Re: [PATCH v2 2/6] uprobes: protected uprobe lifetime with SRCU

[Oleg Nesterov]

On 08/07, Andrii Nakryiko wrote:
>
>  struct uprobe {
> -	struct rb_node		rb_node;	/* node in the rb tree */
> +	union {
> +		struct rb_node		rb_node;	/* node in the rb tree */
> +		struct rcu_head		rcu;		/* mutually exclusive with rb_node */

Andrii, I am sorry.

I suggested this in reply to 3/8 before I read
[PATCH 7/8] uprobes: perform lockless SRCU-protected uprobes_tree lookup

I have no idea if rb_erase() is rcu-safe or not, but this union certainly
doesn't look right if we use rb_find_rcu/etc.

Yes, this version doesn't include the SRCU-protected uprobes_tree changes,
but still...

Oleg.