From patchwork Tue Apr 21 08:52:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 284152 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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED 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 A4ADAC2BA19 for ; Tue, 21 Apr 2020 08:59:35 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 7022C206B8 for ; Tue, 21 Apr 2020 08:59:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="e3H21JNO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7022C206B8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54148 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jQokg-0006ti-Kq for qemu-devel@archiver.kernel.org; Tue, 21 Apr 2020 04:59:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57284) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jQofX-0007jj-S5 for qemu-devel@nongnu.org; Tue, 21 Apr 2020 04:54:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.90_1) (envelope-from ) id 1jQofX-000141-9A for qemu-devel@nongnu.org; Tue, 21 Apr 2020 04:54:15 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:44822 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jQofW-00012T-TZ for qemu-devel@nongnu.org; Tue, 21 Apr 2020 04:54:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587459253; 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=5O9IOf18Q5tNrCWkix6XYufNCtn6qQgs8x9W8pVhcUE=; b=e3H21JNO3kk8boxKJePyz6T90YP7j5v/mbz1QLds+S/NYpmemgyEz+c0wpYVEl929ULcJH InvxF3+BOhtk+ErrnHSphjrPzikh+p8n2A2O9pXHdgNxEaTEnLQ8Ng3ljdCbt5IWuunNB5 3Lz5u72VC2g52OUvEfEwhdF3FjyJd4k= 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-381-Ts3c5l0TND6KWfg2ZNNJDQ-1; Tue, 21 Apr 2020 04:54:07 -0400 X-MC-Unique: Ts3c5l0TND6KWfg2ZNNJDQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2099B8017FC; Tue, 21 Apr 2020 08:54:06 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-245.ams2.redhat.com [10.36.113.245]) by smtp.corp.redhat.com (Postfix) with ESMTP id B421D1001DDE; Tue, 21 Apr 2020 08:54:00 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v4 06/13] exec: Relax range check in ram_block_discard_range() Date: Tue, 21 Apr 2020 10:52:53 +0200 Message-Id: <20200421085300.7734-7-david@redhat.com> In-Reply-To: <20200421085300.7734-1-david@redhat.com> References: <20200421085300.7734-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.81; envelope-from=david@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/04/21 01:28:51 X-ACL-Warn: Detected OS = 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 , "Michael S . Tsirkin" , David Hildenbrand , "Dr . David Alan Gilbert" , Peter Xu , Paolo Bonzini , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.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. Reviewed-by: Peter Xu Cc: Richard Henderson Cc: Paolo Bonzini Cc: Eduardo Habkost Cc: Peter Xu Signed-off-by: David Hildenbrand --- exec.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/exec.c b/exec.c index 78dfab6ec6..591c3b0e32 100644 --- a/exec.c +++ b/exec.c @@ -3887,7 +3887,7 @@ 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", @@ -3954,7 +3954,7 @@ 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: