From owner-svn-src-all@FreeBSD.ORG  Wed Apr  9 14:50:55 2014
Return-Path: <owner-svn-src-all@FreeBSD.ORG>
Delivered-To: svn-src-all@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id CA45771A;
 Wed,  9 Apr 2014 14:50:55 +0000 (UTC)
Received: from svn.freebsd.org (svn.freebsd.org
 [IPv6:2001:1900:2254:2068::e6a:0])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id B705911CF;
 Wed,  9 Apr 2014 14:50:55 +0000 (UTC)
Received: from svn.freebsd.org ([127.0.1.70])
 by svn.freebsd.org (8.14.8/8.14.8) with ESMTP id s39EotSG082385;
 Wed, 9 Apr 2014 14:50:55 GMT (envelope-from tychon@svn.freebsd.org)
Received: (from tychon@localhost)
 by svn.freebsd.org (8.14.8/8.14.8/Submit) id s39Eot5Q082384;
 Wed, 9 Apr 2014 14:50:55 GMT (envelope-from tychon@svn.freebsd.org)
Message-Id: <201404091450.s39Eot5Q082384@svn.freebsd.org>
From: Tycho Nightingale <tychon@FreeBSD.org>
Date: Wed, 9 Apr 2014 14:50:55 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r264302 - head/usr.sbin/bhyve
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-all@freebsd.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: "SVN commit messages for the entire src tree \(except for &quot;
 user&quot; and &quot; projects&quot; \)" <svn-src-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all/>
List-Post: <mailto:svn-src-all@freebsd.org>
List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 09 Apr 2014 14:50:55 -0000

Author: tychon
Date: Wed Apr  9 14:50:55 2014
New Revision: 264302
URL: http://svnweb.freebsd.org/changeset/base/264302

Log:
  Constrain the amount of data returned to what is actually available
  not the size of the buffer.
  
  Approved by:	grehan (co-mentor)

Modified:
  head/usr.sbin/bhyve/pci_ahci.c

Modified: head/usr.sbin/bhyve/pci_ahci.c
==============================================================================
--- head/usr.sbin/bhyve/pci_ahci.c	Wed Apr  9 13:35:52 2014	(r264301)
+++ head/usr.sbin/bhyve/pci_ahci.c	Wed Apr  9 14:50:55 2014	(r264302)
@@ -543,12 +543,14 @@ write_prdt(struct ahci_port *p, int slot
 	for (i = 0; i < hdr->prdtl && len; i++) {
 		uint8_t *ptr;
 		uint32_t dbcsz;
+		int sublen;
 
 		dbcsz = (prdt->dbc & DBCMASK) + 1;
 		ptr = paddr_guest2host(ahci_ctx(p->pr_sc), prdt->dba, dbcsz);
-		memcpy(ptr, from, dbcsz);
-		len -= dbcsz;
-		from += dbcsz;
+		sublen = len < dbcsz ? len : dbcsz;
+		memcpy(ptr, from, sublen);
+		len -= sublen;
+		from += sublen;
 		prdt++;
 	}
 	hdr->prdbc = size - len;