1 | //===-- sanitizer_getauxval.h -----------------------------------*- C++ -*-===// |
---|---|
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | // |
9 | // Common getauxval() guards and definitions. |
10 | // getauxval() is not defined until glibc version 2.16, or until API level 21 |
11 | // for Android. |
12 | // Implement the getauxval() compat function for NetBSD. |
13 | // |
14 | //===----------------------------------------------------------------------===// |
15 | |
16 | #ifndef SANITIZER_GETAUXVAL_H |
17 | #define SANITIZER_GETAUXVAL_H |
18 | |
19 | #include "sanitizer_platform.h" |
20 | #include "sanitizer_glibc_version.h" |
21 | |
22 | #if SANITIZER_LINUX || SANITIZER_FUCHSIA |
23 | |
24 | # if (__GLIBC_PREREQ(2, 16) || SANITIZER_ANDROID || SANITIZER_FUCHSIA) && \ |
25 | !SANITIZER_GO |
26 | # define SANITIZER_USE_GETAUXVAL 1 |
27 | # else |
28 | # define SANITIZER_USE_GETAUXVAL 0 |
29 | # endif |
30 | |
31 | # if SANITIZER_USE_GETAUXVAL |
32 | # include <sys/auxv.h> |
33 | # else |
34 | // The weak getauxval definition allows to check for the function at runtime. |
35 | // This is useful for Android, when compiled at a lower API level yet running |
36 | // on a more recent platform that offers the function. |
37 | extern "C"SANITIZER_WEAK_ATTRIBUTE unsigned long getauxval(unsigned long type); |
38 | # endif |
39 | |
40 | #elif SANITIZER_NETBSD |
41 | |
42 | #define SANITIZER_USE_GETAUXVAL 1 |
43 | |
44 | #include <dlfcn.h> |
45 | #include <elf.h> |
46 | |
47 | static inline decltype(AuxInfo::a_v) getauxval(decltype(AuxInfo::a_type) type) { |
48 | for (const AuxInfo *aux = (const AuxInfo *)_dlauxinfo(); |
49 | aux->a_type != AT_NULL; ++aux) { |
50 | if (type == aux->a_type) |
51 | return aux->a_v; |
52 | } |
53 | |
54 | return 0; |
55 | } |
56 | |
57 | #endif |
58 | |
59 | #endif // SANITIZER_GETAUXVAL_H |
60 |