From: Daniel Colascione <dancol@google.com>
To: Joel Fernandes <joel@joelfernandes.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Lorenzo Colitti <lorenzo@google.com>,
Chenbo Feng <fengc@google.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Joel Fernandes <joelaf@google.com>,
Alexei Starovoitov <ast@fb.com>,
lkml <linux-kernel@vger.kernel.org>,
Tim Murray <timmurray@google.com>,
Daniel Borkmann <daniel@iogearbox.net>,
netdev <netdev@vger.kernel.org>
Subject: Re: [RFC] Add BPF_SYNCHRONIZE bpf(2) command
Date: Fri, 27 Jul 2018 12:17:37 -0700 [thread overview]
Message-ID: <CAKOZueu37C49TGny85_LZ_yp+NgQtWfjpBU0CB7OS6HFF-CeHA@mail.gmail.com> (raw)
In-Reply-To: <20180714181815.GA199777@joelaf.mtv.corp.google.com>
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On Sat, Jul 14, 2018 at 11:18 AM, Joel Fernandes <joel@joelfernandes.org>
wrote:
> By the way just curious I was briefly going through kernel/bpf/arraymap.c.
> How are you protecting against load-store tearing of values of array map
> updates/lookups?
>
> For example, if userspace reads an array map at a particular index, while
> another CPU is updating it, then userspace can read partial values /
> half-updated values right? Since rcu_read_lock is in use, I was hoping to
> find something like rcu_assign_pointer there to protect readers against
> concurrent updates. Thanks for any clarification.
I'm also curious about the answer to this question.
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next prev parent reply other threads:[~2018-07-27 19:17 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20180707015616.25988-1-dancol@google.com>
2018-07-07 2:54 ` [RFC] Add BPF_SYNCHRONIZE bpf(2) command Alexei Starovoitov
2018-07-07 3:22 ` Daniel Colascione
2018-07-07 20:33 ` Joel Fernandes
2018-07-08 20:54 ` Mathieu Desnoyers
2018-07-09 21:09 ` Alexei Starovoitov
2018-07-09 21:35 ` Mathieu Desnoyers
2018-07-09 22:19 ` Paul E. McKenney
2018-07-09 22:19 ` Alexei Starovoitov
2018-07-09 22:48 ` Paul E. McKenney
2018-07-09 21:36 ` Daniel Colascione
2018-07-09 22:10 ` Alexei Starovoitov
2018-07-09 22:21 ` Daniel Colascione
2018-07-09 22:34 ` Alexei Starovoitov
2018-07-10 5:25 ` Chenbo Feng
2018-07-10 23:52 ` Alexei Starovoitov
2018-07-11 2:46 ` Lorenzo Colitti
2018-07-11 3:40 ` Alexei Starovoitov
2018-07-14 18:18 ` Joel Fernandes
2018-07-16 15:29 ` Daniel Colascione
2018-07-16 20:23 ` Joel Fernandes
2018-07-26 16:51 ` [PATCH v2] Add BPF_SYNCHRONIZE_MAPS " Daniel Colascione
2018-07-27 19:17 ` Daniel Colascione [this message]
2018-07-10 5:13 ` [RFC] Add BPF_SYNCHRONIZE " Joel Fernandes
2018-07-10 16:42 ` Paul E. McKenney
2018-07-10 16:57 ` Joel Fernandes
2018-07-10 17:12 ` Paul E. McKenney
2018-07-10 17:29 ` Joel Fernandes
2018-07-10 17:42 ` Paul E. McKenney
2018-07-29 15:57 Alexei Starovoitov
2018-07-30 22:26 ` Joel Fernandes
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