From patchwork Mon Nov 8 10:11:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Borislav Petkov X-Patchwork-Id: 12608195 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 C9C49C433EF for ; Mon, 8 Nov 2021 10:13:34 +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 CF34F61357 for ; Mon, 8 Nov 2021 10:13:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org CF34F61357 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=alien8.de 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 C435C166A; Mon, 8 Nov 2021 11:12:41 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz C435C166A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1636366411; bh=KJ3wDP+0fRfysj/9Nq5eOXO7exeaflX4PL3YRwtc1Vs=; h=From:To:Subject:Date:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=kNZFNe+BLKeH3Y2HWvQGjiU4RSDB0QMzDqB7fTICu7fbnR/ILYt0v5qfnwwOfy2Il BW/r5pkY7Lyj3pj+xZeStu+E6Dge/YNyXl++YW7l3Emt8gAXFJzRUmCd+0J9WsAsge uahErYCXVhUspy4VOA3AKMDdzTWC9GDBmpZtlS0Q= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 61B33F80107; Mon, 8 Nov 2021 11:12:41 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 51594F8049E; Mon, 8 Nov 2021 11:12:38 +0100 (CET) Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id E81C4F80107 for ; Mon, 8 Nov 2021 11:12:29 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz E81C4F80107 Authentication-Results: alsa1.perex.cz; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="GNk0oPHT" Received: from zn.tnic (p200300ec2f33110088892b77bd117736.dip0.t-ipconnect.de [IPv6:2003:ec:2f33:1100:8889:2b77:bd11:7736]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 4A3421EC0502; Mon, 8 Nov 2021 11:12:26 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1636366346; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dV4yMzKrI1TbB2ks8ruZkP157t7OTN1nFaA3SUb88SQ=; b=GNk0oPHTCiJ2Ie3P0UiFdIsZ0u5vyavaxiCWHbuBT8UA06ECOLORBvzPbrc1iS77ZiuzNh QfQfGfVRD7sdOVsI0KmFOU/olLRTH2GnuqOFK+wkoBNLms9AI1VH9nTd76n+hoMsBF0pXh 59/iPfW6ZACUDcSOFrHkV1A4em4teRo= From: Borislav Petkov To: LKML Subject: [PATCH v0 23/42] ASoC: soc-jack: Check notifier registration return value Date: Mon, 8 Nov 2021 11:11:38 +0100 Message-Id: <20211108101157.15189-24-bp@alien8.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20211108101157.15189-1-bp@alien8.de> References: <20211108101157.15189-1-bp@alien8.de> MIME-Version: 1.0 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" From: Borislav Petkov Avoid homegrown notifier registration checks. No functional changes. Signed-off-by: Borislav Petkov Cc: alsa-devel@alsa-project.org --- sound/soc/soc-jack.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/sound/soc/soc-jack.c b/sound/soc/soc-jack.c index d798765d168c..0875f5022066 100644 --- a/sound/soc/soc-jack.c +++ b/sound/soc/soc-jack.c @@ -181,7 +181,8 @@ EXPORT_SYMBOL_GPL(snd_soc_jack_add_pins); void snd_soc_jack_notifier_register(struct snd_soc_jack *jack, struct notifier_block *nb) { - blocking_notifier_chain_register(&jack->notifier, nb); + if (blocking_notifier_chain_register(&jack->notifier, nb)) + pr_warn("Jack status notifier already registered\n"); } EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_register); From patchwork Mon Nov 8 10:11:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Borislav Petkov X-Patchwork-Id: 12608753 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 29092C433F5 for ; Mon, 8 Nov 2021 15:32:37 +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 6BEE9610A2 for ; Mon, 8 Nov 2021 15:32:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6BEE9610A2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=alien8.de 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 CCE0E1681; Mon, 8 Nov 2021 16:31:44 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz CCE0E1681 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1636385554; bh=EyctKuNiZbw9ekrGBmcYazgcWZy2qwXucaI5j0LrqQI=; h=From:To:Subject:Date:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=jNrr4tKkuNzxHfgmAynlTxg4DXHONabmJybwqNHb0BG9au0yVvdzkBwZyWpQbJgS0 9dgrmbEUfza2k4deZh+PeLPqPAYA7KlpOVPLcegYZzM4NkGWcaO0wv0iuxNAWQPKBt 