From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE39DC47409 for ; Thu, 2 Jan 2020 22:29:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B0A0B20863 for ; Thu, 2 Jan 2020 22:29:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578004198; bh=gFmiTIFanl6uDAvj8mEMHH0JSvxZewluyRxF6kMjtPI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xVD+A5m7knhMVCn0fDvJ51Qx5ylDny+AiZruIBFUqxJyOgLEEFooZS516ojaPf7rK ujT9pZCfb/PjujVYSc71Rwa0TLSUkVk9dsZTXAltc6NcAoBkd2UFfMTJ4Nx4xaIJEz ut2LzFicvQlHiURTtiojnI4RkRFwigUsiiLQKf/c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730109AbgABW36 (ORCPT ); Thu, 2 Jan 2020 17:29:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:32896 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730094AbgABW3v (ORCPT ); Thu, 2 Jan 2020 17:29:51 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 960AB20863; Thu, 2 Jan 2020 22:29:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578004191; bh=gFmiTIFanl6uDAvj8mEMHH0JSvxZewluyRxF6kMjtPI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OZtYQPKl7iABZgkwVSmz/rhokJVmcRzdKvflbN1cf6/ryclnBxRzFZVZhSAsWCWJ1 7/pfBCXfhTCC6ORBTsZrz5/8k+6Zz9bZHREFUIREZD0gXDFgqQvCRY59ayC8CnaGaL tz0q5E7njmHkRwZ8GBxGlZHEqLI7jbcXu6AdndHU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Andy Shevchenko , Linus Torvalds , Peter Zijlstra , Sebastian Siewior , Ingo Molnar , Sasha Levin Subject: [PATCH 4.9 041/171] x86/ioapic: Prevent inconsistent state when moving an interrupt Date: Thu, 2 Jan 2020 23:06:12 +0100 Message-Id: <20200102220552.675021311@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200102220546.960200039@linuxfoundation.org> References: <20200102220546.960200039@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner [ Upstream commit df4393424af3fbdcd5c404077176082a8ce459c4 ] There is an issue with threaded interrupts which are marked ONESHOT and using the fasteoi handler: if (IS_ONESHOT()) mask_irq(); .... cond_unmask_eoi_irq() chip->irq_eoi(); if (setaffinity_pending) { mask_ioapic(); ... move_affinity(); unmask_ioapic(); } So if setaffinity is pending the interrupt will be moved and then unconditionally unmasked at the ioapic level, which is wrong in two aspects: 1) It should be kept masked up to the point where the threaded handler finished. 2) The physical chip state and the software masked state are inconsistent Guard both the mask and the unmask with a check for the software masked state. If the line is marked masked then the ioapic line is also masked, so both mask_ioapic() and unmask_ioapic() can be skipped safely. Signed-off-by: Thomas Gleixner Cc: Andy Shevchenko Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Sebastian Siewior Fixes: 3aa551c9b4c4 ("genirq: add threaded interrupt handler support") Link: https://lkml.kernel.org/r/20191017101938.321393687@linutronix.de Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- arch/x86/kernel/apic/io_apic.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 09dd95cabfc2..3401b28f1312 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -1712,9 +1712,10 @@ static bool io_apic_level_ack_pending(struct mp_chip_data *data) static inline bool ioapic_irqd_mask(struct irq_data *data) { - /* If we are moving the irq we need to mask it */ + /* If we are moving the IRQ we need to mask it */ if (unlikely(irqd_is_setaffinity_pending(data))) { - mask_ioapic_irq(data); + if (!irqd_irq_masked(data)) + mask_ioapic_irq(data); return true; } return false; @@ -1751,7 +1752,9 @@ static inline void ioapic_irqd_unmask(struct irq_data *data, bool masked) */ if (!io_apic_level_ack_pending(data->chip_data)) irq_move_masked_irq(data); - unmask_ioapic_irq(data); + /* If the IRQ is masked in the core, leave it: */ + if (!irqd_irq_masked(data)) + unmask_ioapic_irq(data); } } #else -- 2.20.1