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: 13248829 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 alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AA15FC77B75 for ; Fri, 19 May 2023 20:55:12 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id D112D208; Fri, 19 May 2023 22:54:19 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz D112D208 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1684529709; bh=XMfD+fHTTCvtfUV7h2YoT8hriPxayi7IPm7YdA35a9s=; h=Date:From:To:Cc:Subject:List-Id:List-Archive:List-Help:List-Owner: List-Post:List-Subscribe:List-Unsubscribe:From; b=Z7TvK3CRieaOj0UXTqFendM3sf4mZc7THmmJxHurLatG3khc6sAMHuxLRY2eVomN3 LuLCNOjkd5nPHldSTcjppKp5y0taHinFBp94CMokZGdXBqgPKcqoL3RVsZE+uVOkbO NUWlFj9fjMF/7ymTTOxGjHHj/VXXc+2sSZyRHIdU= Received: by alsa1.perex.cz (Postfix, from userid 50401) id AC728F80087; Fri, 19 May 2023 22:54:12 +0200 (CEST) Received: from mailman-core.alsa-project.org (mailman-core.alsa-project.org [10.254.200.10]) by alsa1.perex.cz (Postfix) with ESMTP id 5B601F80272; Fri, 19 May 2023 22:54:12 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 5372DF80272; Fri, 19 May 2023 22:54:08 +0200 (CEST) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 22B83F80087 for ; Fri, 19 May 2023 22:53:59 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 22B83F80087 Authentication-Results: alsa1.perex.cz; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=sBinAhr5 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 24E9B65A4A; 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 Message-ID-Hash: PETZ5G2UJNDD7MH4UEYJDJWBXKIL2QHM X-Message-ID-Hash: PETZ5G2UJNDD7MH4UEYJDJWBXKIL2QHM X-MailFrom: gustavoars@kernel.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-alsa-devel.alsa-project.org-0; header-match-alsa-devel.alsa-project.org-1; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.8 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: 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));