96HgHGBghz9FM9ehTStvgPbmkpVn8DtAcLSVGI2k= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 7274EF804ED; Mon, 8 Nov 2021 16:30:33 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id B0B82F804C1; Mon, 8 Nov 2021 11:12:49 +0100 (CET) Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 63454F80227 for ; Mon, 8 Nov 2021 11:12:44 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 63454F80227 Authentication-Results: alsa1.perex.cz; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="O9utTH7k" Received: from zn.tnic (p200300ec2f33110088892b77bd117736.dip0.t-ipconnect.de [IPv6:2003:ec:2f33:1100:8889:2b77:bd11:7736]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 97BC51EC0535; Mon, 8 Nov 2021 11:12:41 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1636366361; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZSl40zXDlt+0/rSkoDA+/axSBICuEw4xrW9t+JeAzRg=; b=O9utTH7kzvF0ogbSAjrVux8Q2NyGvuXt2DXX+lXMfGwQDD5NsnAlA7vS1HO+tdNI+F2ntn CZwfQStJuxv3i5Q66Ie7iUHTOBEhoA6pq6felnVAUxHBDq6LlMPMTRyA2hQo7p+FfRiqlX omkNlvF2ej63UhZNrO1CmPB0HckLABU= From: Borislav Petkov To: LKML Subject: [PATCH v0 42/42] notifier: Return an error when callback is already registered Date: Mon, 8 Nov 2021 11:11:57 +0100 Message-Id: <20211108101157.15189-43-bp@alien8.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20211108101157.15189-1-bp@alien8.de> References: <20211108101157.15189-1-bp@alien8.de> MIME-Version: 1.0 X-Mailman-Approved-At: Mon, 08 Nov 2021 16:29:18 +0100 Cc: alsa-devel@alsa-project.org, x86@kernel.org, linux-sh@vger.kernel.org, linux-iio@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-fbdev@vger.kernel.org, netdev@vger.kernel.org, Ayush Sawal , sparclinux@vger.kernel.org, linux-clk@vger.kernel.org, linux-leds@vger.kernel.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, Rohit Maheshwari , linux-staging@lists.linux.dev, bcm-kernel-feedback-list@broadcom.com, openipmi-developer@lists.sourceforge.net, xen-devel@lists.xenproject.org, linux-xtensa@linux-xtensa.org, Arnd Bergmann , linux-pm@vger.kernel.org, intel-gfx@lists.freedesktop.org, Vinay Kumar Yadav , linux-um@lists.infradead.org, Steven Rostedt , rcu@vger.kernel.org, linux-tegra@vger.kernel.org, Thomas Gleixner , intel-gvt-dev@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-edac@vger.kernel.org, linux-parisc@vger.kernel.org, Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-mips@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-crypto@vger.kernel.org, linux-alpha@vger.kernel.org, linuxppc-dev@lists.ozlabs.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" From: Borislav Petkov The notifier registration routine doesn't return a proper error value when a callback has already been registered, leading people to track whether that registration has happened at the call site: https://lore.kernel.org/amd-gfx/20210512013058.6827-1-mukul.joshi@amd.com/ Which is unnecessary. Return -EEXIST to signal that case so that callers can act accordingly. Enforce callers to check the return value, leading to loud screaming during build: arch/x86/kernel/cpu/mce/core.c: In function ‘mce_register_decode_chain’: arch/x86/kernel/cpu/mce/core.c:167:2: error: ignoring return value of \ ‘blocking_notifier_chain_register’, declared with attribute warn_unused_result [-Werror=unused-result] blocking_notifier_chain_register(&x86_mce_decoder_chain, nb); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Drop the WARN too, while at it. Suggested-by: Thomas Gleixner Signed-off-by: Borislav Petkov Cc: Arnd Bergmann Cc: Ayush Sawal Cc: Greg Kroah-Hartman Cc: Rohit Maheshwari Cc: Steven Rostedt Cc: Vinay Kumar Yadav Cc: alsa-devel@alsa-project.org Cc: bcm-kernel-feedback-list@broadcom.com Cc: intel-gfx@lists.freedesktop.org Cc: intel-gvt-dev@lists.freedesktop.org Cc: linux-alpha@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-clk@vger.kernel.org Cc: linux-crypto@vger.kernel.org Cc: linux-edac@vger.kernel.org Cc: linux-fbdev@vger.kernel.org Cc: linux-hyperv@vger.kernel.org Cc: linux-iio@vger.kernel.org Cc: