Re: ftrace_direct (used by bpf trampoline) conflicts with live patch

[Steven Rostedt]

On Thu, 31 Mar 2022 21:48:36 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> > Does this make sense to you? Did I miss something?  
> 
> I thought the BPF trampoline does:
> 
> 	call bpf_trace_before_function
> 	call original_function + X86_PATCH_SIZE
> 	call bpf_trace_after_function
> 
> Thus, the bpf direct trampoline calls the unpatched version of the
> function call making the live patch useless. Or is this not what it
> does?

Or perhaps you are only talking about the part of bpf that does not
trace the end of a function?

-- Steve