1 // Copyright 2016 The Chromium OS Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "dso.h"
6
7 #include <elf.h>
8 #include <fcntl.h>
9 #include <gelf.h>
10 #include <libelf.h>
11 #include <stdlib.h>
12 #include <sys/stat.h>
13 #include <sys/types.h>
14 #include <unistd.h>
15
16 #include <vector>
17
18 #include "base/logging.h"
19 #include "buffer_reader.h"
20 #include "compat/string.h"
21 #include "compat/test.h"
22 #include "dso_test_utils.h"
23 #include "scoped_temp_path.h"
24
25 namespace quipper {
26
TEST(DsoTest,ReadsBuildId)27 TEST(DsoTest, ReadsBuildId) {
28 InitializeLibelf();
29 ScopedTempFile elf("/tmp/tempelf.");
30
31 const string expected_buildid = "\xde\xad\xf0\x0d";
32 testing::WriteElfWithBuildid(elf.path(), ".note.gnu.build-id",
33 expected_buildid);
34
35 string buildid;
36 EXPECT_TRUE(ReadElfBuildId(elf.path(), &buildid));
37 EXPECT_EQ(expected_buildid, buildid);
38
39 // Repeat with other spellings of the section name:
40
41 testing::WriteElfWithBuildid(elf.path(), ".notes", expected_buildid);
42 EXPECT_TRUE(ReadElfBuildId(elf.path(), &buildid));
43 EXPECT_EQ(expected_buildid, buildid);
44
45 testing::WriteElfWithBuildid(elf.path(), ".note", expected_buildid);
46 EXPECT_TRUE(ReadElfBuildId(elf.path(), &buildid));
47 EXPECT_EQ(expected_buildid, buildid);
48 }
49
TEST(DsoTest,ReadsBuildId_MissingBuildid)50 TEST(DsoTest, ReadsBuildId_MissingBuildid) {
51 InitializeLibelf();
52 ScopedTempFile elf("/tmp/tempelf.");
53
54 testing::WriteElfWithMultipleBuildids(elf.path(), {/*empty*/});
55
56 string buildid;
57 EXPECT_FALSE(ReadElfBuildId(elf.path(), &buildid));
58 }
59
TEST(DsoTest,ReadsBuildId_WrongSection)60 TEST(DsoTest, ReadsBuildId_WrongSection) {
61 InitializeLibelf();
62 ScopedTempFile elf("/tmp/tempelf.");
63
64 testing::WriteElfWithBuildid(elf.path(), ".unexpected-section", "blah");
65
66 string buildid;
67 EXPECT_FALSE(ReadElfBuildId(elf.path(), &buildid));
68 }
69
TEST(DsoTest,ReadsBuildId_PrefersGnuBuildid)70 TEST(DsoTest, ReadsBuildId_PrefersGnuBuildid) {
71 InitializeLibelf();
72 ScopedTempFile elf("/tmp/tempelf.");
73
74 const string buildid_gnu = "\xde\xad\xf0\x0d";
75 const string buildid_notes = "\xc0\xde\xf0\x0d";
76 const string buildid_note = "\xfe\xed\xba\xad";
77
78 std::vector<std::pair<string, string>> section_buildids{
79 std::make_pair(".notes", buildid_notes),
80 std::make_pair(".note", buildid_note),
81 std::make_pair(".note.gnu.build-id", buildid_gnu),
82 };
83 testing::WriteElfWithMultipleBuildids(elf.path(), section_buildids);
84
85 string buildid;
86 EXPECT_TRUE(ReadElfBuildId(elf.path(), &buildid));
87 EXPECT_EQ(buildid_gnu, buildid);
88
89 // Also prefer ".notes" over ".note"
90 section_buildids = {
91 std::make_pair(".note", buildid_note),
92 std::make_pair(".notes", buildid_notes),
93 };
94 testing::WriteElfWithMultipleBuildids(elf.path(), section_buildids);
95
96 EXPECT_TRUE(ReadElfBuildId(elf.path(), &buildid));
97 EXPECT_EQ(buildid_notes, buildid);
98 }
99
TEST(DsoTest,ReadsSysfsModuleBuildidNote)100 TEST(DsoTest, ReadsSysfsModuleBuildidNote) {
101 // Mimic contents of a /sys/module/<name>/notes/.note.gnu.build-id file.
102 const size_t namesz = 4;
103 const size_t descsz = 0x14;
104 const GElf_Nhdr note_header = {
105 .n_namesz = namesz,
106 .n_descsz = descsz,
107 .n_type = NT_GNU_BUILD_ID,
108 };
109
110 const char note_name[namesz] = ELF_NOTE_GNU;
111 const char note_desc[descsz]{
112 // Note \0 here. This is not null-terminated.
113 '\x1c', '\0', '\x69', '\x27', '\x15', '\x26', '\x6b',
114 '\xe7', '\xcc', '\x69', '\x2c', '\x12', '\xe8', '\x09',
115 '\x20', '\x18', '\x03', '\x5b', '\xb6', '\x4f',
116 };
117
118 string data;
119 data.append(reinterpret_cast<const char*>(¬e_header), sizeof(note_header));
120 data.append(note_name, sizeof(note_name));
121 data.append(note_desc, sizeof(note_desc));
122
123 ASSERT_EQ(0x24, data.size()) << "Sanity";
124
125 BufferReader data_reader(data.data(), data.size());
126 string buildid;
127 EXPECT_TRUE(ReadBuildIdNote(&data_reader, &buildid));
128 EXPECT_EQ(string(note_desc, sizeof(note_desc)), buildid);
129 }
130
131 } // namespace quipper
132