1 | /* ABI compatibility for 'system' symbol in libpthread ABI. |
2 | Copyright (C) 2002-2016 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either |
9 | version 2.1 of the License, or (at your option) any later version. |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | Lesser General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #include <stdlib.h> |
21 | #include <shlib-compat.h> |
22 | |
23 | /* libpthread once had its own 'system', though there was no apparent |
24 | reason for it. There is no use in having a separate symbol in |
25 | libpthread, but the historical ABI requires it. For static linking, |
26 | there is no need to provide anything here--the libc version will be |
27 | linked in. For shared library ABI compatibility, there must be a |
28 | 'system' symbol in libpthread.so; so we define it using IFUNC to |
29 | redirect to the libc function. */ |
30 | |
31 | #if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22) |
32 | |
33 | # if HAVE_IFUNC |
34 | |
35 | static __typeof (system) * |
36 | __attribute__ ((used)) |
37 | system_resolve (void) |
38 | { |
39 | return &__libc_system; |
40 | } |
41 | |
42 | asm (".globl system_ifunc\n" |
43 | ".type system_ifunc, %gnu_indirect_function" ); |
44 | |
45 | # ifdef HAVE_ASM_SET_DIRECTIVE |
46 | asm (".set system_ifunc, system_resolve" ); |
47 | # else |
48 | asm ("system_ifunc = system_resolve" ); |
49 | # endif |
50 | |
51 | # else /* !HAVE_IFUNC */ |
52 | |
53 | static int __attribute__ ((used)) |
54 | system_compat (const char *line) |
55 | { |
56 | return __libc_system (line); |
57 | } |
58 | strong_alias (system_compat, system_ifunc) |
59 | |
60 | # endif /* HAVE_IFUNC */ |
61 | |
62 | compat_symbol (libpthread, system_ifunc, system, GLIBC_2_0); |
63 | |
64 | #endif |
65 | |