSERT_THAT(fd = open("/dev/zero", O_RDONLY), SyscallSucceeds());
std::vector<char> buf(kReadSize, 1);
EXPECT_THAT(ReadFd(fd, buf.data(), kReadSize),
SyscallSucceedsWithValue(kReadSize));
EXPECT_THAT(close(fd), SyscallSucceeds());
EXPECT_EQ(std::vector<char>(kReadSize, 0), buf);
}
TEST_F(ReadTest, ReadDirectoryFails) {
const FileDescriptor file =
ASSERT_NO_ERRNO_AND_VALUE(Open(GetAbsoluteTestTmpdir(), O_RDONLY));
std::vector<char> buf(1);
EXPECT_THAT(ReadFd(file.get(), buf.data(), 1), SyscallFailsWithErrno(EISDIR));
}
TEST_F(ReadTest, ReadWithOpath) {
SKIP_IF(IsRunningWithVFS1());
const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
const FileDescriptor fd =
ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_PATH));
std::vector<char> buf(1);
EXPECT_THAT(ReadFd(fd.get(), buf.data(), 1), SyscallFailsWithErrno(EBADF));
}
// Test that partial writes that hit SIGSEGV are correctly handled and return
// partial write.
TEST_F(ReadTest, PartialReadSIGSEGV) {
// Allocate 2 pages and remove permission from the second.
const size_t size = 2 * kPageSize;
void* addr =
mmap(0, size, PROT_WRITE | PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
ASSERT_NE(addr, MAP_FAILED);
auto cleanup = Cleanup(
[addr, size] { EXPECT_THAT(munmap(addr, size), SyscallSucceeds()); });
FileDescriptor fd =
ASSERT_NO_ERRNO_AND_VALUE(Open(name_.c_str(), O_RDWR, 0666));
for (size_t i = 0; i < 2; i++) {
EXPECT_THAT(pwrite(fd.get(), addr, size, 0),
SyscallSucceedsWithValue(size));
}
void* badAddr = reinterpret_cast<char*>(addr) + kPageSize;
ASSERT_THAT(mprotect(badAddr, kPageSize, PROT_NONE), SyscallSucceeds());
// Attempt to read to both pages. Create a non-contiguous iovec pair to
// ensure operation is done in 2 steps.
struct iovec iov[] = {
{
.iov_base = addr,
.iov_len = kPageSize,
},
{
.iov_base = addr,
.iov_len = size,
},
};
EXPECT_THAT(lseek(fd.get(), 0, SEEK_SET), SyscallSucceeds());
EXPECT_THAT(readv(fd.get(), iov, ABSL_ARRAYSIZE(iov)),
SyscallSucceedsWithValue(size));
}
} // namespace
} // namespace testing
} // namespace gvisor
|
