Re: Crash when attaching uretprobes to processes running in Docker

[Jiri Olsa]

On Wed, Jan 15, 2025 at 10:36:51AM +0100, Jiri Olsa wrote:
> 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

nah, other threads could be in there already.. :-\

jirka

>   - 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