From: Eric Dumazet <eric.dumazet@gmail.com>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>,
Eric Dumazet <eric.dumazet@gmail.com>
Cc: cai@lca.pw, Netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Marco Elver <elver@google.com>,
Dmitry Vyukov <dvyukov@google.com>
Subject: Re: [PATCH v3] skbuff: fix a data race in skb_queue_len()
Date: Thu, 6 Feb 2020 10:22:02 -0800 [thread overview]
Message-ID: <495f79f5-ae27-478a-2a1d-6d3fba2d4334@gmail.com> (raw)
In-Reply-To: <CAHmME9pGhQoY8MjR8uvEZpF66Y_DvReAjKBx8L4SRiqbL_9itw@mail.gmail.com>
On 2/6/20 10:12 AM, Jason A. Donenfeld wrote:
> On Thu, Feb 6, 2020 at 6:10 PM Eric Dumazet <eric.dumazet@gmail.com> wrote:
>> Unfortunately we do not have ADD_ONCE() or something like that.
>
> I guess normally this is called "atomic_add", unless you're thinking
> instead about something like this, which generates the same
> inefficient code as WRITE_ONCE:
>
> #define ADD_ONCE(d, s) *(volatile typeof(d) *)&(d) += (s)
>
Dmitry Vyukov had a nice suggestion few months back how to implement this.
https://lkml.org/lkml/2019/10/5/6
next prev parent reply other threads:[~2020-02-06 18:22 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-04 18:40 [PATCH v3] skbuff: fix a data race in skb_queue_len() Qian Cai
2020-02-06 12:59 ` David Miller
2020-02-06 16:38 ` Jason A. Donenfeld
2020-02-06 17:10 ` Eric Dumazet
2020-02-06 18:12 ` Jason A. Donenfeld
2020-02-06 18:22 ` Eric Dumazet [this message]
2020-02-06 18:43 ` Jason A. Donenfeld
2020-02-06 19:29 ` Marco Elver
2020-02-06 21:55 ` Jason A. Donenfeld
2020-02-07 10:35 ` Marco Elver
2020-02-17 3:24 ` Herbert Xu
2020-02-17 7:39 ` Jason A. Donenfeld
2020-02-17 10:20 ` Herbert Xu
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