Re: [PATCHv4 02/14] uprobe: Add support for session consumer
From: Oleg Nesterov
Date: Mon Sep 23 2024 - 06:07:34 EST
On 09/23, Jiri Olsa wrote:
>
> change below should do what you proposed originally
LGTM, just one nit below.
But I guess you need to do this on top of bpf/bpf.git, Andrii has already
applied your series.
And to remind, 02/14 must be fixed in any case unless I am totally confused,
handler_chain() can leak return_instance.
> also on top of that.. I discussed with Andrii the possibility of dropping
> the UPROBE_HANDLER_IWANTMYCOOKIE completely and setup cookie for any consumer
> that has both 'handler' and 'ret_handler' defined, wdyt?
Up to you. As I said from the very beginning I won't insist on _IWANTMYCOOKIE.
> list_for_each_entry_srcu(uc, &uprobe->consumers, cons_node,
> srcu_read_lock_held(&uprobes_srcu)) {
> + ric = return_consumer_find(ri, &ric_idx, uc->id);
> if (uc->ret_handler)
> - uc->ret_handler(uc, ri->func, regs);
> + uc->ret_handler(uc, ri->func, regs, ric ? &ric->cookie : NULL);
> }
> srcu_read_unlock(&uprobes_srcu, srcu_idx);
return_consumer_find() makes no sense if !uc->ret_handler, can you move
ric = return_consumer_find(ri, &ric_idx, uc->id);
into the "if (uc->ret_handler)" block?
Oleg.