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=-9.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 CB8C4C433ED for ; Wed, 21 Apr 2021 17:57:52 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6A54E61427 for ; Wed, 21 Apr 2021 17:57:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6A54E61427 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Subject:Cc:To: From:Message-ID:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=RdepaIwktFHczmf0br+VwqjvSrXWau2LSFha1vNkqko=; b=m5pCW5HVg2jKGhuZHXYcrnnEJ oNVcKBTEz/hkSKW7mDvU1bTv78V5+ia7EmeVetazHUR02FtyRM/AWOlPCke0CKM7v0bWgF85tHQWZ 8KwvEYAkooMmOCWA75VES7K3MuyQFDAjCJm98FeIV2ZBhA09rmmhY0jXL7fxfDqVSMn3OUh6D/056 iJBuWz27tNhGo0s005mSO+9JeZ2qA/5GFA+U6aK0oxwnrSr0C8F9OQz0tKQ3gIcdTR7sJ+S0Mgd9M ix9Ci1dIRlbmAj2zG6FXQo4A/ro7O5fQOFwCJD+cmxZw2Ur09KuoKgpezZNDm0zga62FBaqlJbTam BWlQ0pl7g==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lZH5E-00EvKH-Rf; Wed, 21 Apr 2021 17:56:17 +0000 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lZH5B-00EvK2-DA for linux-arm-kernel@desiato.infradead.org; Wed, 21 Apr 2021 17:56:13 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Type:MIME-Version:References: In-Reply-To:Subject:Cc:To:From:Message-ID:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=E2QwD0RJ2sQlRqP2dLHSyKF38dF/mah2pEmxR1hLuHg=; b=VpBHj6LfuEAtgdH/RqPo5nBudz R5ZQXisYb/KzmuEUBGsvt+aGYqMQfEkCB5e3cgUiaaH4D48jIfogaynlZE5D9mWDgEjC18CT1Pden x7CEWjDMcRTziftw4m2J8+GXG38pgw4u05kjEK5LMFz8CAVj9uTsLSHjmpsgOR4Xji55MZeA6fr4Q e8aaarqTC4GsACkid4AqyEyNweQsFpZd6+qMAfYOjqm0BYrie1TH5vvWa+d2jrVs3PFA8nYBsZuFU si6/hEHYIHHDCNpCuKOrr5jRDfzkHQ/xKK+hEcY6FtbAGt2saggVK3uSYoAB+bh1nZ/WGN3gh13CZ 6KFCVhxw==; Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lZH58-00D5Ea-Qg for linux-arm-kernel@lists.infradead.org; Wed, 21 Apr 2021 17:56:12 +0000 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (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 5DE48613D1; Wed, 21 Apr 2021 17:56:10 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lZH56-008kJ3-4I; Wed, 21 Apr 2021 18:56:08 +0100 Date: Wed, 21 Apr 2021 18:56:07 +0100 Message-ID: <87tunzsers.wl-maz@kernel.org> From: Marc Zyngier To: Sudeep Holla Cc: Lorenzo Pieralisi , Hanjun Guo , dann frazier , Fu Wei , Len Brown , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH 2/2] ACPI: irq: Prevent unregistering of GIC SGIs In-Reply-To: <20210421171516.hg3ex7jqigqjqa6i@bogus> References: <20210421164317.1718831-1-maz@kernel.org> <20210421164317.1718831-3-maz@kernel.org> <20210421171516.hg3ex7jqigqjqa6i@bogus> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: sudeep.holla@arm.com, lorenzo.pieralisi@arm.com, guohanjun@huawei.com, dann.frazier@canonical.com, wefu@redhat.com, lenb@kernel.org, rjw@rjwysocki.net, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210421_105610_913775_0040A7F9 X-CRM114-Status: GOOD ( 23.01 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, 21 Apr 2021 18:15:16 +0100, Sudeep Holla wrote: > > On Wed, Apr 21, 2021 at 05:43:17PM +0100, Marc Zyngier wrote: > > When using ACPI on arm64, which implies the GIC IRQ model, no > > table should ever provide a GSI number in the range [0:15], > > as these are reserved for IPIs. > > > > However, drivers tend to call acpi_unregister_gsi() with any > > random GSI number provided by half baked tables, which results > > in an exploding kernel when its IPIs have been unconfigured. > > > > In order to catch this, check for the silly case early, warn > > that something is going wrong and avoid the above disaster. > > > > Reviewed-by: Sudeep Holla > > Just curious if this is just precaution or do we have a platform doing > something stupid like this ? Without this, it could be really hard to pinpoint which driver messes with IPIs. Having this in place would have caught the GTDT bug much earlier (several years ago actually). The only reason I managed to track it down in a short amount of time is that the driver actually printed an error message before the kernel exploded while probing a completely unrelated driver. Without this message, I'd still be scratching my head. The WARN_ON() would definitely point at the guilty party, and keep the kernel running. Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel