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