Re: Crash when attaching uretprobes to processes running in Docker

Jiri Olsa
2025-01-15T09:36:55Z

On Tue, Jan 14, 2025 at 06:25:20PM +0100, Oleg Nesterov wrote:
> On 01/14, Jiri Olsa wrote:
> >
> > ugh.. could we just 'disable' uretprobe trampoline when seccomp gets enabled?
> > overwrite first byte with int3.. and similarly check on seccomp when installing
> > uretprobe and switch to int3
>
> 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

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

jirka