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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 0EDDDC433ED for ; Fri, 23 Apr 2021 10:45:32 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 9984161463 for ; Fri, 23 Apr 2021 10:45:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9984161463 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.116093.221537 (Exim 4.92) (envelope-from ) id 1lZtJG-0001yL-0r; Fri, 23 Apr 2021 10:45:18 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 116093.221537; Fri, 23 Apr 2021 10:45:17 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lZtJF-0001yE-Tu; Fri, 23 Apr 2021 10:45:17 +0000 Received: by outflank-mailman (input) for mailman id 116093; Fri, 23 Apr 2021 10:45:16 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lZtJE-0001xz-G8 for xen-devel@lists.xenproject.org; Fri, 23 Apr 2021 10:45:16 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 4d0d4d02-307f-436f-ba9d-2e1f935d08d5; Fri, 23 Apr 2021 10:45:15 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A3CE7AFE6; Fri, 23 Apr 2021 10:45:14 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 4d0d4d02-307f-436f-ba9d-2e1f935d08d5 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1619174714; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JdrIaMPT2kQNkCRzSufS4y3iIccV3WIfQ36B2QepM8Q=; b=F6OA6zBFwYowoTi5mL7ruNxq4nRZAKS1B+D63XzFQciVxx8ij8qMovOBCYjB6pqTIFeOlU CKGein2UNAT6IffJ1tuauxYvM0L+UMCZJSLrMZQPqG9GQftx3z0n/bvEg2TIWvbpFv2Szd biGkSnoSNjr725bH2Qf27vRLf5KsGlQ= Subject: Re: [PATCH 7/8] x86/EFI: keep debug info in xen.efi To: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= Cc: "xen-devel@lists.xenproject.org" , Andrew Cooper , Wei Liu References: <3cda296d-e88e-5fe0-4924-4cf974c4f909@suse.com> <8fabc56b-8e2d-96cd-e9b2-81bf38777d52@suse.com> <98431d14-d4a0-61a8-148e-221652f37b61@suse.com> <32bba278-12cc-d105-7b95-6a788992d70c@suse.com> From: Jan Beulich Message-ID: Date: Fri, 23 Apr 2021 12:45:14 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit On 23.04.2021 12:07, Roger Pau Monné wrote: > On Fri, Apr 23, 2021 at 10:51:40AM +0200, Jan Beulich wrote: >> On 23.04.2021 09:30, Roger Pau Monné wrote: >>> /* >>> * Explicitly list debug section for the PE output so that they don't >>> * end up at VA 0 which is below image base and thus invalid. Also use >>> * the NOLOAD directive, even when currently ignored by PE output, in >>> * order to note those sections shouldn't be loaded into memory. >>> * >>> * Note such sections are past _end, so if loaded will be discarded by >>> * Xen anyway. >>> */ >>> >>> Feel free to reword or expand the comment. >> >> Yes, I've edited it some while inserting. Will see to get to >> submitting v2 then. >> >>> Not sure there's some >>> reference we could add here about how debug sections are placed in PE >>> files usually. >> >> As said before - I don't think there's any "usually" here, which is >> why different environments have invented different ways. The debug >> info native to COFF is more like ELF's symbol table (with a little >> bit of extra information) plus Dwarf's .debug_line, but not really >> fully covering what you'd expect from debug info. > > One last thing, do you know if the newly added debug_* sections get > the IMAGE_SCN_MEM_DISCARDABLE section flag set? At least with an up-to-date ld (i.e. one meeting the requirements so we wouldn't force debug info to be stripped) they do. > Not sure there's a way we can force it from the linker script TBH, but > would be nice and seems to be a recommended flag for debug sections > according to Microsoft [0]. The linker does this for debugging sections irrespective of what the linker script says: if ((sec_flags & SEC_DEBUGGING) != 0) styp_flags |= IMAGE_SCN_MEM_DISCARDABLE; Jan