linux-kernel - Re: [patch V2 2/6] genirq: Fix misleading synchronize

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 linux-cve-announce 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]

Message-ID: <20190701145340.GB3402@hirez.programming.kicks-ass.net>
Date:   Mon, 1 Jul 2019 16:53:40 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     LKML <linux-kernel@...r.kernel.org>, x86@...nel.org,
        Marc Zyngier <marc.zyngier@....com>
Subject: Re: [patch V2 2/6] genirq: Fix misleading synchronize_irq()
 documentation

On Fri, Jun 28, 2019 at 01:11:50PM +0200, Thomas Gleixner wrote:
> The function might sleep, so it cannot be called from interrupt
> context. Not even with care.
> 
> Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
> ---
>  kernel/irq/manage.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> --- a/kernel/irq/manage.c
> +++ b/kernel/irq/manage.c
> @@ -96,7 +96,8 @@ EXPORT_SYMBOL(synchronize_hardirq);
>   *	to complete before returning. If you use this function while
>   *	holding a resource the IRQ handler may need you will deadlock.
>   *
> - *	This function may be called - with care - from IRQ context.
> + *	Can only be called from preemptible code as it might sleep when
> + *	an interrupt thread is associated to @irq.
>   */
>  void synchronize_irq(unsigned int irq)
>  {

+	might_sleep();

?