From patchwork Fri Sep 24 19:24:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre-Louis Bossart X-Patchwork-Id: 12516733 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B56DAC433F5 for ; Fri, 24 Sep 2021 19:27:25 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 351606054E for ; Fri, 24 Sep 2021 19:27:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 351606054E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 94603166E; Fri, 24 Sep 2021 21:26:33 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 94603166E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1632511643; bh=F0zrMSjbExXLomQxU3Tj7Rz7WLaZuT3QEKEiYprk0C4=; h=From:To:Subject:Date:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=QZ/ze8Uol7YUeoLrjaF+6IUmJyc6N8dGsBdPZc7R3jNJtF1kJ28m5HcDw7zqo5rKl hFFHYv+85LACLxJ2Siw/UX5rauEwAgwrfmTxQ1Iv2gJ270U7y+oi79AhGL5+y8z6lV YSxU5RAzkKg0xKZ7KvXXXeVOR/T2ZYRmXvXk310M= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 5558FF804F3; Fri, 24 Sep 2021 21:25:02 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 3F05CF800BC; Fri, 24 Sep 2021 21:24:59 +0200 (CEST) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id B61C0F800BC for ; Fri, 24 Sep 2021 21:24:48 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz B61C0F800BC X-IronPort-AV: E=McAfee;i="6200,9189,10117"; a="203643412" X-IronPort-AV: E=Sophos;i="5.85,320,1624345200"; d="scan'208";a="203643412" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Sep 2021 12:24:39 -0700 X-IronPort-AV: E=Sophos;i="5.85,320,1624345200"; d="scan'208";a="551922500" Received: from bordone-mobl1.amr.corp.intel.com (HELO pbossart-mobl3.intel.com) ([10.209.164.235]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Sep 2021 12:24:38 -0700 From: Pierre-Louis Bossart To: alsa-devel@alsa-project.org Subject: [RFC PATCH 3/4] ALSA: hda: hdac_ext_stream: fix potential locking issues Date: Fri, 24 Sep 2021 14:24:16 -0500 Message-Id: <20210924192417.169243-4-pierre-louis.bossart@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210924192417.169243-1-pierre-louis.bossart@linux.intel.com> References: <20210924192417.169243-1-pierre-louis.bossart@linux.intel.com> MIME-Version: 1.0 Cc: tiwai@suse.de, vkoul@kernel.org, broonie@kernel.org, Cezary Rojewski , Pierre-Louis Bossart X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" The code for hdac_ext_stream seems inherited from hdac_stream, and similar locking issues are present: the use of the bus->reg_lock spinlock is inconsistent, with only writes to specific fields being protected. Apply similar fix as in hdac_stream by protecting all accesses to 'link_locked' and 'decoupled' fields, with a new helper snd_hdac_ext_stream_decouple_locked() added to simplify code changes. Signed-off-by: Pierre-Louis Bossart --- include/sound/hdaudio_ext.h | 2 ++ sound/hda/ext/hdac_ext_stream.c | 46 ++++++++++++++++++++------------- 2 files changed, 30 insertions(+), 18 deletions(-) diff --git a/include/sound/hdaudio_ext.h b/include/sound/hdaudio_ext.h index 375581634143..d4e31ea16aba 100644 --- a/include/sound/hdaudio_ext.h +++ b/include/sound/hdaudio_ext.h @@ -88,6 +88,8 @@ struct hdac_ext_stream *snd_hdac_ext_stream_assign(struct hdac_bus *bus, struct snd_pcm_substream *substream, int type); void snd_hdac_ext_stream_release(struct hdac_ext_stream *azx_dev, int type); +void snd_hdac_ext_stream_decouple_locked(struct hdac_bus *bus, + struct hdac_ext_stream *azx_dev, bool decouple); void snd_hdac_ext_stream_decouple(struct hdac_bus *bus, struct hdac_ext_stream *azx_dev, bool decouple); void snd_hdac_ext_stop_streams(struct hdac_bus *bus); diff --git a/sound/hda/ext/hdac_ext_stream.c b/sound/hda/ext/hdac_ext_stream.c index 0c005d67fa89..37154ed43bd5 