1 /* Stack executability handling for GNU dynamic linker. Linux version.
2 Copyright (C) 2003-2019 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
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/>. */
24 #include <stackinfo.h>
28 extern int __stack_prot attribute_relro attribute_hidden
;
32 _dl_make_stack_executable (void **stack_endp
)
34 /* This gives us the highest/lowest page that needs to be changed. */
35 uintptr_t page
= ((uintptr_t) *stack_endp
36 & -(intptr_t) GLRO(dl_pagesize
));
39 if (__builtin_expect (__mprotect ((void *) page
, GLRO(dl_pagesize
),
40 __stack_prot
) == 0, 1))
46 /* Clear the address. */
49 /* Remember that we changed the permission. */
50 GL(dl_stack_flags
) |= PF_X
;
53 #ifdef check_consistency
59 rtld_hidden_def (_dl_make_stack_executable
)