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main.c
| @@ -4,8 +4,6 @@ | |||
| 4 | 4 | #include <sys/mman.h> | |
| 5 | 5 | #include <unistd.h> | |
| 6 | 6 | ||
| 7 | - | // 这是 add 函数的机器码，假设它的二进制数据已经嵌入到这里 | |
| 8 | - | // 注意：这个数据需要根据具体架构和编译器生成的机器码来填充 | |
| 9 | 7 | unsigned char add_bin[] = { | |
| 10 | 8 | // 这里是针对 x86_64 架构的 add 函数的二进制机器码 | |
| 11 | 9 | 0x55, // push %rbp | |
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gistfile1.txt(file created)
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| 1 | + | #include <stdio.h> | |
| 2 | + | #include <stdlib.h> | |
| 3 | + | #include <string.h> | |
| 4 | + | #include <sys/mman.h> | |
| 5 | + | #include <unistd.h> | |
| 6 | + | ||
| 7 | + | // 这是 add 函数的机器码，假设它的二进制数据已经嵌入到这里 | |
| 8 | + | // 注意：这个数据需要根据具体架构和编译器生成的机器码来填充 | |
| 9 | + | unsigned char add_bin[] = { | |
| 10 | + | // 这里是针对 x86_64 架构的 add 函数的二进制机器码 | |
| 11 | + | 0x55, // push %rbp | |
| 12 | + | 0x48, 0x89, 0xe5, // mov %rsp,%rbp | |
| 13 | + | 0x89, 0x7d, 0xfc, // mov %edi,-0x4(%rbp) | |
| 14 | + | 0x89, 0x75, 0xf8, // mov %esi,-0x8(%rbp) | |
| 15 | + | 0x8b, 0x55, 0xfc, // mov -0x4(%rbp),%edx | |
| 16 | + | 0x8b, 0x45, 0xf8, // mov -0x8(%rbp),%eax | |
| 17 | + | 0x01, 0xd0, // add %edx,%eax | |
| 18 | + | 0x5d, // pop %rbp | |
| 19 | + | 0xc3 // retq | |
| 20 | + | }; | |
| 21 | + | ||
| 22 | + | void load_and_execute() { | |
| 23 | + | // 获取页面大小 | |
| 24 | + | size_t pagesize = sysconf(_SC_PAGESIZE); | |
| 25 | + | ||
| 26 | + | // 分配可读、可写、可执行的内存页 | |
| 27 | + | void *exec_mem = mmap(NULL, pagesize, PROT_READ | PROT_WRITE | PROT_EXEC, | |
| 28 | + | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); | |
| 29 | + | if (exec_mem == MAP_FAILED) { | |
| 30 | + | perror("mmap"); | |
| 31 | + | exit(EXIT_FAILURE); | |
| 32 | + | } | |
| 33 | + | ||
| 34 | + | // 将函数的机器码复制到可执行内存中 | |
| 35 | + | memcpy(exec_mem, add_bin, sizeof(add_bin)); | |
| 36 | + | ||
| 37 | + | // 定义一个函数指针并指向加载到内存中的代码段 | |
| 38 | + | int (*add_func)(int, int) = (int (*)(int, int))exec_mem; | |
| 39 | + | ||
| 40 | + | // 调用加载的函数 | |
| 41 | + | int result = add_func(2, 3); | |
| 42 | + | printf("Result of add(2, 3): %d\n", result); | |
| 43 | + | ||
| 44 | + | // 释放内存 | |
| 45 | + | if (munmap(exec_mem, pagesize) == -1) { | |
| 46 | + | perror("munmap"); | |
| 47 | + | exit(EXIT_FAILURE); | |
| 48 | + | } | |
| 49 | + | } | |
| 50 | + | ||
| 51 | + | int main() { | |
| 52 | + | load_and_execute(); | |
| 53 | + | return 0; | |
| 54 | + | } | |