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
169
170
171
172
173
174
175
176
|
// Copyright 2018 Google LLC
//
// 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.
package mm
import (
"testing"
"gvisor.googlesource.com/gvisor/pkg/sentry/arch"
"gvisor.googlesource.com/gvisor/pkg/sentry/context"
"gvisor.googlesource.com/gvisor/pkg/sentry/context/contexttest"
"gvisor.googlesource.com/gvisor/pkg/sentry/limits"
"gvisor.googlesource.com/gvisor/pkg/sentry/memmap"
"gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc"
"gvisor.googlesource.com/gvisor/pkg/sentry/platform"
"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
"gvisor.googlesource.com/gvisor/pkg/syserror"
)
func testMemoryManager(ctx context.Context) *MemoryManager {
p := platform.FromContext(ctx)
mfp := pgalloc.MemoryFileProviderFromContext(ctx)
mm := NewMemoryManager(p, mfp)
mm.layout = arch.MmapLayout{
MinAddr: p.MinUserAddress(),
MaxAddr: p.MaxUserAddress(),
BottomUpBase: p.MinUserAddress(),
TopDownBase: p.MaxUserAddress(),
}
return mm
}
func (mm *MemoryManager) realUsageAS() uint64 {
return uint64(mm.vmas.Span())
}
func TestUsageASUpdates(t *testing.T) {
ctx := contexttest.Context(t)
mm := testMemoryManager(ctx)
defer mm.DecUsers(ctx)
addr, err := mm.MMap(ctx, memmap.MMapOpts{
Length: 2 * usermem.PageSize,
})
if err != nil {
t.Fatalf("MMap got err %v want nil", err)
}
realUsage := mm.realUsageAS()
if mm.usageAS != realUsage {
t.Fatalf("usageAS believes %v bytes are mapped; %v bytes are actually mapped", mm.usageAS, realUsage)
}
mm.MUnmap(ctx, addr, usermem.PageSize)
realUsage = mm.realUsageAS()
if mm.usageAS != realUsage {
t.Fatalf("usageAS believes %v bytes are mapped; %v bytes are actually mapped", mm.usageAS, realUsage)
}
}
func TestBrkDataLimitUpdates(t *testing.T) {
limitSet := limits.NewLimitSet()
limitSet.Set(limits.Data, limits.Limit{}) // zero RLIMIT_DATA
ctx := contexttest.WithLimitSet(contexttest.Context(t), limitSet)
mm := testMemoryManager(ctx)
defer mm.DecUsers(ctx)
// Try to extend the brk by one page and expect doing so to fail.
oldBrk, _ := mm.Brk(ctx, 0)
if newBrk, _ := mm.Brk(ctx, oldBrk+usermem.PageSize); newBrk != oldBrk {
t.Errorf("brk() increased data segment above RLIMIT_DATA (old brk = %#x, new brk = %#x", oldBrk, newBrk)
}
}
// TestIOAfterUnmap ensures that IO fails after unmap.
func TestIOAfterUnmap(t *testing.T) {
ctx := contexttest.Context(t)
mm := testMemoryManager(ctx)
defer mm.DecUsers(ctx)
addr, err := mm.MMap(ctx, memmap.MMapOpts{
Length: usermem.PageSize,
Private: true,
Perms: usermem.Read,
MaxPerms: usermem.AnyAccess,
})
if err != nil {
t.Fatalf("MMap got err %v want nil", err)
}
// IO works before munmap.
b := make([]byte, 1)
n, err := mm.CopyIn(ctx, addr, b, usermem.IOOpts{})
if err != nil {
t.Errorf("CopyIn got err %v want nil", err)
}
if n != 1 {
t.Errorf("CopyIn got %d want 1", n)
}
err = mm.MUnmap(ctx, addr, usermem.PageSize)
if err != nil {
t.Fatalf("MUnmap got err %v want nil", err)
}
n, err = mm.CopyIn(ctx, addr, b, usermem.IOOpts{})
if err != syserror.EFAULT {
t.Errorf("CopyIn got err %v want EFAULT", err)
}
if n != 0 {
t.Errorf("CopyIn got %d want 0", n)
}
}
// TestIOAfterMProtect tests IO interaction with mprotect permissions.
func TestIOAfterMProtect(t *testing.T) {
ctx := contexttest.Context(t)
mm := testMemoryManager(ctx)
defer mm.DecUsers(ctx)
addr, err := mm.MMap(ctx, memmap.MMapOpts{
Length: usermem.PageSize,
Private: true,
Perms: usermem.ReadWrite,
MaxPerms: usermem.AnyAccess,
})
if err != nil {
t.Fatalf("MMap got err %v want nil", err)
}
// Writing works before mprotect.
b := make([]byte, 1)
n, err := mm.CopyOut(ctx, addr, b, usermem.IOOpts{})
if err != nil {
t.Errorf("CopyOut got err %v want nil", err)
}
if n != 1 {
t.Errorf("CopyOut got %d want 1", n)
}
err = mm.MProtect(addr, usermem.PageSize, usermem.Read, false)
if err != nil {
t.Errorf("MProtect got err %v want nil", err)
}
// Without IgnorePermissions, CopyOut should no longer succeed.
n, err = mm.CopyOut(ctx, addr, b, usermem.IOOpts{})
if err != syserror.EFAULT {
t.Errorf("CopyOut got err %v want EFAULT", err)
}
if n != 0 {
t.Errorf("CopyOut got %d want 0", n)
}
// With IgnorePermissions, CopyOut should succeed despite mprotect.
n, err = mm.CopyOut(ctx, addr, b, usermem.IOOpts{
IgnorePermissions: true,
})
if err != nil {
t.Errorf("CopyOut got err %v want nil", err)
}
if n != 1 {
t.Errorf("CopyOut got %d want 1", n)
}
}
|
