From patchwork Fri May 19 20:54:46 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 13248828 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93F36C77B7A for ; Fri, 19 May 2023 20:53:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229885AbjESUx7 (ORCPT ); Fri, 19 May 2023 16:53:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36218 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229871AbjESUx6 (ORCPT ); Fri, 19 May 2023 16:53:58 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8FEA0132; Fri, 19 May 2023 13:53:57 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 20FD4615FF; Fri, 19 May 2023 20:53:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE0E7C433D2; Fri, 19 May 2023 20:53:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684529636; bh=XMfD+fHTTCvtfUV7h2YoT8hriPxayi7IPm7YdA35a9s=; h=Date:From:To:Cc:Subject:From; b=sBinAhr5gyilwc61wdhuktUwh92ixozkWmdVaCSMyCebtMWVvmdYuyWVPTV8gIDMK o9IQGwO8DD5G0a00xR5wFUnOoMhq16LAhNwTENB5pFTdkyuyouivAMcMV65KDYqUV/ D34aHq1VRxT2angV5Ea99jtXFwMHR8AMi9/dyDFVAMosZRAoaavRQIKJGtgkY1GLRp bvlB+slkUym0LGY4ATTGL1YYaQrVrIojTicPFth27D3C8CVNyVdCqjdECWwCUxwDuD E/aDoFGHHCQTt3Pb7Uq4fc5R5KO4vLGWi+H67WVF0PlZSxJg34zVzX1tFLJxPPW4u0 Bdd5IHnVaQpNg== Date: Fri, 19 May 2023 14:54:46 -0600 From: "Gustavo A. R. Silva" To: Jaroslav Kysela , Takashi Iwai Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH v2][next] ALSA: mixart: Replace one-element arrays with simple object declarations Message-ID: MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org One-element arrays are deprecated, and we are replacing them with flexible array members instead. However, in this case it seems those one-element arrays have never actually been used as fake flexible arrays. See this code that dates from Linux-2.6.12-rc2 initial git repository build (commit 1da177e4c3f4 ("Linux-2.6.12-rc2")): sound/pci/mixart/mixart_core.h: 215 struct mixart_stream_state_req 216 { 217 u32 delayed; 218 u64 scheduler; 219 u32 reserved4np[3]; 220 u32 stream_count; /* set to 1 for instance */ 221 struct mixart_flow_info stream_info; /* could be an array[stream_count] */ 222 } __attribute__((packed)); sound/pci/mixart/mixart.c: 388 389 memset(&stream_state_req, 0, sizeof(stream_state_req)); 390 stream_state_req.stream_count = 1; 391 stream_state_req.stream_info.stream_desc.uid_pipe = stream->pipe->group_uid; 392 stream_state_req.stream_info.stream_desc.stream_idx = stream->substream->number; 393 So, taking the code above as example, replace multiple one-element arrays with simple object declarations, and refactor the rest of the code, accordingly. This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. This results in no differences in binary output. Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/296 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Signed-off-by: Gustavo A. R. Silva --- Changes in v2: - Keep the code comments (by Takashi Iwai) and explicitly mention that the objects could be arrays, in theory. v1: - Link: https://lore.kernel.org/linux-hardening/ZGVlcpuvx1rSOMP8@work/ sound/pci/mixart/mixart.c | 8 ++++---- sound/pci/mixart/mixart_core.h | 7 +++---- 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/sound/pci/mixart/mixart.c b/sound/pci/mixart/mixart.c index 1b078b789604..7ceaf6a7a77e 100644 --- a/sound/pci/mixart/mixart.c +++ b/sound/pci/mixart/mixart.c @@ -98,7 +98,7 @@ static int mixart_set_pipe_state(struct mixart_mgr *mgr, memset(&group_state, 0, sizeof(group_state)); group_state.pipe_count = 1; - group_state.pipe_uid[0] = pipe->group_uid; + group_state.pipe_uid = pipe->group_uid; if(start) request.message_id = MSG_STREAM_START_STREAM_GRP_PACKET; @@ -185,7 +185,7 @@ static int mixart_set_clock(struct mixart_mgr *mgr, clock_properties.clock_mode = CM_STANDALONE; clock_properties.frequency = rate; clock_properties.nb_callers = 1; /* only one entry in uid_caller ! */ - clock_properties.uid_caller[0] = pipe->group_uid; + clock_properties.uid_caller = pipe->group_uid; dev_dbg(&mgr->pci->dev, "mixart_set_clock to %d kHz\n", rate); @@ -565,8 +565,8 @@ static int mixart_set_format(struct mixart_stream *stream, snd_pcm_format_t form stream_param.pipe_count = 1; /* set to 1 */ stream_param.stream_count = 1; /* set to 1 */ - stream_param.stream_desc[0].uid_pipe = stream->pipe->group_uid; - stream_param.stream_desc[0].stream_idx = stream->substream->number; + stream_param.stream_desc.uid_pipe = stream->pipe->group_uid; + stream_param.stream_desc.stream_idx = stream->substream->number; request.message_id = MSG_STREAM_SET_INPUT_STAGE_PARAM; request.uid = (struct mixart_uid){0,0}; diff --git a/sound/pci/mixart/mixart_core.h b/sound/pci/mixart/mixart_core.h index 2f0e29ed5d63..d39233e0e070 100644 --- a/sound/pci/mixart/mixart_core.h +++ b/sound/pci/mixart/mixart_core.h @@ -231,7 +231,7 @@ struct mixart_group_state_req u64 scheduler; u32 reserved4np[2]; u32 pipe_count; /* set to 1 for instance */ - struct mixart_uid pipe_uid[1]; /* could be an array[pipe_count] */ + struct mixart_uid pipe_uid; /* could be an array[pipe_count], in theory */ } __attribute__((packed)); struct mixart_group_state_resp @@ -314,7 +314,7 @@ struct mixart_clock_properties u32 format; u32 board_mask; u32 nb_callers; /* set to 1 (see below) */ - struct mixart_uid uid_caller[1]; + struct mixart_uid uid_caller; } __attribute__((packed)); struct mixart_clock_properties_resp @@ -401,8 +401,7 @@ struct mixart_stream_param_desc u32 reserved4np[3]; u32 pipe_count; /* set to 1 (array size !) */ u32 stream_count; /* set to 1 (array size !) */ - struct mixart_txx_stream_desc stream_desc[1]; /* only one stream per command, but this could be an array */ - + struct mixart_txx_stream_desc stream_desc; /* only one stream per command, but this could be an array, in theory */ } __attribute__((packed));