generate dynamically patched execution binary

[honggyukim]

It takes time for dynamic patching the target functions in the original execution binary.

It might be possible to generate a new dynamically patched binary for uftrace tracing. There are some benefits as follows:

• a lot faster launching time by removing dynamic analysis and patching time.
• easier debugging because objdump output of dynamically patched binary makes a lot easier to identify which functions are patched and how they look like.
• the target environment doesn't require capstone installed because the newly patched binary can be generated in the host machine.

The output binary contains

• already patched functions for dynamic tracing
• trampoline that redirects to dentry
• original code with jump instruction back to the target function

It requires some work but looks feasible.

[namhyung]

But it requires re-writing the ELF binary which affects section placements or maybe need to add new section(s).

[honggyukim]

It may be difficult to implement it, but I think it has a lot of benefits. I know that it take a lot of effort to implement though.