55 lines
1.8 KiB
C
55 lines
1.8 KiB
C
|
/* Operating system specific code for generic dynamic loader functions. Linux.
|
||
|
|
Copyright (C) 2000-2022 Free Software Foundation, Inc.
|
||
|
|
This file is part of the GNU C Library.
|
||
|
|
|
||
|
|
The GNU C Library is free software; you can redistribute it and/or
|
||
|
|
modify it under the terms of the GNU Lesser General Public
|
||
|
|
License as published by the Free Software Foundation; either
|
||
|
|
version 2.1 of the License, or (at your option) any later version.
|
||
|
|
|
||
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
||
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||
|
|
Lesser General Public License for more details.
|
||
|
|
|
||
|
|
You should have received a copy of the GNU Lesser General Public
|
||
|
|
License along with the GNU C Library; if not, see
|
||
|
|
<https://www.gnu.org/licenses/>. */
|
||
|
|
|
||
|
|
#include <dl-sysdep.h>
|
||
|
|
#include <endian.h>
|
||
|
|
#include <fcntl.h>
|
||
|
|
#include <stdint.h>
|
||
|
|
#include <not-cancel.h>
|
||
|
|
|
||
|
|
static inline uintptr_t __attribute__ ((always_inline))
|
||
|
|
_dl_setup_stack_chk_guard (void *dl_random)
|
||
|
|
{
|
||
|
|
union
|
||
|
|
{
|
||
|
|
uintptr_t num;
|
||
|
|
unsigned char bytes[sizeof (uintptr_t)];
|
||
|
|
} ret;
|
||
|
|
|
||
|
|
/* We need in the moment only 8 bytes on 32-bit platforms and 16
|
||
|
|
bytes on 64-bit platforms. Therefore we can use the data
|
||
|
|
directly and not use the kernel-provided data to seed a PRNG. */
|
||
|
|
memcpy (ret.bytes, dl_random, sizeof (ret));
|
||
|
|
#if BYTE_ORDER == LITTLE_ENDIAN
|
||
|
|
ret.num &= ~(uintptr_t) 0xff;
|
||
|
|
#elif BYTE_ORDER == BIG_ENDIAN
|
||
|
|
ret.num &= ~((uintptr_t) 0xff << (8 * (sizeof (ret) - 1)));
|
||
|
|
#else
|
||
|
|
# error "BYTE_ORDER unknown"
|
||
|
|
#endif
|
||
|
|
return ret.num;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline uintptr_t __attribute__ ((always_inline))
|
||
|
|
_dl_setup_pointer_guard (void *dl_random, uintptr_t stack_chk_guard)
|
||
|
|
{
|
||
|
|
uintptr_t ret;
|
||
|
|
memcpy (&ret, (char *) dl_random + sizeof (ret), sizeof (ret));
|
||
|
|
return ret;
|
||
|
|
}
|