100644 --- a/sound/hda/ext/hdac_ext_stream.c +++ b/sound/hda/ext/hdac_ext_stream.c @@ -106,20 +106,14 @@ void snd_hdac_stream_free_all(struct hdac_bus *bus) } EXPORT_SYMBOL_GPL(snd_hdac_stream_free_all); -/** - * snd_hdac_ext_stream_decouple - decouple the hdac stream - * @bus: HD-audio core bus - * @stream: HD-audio ext core stream object to initialize - * @decouple: flag to decouple - */ -void snd_hdac_ext_stream_decouple(struct hdac_bus *bus, - struct hdac_ext_stream *stream, bool decouple) +void snd_hdac_ext_stream_decouple_locked(struct hdac_bus *bus, + struct hdac_ext_stream *stream, + bool decouple) { struct hdac_stream *hstream = &stream->hstream; u32 val; int mask = AZX_PPCTL_PROCEN(hstream->index); - spin_lock_irq(&bus->reg_lock); val = readw(bus->ppcap + AZX_REG_PP_PPCTL) & mask; if (decouple && !val) @@ -128,6 +122,20 @@ void snd_hdac_ext_stream_decouple(struct hdac_bus *bus, snd_hdac_updatel(bus->ppcap, AZX_REG_PP_PPCTL, mask, 0); stream->decoupled = decouple; +} +EXPORT_SYMBOL_GPL(snd_hdac_ext_stream_decouple_locked); + +/** + * snd_hdac_ext_stream_decouple - decouple the hdac stream + * @bus: HD-audio core bus + * @stream: HD-audio ext core stream object to initialize + * @decouple: flag to decouple + */ +void snd_hdac_ext_stream_decouple(struct hdac_bus *bus, + struct hdac_ext_stream *stream, bool decouple) +{ + spin_lock_irq(&bus->reg_lock); + snd_hdac_ext_stream_decouple_locked(bus, stream, decouple); spin_unlock_irq(&bus->reg_lock); } EXPORT_SYMBOL_GPL(snd_hdac_ext_stream_decouple); @@ -252,6 +260,7 @@ hdac_ext_link_stream_assign(struct hdac_bus *bus, return NULL; } + spin_lock_irq(&bus->reg_lock); list_for_each_entry(stream, &bus->stream_list, list) { struct hdac_ext_stream *hstream = container_of(stream, struct hdac_ext_stream, @@ -266,17 +275,16 @@ hdac_ext_link_stream_assign(struct hdac_bus *bus, } if (!hstream->link_locked) { - snd_hdac_ext_stream_decouple(bus, hstream, true); + snd_hdac_ext_stream_decouple_locked(bus, hstream, true); res = hstream; break; } } if (res) { - spin_lock_irq(&bus->reg_lock); res->link_locked = 1; res->link_substream = substream; - spin_unlock_irq(&bus->reg_lock); } + spin_unlock_irq(&bus->reg_lock); return res; } @@ -292,6 +300,7 @@ hdac_ext_host_stream_assign(struct hdac_bus *bus, return NULL; } + spin_lock_irq(&bus->reg_lock); list_for_each_entry(stream, &bus->stream_list, list) { struct hdac_ext_stream *hstream = container_of(stream, struct hdac_ext_stream, @@ -301,18 +310,17 @@ hdac_ext_host_stream_assign(struct hdac_bus *bus, if (!stream->opened) { if (!hstream->decoupled) - snd_hdac_ext_stream_decouple(bus, hstream, true); + snd_hdac_ext_stream_decouple_locked(bus, hstream, true); res = hstream; break; } } if (res) { - spin_lock_irq(&bus->reg_lock); res->hstream.opened = 1; res->hstream.running = 0; res->hstream.substream = substream; - spin_unlock_irq(&bus->reg_lock); } + spin_unlock_irq(&bus->reg_lock); return res; } @@ -378,15 +386,17 @@ void snd_hdac_ext_stream_release(struct hdac_ext_stream *stream, int type) break; case HDAC_EXT_STREAM_TYPE_HOST: + spin_lock_irq(&bus->reg_lock); if (stream->decoupled && !stream->link_locked) - snd_hdac_ext_stream_decouple(bus, stream, false); + snd_hdac_ext_stream_decouple_locked(bus, stream, false); + spin_unlock_irq(&bus->reg_lock); snd_hdac_stream_release(&stream->hstream); break; case HDAC_EXT_STREAM_TYPE_LINK: - if (stream->decoupled && !stream->hstream.opened) - snd_hdac_ext_stream_decouple(bus, stream, false); spin_lock_irq(&bus->reg_lock); + if (stream->decoupled && !stream->hstream.opened) + snd_hdac_ext_stream_decouple_locked(bus, stream, false); stream->link_locked = 0; stream->link_substream = NULL; spin_unlock_irq(&bus->reg_lock);