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 <sys/auxv.h>
18 
19 #include <errno.h>
20 #include <sys/cdefs.h>
21 #include <sys/utsname.h>
22 #include <gtest/gtest.h>
23 
24 #include "utils.h"
25 
TEST(getauxval,expected_values)26 TEST(getauxval, expected_values) {
27   ASSERT_EQ(0UL, getauxval(AT_SECURE));
28   ASSERT_EQ(getuid(), getauxval(AT_UID));
29   ASSERT_EQ(geteuid(), getauxval(AT_EUID));
30   ASSERT_EQ(getgid(), getauxval(AT_GID));
31   ASSERT_EQ(getegid(), getauxval(AT_EGID));
32   ASSERT_EQ(static_cast<unsigned long>(getpagesize()), getauxval(AT_PAGESZ));
33 
34   ASSERT_NE(0UL, getauxval(AT_PHDR));
35   ASSERT_NE(0UL, getauxval(AT_PHNUM));
36   ASSERT_NE(0UL, getauxval(AT_ENTRY));
37   ASSERT_NE(0UL, getauxval(AT_PAGESZ));
38 }
39 
TEST(getauxval,unexpected_values)40 TEST(getauxval, unexpected_values) {
41   errno = 0;
42   ASSERT_EQ(0UL, getauxval(0xdeadbeef));
43   ASSERT_ERRNO(ENOENT);
44 }
45 
TEST(getauxval,arm_has_AT_HWCAP2)46 TEST(getauxval, arm_has_AT_HWCAP2) {
47 #if defined(__arm__)
48   // There are no known 32-bit processors that implement any of these instructions, so rather
49   // than require that OEMs backport kernel patches, let's just ignore old hardware. Strictly
50   // speaking this would be fooled by someone choosing to ship a 32-bit kernel on 64-bit hardware,
51   // but that doesn't seem very likely in 2016.
52   utsname u;
53   ASSERT_EQ(0, uname(&u));
54   if (strcmp(u.machine, "aarch64") == 0) {
55     // If this test fails, apps that use getauxval to decide at runtime whether crypto hardware is
56     // available will incorrectly assume that it isn't, and will have really bad performance.
57     // If this test fails, ensure that you've enabled COMPAT_BINFMT_ELF in your kernel configuration.
58     // Note that 0 ("I don't support any of these things") is a legitimate response --- we need
59     // to check errno to see whether we got a "true" 0 or a "not found" 0.
60     errno = 0;
61     getauxval(AT_HWCAP2);
62     ASSERT_ERRNO(0) << "64-bit kernel not reporting AT_HWCAP2 to 32-bit ARM process";
63     return;
64   }
65 #endif
66   GTEST_SKIP() << "This test is only meaningful for 32-bit ARM code on 64-bit devices";
67 }
68