From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=BAYES_00,BIGNUM_EMAILS, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E17AC433DB for ; Tue, 2 Feb 2021 08:19:52 +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 DC26764F05 for ; Tue, 2 Feb 2021 08:19:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DC26764F05 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 A4F711776; Tue, 2 Feb 2021 09:18:58 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz A4F711776 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1612253988; bh=PEeFuU+xnkESS4hEWpmClBpcQPsDxt8CmW29cD/tK0o=; h=Date:From:To:Subject:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=pppdCJZN0unBQ77BGuOf89y1rFNFBhBovzMk4XpRWIUnaWXMFmkyk+aaphvO9FAkt mt+t7h6SQ68iH90j3bGoQPGtMLbY67IzC9TGgwBvo0CvNDwMjgTWQY3aA/6KIiPEJI zV/OKTDtgCJPsGjMon0onsc25HlOSvDtXT/QJF/Q= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 2FA2FF800E1; Tue, 2 Feb 2021 09:18:58 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 0FF08F80171; Tue, 2 Feb 2021 09:18:57 +0100 (CET) Received: from mx2.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 6E1F3F800E1 for ; Tue, 2 Feb 2021 09:18:51 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 6E1F3F800E1 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id D7BFFAD57; Tue, 2 Feb 2021 08:18:50 +0000 (UTC) Date: Tue, 02 Feb 2021 09:18:50 +0100 Message-ID: From: Takashi Iwai To: Dan Carpenter Subject: Re: [bug report] potential deadlock in snd_emu10k1_voice_alloc() In-Reply-To: References: User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Cc: alsa-devel@alsa-project.org 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" On Tue, 02 Feb 2021 06:56:08 +0100, Dan Carpenter wrote: > > Hello ALSA devs, > > The patch 1da177e4c3f4: "Linux-2.6.12-rc2" from Apr 16, 2005, leads > to the following static checker warning: > > sound/pci/emu10k1/voice.c:112 snd_emu10k1_voice_alloc() > warn: called with lock held. '&emu->voice_lock' > > sound/pci/emu10k1/voice.c > 101 int snd_emu10k1_voice_alloc(struct snd_emu10k1 *emu, int type, int number, > 102 struct snd_emu10k1_voice **rvoice) > 103 { > 104 unsigned long flags; > 105 int result; > 106 > 107 if (snd_BUG_ON(!rvoice)) > 108 return -EINVAL; > 109 if (snd_BUG_ON(!number)) > 110 return -EINVAL; > 111 > 112 spin_lock_irqsave(&emu->voice_lock, flags); > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > This lock is already held in the caller. > > 113 for (;;) { > 114 result = voice_alloc(emu, type, number, rvoice); > 115 if (result == 0 || type == EMU10K1_SYNTH || type == EMU10K1_MIDI) > 116 break; > 117 > 118 /* free a voice from synth */ > 119 if (emu->get_synth_voice) { > > The call tree is: > > snd_emux_note_on() > takes the lock: spin_lock_irqsave(&emu->voice_lock, flags); > calls vp = emu->ops.get_voice(emu, port); > --> get_voice() > --> snd_emu10k1_voice_alloc() This report looks like a false-positive, too. Both are from different structs, one is from struct snd_emu10k1 and another is struct snd_emux. thanks, Takashi