From patchwork Tue Oct 25 09:02:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tudor Ambarus X-Patchwork-Id: 13018828 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CE5D7C38A2D for ; Tue, 25 Oct 2022 09:08:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=oNhZpZ8C+y7l/nsMK5J91KDTxrg3AmRigMXkuCYoIMk=; b=ovPBWYbZ5ytvdT 7erTEb9i2md8w0buRC0Ao6/nZIc5vwWPUsBRK1psGI47SV4FJDZEwGav5kFYDjBey7YMrvN7iBwju shhkeXMxGCXecT/ri2P3p6E8qEbsnFleS85n03TdNpXadPMlz+Z2P0veehqWOCOd0F0wZATITVArM 5z3Imv3QdSgz5sltvNtjp5xZe3XZR1qho5ENN+33Y82scBOou8qu9Plnk4AMBVTeDl4DPVidVbcp1 wtaOLUtZw9U/VgGq9MlnRdcECMu2PDsTu1XPannGkeA7MZywb1mbineKWQZ2LBoea/K6Iq7BpBojX PXSAJsSWGfLHlntaAgtg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1onFti-004Quo-Gr; Tue, 25 Oct 2022 09:06:58 +0000 Received: from esa.microchip.iphmx.com ([68.232.154.123]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1onFqP-004PHc-B6 for linux-arm-kernel@lists.infradead.org; Tue, 25 Oct 2022 09:03:35 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1666688612; x=1698224612; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=d1t0ow6YIdu9Rv1rkKmxVrPNsexG/0cDcLPtXg9M8P0=; b=qkuZ6BQa+2ZOdi2Xmfdn2NFzmb0feoxs7czrZXjtshWr4xXoMiy54GKP 6kFLaDYTeSHzjrn7hZIjtTZHpiCRv3JSmctHGHrNf6xO2egD6igRYxALq YA7N/lSBZs1CsCbhyH34iXWBtpheRRJRONVKov7VhpHxQDz1jG4eWzhE5 gQgdSkiEv8+pOpi17AqPpleZu3nCA1m+xwq2uEaNz1cRZvvyPt/e5BRPp n8t4iRN9AbwGjmQhD9SGsswxMXg3EP5avudpWpkXZ45vmMd1XGJstZm6k 3GTr3OusnWDjzg8Z49iBwm+w9DKpgdNk99c+Ooo8m7cKcmCsmEdGErKoU Q==; X-IronPort-AV: E=Sophos;i="5.95,211,1661842800"; d="scan'208";a="120221243" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa6.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 25 Oct 2022 02:03:32 -0700 Received: from chn-vm-ex03.mchp-main.com (10.10.85.151) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.12; Tue, 25 Oct 2022 02:03:30 -0700 Received: from ROB-ULT-M18064N.mchp-main.com (10.10.115.15) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server id 15.1.2507.12 via Frontend Transport; Tue, 25 Oct 2022 02:03:28 -0700 From: Tudor Ambarus To: , , Subject: [PATCH v2 06/32] dmaengine: at_hdmac: Protect atchan->status with the channel lock Date: Tue, 25 Oct 2022 12:02:40 +0300 Message-ID: <20221025090306.297886-7-tudor.ambarus@microchip.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221025090306.297886-1-tudor.ambarus@microchip.com> References: <20221025090306.297886-1-tudor.ambarus@microchip.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221025_020333_470715_DAB245B8 X-CRM114-Status: GOOD ( 11.18 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tudor Ambarus , maciej.sosnowski@intel.com, linux-kernel@vger.kernel.org, mripard@kernel.org, linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org, stable@vger.kernel.org, torfl6749@gmail.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Now that the complete callback call was removed from device_terminate_all(), we can protect the atchan->status with the channel lock. The atomic bitops on atchan->status do not substitute proper locking on the status, as one could still modify the status after the lock was dropped in atc_terminate_all() but before the atomic bitops were executed. Fixes: 078a6506141a ("dmaengine: at_hdmac: Fix deadlocks") Reported-by: Peter Rosin Signed-off-by: Tudor Ambarus Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/ --- drivers/dma/at_hdmac.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index 11816484843e..deb4c6027436 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -1460,12 +1460,12 @@ static int atc_terminate_all(struct dma_chan *chan) list_splice_tail_init(&atchan->queue, &atchan->free_list); list_splice_tail_init(&atchan->active_list, &atchan->free_list); - spin_unlock_irqrestore(&atchan->lock, flags); - clear_bit(ATC_IS_PAUSED, &atchan->status); /* if channel dedicated to cyclic operations, free it */ clear_bit(ATC_IS_CYCLIC, &atchan->status); + spin_unlock_irqrestore(&atchan->lock, flags); + return 0; }