From patchwork Mon Feb 1 16:20:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 12059435 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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 19D71C433E0 for ; Mon, 1 Feb 2021 16:21:15 +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 B0FC264E9B for ; Mon, 1 Feb 2021 16:21:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B0FC264E9B 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.80008.146088 (Exim 4.92) (envelope-from ) id 1l6bwf-00062V-UQ; Mon, 01 Feb 2021 16:20:57 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 80008.146088; Mon, 01 Feb 2021 16:20:57 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l6bwf-00062O-RX; Mon, 01 Feb 2021 16:20:57 +0000 Received: by outflank-mailman (input) for mailman id 80008; Mon, 01 Feb 2021 16:20:56 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l6bwe-00062J-Hv for xen-devel@lists.xenproject.org; Mon, 01 Feb 2021 16:20:56 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id b1e149c4-393a-49e8-8ba6-e8a9b5b1b409; Mon, 01 Feb 2021 16:20:55 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id BCA2BAB92; Mon, 1 Feb 2021 16:20:54 +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: b1e149c4-393a-49e8-8ba6-e8a9b5b1b409 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=1612196454; 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; bh=GvGyOpHjxePA3adDxLLV4FpwWSt7Uar0rJSh1I4ST+U=; b=ie48RAdB4XksWzNkS/bCeIoDEds/o1OgfW28Fd15bq0vn6MfN+NrSyH1XhUn0J4pHDBjto QrPswOwnMKsc0YjRzCfUDXWuqE2aHR1Mf6SCa8nxJEYfkGO0Zq7LmBXJuo/eDuWvdkLzyS NXc37/rTyTvFkH+pgCJP+RW14Osh5Nk= To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , George Dunlap , Ian Jackson , Julien Grall , Stefano Stabellini , Wei Liu From: Jan Beulich Subject: [PATCH] memory: fix build with COVERAGE but !HVM Message-ID: <84a05b9e-a0c3-7860-4a59-a591a873b884@suse.com> Date: Mon, 1 Feb 2021 17:20:54 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 Content-Language: en-US Xen is heavily relying on the DCE stage to remove unused code so the linker doesn't throw an error because a function is not implemented yet we defined a prototype for it. On some GCC versions (such as 9.4 provided by Debian sid), the compiler DCE stage will not manage to figure that out for xenmem_add_to_physmap_batch(): ld: ld: prelink.o: in function `xenmem_add_to_physmap_batch': /xen/xen/common/memory.c:942: undefined reference to `xenmem_add_to_physmap_one' /xen/xen/common/memory.c:942:(.text+0x22145): relocation truncated to fit: R_X86_64_PLT32 against undefined symbol `xenmem_add_to_physmap_one' prelink-efi.o: in function `xenmem_add_to_physmap_batch': /xen/xen/common/memory.c:942: undefined reference to `xenmem_add_to_physmap_one' make[2]: *** [Makefile:215: /root/xen/xen/xen.efi] Error 1 make[2]: *** Waiting for unfinished jobs.... ld: /xen/xen/.xen-syms.0: hidden symbol `xenmem_add_to_physmap_one' isn't defined ld: final link failed: bad value It is not entirely clear why the compiler DCE is not detecting the unused code. However, cloning the check introduced by the commit below into xenmem_add_to_physmap_batch() does the trick. No functional change intended. Fixes: d4f699a0df6c ("x86/mm: p2m_add_foreign() is HVM-only") Reported-by: Oleksandr Tyshchenko Signed-off-by: Julien Grall Signed-off-by: Jan Beulich Release-Acked-by: Ian Jackson Acked-by: Andrew Cooper , but I feel this Reviewed-by: Wei Liu --- Julien, since I reused most of your patch'es description, I've kept your S-o-b. Please let me know if you want me to drop it. --- a/xen/common/memory.c +++ b/xen/common/memory.c @@ -904,6 +904,19 @@ static int xenmem_add_to_physmap_batch(s { union add_to_physmap_extra extra = {}; + /* + * While, unlike xenmem_add_to_physmap(), this function is static, there + * still have been cases observed where xatp_permission_check(), invoked + * by our caller, doesn't lead to elimination of this entire function when + * the compile time evaluation of paging_mode_translate(d) is false. Guard + * against this be replicating the same check here. + */ + if ( !paging_mode_translate(d) ) + { + ASSERT_UNREACHABLE(); + return -EACCES; + } + if ( unlikely(xatpb->size < extent) ) return -EILSEQ;