Re: Crash when attaching uretprobes to processes running in Docker

Oleg Nesterov
2025-01-14T11:02:34Z

On 01/14, Peter Zijlstra wrote:
>
> On Tue, Jan 14, 2025 at 10:22:20AM +0100, Jiri Olsa wrote:
> >
> > hack below seems to fix the issue, it's using rbx to signal that uretprobe
> > syscall got executed, if not, trampoline does int3 and executes uretprobe
> > handler in the old way
> >
> > unfortunately now the uretprobe trampoline size crosses the xol slot limit so
> > will need to come up with some generic/arch code solution for that, code below
> > is neglecting that for now
>
> Can't you detect the filter earlier and simply not install the
> trampoline?

Did you mean detect the filter in prepare_uretprobe() ?

The probed function can install the filter before return...

Oleg.