Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753323AbZKVKa5 (ORCPT ); Sun, 22 Nov 2009 05:30:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752206AbZKVKa4 (ORCPT ); Sun, 22 Nov 2009 05:30:56 -0500 Received: from mx1.redhat.com ([209.132.183.28]:19762 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751496AbZKVKaz (ORCPT ); Sun, 22 Nov 2009 05:30:55 -0500 Date: Sun, 22 Nov 2009 12:28:01 +0200 From: "Michael S. Tsirkin" To: Alan Cox , Rusty Russell , virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] vhost: Fix warnings and bad type handling Message-ID: <20091122102801.GA13644@redhat.com> References: <20091117154213.3683.94554.stgit@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091117154213.3683.94554.stgit@localhost.localdomain> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1704 Lines: 49 From: Alan Cox Subject: [PATCH] vhost: fix warnings on 32 bit systems Fix compiler warning about discarding top 32 bit of data on 32 bit systems, and document that dicarded bits must be 0. Signed-off-by: Alan Cox Signed-off-by: Michael S. Tsirkin --- So I think the below slightly tweaked version of Alan's patch is a bit better. OK? drivers/vhost/vhost.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 97233d5..e7b4dea 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -322,6 +322,8 @@ static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp) r = -EOPNOTSUPP; break; } + /* For 32bit, verify that the top 32bits of the user + data are set to zero. */ if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr || (u64)(unsigned long)a.used_user_addr != a.used_user_addr || (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) { @@ -334,7 +336,8 @@ static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp) r = -EINVAL; break; } - r = init_used(vq, (struct vring_used __user *)a.used_user_addr); + r = init_used(vq, (struct vring_used __user *)(unsigned long) + a.used_user_addr); if (r) break; vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG)); -- 1.6.5.2.143.g8cc62 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/