From patchwork Tue Oct 25 09:02:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tudor Ambarus X-Patchwork-Id: 13018780 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 923C1C38A2D for ; Tue, 25 Oct 2022 09:04:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231634AbiJYJEp (ORCPT ); Tue, 25 Oct 2022 05:04:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57318 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232217AbiJYJEC (ORCPT ); Tue, 25 Oct 2022 05:04:02 -0400 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.154.123]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AE99715DB03; Tue, 25 Oct 2022 02:03:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1666688620; x=1698224620; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=oKOZpHo372b5F1wpda/c19+gU8RCyVa1/N7AuJbNJcs=; b=DPWklqiyKwhMADYydzT9a1lUtJ7pNLjpU7Od2KLJvm0QfAPV4+NZG+Kq DjG/Hiw1TxCfWGY2ViXSdWhHvbN9g2U17ppcVjMa/xSldIzJUUK0ucEOS H/oIbmnYPeXRC3FHGflnxueTH3vOkDGrqedmkhVkAWu5u/sqa145G1L7F r1HDxbgJlb8iQvKIcrZpdGrNtm9HRExDSGI6dkYk5jxhFqpUNEIdr1KVT D5NYPVZZyKfmgSSU6M+kK0FLoVj9aMkOrMF5QlTgc2wYzaX/8NZI0BPab LH8buTCCoHHHVegWzNQ5ndLVkiGLm0VXTHzNR6cj8BLCh2kdWAGCUsRCq A==; X-IronPort-AV: E=Sophos;i="5.95,211,1661842800"; d="scan'208";a="180386391" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa4.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 25 Oct 2022 02:03:40 -0700 Received: from chn-vm-ex03.mchp-main.com (10.10.85.151) by chn-vm-ex01.mchp-main.com (10.10.85.143) 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 02:03:36 -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 02:03:34 -0700 From: Tudor Ambarus To: , , CC: , , , , , , , "Tudor Ambarus" , Subject: [PATCH v2 08/32] dmaengine: at_hdmac: Fix concurrency over descriptor Date: Tue, 25 Oct 2022 12:02:42 +0300 Message-ID: <20221025090306.297886-9-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 Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org The descriptor was added to the free_list before calling the callback, which could result in reissuing of the same descriptor and calling of a single callback for both. Move the decriptor to the free list after the callback is invoked. Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller") 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 | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index f1e6fa6af6c2..2012ecc57826 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -469,11 +469,8 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc) desc->memset_buffer = false; } - /* move children to free_list */ - list_splice_init(&desc->tx_list, &atchan->free_list); - /* move myself to free_list */ - list_move(&desc->desc_node, &atchan->free_list); - + /* Remove transfer node from the active list. */ + list_del_init(&desc->desc_node); spin_unlock_irqrestore(&atchan->lock, flags); dma_descriptor_unmap(txd); @@ -483,6 +480,13 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc) dmaengine_desc_get_callback_invoke(txd, NULL); dma_run_dependencies(txd); + + spin_lock_irqsave(&atchan->lock, flags); + /* move children to free_list */ + list_splice_init(&desc->tx_list, &atchan->free_list); + /* add myself to free_list */ + list_add(&desc->desc_node, &atchan->free_list); + spin_unlock_irqrestore(&atchan->lock, flags); } /**