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  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]
Date:   Fri, 12 Jun 2020 21:25:20 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     paulmck@...nel.org
Cc:     LKML <linux-kernel@...r.kernel.org>, rcu@...r.kernel.org,
        Andrew Lutomirski <luto@...nel.org>, X86 ML <x86@...nel.org>,
        Frederic Weisbecker <frederic@...nel.org>,
        Steven Rostedt <rostedt@...dmis.org>,
        Joel Fernandes <joel@...lfernandes.org>,
        Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
        Will Deacon <will@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH x86/entry: Force rcu_irq_enter() when in idle task

"Paul E. McKenney" <paulmck@...nel.org> writes:
> On Fri, Jun 12, 2020 at 10:49:53AM -0700, Paul E. McKenney wrote:
>> I will therefore address this issue in a follow-on patch.
>
> I should add that -your- patch from yesterday did -not- cause this
> problem, in case that is of interest.

So I still can add it back and amend the changelog and comment:

Change the condition from !rcu_is_watching() to is_idle_task(current) ||
rcu_is_watching() which enforces that interrupts in the idle task
unconditionally invoke rcu_irq_enter() independent of the RCU state. For
most scenarios is_idle_task() would be sufficient but Task RCU needs it
according to Paul.

Thanks,

        tglx

Powered by blists - more mailing lists