linux-leds@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-remoteproc@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: linux-staging@lists.linux.dev Cc: linux-tegra@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: linux-usb@vger.kernel.org Cc: linux-xtensa@linux-xtensa.org Cc: netdev@vger.kernel.org Cc: openipmi-developer@lists.sourceforge.net Cc: rcu@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: x86@kernel.org Cc: xen-devel@lists.xenproject.org --- include/linux/notifier.h | 8 ++++---- kernel/notifier.c | 36 +++++++++++++++++++----------------- 2 files changed, 23 insertions(+), 21 deletions(-) diff --git a/include/linux/notifier.h b/include/linux/notifier.h index 87069b8459af..45cc5a8d0fd8 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -141,13 +141,13 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh); #ifdef __KERNEL__ -extern int atomic_notifier_chain_register(struct atomic_notifier_head *nh, +extern int __must_check atomic_notifier_chain_register(struct atomic_notifier_head *nh, struct notifier_block *nb); -extern int blocking_notifier_chain_register(struct blocking_notifier_head *nh, +extern int __must_check blocking_notifier_chain_register(struct blocking_notifier_head *nh, struct notifier_block *nb); -extern int raw_notifier_chain_register(struct raw_notifier_head *nh, +extern int __must_check raw_notifier_chain_register(struct raw_notifier_head *nh, struct notifier_block *nb); -extern int srcu_notifier_chain_register(struct srcu_notifier_head *nh, +extern int __must_check srcu_notifier_chain_register(struct srcu_notifier_head *nh, struct notifier_block *nb); extern int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, diff --git a/kernel/notifier.c b/kernel/notifier.c index b8251dc0bc0f..451ef3f73ad2 100644 --- a/kernel/notifier.c +++ b/kernel/notifier.c @@ -20,13 +20,11 @@ BLOCKING_NOTIFIER_HEAD(reboot_notifier_list); */ static int notifier_chain_register(struct notifier_block **nl, - struct notifier_block *n) + struct notifier_block *n) { while ((*nl) != NULL) { - if (unlikely((*nl) == n)) { - WARN(1, "double register detected"); - return 0; - } + if (unlikely((*nl) == n)) + return -EEXIST; if (n->priority > (*nl)->priority) break; nl = &((*nl)->next); @@ -134,10 +132,11 @@ static int notifier_call_chain_robust(struct notifier_block **nl, * * Adds a notifier to an atomic notifier chain. * - * Currently always returns zero. + * Returns 0 on success, %-EEXIST on error. */ -int atomic_notifier_chain_register(struct atomic_notifier_head *nh, - struct notifier_block *n) +int __must_check +atomic_notifier_chain_register(struct atomic_notifier_head *nh, + struct notifier_block *n) { unsigned long flags; int ret; @@ -216,10 +215,11 @@ NOKPROBE_SYMBOL(atomic_notifier_call_chain); * Adds a notifier to a blocking notifier chain. * Must be called in process context. * - * Currently always returns zero. + * Returns 0 on success, %-EEXIST on error. */ -int blocking_notifier_chain_register(struct blocking_notifier_head *nh, - struct notifier_block *n) +int __must_check +blocking_notifier_chain_register(struct blocking_notifier_head *nh, + struct notifier_block *n) { int ret; @@ -335,10 +335,11 @@ EXPORT_SYMBOL_GPL(blocking_notifier_call_chain); * Adds a notifier to a raw notifier chain. * All locking must be provided by the caller. * - * Currently always returns zero. + * Returns 0 on success, %-EEXIST on error. */ -int raw_notifier_chain_register(struct raw_notifier_head *nh, - struct notifier_block *n) +int __must_check +raw_notifier_chain_register(struct raw_notifier_head *nh, + struct notifier_block *n) { return notifier_chain_register(&nh->head, n); } @@ -406,10 +407,11 @@ EXPORT_SYMBOL_GPL(raw_notifier_call_chain); * Adds a notifier to an SRCU notifier chain. * Must be called in process context. * - * Currently always returns zero. + * Returns 0 on success, %-EEXIST on error. */ -int srcu_notifier_chain_register(struct srcu_notifier_head *nh, - struct notifier_block *n) +int __must_check +srcu_notifier_chain_register(struct srcu_notifier_head *nh, + struct notifier_block *n) { int ret;