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
|
// 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 <poll.h>
#include <signal.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <unistd.h>
#include "gtest/gtest.h"
#include "absl/time/time.h"
#include "test/syscalls/linux/base_poll_test.h"
#include "test/util/signal_util.h"
#include "test/util/test_util.h"
namespace gvisor {
namespace testing {
namespace {
// Linux and glibc have a different idea of the sizeof sigset_t. When calling
// the syscall directly, use what the kernel expects.
unsigned kSigsetSize = SIGRTMAX / 8;
// Linux ppoll(2) differs from the glibc wrapper function in that Linux updates
// the timeout with the amount of time remaining. In order to test this behavior
// we need to use the syscall directly.
int syscallPpoll(struct pollfd* fds, nfds_t nfds, struct timespec* timeout_ts,
const sigset_t* sigmask, unsigned mask_size) {
return syscall(SYS_ppoll, fds, nfds, timeout_ts, sigmask, mask_size);
}
class PpollTest : public BasePollTest {
protected:
void SetUp() override { BasePollTest::SetUp(); }
void TearDown() override { BasePollTest::TearDown(); }
};
TEST_F(PpollTest, InvalidFds) {
// fds is invalid because it's null, but we tell ppoll the length is non-zero.
struct timespec timeout = {};
sigset_t sigmask;
TEST_PCHECK(sigemptyset(&sigmask) == 0);
EXPECT_THAT(syscallPpoll(nullptr, 1, &timeout, &sigmask, kSigsetSize),
SyscallFailsWithErrno(EFAULT));
EXPECT_THAT(syscallPpoll(nullptr, -1, &timeout, &sigmask, kSigsetSize),
SyscallFailsWithErrno(EINVAL));
}
// See that when fds is null, ppoll behaves like sleep.
TEST_F(PpollTest, NullFds) {
struct timespec timeout = absl::ToTimespec(absl::Milliseconds(10));
ASSERT_THAT(syscallPpoll(nullptr, 0, &timeout, nullptr, 0),
SyscallSucceeds());
EXPECT_EQ(timeout.tv_sec, 0);
EXPECT_EQ(timeout.tv_nsec, 0);
}
TEST_F(PpollTest, ZeroTimeout) {
struct timespec timeout = {};
ASSERT_THAT(syscallPpoll(nullptr, 0, &timeout, nullptr, 0),
SyscallSucceeds());
EXPECT_EQ(timeout.tv_sec, 0);
EXPECT_EQ(timeout.tv_nsec, 0);
}
// If random S/R interrupts the ppoll, SIGALRM may be delivered before ppoll
// restarts, causing the ppoll to hang forever.
TEST_F(PpollTest, NoTimeout_NoRandomSave) {
// When there's no timeout, ppoll may never return so set a timer.
SetTimer(absl::Milliseconds(100));
// See that we get interrupted by the timer.
ASSERT_THAT(syscallPpoll(nullptr, 0, nullptr, nullptr, 0),
SyscallFailsWithErrno(EINTR));
EXPECT_TRUE(TimerFired());
}
TEST_F(PpollTest, InvalidTimeoutNegative) {
struct timespec timeout = absl::ToTimespec(absl::Nanoseconds(-1));
EXPECT_THAT(syscallPpoll(nullptr, 0, &timeout, nullptr, 0),
SyscallFailsWithErrno(EINVAL));
}
TEST_F(PpollTest, InvalidTimeoutNotNormalized) {
struct timespec timeout = {0, 1000000001};
EXPECT_THAT(syscallPpoll(nullptr, 0, &timeout, nullptr, 0),
SyscallFailsWithErrno(EINVAL));
}
TEST_F(PpollTest, InvalidMaskSize) {
struct timespec timeout = {};
sigset_t sigmask;
TEST_PCHECK(sigemptyset(&sigmask) == 0);
EXPECT_THAT(syscallPpoll(nullptr, 0, &timeout, &sigmask, 128),
SyscallFailsWithErrno(EINVAL));
}
// Verify that signals blocked by the ppoll mask (that would otherwise be
// allowed) do not interrupt ppoll.
TEST_F(PpollTest, SignalMaskBlocksSignal) {
absl::Duration duration(absl::Seconds(30));
struct timespec timeout = absl::ToTimespec(duration);
absl::Duration timer_duration(absl::Seconds(10));
// Call with a mask that blocks SIGALRM. See that ppoll is not interrupted
// (i.e. returns 0) and that upon completion, the timer has fired.
sigset_t mask;
ASSERT_THAT(sigprocmask(0, nullptr, &mask), SyscallSucceeds());
TEST_PCHECK(sigaddset(&mask, SIGALRM) == 0);
SetTimer(timer_duration);
MaybeSave();
ASSERT_FALSE(TimerFired());
ASSERT_THAT(syscallPpoll(nullptr, 0, &timeout, &mask, kSigsetSize),
SyscallSucceeds());
EXPECT_TRUE(TimerFired());
EXPECT_EQ(absl::DurationFromTimespec(timeout), absl::Duration());
}
// Verify that signals allowed by the ppoll mask (that would otherwise be
// blocked) interrupt ppoll.
TEST_F(PpollTest, SignalMaskAllowsSignal) {
absl::Duration duration(absl::Seconds(30));
struct timespec timeout = absl::ToTimespec(duration);
absl::Duration timer_duration(absl::Seconds(10));
sigset_t mask;
ASSERT_THAT(sigprocmask(0, nullptr, &mask), SyscallSucceeds());
// Block SIGALRM.
auto cleanup =
ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_BLOCK, SIGALRM));
// Call with a mask that unblocks SIGALRM. See that ppoll is interrupted.
SetTimer(timer_duration);
MaybeSave();
ASSERT_FALSE(TimerFired());
ASSERT_THAT(syscallPpoll(nullptr, 0, &timeout, &mask, kSigsetSize),
SyscallFailsWithErrno(EINTR));
EXPECT_TRUE(TimerFired());
EXPECT_GT(absl::DurationFromTimespec(timeout), absl::Duration());
}
} // namespace
} // namespace testing
} // namespace gvisor
|
