From: Johannes Berg <johannes@sipsolutions.net>
To: Paul Turner <commonly@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Hunter <ahh@google.com>,
Andy Lutomirski <luto@amacapital.net>,
Andi Kleen <andi@firstfloor.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Dave Watson <davejwatson@fb.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: linux-api@vger.kernel.org, linux-kernel@vger.kernel.org,
Josh Triplett <josh@joshtriplett.org>,
Ingo Molnar <mingo@redhat.com>, Chris Lameter <cl@linux.com>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [RFC PATCH v2 1/3] restartable sequences: user-space per-cpu critical sections
Date: Thu, 19 Nov 2015 17:38:10 +0100 [thread overview]
Message-ID: <1447951090.2765.9.camel@sipsolutions.net> (raw)
In-Reply-To: <20151027235653.16059.8933.stgit@pjt-glaptop.roam.corp.google.com>
On Tue, 2015-10-27 at 16:56 -0700, Paul Turner wrote:
>
> + * flags is currently unused.
> + */
> +SYSCALL_DEFINE3(restartable_sequences,
> +> > > int, flags, long, event_and_cpu, long, post_commit_instr_addr)
> +{
> + return rseq_configure_current((__user u64 *)event_and_cpu,
> + (__user void *)post_commit_instr_addr);
It seems that, for forward compatibility and actually usefulness of the
'flags' argument, you need to reject the syscall if it's passed non-
zero right now. Otherwise applications can (inadvertedly) pass garbage
and you'll not be able to use it in the future.
johannes
next prev parent reply other threads:[~2015-11-19 16:39 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-27 23:56 [RFC PATCH 0/3] restartable sequences v2: fast user-space percpu critical sections Paul Turner
2015-10-27 23:56 ` [RFC PATCH v2 1/3] restartable sequences: user-space per-cpu " Paul Turner
2015-11-19 16:38 ` Johannes Berg [this message]
2015-12-11 12:56 ` Mathieu Desnoyers
2015-10-27 23:57 ` [RFC PATCH v2 2/3] restartable sequences: x86 ABI Paul Turner
2015-10-28 5:03 ` Peter Zijlstra
2015-10-28 5:19 ` Paul Turner
2015-12-11 13:30 ` Mathieu Desnoyers
2015-10-27 23:57 ` [RFC PATCH v2 3/3] restartable sequences: basic self-tests Paul Turner
2016-04-05 20:33 ` Mathieu Desnoyers
2016-04-06 7:43 ` Peter Zijlstra
2016-04-06 13:39 ` Mathieu Desnoyers
2016-04-06 19:25 ` Peter Zijlstra
2015-10-28 14:44 ` [RFC PATCH 0/3] restartable sequences v2: fast user-space percpu critical sections Dave Watson
2015-12-11 12:05 ` Mathieu Desnoyers
2015-12-11 13:39 ` Mathieu Desnoyers
2016-04-06 15:56 ` Andy Lutomirski
2016-04-07 12:02 ` Peter Zijlstra
2016-04-07 14:35 ` Andy Lutomirski
2016-04-07 15:24 ` Peter Zijlstra
2016-04-07 15:39 ` Peter Zijlstra
2016-04-07 15:44 ` Andy Lutomirski
2016-04-07 15:53 ` Peter Zijlstra
2016-04-07 16:43 ` Andy Lutomirski
2016-04-07 20:11 ` Peter Zijlstra
2016-04-07 22:05 ` Andy Lutomirski
2016-04-08 1:11 ` Mathieu Desnoyers
2016-04-08 1:21 ` Andy Lutomirski
2016-04-08 2:05 ` Mathieu Desnoyers
2016-04-08 17:46 ` Mathieu Desnoyers
2016-04-08 21:16 ` Andy Lutomirski
2016-04-08 21:25 ` Linus Torvalds
2016-04-10 14:07 ` Mathieu Desnoyers
2016-04-08 11:02 ` Peter Zijlstra
2016-04-08 15:57 ` Andy Lutomirski
2016-04-08 6:41 ` Peter Zijlstra
2016-04-08 15:58 ` Andy Lutomirski
2016-04-11 21:55 ` Mathieu Desnoyers
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