From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:33298 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751788AbdJOOHG (ORCPT ); Sun, 15 Oct 2017 10:07:06 -0400 Subject: Patch "genirq/cpuhotplug: Add sanity check for effective affinity mask" has been added to the 4.13-stable tree To: tglx@linutronix.de, gregkh@linuxfoundation.org, hch@lst.de, marc.zyngier@arm.com Cc: , From: Date: Sun, 15 Oct 2017 16:06:49 +0200 Message-ID: <1508076409182250@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled genirq/cpuhotplug: Add sanity check for effective affinity mask to the 4.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: genirq-cpuhotplug-add-sanity-check-for-effective-affinity-mask.patch and it can be found in the queue-4.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 60b09c51bb4fb46e2331fdbb39f91520f31d35f7 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 9 Oct 2017 12:47:24 +0200 Subject: genirq/cpuhotplug: Add sanity check for effective affinity mask From: Thomas Gleixner commit 60b09c51bb4fb46e2331fdbb39f91520f31d35f7 upstream. The effective affinity mask handling has no safety net when the mask is not updated by the interrupt chip or the mask contains offline CPUs. If that happens the CPU unplug code fails to migrate interrupts. Add sanity checks and emit a warning when the mask contains only offline CPUs. Fixes: 415fcf1a2293 ("genirq/cpuhotplug: Use effective affinity mask") Signed-off-by: Thomas Gleixner Cc: Marc Zyngier Cc: Christoph Hellwig Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1710042208400.2406@nanos Signed-off-by: Greg Kroah-Hartman --- kernel/irq/cpuhotplug.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) --- a/kernel/irq/cpuhotplug.c +++ b/kernel/irq/cpuhotplug.c @@ -18,8 +18,34 @@ static inline bool irq_needs_fixup(struct irq_data *d) { const struct cpumask *m = irq_data_get_effective_affinity_mask(d); + unsigned int cpu = smp_processor_id(); - return cpumask_test_cpu(smp_processor_id(), m); +#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK + /* + * The cpumask_empty() check is a workaround for interrupt chips, + * which do not implement effective affinity, but the architecture has + * enabled the config switch. Use the general affinity mask instead. + */ + if (cpumask_empty(m)) + m = irq_data_get_affinity_mask(d); + + /* + * Sanity check. If the mask is not empty when excluding the outgoing + * CPU then it must contain at least one online CPU. The outgoing CPU + * has been removed from the online mask already. + */ + if (cpumask_any_but(m, cpu) < nr_cpu_ids && + cpumask_any_and(m, cpu_online_mask) >= nr_cpu_ids) { + /* + * If this happens then there was a missed IRQ fixup at some + * point. Warn about it and enforce fixup. + */ + pr_warn("Eff. affinity %*pbl of IRQ %u contains only offline CPUs after offlining CPU %u\n", + cpumask_pr_args(m), d->irq, cpu); + return true; + } +#endif + return cpumask_test_cpu(cpu, m); } static bool migrate_one_irq(struct irq_desc *desc) Patches currently in stable-queue which might be from tglx@linutronix.de are queue-4.13/genirq-cpuhotplug-add-sanity-check-for-effective-affinity-mask.patch queue-4.13/genirq-cpuhotplug-enforce-affinity-setting-on-startup-of-managed-irqs.patch