Re: Crash when attaching uretprobes to processes running in Docker

[Oleg Nesterov]

On 01/15, Jiri Olsa wrote:
>
> On Tue, Jan 14, 2025 at 06:25:20PM +0100, Oleg Nesterov wrote:
> >
> > Sorry, I don't understand... What exactly we can do? Aside from checking
> > IS_ENABLED(CONFIG_SECCOMP) in arch_uprobe_trampoline() ?
>
> I need to check more on seccomp, but I imagine we could do following:
>   - when seccomp filter is installed we could check uprobe trampoline
>     and if it's already installed we change it to int3 trampoline
>   - when uprobe trampoline is getting installed we check if there's
>     seccomp filter installed for task and we use int3 trampoline

I still don't understand... But whatever you meant, I doubt it can work.

> other than that I guess we will have to add sysctl to enable uretprobe
> trampoline..

Or we can change __secure_computing() to do nothing if
this_syscall == __NR_uretprobe. Or even change syscall_trace_enter/exit
to do this check.

But I don't really like this idea, I don't feel this is the right solution...

Oleg.