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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 2D126C433DF for ; Fri, 16 Oct 2020 16:00:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFB0220874 for ; Fri, 16 Oct 2020 16:00:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602864037; bh=rRT3tHLcdzv7BqdvawudyxdgXqsmZ6I4d2gIJKnFiCM=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=csHLZFc4YL1YF2epKtzjqmNV5hL1k2UDl9bXUE9dZLzNblg9kF9K2Pdj/RouThtPD bB+rqPlDhKWQwYcDRyt9M+ne2/30O59KaZVe++ozbai1teCrhXS+RxzOWXq0LHMQdd DJsp0r2AL07HuFZzzTxG+6WndQZVkclsZ9kFaeOc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2409076AbgJPQAh (ORCPT ); Fri, 16 Oct 2020 12:00:37 -0400 Received: from mail-ot1-f67.google.com ([209.85.210.67]:46847 "EHLO mail-ot1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2408468AbgJPQAh (ORCPT ); Fri, 16 Oct 2020 12:00:37 -0400 Received: by mail-ot1-f67.google.com with SMTP id m11so2803738otk.13 for ; Fri, 16 Oct 2020 09:00:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=nFCzqKn5rqHfe/qUj17znJrSjRNjpAWf9smqu4k77K8=; b=dMiDKf5W8/F59MVlV1amY2O+pjH+k/jc+Hdy1CxE4vRg076rMhp3z65KPYYIMeHRzM hgm/zS7MNxvf6HfVU7HiXtOyyToQPLN4RXZ0HCUcvZ2ENFKaFPtybdXKIjbLPl5ix5WG 06WUTj2HbbIfn1CG01s6jfveTKNsOic5iFxrqrsbXwKsKUpoIDzEVzV8ruMiIgAL4XkW udFceW85LLVKGk+rIfzCR527mvcZo26YgjNy6p0tMNL9h6Yu9lak/uUaB6gpRO0fbvMr CFL3D7wmPJse+qwFGdm0xaj7XB/1Hhpl5UJXKt1GUqgh+qqeuLEAr45D4FdKMfGpagmr dqzg== X-Gm-Message-State: AOAM530ODb7s2JIHVGlqJjPSIz3uZfj1qHc1zMnAAizVNMkshNTsaTCE VgXmBXv2wNBslycGTO/bOBHCRAiyftHcQLpEGgo= X-Google-Smtp-Source: ABdhPJxDx62rm+kEKb0QD0zknN91GJcA+3+zlhflhqt3uzamBbjVTII099mytz16moH7/K1dQA3cn6Oa9IH6fMCwRPc= X-Received: by 2002:a9d:734f:: with SMTP id l15mr3288124otk.260.1602864036288; Fri, 16 Oct 2020 09:00:36 -0700 (PDT) MIME-Version: 1.0 References: <20201009152116.35184-1-jamie@nuviainc.com> <20201012130446.57325-1-jamie@nuviainc.com> In-Reply-To: <20201012130446.57325-1-jamie@nuviainc.com> From: "Rafael J. Wysocki" Date: Fri, 16 Oct 2020 18:00:25 +0200 Message-ID: Subject: Re: [PATCHv2] ACPI: debug: don't allow debugging when ACPI is disabled To: Jamie Iles Cc: ACPI Devel Maling List , Hanjun Guo , "Rafael J. Wysocki" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Mon, Oct 12, 2020 at 3:05 PM Jamie Iles wrote: > > If ACPI is disabled then loading the acpi_dbg module will result in the > following splat when lock debugging is enabled. > > DEBUG_LOCKS_WARN_ON(lock->magic != lock) > WARNING: CPU: 0 PID: 1 at kernel/locking/mutex.c:938 __mutex_lock+0xa10/0x1290 > Kernel panic - not syncing: panic_on_warn set ... > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.9.0-rc8+ #103 > Hardware name: linux,dummy-virt (DT) > Call trace: > dump_backtrace+0x0/0x4d8 > show_stack+0x34/0x48 > dump_stack+0x174/0x1f8 > panic+0x360/0x7a0 > __warn+0x244/0x2ec > report_bug+0x240/0x398 > bug_handler+0x50/0xc0 > call_break_hook+0x160/0x1d8 > brk_handler+0x30/0xc0 > do_debug_exception+0x184/0x340 > el1_dbg+0x48/0xb0 > el1_sync_handler+0x170/0x1c8 > el1_sync+0x80/0x100 > __mutex_lock+0xa10/0x1290 > mutex_lock_nested+0x6c/0xc0 > acpi_register_debugger+0x40/0x88 > acpi_aml_init+0xc4/0x114 > do_one_initcall+0x24c/0xb10 > kernel_init_freeable+0x690/0x728 > kernel_init+0x20/0x1e8 > ret_from_fork+0x10/0x18 > > This is because acpi_debugger.lock has not been initialized as > acpi_debugger_init() is not called when ACPI is disabled. Fail module > loading to avoid this and any subsequent problems that might arise by > trying to debug AML when ACPI is disabled. > > Fixes: 8cfb0cdf07e2 ("ACPI / debugger: Add IO interface to access debugger functionalities") > Reviewed-by: Hanjun Guo > Cc: "Rafael J. Wysocki" > Signed-off-by: Jamie Iles > --- > drivers/acpi/acpi_dbg.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/acpi/acpi_dbg.c b/drivers/acpi/acpi_dbg.c > index 6041974c7627..fb7290338593 100644 > --- a/drivers/acpi/acpi_dbg.c > +++ b/drivers/acpi/acpi_dbg.c > @@ -749,6 +749,9 @@ static int __init acpi_aml_init(void) > { > int ret; > > + if (acpi_disabled) > + return -ENODEV; > + > /* Initialize AML IO interface */ > mutex_init(&acpi_aml_io.lock); > init_waitqueue_head(&acpi_aml_io.wait); > -- Applied as 5.10-rc material, thanks!