36 lines
589 B
C++
36 lines
589 B
C++
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#include <stdio.h>
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#include <sys/mman.h>
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#include <sys/wait.h>
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#include <unistd.h>
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int main()
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{
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void* address = mmap(nullptr, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0);
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if (address == MAP_FAILED)
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{
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perror("mmap");
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return 1;
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}
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int* ptr = (int*)address;
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*ptr = 16;
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pid_t child = fork();
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if (child < 0)
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{
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perror("fork");
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return 1;
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}
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if (child == 0)
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{
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*ptr = 32;
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_exit(0);
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}
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waitpid(child, NULL, 0);
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printf("the value is %d\n", *ptr);
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return 0;
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}
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