Re: [PATCH v2] tracing/uprobe: Add missing PID filter for uretprobe

Oleg Nesterov
2024-08-25T17:01:18Z

On 08/23, Andrii Nakryiko wrote:
>
> This is a bit confusing, because even if the kernel-side uretprobe
> handler doesn't do the filtering by itself, uprobe subsystem shouldn't
> install breakpoints on processes which don't have uretprobe requested
> for (unless I'm missing something, of course).

Yes, but in this case uprobe_register/apply will install breakpoints
on both tasks, with PID1 and PID2.

> It still needs to be fixed

Agreed,

> like you do in your patch,

Not sure...

> more, we probably need a similar UPROBE_HANDLER_REMOVE handling in
> handle_uretprobe_chain() to clean up breakpoint for processes which
> don't have uretprobe attached anymore (but I think that's a separate
> follow up).

Probably yes... but yes, this is another issue.

Oleg.