On Mon, Apr 28, 2025 at 12:51:57PM +0200, Jiri Olsa wrote: > On Sun, Apr 27, 2025 at 04:13:35PM +0200, Oleg Nesterov wrote:
SNIP > > > > ------------------------------------------------------------------------------- > > OTOH, I think that the current logic is not really correct too, > > > > /* Revert back reference counter if instruction update failed. */ > > if (ret < 0 && is_register && ref_ctr_updated) > > update_ref_ctr(uprobe, mm, -1); > > > > I think that "Revert back reference counter" logic should not depend on > > is_register. Otherwise we can have the unbalanced update_ref_ctr(-1) if > > uprobe_unregister() fails, then another uprobe_register() comes at the > > same address, and after that uprobe_unregister() succeeds. > > sounds good to me actualy after closer look, I don't see how this code could be triggered in the first place.. any hint on how to hit such case? like: - ref_ctr_offset is updated - we fail somehow - "if (ret < 0 && ref_ctr_updated)" is true on the way out thanks, jirka
