From nobody Mon Feb 9 00:20:39 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1562358138; cv=none; d=zoho.com; s=zohoarc; b=OPCOG8qlsxsI7C3RtT7A2CVLaCJ90j3CTjGdX3EYig2e6DbJkXmqt0bEYDMk0YpkSTuTQkz6g9RT3rI4ld9qSE7JO2gXSmkJKs00fj1512T6qpQ9hUVvK+fXOcBDd+KREAUE178fiGPsLkaWVW4t4/L3e7cjh2C4NigrAQh1a/I= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1562358138; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=40m6tW7TE8rcZnWVYjHWrjyCmfSKjCEIWBr2AlmoKkI=; b=CEXWJrM586G6uaqT4tosHB6maZknI7LhsXtYoPW/BNE9qFctwQefl8cXngp07wUJuzb1f/9TRXNZq6K3bx0nhArSwpgUf2adti2jtliWKBR+JY4HKhfYGxCswGBiMXVZD9lV1iAXrJJbAjR45E3OayoZdx1Co+qzYD8UlbJkhC0= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1562358138826557.1793928876118; Fri, 5 Jul 2019 13:22:18 -0700 (PDT) Received: from localhost ([::1]:55806 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hjUin-000308-H0 for importer@patchew.org; Fri, 05 Jul 2019 16:22:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60980) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hjUds-0005Od-MX for qemu-devel@nongnu.org; Fri, 05 Jul 2019 16:17:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hjUdq-00071J-OP for qemu-devel@nongnu.org; Fri, 05 Jul 2019 16:17:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46026) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hjUdk-0006s3-Tk; Fri, 05 Jul 2019 16:17:05 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5A2983083394; Fri, 5 Jul 2019 20:17:02 +0000 (UTC) Received: from probe.redhat.com (ovpn-122-149.rdu2.redhat.com [10.10.122.149]) by smtp.corp.redhat.com (Postfix) with ESMTP id F259086432; Fri, 5 Jul 2019 20:16:59 +0000 (UTC) From: John Snow To: qemu-devel@nongnu.org, qemu-block@nongnu.org Date: Fri, 5 Jul 2019 16:16:20 -0400 Message-Id: <20190705201631.26266-8-jsnow@redhat.com> In-Reply-To: <20190705201631.26266-1-jsnow@redhat.com> References: <20190705201631.26266-1-jsnow@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Fri, 05 Jul 2019 20:17:02 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v3 07/18] hbitmap: Fix merge when b is empty, and result is not an alias of a X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Fam Zheng , Kevin Wolf , vsementsov@virtuozzo.com, Juan Quintela , Wen Congyang , Xie Changlong , "Dr. David Alan Gilbert" , Markus Armbruster , John Snow , Stefan Hajnoczi , Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" Nobody calls the function like this currently, but we neither prohibit or cope with this behavior. I decided to make the function cope with it. Reviewed-by: Max Reitz Signed-off-by: John Snow --- util/hbitmap.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/util/hbitmap.c b/util/hbitmap.c index 7905212a8b..3b6acae42b 100644 --- a/util/hbitmap.c +++ b/util/hbitmap.c @@ -781,8 +781,9 @@ bool hbitmap_can_merge(const HBitmap *a, const HBitmap = *b) } =20 /** - * Given HBitmaps A and B, let A :=3D A (BITOR) B. - * Bitmap B will not be modified. + * Given HBitmaps A and B, let R :=3D A (BITOR) B. + * Bitmaps A and B will not be modified, + * except when bitmap R is an alias of A or B. * * @return true if the merge was successful, * false if it was not attempted. @@ -797,7 +798,13 @@ bool hbitmap_merge(const HBitmap *a, const HBitmap *b,= HBitmap *result) } assert(hbitmap_can_merge(b, result)); =20 - if (hbitmap_count(b) =3D=3D 0) { + if ((!hbitmap_count(a) && result =3D=3D b) || + (!hbitmap_count(b) && result =3D=3D a)) { + return true; + } + + if (!hbitmap_count(a) && !hbitmap_count(b)) { + hbitmap_reset_all(result); return true; } =20 --=20 2.21.0