From: Will Deacon <will.deacon@arm.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Brian Gerst <brgerst@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Peter Anvin <hpa@zytor.com>, Oleg Nesterov <oleg@redhat.com>,
linux-arch@vger.kernel.org, Tejun Heo <tj@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Rusty Russell <rusty@rustcorp.com.au>,
Paul McKenney <paulmck@linux.vnet.ibm.com>,
Rafael Wysocki <rafael.j.wysocki@intel.com>,
Arjan van de Ven <arjan@linux.intel.com>,
Rik van Riel <riel@redhat.com>,
"Srivatsa S. Bhat" <srivatsa@mit.edu>,
Sebastian Siewior <bigeasy@linutronix.de>,
Paul Turner <pjt@google.com>,
Russell King <linux@arm.linux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Ralf Baechle <ralf@linux-mips.org>,
Yoshinori Sato <ysato@users.sourceforge.jp>
Subject: Re: [patch 01/20] idle: Move x86ism out of generic code
Date: Mon, 29 Feb 2016 19:48:10 +0000 [thread overview]
Message-ID: <20160229194810.GI14848@arm.com> (raw)
In-Reply-To: <alpine.DEB.2.11.1602292026050.3638@nanos>
On Mon, Feb 29, 2016 at 08:35:41PM +0100, Thomas Gleixner wrote:
> On Sat, 27 Feb 2016, Brian Gerst wrote:
> > > arch_cpu_idle_prepare();
> > > cpu_idle_loop();
> > > }
> >
> > Does this actually work with stack protector enabled?
> > boot_init_stack_canary() is inlined while arch_cpu_idle_prepare() is
> > not.
>
> Stupid me. No it does of course not. I could have sworn that I tested that,
> but obvioulsy not.
>
> I drop that patch, but actually the real question is whether we can drop that
> '#ifdef x86' around that boot_init_stack_canary() invocation.
>
> AFAICT, neither arm, arm64 nor mips and sh call it on anything else than the
> boot cpu. I can't see why that would be an issue on those architectures and
> why it would be a problem if the boot cpu calls it again here.
>
> CC'ed the relevant maintainers. Is there any issue with the patch below?
On arm[64], the canary is unfortunately global, so I don't think it would
be safe to update it live like this without effectively stopping the
machine and forcing everybody into idle.
Will
next prev parent reply other threads:[~2016-02-29 19:48 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-26 18:43 [patch 00/20] cpu/hotplug: Core infrastructure for cpu hotplug rework Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 01/20] idle: Move x86ism out of generic code Thomas Gleixner
2016-02-27 20:29 ` Brian Gerst
2016-02-29 19:35 ` Thomas Gleixner
2016-02-29 19:48 ` Will Deacon [this message]
2016-02-29 20:06 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 02/20] cpu/hotplug: Restructure FROZEN state handling Thomas Gleixner
2016-02-26 18:43 ` [patch 03/20] cpu/hotplug: Restructure cpu_up code Thomas Gleixner
2016-02-26 18:43 ` [patch 04/20] cpu/hotplug: Split out cpu down functions Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 05/20] cpu/hotplug: Add tracepoints Thomas Gleixner
2016-02-26 18:43 ` [patch 06/20] cpu/hotplug: Convert to a state machine for the control processor Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 07/20] cpu/hotplug: Convert the hotplugged cpu work to a state machine Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 08/20] cpu/hotplug: Hand in target state to _cpu_up/down Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 09/20] cpu/hotplug: Add sysfs state interface Thomas Gleixner
2016-02-26 18:43 ` [patch 10/20] cpu/hotplug: Make target state writeable Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 23:46 ` Rafael J. Wysocki
2016-02-27 7:39 ` Thomas Gleixner
2016-02-27 14:43 ` Rafael J. Wysocki
2016-02-28 14:49 ` Thomas Gleixner
2016-02-28 14:49 ` Thomas Gleixner
2016-02-29 15:49 ` Thomas Gleixner
2016-03-01 1:53 ` Rafael J. Wysocki
2016-02-26 18:43 ` [patch 11/20] cpu/hotplug: Implement setup/removal interface Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 12/20] cpu/hotplug: Move scheduler cpu_online notifier to hotplug core Thomas Gleixner
2016-02-26 18:43 ` [patch 13/20] cpu/hotplug: Unpark smpboot threads from the state machine Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 14/20] cpu/hotplug: Split out the state walk into functions Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 15/20] cpu/hotplug: Create hotplug threads Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 16/20] cpu/hotplug: Move online calls to hotplugged cpu Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 17/20] arch/hotplug: Call into idle with a proper state Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 18/20] cpu/hotplug: Let upcoming cpu bring itself fully up Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-03-02 17:28 ` Richard Cochran
2016-02-26 18:43 ` [patch 19/20] cpu/hotplug: Make wait for dead cpu completion based Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-26 18:43 ` [patch 20/20] rcu: Make CPU_DYING_IDLE an explicit call Thomas Gleixner
2016-02-26 18:43 ` Thomas Gleixner
2016-02-27 2:14 ` Paul E. McKenney
2016-02-27 2:23 ` Paul E. McKenney
2016-02-27 7:47 ` Thomas Gleixner
2016-02-27 11:05 ` Paul E. McKenney
2016-02-27 11:30 ` Thomas Gleixner
2016-02-27 11:30 ` Thomas Gleixner
2016-02-27 16:33 ` Paul E. McKenney
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