From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5ADBDFC00 for ; Mon, 15 May 2023 17:30:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2258C433EF; Mon, 15 May 2023 17:30:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1684171853; bh=F4VmDvo9vhiaWp/qqDmfCbSrANSvjEq2IIoUGwzChOs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Un62rheKXTiDgfuPJdHWu4uiOOdMWeWMX4OHdhdVKRT4ipA1OkJd7emS2pD6Hx9zc iKa2f1tGdZ4EGfGPptNlahd554SpB/ygxzl+w7EYsPqp78aiHuaN1Rx1l9a+oGXuGX rbhJbYLC3FJctkTCJXWucpjZKXT9DWH37U4MuHI8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Takashi Iwai , Mark Brown , Marek Szyprowski Subject: [PATCH 5.15 099/134] ASoC: soc-pcm: Move debugfs removal out of spinlock Date: Mon, 15 May 2023 18:29:36 +0200 Message-Id: <20230515161706.435184021@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230515161702.887638251@linuxfoundation.org> References: <20230515161702.887638251@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Takashi Iwai commit 9f620684c1ef5a002b6622ecc7b5818e81252f48 upstream. The recent fix for DPCM locking also covered the loop in dpcm_be_disconnect() with the FE stream lock. This caused an unexpected side effect, thought: calling debugfs_remove_recursive() in the spinlock may lead to lockdep splats as the code there assumes the SOFTIRQ-safe context. For avoiding the problem, this patch changes the disconnection procedure to two phases: at first, the matching entries are removed from the linked list, then the resources are freed outside the lock. Fixes: b7898396f4bb ("ASoC: soc-pcm: Fix and cleanup DPCM locking") Reported-and-tested-by: Marek Szyprowski Signed-off-by: Takashi Iwai Link: https://lore.kernel.org/r/20220119155249.26754-3-tiwai@suse.de Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- sound/soc/soc-pcm.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -1289,6 +1289,7 @@ static void dpcm_be_reparent(struct snd_ void dpcm_be_disconnect(struct snd_soc_pcm_runtime *fe, int stream) { struct snd_soc_dpcm *dpcm, *d; + LIST_HEAD(deleted_dpcms); snd_soc_dpcm_mutex_assert_held(fe); @@ -1308,13 +1309,18 @@ void dpcm_be_disconnect(struct snd_soc_p /* BEs still alive need new FE */ dpcm_be_reparent(fe, dpcm->be, stream); - dpcm_remove_debugfs_state(dpcm); - list_del(&dpcm->list_be); + list_move(&dpcm->list_fe, &deleted_dpcms); + } + snd_soc_dpcm_stream_unlock_irq(fe, stream); + + while (!list_empty(&deleted_dpcms)) { + dpcm = list_first_entry(&deleted_dpcms, struct snd_soc_dpcm, + list_fe); list_del(&dpcm->list_fe); + dpcm_remove_debugfs_state(dpcm); kfree(dpcm); } - snd_soc_dpcm_stream_unlock_irq(fe, stream); } /* get BE for DAI widget and stream */