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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@elte.hu>
Subject: [patch 0/5] genirq: Sanitize irq_set_affinity callbacks
Date: Tue, 04 Mar 2014 20:43:38 -0000	[thread overview]
Message-ID: <20140304202425.102779779@linutronix.de> (raw)

In my last tree wide sweep of irq controller related oddities I
discovered that some controllers have an broken implementation versus
selecting a single target cpu from the given cpu mask.

The core merily guarantees that at least one of the cpus in the mask
is online.

If the controller callback does not restrict the search for a single
target to the online cpus it might run into the following situation:

     Assume 4 cores online: online mask = 0x0f

     Offline Core 1 	    online mask = 0x0d

     Set affinity to 0xe    is valid due to online mask 0xd

     cpumask_first(0xe)     picks core 1, which is offline

The following series takes care of this. The patches should be tagged
stable if there are no objections.

I'm pondering to extend the core functionality to select a target cpu
before calling into irq_set_affinity() to prevent future copy and
paste failures and get rid of all the duplicated code.

Thanks,

	tglx






             reply	other threads:[~2014-03-04 20:43 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-04 20:43 Thomas Gleixner [this message]
2014-03-04 20:43 ` [patch 1/5] ia64: Validate online cpus in irq_set_affinity() callbacks Thomas Gleixner
2014-03-04 20:43   ` Thomas Gleixner
2014-03-12 12:15   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2014-03-12 12:15     ` tip-bot for Thomas Gleixner
2014-03-04 20:43 ` [patch 2/5] mips: " Thomas Gleixner
2014-03-05 11:20   ` Peter Zijlstra
2014-03-05 14:54     ` Thomas Gleixner
2014-03-12 12:15   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2014-03-04 20:43 ` [patch 3/5] parisc: " Thomas Gleixner
2014-03-12 12:16   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2014-03-04 20:43 ` [patch 4/5] xen: Validate online cpus in set_affinity Thomas Gleixner
2014-03-04 20:43   ` Thomas Gleixner
2014-03-05 10:36   ` David Vrabel
2014-03-05 10:36   ` David Vrabel
2014-03-12 12:15   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2014-03-12 12:15   ` tip-bot for Thomas Gleixner
2014-03-04 20:43 ` [patch 5/5] irqchip: armanda: Sanitize set_irq_affinity() Thomas Gleixner
2014-03-06 19:05   ` Jason Cooper
2014-03-07 16:02     ` Gregory CLEMENT
2014-03-07 17:17       ` Thomas Gleixner
2014-03-18 14:06         ` Gregory CLEMENT
2014-03-18 20:55           ` Thomas Gleixner
2014-03-18 21:04             ` Gregory CLEMENT
2014-04-24 16:04               ` Gregory CLEMENT
2014-04-25 11:15                 ` Jason Cooper
2014-04-28 19:05                   ` Thomas Gleixner
2014-04-28 19:33   ` [tip:irq/urgent] " tip-bot for Thomas Gleixner

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