From patchwork Wed Sep 27 14:18:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Damien Le Moal X-Patchwork-Id: 13400929 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 037EBE80AB1 for ; Wed, 27 Sep 2023 14:18:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232094AbjI0OSf (ORCPT ); Wed, 27 Sep 2023 10:18:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232011AbjI0OSd (ORCPT ); Wed, 27 Sep 2023 10:18:33 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF4FDF9; Wed, 27 Sep 2023 07:18:32 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E49AC433C9; Wed, 27 Sep 2023 14:18:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1695824312; bh=TdYao4qTrR7cQFg+fTNLMuMLao4Qjs08k5wl3GDngQk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uHL3Q8VOymr58o8NWwsgW9pVFAEDUWqbO4MQ+aG7n+hqxU3UHzaqcCUJ8NfFe4RTZ m2P9G5alhuV+hLUlqfKl4KxGKA8yJNjssn+jt/PrHMxs4rnjwUt4a+YvZycngJGV2a uteXGr3Vh/cxeV0xWEwB6dxm+w5HXQlBEVF/0GfAgLepCG5sbva820lNmRlcDm1Le4 acmevT8k1HT/KnoEwQELCIlavWRxht7F9thWHqHewHKhEKXbgvcWDk95ZDccFPVCbu DHa4k3nq2gw3MuJV2AFz3g4o8zACcXyBmj7W7dSee0b2aNhxK+1wgT038Vk04BvWVr tIYt5dbbjKFvw== From: Damien Le Moal To: linux-ide@vger.kernel.org Cc: linux-scsi@vger.kernel.org, "Martin K . Petersen" , John Garry , Rodrigo Vivi , Paul Ausbeck , Kai-Heng Feng , Joe Breuer , Geert Uytterhoeven , Chia-Lin Kao Subject: [PATCH v8 01/23] ata: libata-core: Fix ata_port_request_pm() locking Date: Wed, 27 Sep 2023 23:18:06 +0900 Message-ID: <20230927141828.90288-2-dlemoal@kernel.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230927141828.90288-1-dlemoal@kernel.org> References: <20230927141828.90288-1-dlemoal@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org The function ata_port_request_pm() checks the port flag ATA_PFLAG_PM_PENDING and calls ata_port_wait_eh() if this flag is set to ensure that power management operations for a port are not scheduled simultaneously. However, this flag check is done without holding the port lock. Fix this by taking the port lock on entry to the function and checking the flag under this lock. The lock is released and re-taken if ata_port_wait_eh() needs to be called. The two WARN_ON() macros checking that the ATA_PFLAG_PM_PENDING flag was cleared are removed as the first call is racy and the second one done without holding the port lock. Fixes: 5ef41082912b ("ata: add ata port system PM callbacks") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Tested-by: Chia-Lin Kao (AceLan) Reviewed-by: Niklas Cassel Tested-by: Geert Uytterhoeven Reviewed-by: Martin K. Petersen Reviewed-by: Bart Van Assche --- drivers/ata/libata-core.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 0072e0f9ad39..732f3d0b4fd9 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -5037,17 +5037,19 @@ static void ata_port_request_pm(struct ata_port *ap, pm_message_t mesg, struct ata_link *link; unsigned long flags; - /* Previous resume operation might still be in - * progress. Wait for PM_PENDING to clear. + spin_lock_irqsave(ap->lock, flags); + + /* + * A previous PM operation might still be in progress. Wait for + * ATA_PFLAG_PM_PENDING to clear. */ if (ap->pflags & ATA_PFLAG_PM_PENDING) { + spin_unlock_irqrestore(ap->lock, flags); ata_port_wait_eh(ap); - WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING); + spin_lock_irqsave(ap->lock, flags); } - /* request PM ops to EH */ - spin_lock_irqsave(ap->lock, flags); - + /* Request PM operation to EH */ ap->pm_mesg = mesg; ap->pflags |= ATA_PFLAG_PM_PENDING; ata_for_each_link(link, ap, HOST_FIRST) { @@ -5059,10 +5061,8 @@ static void ata_port_request_pm(struct ata_port *ap, pm_message_t mesg, spin_unlock_irqrestore(ap->lock, flags); - if (!async) { + if (!async) ata_port_wait_eh(ap); - WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING); - } } /*