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彻底毁掉了我的 gcc 编译器。需要帮助使其达到正确的状态

tag-icon • tag-icon kali-linux gcc
彻底毁掉了我的 gcc 编译器。需要帮助使其达到正确的状态

首先，我试图编译这个c代码。

我正在使用开发人员推荐的命令，例如

gcc 40049.c -m32 -O2 -o decr

并收到此错误

/usr/include/features.h:323:26: fatal error: bits/predefs.h: No such file or directory

执行此命令后

sudo apt-get install gcc-multilib

我以为代码可以编译，但我错了。

运行相同的命令后，我在 Kali Linux 机器的终端中收到了错误的全文，如图所示。

/bin/bash: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2

这是我收到的错误片段。

40049.c: In function ‘main’:
40049.c:200:19: warning: incompatible implicit declaration of built-in function ‘malloc’
  200 |  stack = (void *) malloc(65536);
      |                   ^~~~~~
40049.c:200:19: note: include ‘<stdlib.h>’ or provide a declaration of ‘malloc’
40049.c: At top level:
40049.c:214:1: error: expected identifier or ‘(’ before ‘--’ token
  214 | --------------------------------------------------- pwn.c ---------------------------------------------------
      | ^~
40049.c: In function ‘privesc’:
40049.c:240:42: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  240 |         commit_creds(prepare_kernel_cred((uint64_t)NULL));
      |                                          ^
40049.c: At top level:
40049.c:243:5: error: redefinition of ‘main’
  243 | int main() {
      |     ^~~~
40049.c:178:5: note: previous definition of ‘main’ was here
  178 | int main(void) {
      |     ^~~~
40049.c: In function ‘main’:
40049.c:249:2: warning: incompatible implicit declaration of built-in function ‘memset’
  249 |  memset(shellcode, 0, 0x300000);
      |  ^~~~~~
40049.c:249:2: note: include ‘<string.h>’ or provide a declaration of ‘memset’
40049.c:251:14: warning: implicit declaration of function ‘memcpy’ [-Wimplicit-function-declaration]
  251 |  void *ret = memcpy(shellcode, &privesc, 0x300);
      |              ^~~~~~
40049.c:251:14: warning: incompatible implicit declaration of built-in function ‘memcpy’
40049.c:251:14: note: include ‘<string.h>’ or provide a declaration of ‘memcpy’

我对此很陌生，所以感谢大家的帮助。

答案1

我还没有测试过它，但该代码旨在分为两个不同的文件：decr.c和pwn.c.您将其全部保存为40049.c.

看：

40049.c:214:1: error: expected identifier or ‘(’ before ‘--’ token
  214 | --------------------------------------------------- pwn.c ---------------------------------------------------
      | ^~

第 214 行是一个标记，告诉您这是文件的开头pwn.c。此行无效 C.

另外，你还有这个：

40049.c:243:5: error: redefinition of ‘main’
  243 | int main() {
      |     ^~~~
40049.c:178:5: note: previous definition of ‘main’ was here
  178 | int main(void) {
      |     ^~~~

这两个主电源是两个不同可执行文件的一部分。

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