From patchwork Tue Dec 10 13:02:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takashi Iwai X-Patchwork-Id: 11282411 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 753F4138C for ; Tue, 10 Dec 2019 13:03:20 +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 0E9AC207FF for ; Tue, 10 Dec 2019 13:03:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="Ou6veftW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0E9AC207FF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@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 01EC986F; Tue, 10 Dec 2019 14:02:28 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 01EC986F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1575982998; bh=04kmEUnwuNTfxEtN1ui4P4+TinyR2fiv+1TNL9DWHno=; h=From:To:Date:Cc:Subject:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From; b=Ou6veftWwmMTWjZ6B+RunKiuUUqGNi35Q9So32A/YimOaavCVyqOgLheCFiLd8lBJ 4NL4DX0rBDmZtHmBfOhjRilPhR+sqDmKjdSFioFtwEetARRNnRAP3CI4a/YJMny9LP kpTS1Uf7o/61dqi4AjBAxF+jDXzx59eXAu2sMfCM= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 5F956F801D8; Tue, 10 Dec 2019 14:02:27 +0100 (CET) X-Original-To: alsa-devel@alsa-project.org Delivered-To: alsa-devel@alsa-project.org Received: by alsa1.perex.cz (Postfix, from userid 50401) id 87CEFF8020C; Tue, 10 Dec 2019 14:02:25 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on alsa1.perex.cz X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=SPF_HELO_NONE,SPF_PASS, SURBL_BLOCKED,URIBL_BLOCKED autolearn=disabled version=3.4.0 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id C0938F8011E for ; Tue, 10 Dec 2019 14:02:22 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz C0938F8011E X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 8FF7BAC6F; Tue, 10 Dec 2019 13:02:21 +0000 (UTC) From: Takashi Iwai To: alsa-devel@alsa-project.org Date: Tue, 10 Dec 2019 14:02:19 +0100 Message-Id: <20191210130219.27919-1-tiwai@suse.de> X-Mailer: git-send-email 2.16.4 Cc: Lionel Koenig Subject: [alsa-devel] [PATCH] ALSA: pcm: Fill silence on buffers at hw_params 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: , MIME-Version: 1.0 Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" The current PCM code doesn't initialize explicitly the buffers allocated for PCM streams, hence it might leak some uninitialized kernel data by mmapping or reading the buffer before actually reading or writing. Since this is a common problem, let's initialize the data on the buffers each hw_params properly. For that, an existing helper function is exposed as snd_pcm_fill_silence_frames() and call it from snd_pcm_hw_params(). Reported-and-tested-by: Lionel Koenig Cc: Signed-off-by: Takashi Iwai --- sound/core/pcm_lib.c | 13 ++++--------- sound/core/pcm_local.h | 2 ++ sound/core/pcm_native.c | 3 +++ 3 files changed, 9 insertions(+), 9 deletions(-) diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 2236b5e0c1f2..3c63324b8bb7 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -30,9 +30,6 @@ #define trace_applptr(substream, prev, curr) #endif -static int fill_silence_frames(struct snd_pcm_substream *substream, - snd_pcm_uframes_t off, snd_pcm_uframes_t frames); - /* * fill ring buffer with silence * runtime->silence_start: starting pointer to silence area @@ -100,7 +97,7 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram ofs = runtime->silence_start % runtime->buffer_size; while (frames > 0) { transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames; - err = fill_silence_frames(substream, ofs, transfer); + err = snd_pcm_fill_silence_frames(substream, ofs, transfer); snd_BUG_ON(err < 0); runtime->silence_filled += transfer; frames -= transfer; @@ -1945,8 +1942,6 @@ static int fill_silence(struct snd_pcm_substream *substream, int channel, { struct snd_pcm_runtime *runtime = substream->runtime; - if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK) - return 0; if (substream->ops->fill_silence) return substream->ops->fill_silence(substream, channel, hwoff, bytes); @@ -2030,10 +2025,10 @@ static int noninterleaved_copy(struct snd_pcm_substream *substream, } /* fill silence on the given buffer position; - * called from snd_pcm_playback_silence() + * called from snd_pcm_playback_silence() and snd_pcm_hw_params() */ -static int fill_silence_frames(struct snd_pcm_substream *substream, - snd_pcm_uframes_t off, snd_pcm_uframes_t frames) +int snd_pcm_fill_silence_frames(struct snd_pcm_substream *substream, + snd_pcm_uframes_t off, snd_pcm_uframes_t frames) { if (substream->runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED || substream->runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) diff --git a/sound/core/pcm_local.h b/sound/core/pcm_local.h index 384efd002984..ac4f455b1fff 100644 --- a/sound/core/pcm_local.h +++ b/sound/core/pcm_local.h @@ -34,6 +34,8 @@ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream); void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr); +int snd_pcm_fill_silence_frames(struct snd_pcm_substream *substream, + snd_pcm_uframes_t off, snd_pcm_uframes_t frames); static inline snd_pcm_uframes_t snd_pcm_avail(struct snd_pcm_substream *substream) diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 1fe581167b7b..d6f270c639b4 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -739,6 +739,9 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream, while (runtime->boundary * 2 <= LONG_MAX - runtime->buffer_size) runtime->boundary *= 2; + /* clear the buffer once for avoiding information leaks */ + snd_pcm_fill_silence_frames(substream, 0, runtime->period_size); + snd_pcm_timer_resolution_change(substream); snd_pcm_set_state(substream, SNDRV_PCM_STATE_SETUP);