1/* Stack executability handling for GNU dynamic linker. Hurd version.
2 Copyright (C) 2004-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <ldsodefs.h>
20#include <hurdstartup.h>
21#include <errno.h>
22
23extern struct hurd_startup_data *_dl_hurd_data attribute_hidden;
24
25/* There is no portable way to know the bounds of the initial thread's stack
26 so as to mprotect it. */
27
28int
29_dl_make_stack_executable (void **stack_endp)
30{
31 /* Challenge the caller. */
32 if (__builtin_expect (*stack_endp != __libc_stack_end, 0))
33 return EPERM;
34 *stack_endp = NULL;
35
36#if IS_IN (rtld)
37 if (__mprotect ((void *)_dl_hurd_data->stack_base, _dl_hurd_data->stack_size,
38 PROT_READ|PROT_WRITE|PROT_EXEC) != 0)
39 return errno;
40
41 /* Remember that we changed the permission. */
42 GL(dl_stack_flags) |= PF_X;
43
44 return 0;
45#else
46 /* We don't bother to implement this for static linking. */
47 return ENOSYS;
48#endif
49}
50rtld_hidden_def (_dl_make_stack_executable)
51

source code of glibc/sysdeps/mach/hurd/dl-execstack.c