From nobody Fri Sep 12 06:19:10 2025 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 9F4FEECAAD1 for ; Thu, 1 Sep 2022 14:28:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234669AbiIAO2a (ORCPT ); Thu, 1 Sep 2022 10:28:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233348AbiIAO2Y (ORCPT ); Thu, 1 Sep 2022 10:28:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D76132D93 for ; Thu, 1 Sep 2022 07:28:22 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 33A3061D10 for ; Thu, 1 Sep 2022 14:28:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 86CF3C4347C; Thu, 1 Sep 2022 14:28:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662042501; bh=6H3NdcsF1XZsaJlgrF7qf48qrgCNTKj+8GVztoNi+DY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SRIe1LiMDcg/qzTXHySXOgir56mX854wgQ2iVmmj977mh+JHZcizucJ9xtRu5KwKp qLxipWU0PGjGCNolfAgOBrWkTyznYyEn5C96bOB7K3FyPZxf3DZhy8qaBYR73y/92E MyXG6g1ekf+16rKJ3IXfxdGkOsPhDgSkdUxLkNdUEQwtbjlFpIlX2AC3PYx/6Unudu qvDXPY4vgQHz0pX1BidYiaxZNXyRUaM+hn71cQuE/jJe83qw10jpONdDFeKkWl0Y3/ wkBHglpYCvP9Sa6toiuv4E4MLlUdTcq09U89qsafQFcL/fXviTceuqcNDi9OlWDFnd cp/aLqiUROoJg== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1oTlB8-0003Zq-VK; Thu, 01 Sep 2022 16:28:22 +0200 From: Johan Hovold To: Marc Zyngier Cc: Thomas Gleixner , Greg Kroah-Hartman , Rob Herring , linux-kernel@vger.kernel.org, Johan Hovold , Dmitry Torokhov , Jon Hunter Subject: [PATCH v2 2/4] irqdomain: Fix mapping-creation race Date: Thu, 1 Sep 2022 16:28:14 +0200 Message-Id: <20220901142816.13731-3-johan+linaro@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220901142816.13731-1-johan+linaro@kernel.org> References: <20220901142816.13731-1-johan+linaro@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Parallel probing (e.g. due to asynchronous probing) of devices that share interrupts can currently result in two mappings for the same hardware interrupt to be created. Add a serialising mapping mutex so that looking for an existing mapping before creating a new one is done atomically. Fixes: 765230b5f084 ("driver-core: add asynchronous probing support for dri= vers") Fixes: b62b2cf5759b ("irqdomain: Fix handling of type settings for existing= mappings") Cc: Dmitry Torokhov Cc: Jon Hunter Link: https://lore.kernel.org/r/YuJXMHoT4ijUxnRb@hovoldconsulting.com Signed-off-by: Johan Hovold --- include/linux/irqdomain.h | 2 ++ kernel/irq/irqdomain.c | 33 ++++++++++++++++++++++++--------- 2 files changed, 26 insertions(+), 9 deletions(-) diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index 00d577f90883..8df9b9586e29 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -144,6 +144,7 @@ struct irq_domain_chip_generic; * core code. * @flags: host per irq_domain flags * @mapcount: The number of mapped interrupts + * @map_mutex: Mapping lock * * Optional elements * @fwnode: Pointer to firmware node associated with the irq_domain. Prett= y easy @@ -168,6 +169,7 @@ struct irq_domain { void *host_data; unsigned int flags; unsigned int mapcount; + struct mutex map_mutex; =20 /* Optional data */ struct fwnode_handle *fwnode; diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 24ddd8d9b597..1af1d141e165 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -215,6 +215,7 @@ struct irq_domain *__irq_domain_add(struct fwnode_handl= e *fwnode, unsigned int s /* Fill structure */ INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL); mutex_init(&domain->revmap_mutex); + mutex_init(&domain->map_mutex); domain->ops =3D ops; domain->host_data =3D host_data; domain->hwirq_max =3D hwirq_max; @@ -721,14 +722,20 @@ unsigned int irq_create_mapping_affinity(struct irq_d= omain *domain, return 0; } =20 + mutex_lock(&domain->map_mutex); + /* Check if mapping already exists */ virq =3D irq_find_mapping(domain, hwirq); if (virq) { pr_debug("existing mapping on virq %d\n", virq); - return virq; + goto out; } =20 - return __irq_create_mapping_affinity(domain, hwirq, affinity); + virq =3D __irq_create_mapping_affinity(domain, hwirq, affinity); +out: + mutex_unlock(&domain->map_mutex); + + return virq; } EXPORT_SYMBOL_GPL(irq_create_mapping_affinity); =20 @@ -795,6 +802,8 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspe= c *fwspec) if (WARN_ON(type & ~IRQ_TYPE_SENSE_MASK)) type &=3D IRQ_TYPE_SENSE_MASK; =20 + mutex_lock(&domain->map_mutex); + /* * If we've already configured this interrupt, * don't do it again, or hell will break loose. @@ -807,7 +816,7 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspe= c *fwspec) * interrupt number. */ if (type =3D=3D IRQ_TYPE_NONE || type =3D=3D irq_get_trigger_type(virq)) - return virq; + goto out; =20 /* * If the trigger type has not been set yet, then set @@ -816,26 +825,26 @@ unsigned int irq_create_fwspec_mapping(struct irq_fws= pec *fwspec) if (irq_get_trigger_type(virq) =3D=3D IRQ_TYPE_NONE) { irq_data =3D irq_get_irq_data(virq); if (!irq_data) - return 0; + goto err; =20 irqd_set_trigger_type(irq_data, type); - return virq; + goto out; } =20 pr_warn("type mismatch, failed to map hwirq-%lu for %s!\n", hwirq, of_node_full_name(to_of_node(fwspec->fwnode))); - return 0; + goto err; } =20 if (irq_domain_is_hierarchy(domain)) { virq =3D irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, fwspec); if (virq <=3D 0) - return 0; + goto err; } else { /* Create mapping */ virq =3D __irq_create_mapping_affinity(domain, hwirq, NULL); if (!virq) - return virq; + goto err; } =20 irq_data =3D irq_get_irq_data(virq); @@ -844,13 +853,19 @@ unsigned int irq_create_fwspec_mapping(struct irq_fws= pec *fwspec) irq_domain_free_irqs(virq, 1); else irq_dispose_mapping(virq); - return 0; + goto err; } =20 /* Store trigger type */ irqd_set_trigger_type(irq_data, type); +out: + mutex_unlock(&domain->map_mutex); =20 return virq; +err: + mutex_unlock(&domain->map_mutex); + + return 0; } EXPORT_SYMBOL_GPL(irq_create_fwspec_mapping); =20 --=20 2.35.1