From nobody Fri Dec 19 21:46:35 2025 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 14116C38A2D for ; Mon, 24 Oct 2022 20:22:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234240AbiJXUV7 (ORCPT ); Mon, 24 Oct 2022 16:21:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55882 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229798AbiJXUVM (ORCPT ); Mon, 24 Oct 2022 16:21:12 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E14CA186D78; Mon, 24 Oct 2022 11:37:44 -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 ams.source.kernel.org (Postfix) with ESMTPS id B3599B81269; Mon, 24 Oct 2022 12:09:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16A3CC433D6; Mon, 24 Oct 2022 12:09:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666613345; bh=PKw48NvRM6Pv0obQueP1baQfXMf9H18bxdys05abGAI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cDPJkvEoVf5VVGFSVChPWwcUa6F5K2RTuWFWgCXITjrxsQm52HkplZQSOrUDT1z75 8EIKvFmXZ2F0Z40J4iwzyfQj889pn8PeNKiD6FJlGa+DsB67Rwki+I9V1uuSQYYz2H 1r2DkYphgddakRQ729o5EZ8RDJlYZWDR6rkFlraA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andreas Pape , Eugeniu Rosca , Takashi Iwai , Sasha Levin Subject: [PATCH 5.4 102/255] ALSA: dmaengine: increment buffer pointer atomically Date: Mon, 24 Oct 2022 13:30:12 +0200 Message-Id: <20221024113005.863585249@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024113002.471093005@linuxfoundation.org> References: <20221024113002.471093005@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Andreas Pape [ Upstream commit d1c442019594692c64a70a86ad88eb5b6db92216 ] Setting pointer and afterwards checking for wraparound leads to the possibility of returning the inconsistent pointer position. This patch increments buffer pointer atomically to avoid this issue. Fixes: e7f73a1613567a ("ASoC: Add dmaengine PCM helper functions") Signed-off-by: Andreas Pape Signed-off-by: Eugeniu Rosca Link: https://lore.kernel.org/r/1664211493-11789-1-git-send-email-erosca@de= .adit-jv.com Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/pcm_dmaengine.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c index 89a05926ac73..5d9a24ca6f3e 100644 --- a/sound/core/pcm_dmaengine.c +++ b/sound/core/pcm_dmaengine.c @@ -130,12 +130,14 @@ EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_d= ai_data); =20 static void dmaengine_pcm_dma_complete(void *arg) { + unsigned int new_pos; struct snd_pcm_substream *substream =3D arg; struct dmaengine_pcm_runtime_data *prtd =3D substream_to_prtd(substream); =20 - prtd->pos +=3D snd_pcm_lib_period_bytes(substream); - if (prtd->pos >=3D snd_pcm_lib_buffer_bytes(substream)) - prtd->pos =3D 0; + new_pos =3D prtd->pos + snd_pcm_lib_period_bytes(substream); + if (new_pos >=3D snd_pcm_lib_buffer_bytes(substream)) + new_pos =3D 0; + prtd->pos =3D new_pos; =20 snd_pcm_period_elapsed(substream); } --=20 2.35.1