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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 BD659C3B1AF for ; Fri, 14 Feb 2020 17:45:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9747B206B6 for ; Fri, 14 Feb 2020 17:45:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581702319; bh=CqYiNBMlMWHKkp/lCav82O14317gOiqR2e73IbrS+zI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ntswr/wKEBL0QF4msNfRtmKV3eomak1TwLxXtVl5XLYA50LF1dcAWTZjhzBIiYlCY fEJbB48jGgJOqt2D0ekJK3eK7U/sf9zOLsFO15yEGE9FZNq5jk+ecJ6Ut7CYJRhDh2 bV7k2ZNtmy6vNPg8sWooew9tfl7Qt8ES+f0Yss68= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389456AbgBNQCr (ORCPT ); Fri, 14 Feb 2020 11:02:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:48782 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389352AbgBNQC1 (ORCPT ); Fri, 14 Feb 2020 11:02:27 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 767612187F; Fri, 14 Feb 2020 16:02:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581696147; bh=CqYiNBMlMWHKkp/lCav82O14317gOiqR2e73IbrS+zI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hVJkRxztOK3mEZ60KaDjDs9cGuErzGpFyOvgjUSl+sxpULUxc8hYH4a8yRvHBTS8P 9Mw3CICt8pkq4MH71Vnci7myJnPzXhpcpYvVBDk6+pSts2LRmGpvdFZIbIwSV8XJnp ClloMaXZ3AiznwSprJ4ckQTsjb+dFgoU0mZi6K3c= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Takashi Sakamoto , Jaroslav Kysela , Takashi Iwai , Sasha Levin , alsa-devel@alsa-project.org Subject: [PATCH AUTOSEL 5.4 027/459] ALSA: ctl: allow TLV read operation for callback type of element in locked case Date: Fri, 14 Feb 2020 10:54:37 -0500 Message-Id: <20200214160149.11681-27-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214160149.11681-1-sashal@kernel.org> References: <20200214160149.11681-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Takashi Sakamoto [ Upstream commit d61fe22c2ae42d9fd76c34ef4224064cca4b04b0 ] A design of ALSA control core allows applications to execute three operations for TLV feature; read, write and command. Furthermore, it allows driver developers to process the operations by two ways; allocated array or callback function. In the former, read operation is just allowed, thus developers uses the latter when device driver supports variety of models or the target model is expected to dynamically change information stored in TLV container. The core also allows applications to lock any element so that the other applications can't perform write operation to the element for element value and TLV information. When the element is locked, write and command operation for TLV information are prohibited as well as element value. Any read operation should be allowed in the case. At present, when an element has callback function for TLV information, TLV read operation returns EPERM if the element is locked. On the other hand, the read operation is success when an element has allocated array for TLV information. In both cases, read operation is success for element value expectedly. This commit fixes the bug. This change can be backported to v4.14 kernel or later. Signed-off-by: Takashi Sakamoto Reviewed-by: Jaroslav Kysela Link: https://lore.kernel.org/r/20191223093347.15279-1-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/control.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/sound/core/control.c b/sound/core/control.c index 7a4d8690ce41f..08ca7666e84cf 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -1430,8 +1430,9 @@ static int call_tlv_handler(struct snd_ctl_file *file, int op_flag, if (kctl->tlv.c == NULL) return -ENXIO; - /* When locked, this is unavailable. */ - if (vd->owner != NULL && vd->owner != file) + /* Write and command operations are not allowed for locked element. */ + if (op_flag != SNDRV_CTL_TLV_OP_READ && + vd->owner != NULL && vd->owner != file) return -EPERM; return kctl->tlv.c(kctl, op_flag, size, buf); -- 2.20.1