27 lines
532 B
C
27 lines
532 B
C
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#include <string.h>
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#include <unistd.h>
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#include <sys/mman.h>
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int
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main(void)
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{
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const size_t page_len = sysconf(_SC_PAGESIZE);
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const size_t tail_len = 257;
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if (tail_len >= page_len)
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return 77;
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void *p = mmap(NULL, page_len * 2, PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
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if (p == MAP_FAILED || mprotect(p + page_len, page_len, PROT_NONE))
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return 77;
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memset(p, 0, page_len);
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char *addr = p + page_len - tail_len;
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memset(addr, '/', tail_len - 1);
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if (chdir(addr))
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return 77;
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return 0;
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}
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