linux-kernel - How to know if there is a pending interrupt when they are masked?

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-next>] [day] [month] [year] [list]

Message-ID: <bf2e6e81-7218-05e0-fd6e-27c9c5418813@linaro.org>
Date:   Thu, 14 Feb 2019 15:34:45 +0100
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Marc Zyngier <Marc.Zyngier@....com>
Cc:     Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>
Subject: How to know if there is a pending interrupt when they are masked?

Hi,

today we have the possibility to mask the local interrupt with the
command local_irq_disable / local_irq_enable.

The power management path disables the local interrupt in order to
initiate a power down sequence. If there is a pending interrupt this one
will make the power down function to abort, thus exiting right after
calling the shutdown function after costly operations. It could be
interesting to check if there is a pending interrupt before initiating
the power down sequence.

Is there a way to know if there is a pending interrupt on the current
CPU when the local interrupt are disabled? Something like,
local_irq_pending() function ?

Thanks
  -- Daniel

-- 
 <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog