Plan to start learning shellcode

We plan to start learning shellcode-general Linux technology-Linux programming and kernel information. The following is a detailed description. Next, prepare a tool to track the memory usage of another program and plan to use the malloc hook method.

Currently, a limitation of malloc hook is that the program must make some code changes and run the hook program. Now we plan to use the shellcode method to inject the corresponding hook to the outside, so that we do not have to change the source program.

One difficulty is:

The hook function of malloc must involve some dynamic connection libraries. If code execution is injected outside, it will not conflict with dynamic connections.

Difficulty 2:

In the malloc hook function, the dl_addr function is used, which runs slowly. In the embedded environment, the program running speed is greatly affected. Consider not to run dl_addr first, but to print the eip of the runtime. After the operation is complete, parse it. There are some concerns that dl_addr may be related to the runtime environment and cannot be reproduced.