linux-kernel - Re: [RT PATCH] sched: rt: fix two possible deadlocks in push_irq_work

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: <alpine.DEB.2.11.1511150925040.3761@nanos>
Date:	Sun, 15 Nov 2015 09:26:14 +0100 (CET)
From:	Thomas Gleixner <tglx@...utronix.de>
To:	yjin <yanjiang.jin@...driver.com>
cc:	Steven Rostedt <rostedt@...dmis.org>, mingo@...hat.com,
	bigeasy@...utronix.de, peterz@...radead.org,
	linux-kernel@...r.kernel.org, jinyanjiang@...il.com,
	stable-rt@...r.kernel.org, linux-rt-users@...r.kernel.org
Subject: Re: [RT PATCH] sched: rt: fix two possible deadlocks in
 push_irq_work_func

On Sun, 15 Nov 2015, Thomas Gleixner wrote:
> On Sat, 14 Nov 2015, yjin wrote:
> > > > Use raw_spin_{un,}lock_irq{save,restore} in push_irq_work_func() to
> > > > prevent following potentially deadlock scenario:
> > > Ug. No, the real fix is that the irq work is to be run from hard
> > > interrupt context.
> > But if so, we shouldn't call irq_work_tick() in run_timer_softirq(), right?
> 
> The work is marked IRQ_WORK_HARD_IRQ so it should be run from hard irq
> context. We only run the work, which is not marked IRQ_WORK_HARD_IRQ
> from the softirq on RT.

Which does not happen on MIPS as it uses the generic
arch_irq_work_has_interrupt() implementation which returns 'false'.

Thanks,

	tglx
--
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/