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
177
178
179
180
181
182
183
184
185
186
187
|
package kallsyms
import (
"bytes"
"os"
"testing"
"github.com/go-quicktest/qt"
"github.com/cilium/ebpf/internal"
"github.com/cilium/ebpf/internal/testutils"
)
var syms = []byte(`0000000000000001 t hid_generic_probe [hid_generic]
00000000000000EA t writenote
00000000000000A0 T tcp_connect
00000000000000B0 B empty_zero_page
00000000000000C0 D kimage_vaddr
00000000000000D0 R __start_pci_fixups_early
00000000000000E0 V hv_root_partition
00000000000000F0 W calibrate_delay_is_known
A0000000000000AA a nft_counter_seq [nft_counter]
A0000000000000BA b bootconfig_found
A0000000000000CA d __func__.10
A0000000000000DA r __ksymtab_LZ4_decompress_fast
A0000000000000EA t writenote`)
func TestParseSyms(t *testing.T) {
r := newReader(bytes.NewReader(syms))
i := 0
for ; r.Line(); i++ {
s, err, skip := parseSymbol(r, nil)
qt.Assert(t, qt.IsNil(err))
qt.Assert(t, qt.IsFalse(skip))
qt.Assert(t, qt.Not(qt.Equals(s.addr, 0)))
qt.Assert(t, qt.Not(qt.Equals(s.name, "")))
}
qt.Assert(t, qt.IsNil(r.Err()))
qt.Assert(t, qt.Equals(i, 13))
}
func TestParseProcKallsyms(t *testing.T) {
// Read up to 50k symbols from kallsyms to avoid a slow test.
r := newReader(mustOpenProcKallsyms(t))
for i := 0; r.Line() && i < 50_000; i++ {
s, err, skip := parseSymbol(r, nil)
qt.Assert(t, qt.IsNil(err))
qt.Assert(t, qt.IsFalse(skip))
qt.Assert(t, qt.Not(qt.Equals(s.name, "")))
}
qt.Assert(t, qt.IsNil(r.Err()))
}
func TestAssignModulesCaching(t *testing.T) {
err := AssignModules(
map[string]string{
"bpf_perf_event_output": "",
"foo": "",
},
)
testutils.SkipIfNotSupportedOnOS(t, err)
qt.Assert(t, qt.IsNil(err))
// Can't assume any kernel modules are loaded, but this symbol should at least
// exist in the kernel. There is no semantic difference between a missing
// symbol and a symbol that doesn't belong to a module.
v, ok := symModules.Load("bpf_perf_event_output")
qt.Assert(t, qt.IsTrue(ok))
qt.Assert(t, qt.Equals(v, ""))
v, ok = symModules.Load("foo")
qt.Assert(t, qt.IsTrue(ok))
qt.Assert(t, qt.Equals(v, ""))
}
func TestAssignModules(t *testing.T) {
mods := map[string]string{
"hid_generic_probe": "",
"nft_counter_seq": "",
"tcp_connect": "",
"foo": "",
}
qt.Assert(t, qt.IsNil(assignModules(bytes.NewBuffer(syms), mods)))
qt.Assert(t, qt.DeepEquals(mods, map[string]string{
"hid_generic_probe": "hid_generic",
"nft_counter_seq": "", // wrong symbol type
"tcp_connect": "",
"foo": "",
}))
qt.Assert(t, qt.ErrorIs(assignModules(bytes.NewBuffer(syms),
map[string]string{"writenote": ""}), errAmbiguousKsym))
}
func TestAssignAddressesCaching(t *testing.T) {
err := AssignAddresses(
map[string]uint64{
"bpf_perf_event_output": 0,
"foo": 0,
},
)
testutils.SkipIfNotSupportedOnOS(t, err)
qt.Assert(t, qt.IsNil(err))
v, ok := symAddrs.Load("bpf_perf_event_output")
qt.Assert(t, qt.IsTrue(ok))
qt.Assert(t, qt.Not(qt.Equals(v, 0)))
v, ok = symAddrs.Load("foo")
qt.Assert(t, qt.IsTrue(ok))
qt.Assert(t, qt.Equals(v, 0))
}
func TestAssignAddresses(t *testing.T) {
b := bytes.NewBuffer(syms)
ksyms := map[string]uint64{
"hid_generic_probe": 0,
"tcp_connect": 0,
"bootconfig_found": 0,
}
qt.Assert(t, qt.IsNil(assignAddresses(b, ksyms)))
qt.Assert(t, qt.Equals(ksyms["hid_generic_probe"], 0x1))
qt.Assert(t, qt.Equals(ksyms["tcp_connect"], 0xA0))
qt.Assert(t, qt.Equals(ksyms["bootconfig_found"], 0xA0000000000000BA))
b = bytes.NewBuffer(syms)
ksyms = map[string]uint64{
"hid_generic_probe": 0,
"writenote": 0,
}
qt.Assert(t, qt.ErrorIs(assignAddresses(b, ksyms), errAmbiguousKsym))
}
func BenchmarkSymbolKmods(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
b.StopTimer()
f := mustOpenProcKallsyms(b)
want := map[string]string{
"bpf_trace_vprintk": "",
"bpf_send_signal": "",
"bpf_event_notify": "",
"bpf_trace_printk": "",
"bpf_perf_event_output": "",
}
b.StartTimer()
if err := assignModules(f, want); err != nil {
b.Fatal(err)
}
}
}
// Benchmark getting 5 kernel symbols from /proc/kallsyms.
func BenchmarkAssignAddresses(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
b.StopTimer()
f := mustOpenProcKallsyms(b)
want := map[string]uint64{
"bpf_trace_vprintk": 0,
"bpf_send_signal": 0,
"bpf_event_notify": 0,
"bpf_trace_printk": 0,
"bpf_perf_event_output": 0,
}
b.StartTimer()
if err := assignAddresses(f, want); err != nil {
b.Fatal(err)
}
}
}
func mustOpenProcKallsyms(tb testing.TB) *os.File {
tb.Helper()
if !internal.OnLinux {
tb.Skip("/proc/kallsyms is a Linux concept")
}
f, err := os.Open("/proc/kallsyms")
qt.Assert(tb, qt.IsNil(err))
tb.Cleanup(func() { f.Close() })
return f
}
|
