52 lines
1.1 KiB
C
52 lines
1.1 KiB
C
#define _GNU_SOURCE /* See feature_test_macros(7) */
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#include <unistd.h>
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#include <stdio.h>
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#include <sys/mman.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include "util.h"
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#define DEBUG
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int sz_unit[] = {
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4 * (1ULL<<10),
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2 * (1ULL<<20),
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1 * (1ULL<<30)};
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#define SZ_INDEX 0
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int main(int argc, char **argv)
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{
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void *mem;
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int ret = 0;
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int fd;
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fd = open("./file", O_RDWR);
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CHKANDJUMP(fd == -1, 255, "open failed\n");
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mem = mmap(0, 2 * sz_unit[SZ_INDEX], PROT_READ | PROT_WRITE,
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MAP_SHARED, fd, 0);
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CHKANDJUMP(mem == MAP_FAILED, 255, "mmap failed\n");
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ret = remap_file_pages(mem + 0 * sz_unit[SZ_INDEX],
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sz_unit[SZ_INDEX], 0, 1, MAP_SHARED);
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CHKANDJUMP(ret != 0, 255, "remap_file_pages failed\n");
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ret = remap_file_pages(mem + 1 * sz_unit[SZ_INDEX],
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sz_unit[SZ_INDEX], 0, 0, MAP_SHARED);
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CHKANDJUMP(ret != 0, 255, "remap_file_pages failed\n");
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*((unsigned long *)mem) = 0x123456789abcdef0;
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*(unsigned long *)((char *)mem + 1 * sz_unit[SZ_INDEX]) =
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0x123456789abcdef0;
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munmap(mem, 2 * sz_unit[SZ_INDEX]);
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fn_exit:
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return ret;
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fn_fail:
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goto fn_exit;
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}
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