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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC39FFA3740 for ; Tue, 25 Oct 2022 09:04:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231723AbiJYJEL (ORCPT ); Tue, 25 Oct 2022 05:04:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231664AbiJYJDv (ORCPT ); Tue, 25 Oct 2022 05:03:51 -0400 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.154.123]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 779C915A8F6; Tue, 25 Oct 2022 02:03:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1666688613; x=1698224613; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=d1t0ow6YIdu9Rv1rkKmxVrPNsexG/0cDcLPtXg9M8P0=; b=fbI44eC+HEcCvmNe+U6FGf+28WIeYrckJcNXrP7eMaC+7/tdGbnC4Cs/ 4wlo9zcE8+8czfWX1ErMJ81Uzo0EbXCAo2Ng9alGy0tXCcfJdsAea+sFM m/Hf47iVdXrgKjREYInOOTd3wvYqQfesjxaPhZnzyAah6G4Rtp+0ozQ/x GDyGoab82KIl4ORr1HS1XgmkKVnsq43KYpz3uTzQ5c5oGEF2bmg4epOFh WPYaREwZOLEThOK5SVvb7iGf6a1yNKTigT3KkT2aAAAiUwIA0r7Dqse2j venIANILdUZILoe+NfqJv7b/8FBPj6+zW4RyNPPdB6OkpQ6By1tZ2XyfH g==; 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: , , CC: , , , , , , , "Tudor Ambarus" , 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 Content-Transfer-Encoding: 8bit Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.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; } -- 2.25.1