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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 7F5EAC43143 for ; Fri, 22 Jun 2018 09:53:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 42E9523FCE for ; Fri, 22 Jun 2018 09:53:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 42E9523FCE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754534AbeFVJxj (ORCPT ); Fri, 22 Jun 2018 05:53:39 -0400 Received: from foss.arm.com ([217.140.101.70]:60840 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754562AbeFVJxJ (ORCPT ); Fri, 22 Jun 2018 05:53:09 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 985AD1596; Fri, 22 Jun 2018 02:53:09 -0700 (PDT) Received: from approximate.cambridge.arm.com (approximate.cambridge.arm.com [10.1.206.75]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 671203F819; Fri, 22 Jun 2018 02:53:08 -0700 (PDT) From: Marc Zyngier To: Thomas Gleixner , Jason Cooper Cc: linux-kernel@vger.kernel.org, Alexandre Belloni , Yang Yingliang , Sumit Garg Subject: [PATCH v2 5/7] irqchip/gic-v3-its: Only emit SYNC if targetting a valid collection Date: Fri, 22 Jun 2018 10:52:52 +0100 Message-Id: <20180622095254.5906-6-marc.zyngier@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180622095254.5906-1-marc.zyngier@arm.com> References: <20180622095254.5906-1-marc.zyngier@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is possible, under obscure circumstances, to convince the ITS driver to emit a SYNC operation that targets a collection that is not bound to any redistributor (and the target_address field is zero) because the corresponding CPU has not been seen yet (the system has been booted with max_cpus="something small"). If the ITS is using the linear CPU number as the target, this is not a big deal, as we just end-up issuing a SYNC to CPU0. But if the ITS requires the physical address of the redistributor (with GITS_TYPER.PTA==1), we end-up asking the ITS to write to the physical address zero, which is not exactly a good idea (there has been report of the ITS locking up). This should of course never happen, but hey, this is SW... In order to avoid the above disaster, let's track which collections have been actually initialized, and let's not generate a SYNC if the collection hasn't been properly bound to a redistributor. We take this opportunity to spit our a warning, in the hope that someone may report the issue if it arrises again. Reported-by: Yang Yingliang Signed-off-by: Marc Zyngier --- drivers/irqchip/irq-gic-v3-its.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index cae53937feeb..fcfc96f8e0de 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -182,6 +182,14 @@ static struct its_collection *dev_event_to_col(struct its_device *its_dev, return its->collections + its_dev->event_map.col_map[event]; } +static struct its_collection *valid_col(struct its_collection *col) +{ + if (WARN_ON_ONCE(col->target_address & GENMASK_ULL(0, 15))) + return NULL; + + return col; +} + /* * ITS command descriptors - parameters to be encoded in a command * block. @@ -439,7 +447,7 @@ static struct its_collection *its_build_mapti_cmd(struct its_node *its, its_fixup_cmd(cmd); - return col; + return valid_col(col); } static struct its_collection *its_build_movi_cmd(struct its_node *its, @@ -458,7 +466,7 @@ static struct its_collection *its_build_movi_cmd(struct its_node *its, its_fixup_cmd(cmd); - return col; + return valid_col(col); } static struct its_collection *its_build_discard_cmd(struct its_node *its, @@ -476,7 +484,7 @@ static struct its_collection *its_build_discard_cmd(struct its_node *its, its_fixup_cmd(cmd); - return col; + return valid_col(col); } static struct its_collection *its_build_inv_cmd(struct its_node *its, @@ -494,7 +502,7 @@ static struct its_collection *its_build_inv_cmd(struct its_node *its, its_fixup_cmd(cmd); - return col; + return valid_col(col); } static struct its_collection *its_build_int_cmd(struct its_node *its, @@ -512,7 +520,7 @@ static struct its_collection *its_build_int_cmd(struct its_node *its, its_fixup_cmd(cmd); - return col; + return valid_col(col); } static struct its_collection *its_build_clear_cmd(struct its_node *its, @@ -530,7 +538,7 @@ static struct its_collection *its_build_clear_cmd(struct its_node *its, its_fixup_cmd(cmd); - return col; + return valid_col(col); } static struct its_collection *its_build_invall_cmd(struct its_node *its, @@ -1824,11 +1832,16 @@ static int its_alloc_tables(struct its_node *its) static int its_alloc_collections(struct its_node *its) { + int i; + its->collections = kcalloc(nr_cpu_ids, sizeof(*its->collections), GFP_KERNEL); if (!its->collections) return -ENOMEM; + for (i = 0; i < nr_cpu_ids; i++) + its->collections[i].target_address = ~0ULL; + return 0; } -- 2.17.1