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https://github.com/freebsd/freebsd-src
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51 lines
1.1 KiB
C
51 lines
1.1 KiB
C
/*-
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* Copyright (c) 2023 Dmitry Chagin <dchagin@FreeBSD.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <sys/mman.h>
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#include <err.h>
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#include <fcntl.h>
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#include <stdlib.h>
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#include <unistd.h>
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#define MAP_32BIT_MAX_ADDR ((vm_offset_t)1 << 31)
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int
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main(void)
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{
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size_t pagesize;
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void *s32;
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int fd;
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if ((pagesize = getpagesize()) <= 0)
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err(1, "getpagesize");
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fd = open("/dev/zero", O_RDONLY);
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if (fd <= 0)
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err(1, "open failed");
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s32 = mmap(NULL, pagesize, PROT_READ, MAP_32BIT | MAP_PRIVATE, fd, 0);
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if (s32 == MAP_FAILED)
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err(1, "mmap MAP_32BIT | MAP_PRIVATE failed");
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if (((vm_offset_t)s32 + pagesize) > MAP_32BIT_MAX_ADDR)
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errx(1, "mmap invalid result %p", s32);
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close(fd);
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if (munmap(s32, pagesize) != 0)
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err(1, "munmap failed");
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s32 = mmap(NULL, pagesize, PROT_READ | PROT_WRITE,
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MAP_32BIT | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
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if (s32 == MAP_FAILED)
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err(1, "mmap MAP_32BIT | MAP_ANONYMOUS | MAP_PRIVATE failed");
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if (((vm_offset_t)s32 + pagesize) > MAP_32BIT_MAX_ADDR)
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errx(1, "mmap invalid result %p", s32);
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if (munmap(s32, pagesize) != 0)
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err(1, "munmap failed");
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exit(0);
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}
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