[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20140903120406.GK30467@titan.lakedaemon.net>
Date: Wed, 3 Sep 2014 08:04:06 -0400
From: Jason Cooper <jason@...edaemon.net>
To: Marc Zyngier <marc.zyngier@....com>
Cc: Thomas Gleixner <tglx@...utronix.de>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-omap@...r.kernel.org" <linux-omap@...r.kernel.org>,
"linux@...nrisc.net" <linux@...nrisc.net>,
"linux@....linux.org.uk" <linux@....linux.org.uk>,
"shawn.guo@...escale.com" <shawn.guo@...escale.com>,
"kernel@...gutronix.de" <kernel@...gutronix.de>,
"tony@...mide.com" <tony@...mide.com>,
Catalin Marinas <Catalin.Marinas@....com>,
Will Deacon <Will.Deacon@....com>,
"jonas@...thpole.se" <jonas@...thpole.se>,
"shc_work@...l.ru" <shc_work@...l.ru>,
"baohua@...nel.org" <baohua@...nel.org>,
"maxime.ripard@...e-electrons.com" <maxime.ripard@...e-electrons.com>,
"khilman@...aro.org" <khilman@...aro.org>,
"sboyd@...eaurora.org" <sboyd@...eaurora.org>,
Lorenzo Pieralisi <Lorenzo.Pieralisi@....com>,
"larry.bassel@...aro.org" <larry.bassel@...aro.org>,
Mark R utland <Mark.Rutland@....com>,
Sudeep Holla <Sudeep.Holla@....com>,
"stefan.kristiansson@...nalahti.fi"
<stefan.kristiansson@...nalahti.fi>,
"vkale@....com" <vkale@....com>,
"schwidefsky@...ibm.com" <schwidefsky@...ibm.com>
Subject: Re: [PATCH v2 00/26] genirq: fix use of irq_find_mapping outside
of legal RCU context
On Wed, Aug 27, 2014 at 10:33:44AM +0100, Marc Zyngier wrote:
> Hi Thomas,
>
> On Tue, Aug 26 2014 at 10:34:51 pm BST, Thomas Gleixner <tglx@...utronix.de> wrote:
> > On Tue, 26 Aug 2014, Marc Zyngier wrote:
> >
> >> A number of irqchip drivers are directly calling irq_find_mapping,
> >> which may use a rcu_read_lock call when walking the radix tree.
> >>
> >> Turns out that if you hit that point with CONFIG_PROVE_RCU enabled,
> >> the kernel will shout at you, as using RCU in this context may be
> >> illegal (specially if coming from the idle state, where RCU would be
> >> in a quiescent state).
> >>
> >> A possible fix would be to wrap calls to irq_find_mapping into a
> >> RCU_NONIDLE macro, but that really looks ugly.
> >>
> >> This patch series introduce another generic IRQ entry point
> >> (handle_domain_irq), which has the exact same behaviour as handle_IRQ
> >> (as defined on arm, arm64 and openrisc), except that it also takes a
> >> irq_domain pointer. This allows the logical IRQ lookup to be done
> >> inside the irq_{enter,exit} section, which contains a
> >> rcu_irq_{enter,exit}, making it safe.
> >
> > Looks good. Should this be routed to the genirq tree?
>
> I'm happy for you to take this series, provided the architecture
> maintainers agree on it (I'm still to hear from the openrisc guys, and
> their mailing-list seems to positively hate my guts).
I think everyone's had a chance to look over it by now. Thomas, shall I
take the series?
thx,
Jason.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists