From patchwork Fri Apr 21 13:15:42 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jennifer Herbert X-Patchwork-Id: 9692817 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 96B0460328 for ; Fri, 21 Apr 2017 13:18:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 886A7277D9 for ; Fri, 21 Apr 2017 13:18:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7D4D828623; Fri, 21 Apr 2017 13:18:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 30583277D9 for ; Fri, 21 Apr 2017 13:18:26 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d1YPv-0002zR-EL; Fri, 21 Apr 2017 13:16:07 +0000 Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d1YPu-0002yy-Km for xen-devel@lists.xen.org; Fri, 21 Apr 2017 13:16:06 +0000 Received: from [193.109.254.147] by server-7.bemta-6.messagelabs.com id DF/E2-03620-5160AF85; Fri, 21 Apr 2017 13:16:05 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmphkeJIrShJLcpLzFFi42JxWrrBXleI7Ve EwaljJhZLPi5mcWD0OLr7N1MAYxRrZl5SfkUCa0bP7gtsBY/4Ky6du8bWwNjC08XIySEh4C/R ev4zM4jNJqAs0TvxNZgtIqAucbrjImsXIxcHs8A/RoldXROBHA4OYYE8iamLtUBqWARUJY5Mu gdWzyvgLbFj+3JWiJlyEueP/wSLcwr4SJzf+JIRxBYCqjnTe5IdwtaQ6D94nxWiV1Di5MwnLC A2s4CExMEXL5gnMPLOQpKahSS1gJFpFaN6cWpRWWqRroVeUlFmekZJbmJmjq6hgZlebmpxcWJ 6ak5iUrFecn7uJkZg6DAAwQ7G2Zf9DzFKcjApifKG/P4ZIcSXlJ9SmZFYnBFfVJqTWnyIUYaD Q0mCV5r1V4SQYFFqempFWmYOMIhh0hIcPEoivFNZgNK8xQWJucWZ6RCpU4yKUuK8j0ESAiCJj NI8uDZY5FxilJUS5mUEOkSIpyC1KDezBFX+FaM4B6OSMO9akCk8mXklcNNfAS1mAlp81u8HyO KSRISUVAMjM9ukHx9spza0TTG7O/u52P6zEXK8WQ39Pt5uonfvs3cyCyitdbGIeyihVrMladb HQ6dC7B7ekzHVP+MT7eIY/fOE5V0vO+3t5z5q3rZYnXyosX+nRo1XxAahJaul9Wba6X36ln5R s6X0vJLGDf5ph5Ve3fB0OL5Bbdpaq2dxgpaZtQyntzMrsRRnJBpqMRcVJwIAsnfp3pcCAAA= X-Env-Sender: prvs=277b21c2f=jennifer.herbert@citrix.com X-Msg-Ref: server-4.tower-27.messagelabs.com!1492780552!97548569!3 X-Originating-IP: [66.165.176.63] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogNjYuMTY1LjE3Ni42MyA9PiAzMDYwNDg=\n, received_headers: No Received headers X-StarScan-Received: X-StarScan-Version: 9.4.12; banners=-,-,- X-VirusChecked: Checked Received: (qmail 40926 invoked from network); 21 Apr 2017 13:16:02 -0000 Received: from smtp02.citrix.com (HELO SMTP02.CITRIX.COM) (66.165.176.63) by server-4.tower-27.messagelabs.com with RC4-SHA encrypted SMTP; 21 Apr 2017 13:16:02 -0000 X-IronPort-AV: E=Sophos;i="5.37,230,1488844800"; d="scan'208";a="429019976" From: To: Xen-devel Date: Fri, 21 Apr 2017 13:15:42 +0000 Message-ID: <1492780545-22401-2-git-send-email-jennifer.herbert@citrix.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1492780545-22401-1-git-send-email-jennifer.herbert@citrix.com> References: <1492780545-22401-1-git-send-email-jennifer.herbert@citrix.com> MIME-Version: 1.0 Cc: Andrew Cooper , Julien Grall , Paul Durrant , Jennifer Herbert , Jan Beulich Subject: [Xen-devel] [PATCH v7 for-4.9 2/5] hvm/dmop: Make copy_buf_{from, to}_guest for a buffer not big enough an error. X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Jennifer Herbert This makes copying to or from a buf that isn't big enough an error. If the buffer isnt big enough, trying to carry on regardless can only cause trouble later on. Signed-off-by: Jennifer Herbert --- CC: Paul Durrant CC: Andrew Cooper CC: Jan Beulich CC: Julien Grall --- This patch takes the behaviour change part of patch the previouse [patch 2/4]. --- xen/arch/x86/hvm/dm.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/xen/arch/x86/hvm/dm.c b/xen/arch/x86/hvm/dm.c index e583e41..63aa46c 100644 --- a/xen/arch/x86/hvm/dm.c +++ b/xen/arch/x86/hvm/dm.c @@ -36,30 +36,32 @@ static bool copy_buf_from_guest(const xen_dm_op_buf_t bufs[], unsigned int nr_bufs, void *dst, unsigned int idx, size_t dst_size) { - size_t size; + size_t buf_bytes; if ( idx >= nr_bufs ) return false; - memset(dst, 0, dst_size); - - size = min_t(size_t, dst_size, bufs[idx].size); + buf_bytes = bufs[idx].size; + if ( dst_size > buf_bytes ) + return false; - return !copy_from_guest(dst, bufs[idx].h, size); + return !copy_from_guest(dst, bufs[idx].h, buf_bytes); } static bool copy_buf_to_guest(const xen_dm_op_buf_t bufs[], unsigned int nr_bufs, unsigned int idx, const void *src, size_t src_size) { - size_t size; + size_t buf_bytes; if ( idx >= nr_bufs ) return false; - size = min_t(size_t, bufs[idx].size, src_size); + buf_bytes = bufs[idx].size; + if ( src_size > buf_bytes ) + return false; - return !copy_to_guest(bufs[idx].h, src, size); + return !copy_to_guest(bufs[idx].h, src, buf_bytes); } static int track_dirty_vram(struct domain *d, xen_pfn_t first_pfn,