Re: [PATCH 2/8] uprobes: revamp uprobe refcounting and lifetime management

Oleg Nesterov
2024-08-02T08:50:57Z

On 08/01, Andrii Nakryiko wrote:
>
> > + /* TODO : cant unregister? schedule a worker thread */
> > + WARN(err, "leaking uprobe due to failed unregistration");

> Ok, so now that I added this very loud warning if
> register_for_each_vma(uprobe, NULL) returns error, it turns out it's
> not that unusual for this unregistration to fail.

...

> So, is there something smarter we can do in this case besides leaking
> an uprobe (and note, my changes don't change this behavior)?

Something like schedule_work() which retries register_for_each_vma()...

> I can of course just drop the WARN given it's sort of expected now,

Or least replace it with pr_warn() or uprobe_warn(), WARN() certainly
makes no sense imo...

> I don't
> think that should block optimization work, but just something to keep
> in mind and maybe fix as a follow up.

Agreed, lets do this separately.

Oleg.