From mboxrd@z Thu Jan 1 00:00:00 1970 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=-4.9 required=3.0 tests=DATE_IN_PAST_96_XX, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS 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 1AE71C43387 for ; Wed, 16 Jan 2019 23:04:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E437720675 for ; Wed, 16 Jan 2019 23:04:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730097AbfAPXEC (ORCPT ); Wed, 16 Jan 2019 18:04:02 -0500 Received: from mailgw1.fjfi.cvut.cz ([147.32.9.3]:45658 "EHLO mailgw1.fjfi.cvut.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727080AbfAPXDy (ORCPT ); Wed, 16 Jan 2019 18:03:54 -0500 Received: from localhost (localhost [127.0.0.1]) by mailgw1.fjfi.cvut.cz (Postfix) with ESMTP id 913E8B0439; Wed, 16 Jan 2019 23:55:49 +0100 (CET) X-CTU-FNSPE-Virus-Scanned: amavisd-new at fjfi.cvut.cz Received: from mailgw1.fjfi.cvut.cz ([127.0.0.1]) by localhost (mailgw1.fjfi.cvut.cz [127.0.0.1]) (amavisd-new, port 10022) with ESMTP id 3g05-g5j8Isg; Wed, 16 Jan 2019 23:55:45 +0100 (CET) Received: from linux.fjfi.cvut.cz (linux.fjfi.cvut.cz [147.32.5.111]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mailgw1.fjfi.cvut.cz (Postfix) with ESMTPS id AD9E6B03CB; Wed, 16 Jan 2019 23:55:43 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 mailgw1.fjfi.cvut.cz AD9E6B03CB Received: by linux.fjfi.cvut.cz (Postfix, from userid 1001) id 931996004E; Wed, 16 Jan 2019 23:55:43 +0100 (CET) From: Jonas Rabenstein Date: Mon, 19 Mar 2018 19:36:48 +0100 Subject: [PATCH 09/16] block: sed-opal: split generation of bytestring header and content To: Jens Axboe , Scott Bauer , Jonathan Derrick , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jonas Rabenstein Message-Id: <20190116225543.931996004E@linux.fjfi.cvut.cz> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Split the header generation from the (normal) memcpy part if a bytestring is copied into the command buffer. This allows in-place generation of the bytestring content. For example, copy_from_user may be used without an intermediate buffer. Signed-off-by: Jonas Rabenstein --- block/sed-opal.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/block/sed-opal.c b/block/sed-opal.c index 4225f23b2165..db966bbc5a05 100644 --- a/block/sed-opal.c +++ b/block/sed-opal.c @@ -586,14 +586,11 @@ static void add_token_u64(int *err, struct opal_dev *cmd, u64 number) add_token_u8(err, cmd, number >> (len * 8)); } -static void add_token_bytestring(int *err, struct opal_dev *cmd, - const u8 *bytestring, size_t len) +static u8 *add_bytestring_header(int *err, struct opal_dev *cmd, size_t len) { size_t header_len = 1; bool is_short_atom = true; - - if (*err) - return; + char *start; if (len & ~SHORT_ATOM_LEN_MASK) { header_len = 2; @@ -602,17 +599,27 @@ static void add_token_bytestring(int *err, struct opal_dev *cmd, if (!can_add(err, cmd, header_len + len)) { pr_debug("Error adding bytestring: end of buffer.\n"); - return; + return NULL; } if (is_short_atom) add_short_atom_header(cmd, true, false, len); else add_medium_atom_header(cmd, true, false, len); - - memcpy(&cmd->cmd[cmd->pos], bytestring, len); + start = &cmd->cmd[cmd->pos]; cmd->pos += len; + return start; +} +static void add_token_bytestring(int *err, struct opal_dev *cmd, + const u8 *bytestring, size_t len) +{ + u8 *start; + + start = add_bytestring_header(err, cmd, len); + if (!start) + return; + memcpy(start, bytestring, len); } static int build_locking_range(u8 *buffer, size_t length, u8 lr) -- 2.20.1