linux-kernel - Re: [PATCH 2/2] mm/slab: break up RCU readers on SLAB_TYPESAFE_BY

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZDoRSlHiyIvAz+pR@casper.infradead.org>
Date:   Sat, 15 Apr 2023 03:51:54 +0100
From:   Matthew Wilcox <willy@...radead.org>
To:     SeongJae Park <sj@...nel.org>
Cc:     akpm@...ux-foundation.org, vbabka@...e.cz, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] mm/slab: break up RCU readers on
 SLAB_TYPESAFE_BY_RCU example code

On Sat, Apr 15, 2023 at 12:37:53AM +0000, SeongJae Park wrote:
>   *
> + * begin:
>   *  rcu_read_lock();
> - * again:
>   *  obj = lockless_lookup(key);
>   *  if (obj) {
>   *    if (!try_get_ref(obj)) // might fail for free objects
> - *      goto again;
> + *      goto begin;
>   *
>   *    if (obj->key != key) { // not the object we expected
>   *      put_ref(obj);
> + *      rcu_read_unlock();
>   *      goto again;

- *      goto again;
+ *      goto begin;