1 /*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <errno.h>
18 #include <sys/cdefs.h>
19 #include <sys/utsname.h>
20 #include <gtest/gtest.h>
21
22 // getauxval() was only added as of glibc version 2.16.
23 // See: http://lwn.net/Articles/519085/
24 // Don't try to compile this code on older glibc versions.
25
26 #if defined(__BIONIC__)
27 #define GETAUXVAL_CAN_COMPILE 1
28 #elif defined(__GLIBC_PREREQ)
29 #if __GLIBC_PREREQ(2, 16)
30 #define GETAUXVAL_CAN_COMPILE 1
31 #endif
32 #endif
33
34 #if defined(GETAUXVAL_CAN_COMPILE)
35 #include <sys/auxv.h>
36 #endif
37
TEST(getauxval,expected_values)38 TEST(getauxval, expected_values) {
39 #if defined(GETAUXVAL_CAN_COMPILE)
40 ASSERT_EQ(0UL, getauxval(AT_SECURE));
41 ASSERT_EQ(getuid(), getauxval(AT_UID));
42 ASSERT_EQ(geteuid(), getauxval(AT_EUID));
43 ASSERT_EQ(getgid(), getauxval(AT_GID));
44 ASSERT_EQ(getegid(), getauxval(AT_EGID));
45 ASSERT_EQ(static_cast<unsigned long>(getpagesize()), getauxval(AT_PAGESZ));
46
47 ASSERT_NE(0UL, getauxval(AT_PHDR));
48 ASSERT_NE(0UL, getauxval(AT_PHNUM));
49 ASSERT_NE(0UL, getauxval(AT_ENTRY));
50 ASSERT_NE(0UL, getauxval(AT_PAGESZ));
51 #else
52 GTEST_LOG_(INFO) << "This test requires a C library with getauxval.\n";
53 #endif
54 }
55
TEST(getauxval,unexpected_values)56 TEST(getauxval, unexpected_values) {
57 #if defined(GETAUXVAL_CAN_COMPILE)
58 errno = 0;
59 ASSERT_EQ(0UL, getauxval(0xdeadbeef));
60 ASSERT_EQ(ENOENT, errno);
61 #else
62 GTEST_LOG_(INFO) << "This test requires a C library with getauxval.\n";
63 #endif
64 }
65
TEST(getauxval,arm_has_AT_HWCAP2)66 TEST(getauxval, arm_has_AT_HWCAP2) {
67 #if defined(__arm__)
68 // There are no known 32-bit processors that implement any of these instructions, so rather
69 // than require that OEMs backport kernel patches, let's just ignore old hardware. Strictly
70 // speaking this would be fooled by someone choosing to ship a 32-bit kernel on 64-bit hardware,
71 // but that doesn't seem very likely in 2016.
72 utsname u;
73 ASSERT_EQ(0, uname(&u));
74 if (strcmp(u.machine, "aarch64") == 0) {
75 // If this test fails, apps that use getauxval to decide at runtime whether crypto hardware is
76 // available will incorrectly assume that it isn't, and will have really bad performance.
77 // If this test fails, ensure that you've enabled COMPAT_BINFMT_ELF in your kernel configuration.
78 // Note that 0 ("I don't support any of these things") is a legitimate response --- we need
79 // to check errno to see whether we got a "true" 0 or a "not found" 0.
80 errno = 0;
81 getauxval(AT_HWCAP2);
82 ASSERT_EQ(0, errno) << "64-bit kernel not reporting AT_HWCAP2 to 32-bit ARM process";
83 return;
84 }
85 #endif
86 GTEST_LOG_(INFO) << "This test is only meaningful for 32-bit ARM code on 64-bit devices.\n";
87 }
88