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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C31CBC433FE for ; Wed, 6 Apr 2022 00:40:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243504AbiDFATt (ORCPT ); Tue, 5 Apr 2022 20:19:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236782AbiDEKfq (ORCPT ); Tue, 5 Apr 2022 06:35:46 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 661F14AE19; Tue, 5 Apr 2022 03:21:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 91556B81BC5; Tue, 5 Apr 2022 10:21:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E72CDC385A1; Tue, 5 Apr 2022 10:21:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649154099; bh=vYsMLDYVMr0DTK/i9DNXbMo0fVtarin0N+Axfv9aNdA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NhUJXBcpKhaZf/ljG4jgsnezmajVcY5ohtatF2bWTGXPj+hSAet6sI+S0r5htoVVM WrvXAYqa13gBqV8sYKG4NuwhCcM9Pb1veOaO6kOpHB3c93ek/nGL1SP8z7xnfit73s cN8xhjoKKxNJzaskAKsmFDYSRe5GCRM75gZ8n6lA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marc Zyngier , Maulik Shah , Sasha Levin Subject: [PATCH 5.10 458/599] irqchip/qcom-pdc: Fix broken locking Date: Tue, 5 Apr 2022 09:32:32 +0200 Message-Id: <20220405070312.458810745@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070258.802373272@linuxfoundation.org> References: <20220405070258.802373272@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marc Zyngier [ Upstream commit a6aca2f460e203781dc41391913cc5b54f4bc0ce ] pdc_enable_intr() serves as a primitive to qcom_pdc_gic_{en,dis}able, and has a raw spinlock for mutual exclusion, which is uses with interruptible primitives. This means that this critical section can itself be interrupted. Should the interrupt also be a PDC interrupt, and the endpoint driver perform an irq_disable() on that interrupt, we end-up in a deadlock. Fix this by using the irqsave/irqrestore variants of the locking primitives. Signed-off-by: Marc Zyngier Reviewed-by: Maulik Shah Link: https://lore.kernel.org/r/20220224101226.88373-5-maz@kernel.org Signed-off-by: Sasha Levin --- drivers/irqchip/qcom-pdc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/irqchip/qcom-pdc.c b/drivers/irqchip/qcom-pdc.c index 5dc63c20b67e..fc747b7f4983 100644 --- a/drivers/irqchip/qcom-pdc.c +++ b/drivers/irqchip/qcom-pdc.c @@ -74,17 +74,18 @@ static int qcom_pdc_gic_set_irqchip_state(struct irq_data *d, static void pdc_enable_intr(struct irq_data *d, bool on) { int pin_out = d->hwirq; + unsigned long flags; u32 index, mask; u32 enable; index = pin_out / 32; mask = pin_out % 32; - raw_spin_lock(&pdc_lock); + raw_spin_lock_irqsave(&pdc_lock, flags); enable = pdc_reg_read(IRQ_ENABLE_BANK, index); enable = on ? ENABLE_INTR(enable, mask) : CLEAR_INTR(enable, mask); pdc_reg_write(IRQ_ENABLE_BANK, index, enable); - raw_spin_unlock(&pdc_lock); + raw_spin_unlock_irqrestore(&pdc_lock, flags); } static void qcom_pdc_gic_disable(struct irq_data *d) -- 2.34.1