mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-29 05:51:10 +00:00
80 lines
2.8 KiB
C
80 lines
2.8 KiB
C
/* Operating system specific code for generic dynamic loader functions. Linux.
|
|
Copyright (C) 2000-2020 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>
|
|
|
|
#ifndef MIN
|
|
# define MIN(a,b) (((a)<(b))?(a):(b))
|
|
#endif
|
|
|
|
#define DL_SYSDEP_OSCHECK(FATAL) \
|
|
do { \
|
|
/* Test whether the kernel is new enough. This test is only performed \
|
|
if the library is not compiled to run on all kernels. */ \
|
|
\
|
|
int version = _dl_discover_osversion (); \
|
|
if (__glibc_likely (version >= 0)) \
|
|
{ \
|
|
if (__builtin_expect (GLRO(dl_osversion) == 0, 1) \
|
|
|| GLRO(dl_osversion) > version) \
|
|
GLRO(dl_osversion) = version; \
|
|
\
|
|
/* Now we can test with the required version. */ \
|
|
if (__LINUX_KERNEL_VERSION > 0 && version < __LINUX_KERNEL_VERSION) \
|
|
/* Not sufficent. */ \
|
|
FATAL ("FATAL: kernel too old\n"); \
|
|
} \
|
|
else if (__LINUX_KERNEL_VERSION > 0) \
|
|
FATAL ("FATAL: cannot determine kernel version\n"); \
|
|
} while (0)
|
|
|
|
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;
|
|
}
|