From nobody Wed Sep 3 06:01:27 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 32150C38A2D for ; Mon, 24 Oct 2022 17:14:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231449AbiJXROn (ORCPT ); Mon, 24 Oct 2022 13:14:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231697AbiJXRNa (ORCPT ); Mon, 24 Oct 2022 13:13:30 -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 E88405A8C8; Mon, 24 Oct 2022 08:49:05 -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 9578D6129A; Mon, 24 Oct 2022 11:59:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A479BC433C1; Mon, 24 Oct 2022 11:59:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666612746; bh=bZwGPZDTogpLUxzxQ5yHMwfGBVlcNdR2myoMTG7FLZA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TH8i8gCU3hrYEcz6rEEgo865pgk7d1YaUVyJ5TvXUFMcwzOjWLkvTNVJauDLlGC79 cGUGjcb2mcs83nPB8fVmOXouRnWUB2RYRjzNOCdBUplqqbHUlSunwkmm0CBg8z+w5P KyxFiXcOSlZhoR1EvKA+nlALyImmBJhkIkBLNgXQ= 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 4.19 103/229] ALSA: dmaengine: increment buffer pointer atomically Date: Mon, 24 Oct 2022 13:30:22 +0200 Message-Id: <20221024113002.353044201@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024112959.085534368@linuxfoundation.org> References: <20221024112959.085534368@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 8eb58c709b14..6f6da1128edc 100644 --- a/sound/core/pcm_dmaengine.c +++ b/sound/core/pcm_dmaengine.c @@ -139,12 +139,14 @@ 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