From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755269AbbHNOYl (ORCPT ); Fri, 14 Aug 2015 10:24:41 -0400 Received: from mga01.intel.com ([192.55.52.88]:62993 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753428AbbHNOYk (ORCPT ); Fri, 14 Aug 2015 10:24:40 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,678,1432623600"; d="scan'208";a="784148096" Message-ID: <55CDF969.6070704@intel.com> Date: Fri, 14 Aug 2015 07:21:29 -0700 From: Tadeusz Struk User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Herbert Xu CC: keescook@chromium.org, jwboyer@redhat.com, smueller@chronox.de, richard@nod.at, steved@redhat.com, linux-kernel@vger.kernel.org, dhowells@redhat.com, linux-crypto@vger.kernel.org, james.l.morris@oracle.com, jkosina@suse.cz, zohar@linux.vnet.ibm.com, davem@davemloft.net, vgoyal@redhat.com Subject: Re: [PATCH 2/2] crypto: qat - Don't move data inside output buffer References: <20150813035433.25108.3065.stgit@tstruk-mobl1> <20150813035445.25108.76927.stgit@tstruk-mobl1> <20150814051410.GA2370@gondor.apana.org.au> <55CD8733.2000904@intel.com> <20150814062636.GA2799@gondor.apana.org.au> In-Reply-To: <20150814062636.GA2799@gondor.apana.org.au> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Herbert, On 08/13/2015 11:26 PM, Herbert Xu wrote: > On Thu, Aug 13, 2015 at 11:14:11PM -0700, Tadeusz Struk wrote: >> >> Right, but we don't need that anymore. > > Why not? If you reduce the size without moving the buffer wouldn't > it begin with a bunch of zeroes and wouldn't you lose the real bytes > at the end? Yes, that was wrong, sorry. The reason I wanted to change it is that the SW implementation can return a number with leading zeros. This is because mpi_read_buffer() returns the whole thing. Because the format of the module signature starts with 0x00, 0x01 the two implementations return a different thing. For instance SW returned a 512 bytes number starting with 0x00, 0x01 and HW returned 511 bytes number without the 0x00 at the beginning. Technically both are correct, but then the rsa_signture_verify() needs to check for both cases, which is not ideal. To make it return the same thing as SW we can do something like this: ---8<--- Allow for leading zeros in output to make it exactly the same as the SW implementation. Change memcpy to memmove because the copy is done within the same buffer. diff --git a/drivers/crypto/qat/qat_common/qat_asym_algs.c b/drivers/crypto/qat/qat_common/qat_asym_algs.c index fe352a6..cc450fa 100644 --- a/drivers/crypto/qat/qat_common/qat_asym_algs.c +++ b/drivers/crypto/qat/qat_common/qat_asym_algs.c @@ -118,7 +118,13 @@ static void qat_rsa_cb(struct icp_qat_fw_pke_resp *resp) struct device *dev = &GET_DEV(req->ctx->inst->accel_dev); int err = ICP_QAT_FW_PKE_RESP_PKE_STAT_GET( resp->pke_resp_hdr.comn_resp_flags); - char *ptr = areq->dst; +#if BYTES_PER_MPI_LIMB == 4 + u32 *ptr = areq->dst; +#elif BYTES_PER_MPI_LIMB == 8 + u64 *ptr = areq->dst; +#else +#error please implement for this limb size. +#endif err = (err == ICP_QAT_FW_COMN_STATUS_FLAG_OK) ? 0 : -EINVAL; @@ -140,12 +146,12 @@ static void qat_rsa_cb(struct icp_qat_fw_pke_resp *resp) areq->dst_len = req->ctx->key_sz; /* Need to set the corect length of the output */ while (!(*ptr) && areq->dst_len) { - areq->dst_len--; + areq->dst_len -= sizeof(*ptr); ptr++; } if (areq->dst_len != req->ctx->key_sz) - memcpy(areq->dst, ptr, areq->dst_len); + memmove(areq->dst, ptr, areq->dst_len); akcipher_request_complete(areq, err); }