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
|
// 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.
// Tests to verify that the behavior of linux and gvisor matches when
// 'sysret' returns to bad (aka non-canonical) %rip or %rsp.
#include <linux/elf.h>
#include <sys/ptrace.h>
#include <sys/user.h>
#include "gtest/gtest.h"
#include "test/util/logging.h"
#include "test/util/test_util.h"
namespace gvisor {
namespace testing {
namespace {
constexpr uint64_t kNonCanonicalRip = 0xCCCC000000000000;
constexpr uint64_t kNonCanonicalRsp = 0xFFFF000000000000;
class SysretTest : public ::testing::Test {
protected:
struct user_regs_struct regs_;
struct iovec iov;
pid_t child_;
void SetUp() override {
pid_t pid = fork();
// Child.
if (pid == 0) {
TEST_PCHECK(ptrace(PTRACE_TRACEME, 0, 0, 0) == 0);
MaybeSave();
TEST_PCHECK(raise(SIGSTOP) == 0);
MaybeSave();
_exit(0);
}
// Parent.
int status;
memset(&iov, 0, sizeof(iov));
ASSERT_THAT(pid, SyscallSucceeds()); // Might still be < 0.
ASSERT_THAT(waitpid(pid, &status, 0), SyscallSucceedsWithValue(pid));
EXPECT_TRUE(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP);
iov.iov_base = ®s_;
iov.iov_len = sizeof(regs_);
ASSERT_THAT(ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov), SyscallSucceeds());
child_ = pid;
}
void Detach() {
ASSERT_THAT(ptrace(PTRACE_DETACH, child_, 0, 0), SyscallSucceeds());
}
void SetRip(uint64_t newrip) {
#if defined(__x86_64__)
regs_.rip = newrip;
#elif defined(__aarch64__)
regs_.pc = newrip;
#else
#error "Unknown architecture"
#endif
ASSERT_THAT(ptrace(PTRACE_SETREGSET, child_, NT_PRSTATUS, &iov), SyscallSucceeds());
}
void SetRsp(uint64_t newrsp) {
#if defined(__x86_64__)
regs_.rsp = newrsp;
#elif defined(__aarch64__)
regs_.sp = newrsp;
#else
#error "Unknown architecture"
#endif
ASSERT_THAT(ptrace(PTRACE_SETREGSET, child_, NT_PRSTATUS, &iov), SyscallSucceeds());
}
// Wait waits for the child pid and returns the exit status.
int Wait() {
int status;
while (true) {
int rval = wait4(child_, &status, 0, NULL);
if (rval < 0) {
return rval;
}
if (rval == child_) {
return status;
}
}
}
};
TEST_F(SysretTest, JustDetach) {
Detach();
int status = Wait();
EXPECT_TRUE(WIFEXITED(status) && WEXITSTATUS(status) == 0)
<< "status = " << status;
}
TEST_F(SysretTest, BadRip) {
SetRip(kNonCanonicalRip);
Detach();
int status = Wait();
EXPECT_TRUE(WIFSIGNALED(status) && WTERMSIG(status) == SIGSEGV)
<< "status = " << status;
}
TEST_F(SysretTest, BadRsp) {
SetRsp(kNonCanonicalRsp);
Detach();
int status = Wait();
#if defined(__x86_64__)
EXPECT_TRUE(WIFSIGNALED(status) && WTERMSIG(status) == SIGBUS)
<< "status = " << status;
#elif defined(__aarch64__)
EXPECT_TRUE(WIFSIGNALED(status) && WTERMSIG(status) == SIGSEGV)
<< "status = " << status;
#else
#error "Unknown architecture"
#endif
}
} // namespace
} // namespace testing
} // namespace gvisor
|
