From patchwork Wed May 12 16:48:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 12254303 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=-18.8 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,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 37C24C433ED for ; Wed, 12 May 2021 16:48:30 +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 BBD626101B for ; Wed, 12 May 2021 16:48:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BBD626101B 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.126314.237792 (Exim 4.92) (envelope-from ) id 1lgs1l-0003NG-Aa; Wed, 12 May 2021 16:48:05 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 126314.237792; Wed, 12 May 2021 16:48:05 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lgs1l-0003N9-7R; Wed, 12 May 2021 16:48:05 +0000 Received: by outflank-mailman (input) for mailman id 126314; Wed, 12 May 2021 16:48:04 +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 1lgs1k-0003N3-2y for xen-devel@lists.xenproject.org; Wed, 12 May 2021 16:48:04 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 50807ee1-380d-46ec-8392-41edfec7e43a; Wed, 12 May 2021 16:48:02 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 01685B148; Wed, 12 May 2021 16:48:02 +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: 50807ee1-380d-46ec-8392-41edfec7e43a 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=1620838082; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=20PFQ0WahlPjBf4V0QLtvAJuN8ggnfjR+YmNs21FlUs=; b=KSaojBZAv6QL6z8bbdHkOBHaT7gzzBz8CKCmmAMgbasuQUvm6HTaufvR+ynqSWVNY6xl7H erUk4Zo7tv8Z/wUUmyd9P/wf8wHKLIOESLxmNQBah+ROXdJsSBrrfAC+egdtadr3gn9wFl 30mdm0/15TwjV7aDuTu/yYOAJBmSw9Q= From: Juergen Gross To: xen-devel@lists.xenproject.org Cc: Juergen Gross Subject: [PATCH] include/public: add RING_RESPONSE_PROD_OVERFLOW macro Date: Wed, 12 May 2021 18:48:00 +0200 Message-Id: <20210512164800.26236-1-jgross@suse.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Add a new RING_RESPONSE_PROD_OVERFLOW() macro for being able to detect an ill-behaved backend tampering with the response producer index. Signed-off-by: Juergen Gross Acked-by: Jan Beulich --- xen/include/public/io/ring.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/xen/include/public/io/ring.h b/xen/include/public/io/ring.h index 0b08b2697e..c486c457e0 100644 --- a/xen/include/public/io/ring.h +++ b/xen/include/public/io/ring.h @@ -259,6 +259,10 @@ typedef struct __name##_back_ring __name##_back_ring_t #define RING_REQUEST_PROD_OVERFLOW(_r, _prod) \ (((_prod) - (_r)->rsp_prod_pvt) > RING_SIZE(_r)) +/* Ill-behaved backend determination: Can there be this many responses? */ +#define RING_RESPONSE_PROD_OVERFLOW(_r, _prod) \ + (((_prod) - (_r)->rsp_cons) > RING_SIZE(_r)) + #define RING_PUSH_REQUESTS(_r) do { \ xen_wmb(); /* back sees requests /before/ updated producer index */ \ (_r)->sring->req_prod = (_r)->req_prod_pvt; \