Dmitry V. Levin
0f303f99c6
* tests/tail_alloc.c (tail_alloc): Create additional memory mapping holes before and after the allocated memory.
64 lines
2.3 KiB
C
64 lines
2.3 KiB
C
/*
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* Copyright (c) 2015-2016 Dmitry V. Levin <ldv@altlinux.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "tests.h"
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#include <string.h>
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#include <sys/mman.h>
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void *
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tail_alloc(const size_t size)
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{
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const size_t page_size = get_page_size();
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const size_t len = (size + page_size - 1) & -page_size;
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const size_t alloc_size = len + 6 * page_size;
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void *p = mmap(NULL, alloc_size, PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
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if (MAP_FAILED == p)
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perror_msg_and_fail("mmap(%zu)", alloc_size);
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void *start_work = p + 3 * page_size;
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void *tail_guard = start_work + len;
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if (munmap(p, page_size) ||
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munmap(p + 2 * page_size, page_size) ||
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munmap(tail_guard, page_size) ||
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munmap(tail_guard + 2 * page_size, page_size))
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perror_msg_and_fail("munmap");
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memset(start_work, 0xff, len);
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return tail_guard - size;
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}
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void *
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tail_memdup(const void *p, const size_t size)
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{
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void *dest = tail_alloc(size);
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memcpy(dest, p, size);
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return dest;
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}
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