From patchwork Fri Feb 21 16:41:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 1242226 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=TMte7PXM; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 48PHPS0MTBz9sNg for ; Sat, 22 Feb 2020 03:45:00 +1100 (AEDT) Received: from localhost ([::1]:33091 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j5BQ9-00028R-Ta for incoming@patchwork.ozlabs.org; Fri, 21 Feb 2020 11:44:57 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52765) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j5BOc-0008LF-GJ for qemu-devel@nongnu.org; Fri, 21 Feb 2020 11:43:23 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j5BOb-0006wl-JA for qemu-devel@nongnu.org; Fri, 21 Feb 2020 11:43:22 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:22151 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j5BOb-0006wH-Fb for qemu-devel@nongnu.org; Fri, 21 Feb 2020 11:43:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582303401; h=from:from:reply-to:subject:subject: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=EJq972UhjpkmcHCdnxALNgVTNAc8KQY0NgduEwRuRMw=; b=TMte7PXMRgeBvjjqGpkijBcwBVNomDC4irfCe/ZZvKj7ddEM2kb4MUBPlUiLyVepAZMURl XUXxDYf6gaiYsAu5BNl2H9W7hEEH6Z3PR3OKWZkA4HTqr7QExubEq58/CIQUAtTKGoIVB1 /AA/uLKrOFkBdwvIXdVv84g2oKd6Yd8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-5-yv3BARUZPWKVHwrPkxlv-w-1; Fri, 21 Feb 2020 11:43:19 -0500 X-MC-Unique: yv3BARUZPWKVHwrPkxlv-w-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id 72924800D4E; Fri, 21 Feb 2020 16:43:18 +0000 (UTC) Received: from t480s.redhat.com (ovpn-117-197.ams2.redhat.com [10.36.117.197]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1B3055C105; Fri, 21 Feb 2020 16:43:13 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v2 06/13] exec: Relax range check in ram_block_discard_range() Date: Fri, 21 Feb 2020 17:41:57 +0100 Message-Id: <20200221164204.105570-7-david@redhat.com> In-Reply-To: <20200221164204.105570-1-david@redhat.com> References: <20200221164204.105570-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 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: Eduardo Habkost , Juan Quintela , David Hildenbrand , "Dr . David Alan Gilbert" , Peter Xu , Paolo Bonzini , Richard Henderson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" We want to make use of ram_block_discard_range() in the RAM block resize callback when growing a RAM block, *before* used_length is changed. Let's relax the check. We always have a reserved mapping for the whole max_length, so we cannot corrupt unrelated data. Cc: Richard Henderson Cc: Paolo Bonzini Cc: Eduardo Habkost Cc: Peter Xu Signed-off-by: David Hildenbrand Reviewed-by: Peter Xu --- exec.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/exec.c b/exec.c index 8b015821d6..8737acedab 100644 --- a/exec.c +++ b/exec.c @@ -3915,7 +3915,7 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length) goto err; } - if ((start + length) <= rb->used_length) { + if ((start + length) <= rb->max_length) { bool need_madvise, need_fallocate; if (!QEMU_IS_ALIGNED(length, rb->page_size)) { error_report("ram_block_discard_range: Unaligned length: %zx", @@ -3982,7 +3982,7 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length) } else { error_report("ram_block_discard_range: Overrun block '%s' (%" PRIu64 "/%zx/" RAM_ADDR_FMT")", - rb->idstr, start, length, rb->used_length); + rb->idstr, start, length, rb->max_length); } err: