From patchwork Sat Aug 20 12:56:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tudor Ambarus X-Patchwork-Id: 12949649 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 0DA1AC32792 for ; Sat, 20 Aug 2022 12:58:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346923AbiHTM6m (ORCPT ); Sat, 20 Aug 2022 08:58:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346775AbiHTM6b (ORCPT ); Sat, 20 Aug 2022 08:58:31 -0400 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.154.123]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C05C486C02; Sat, 20 Aug 2022 05:58:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1661000285; x=1692536285; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=HC98+2Q3J7wqLV6loiePisXOhcp5INxBFqCWpy13QbI=; b=t0wg/mFof51+s38D7c2SoI5bU3q5pWDd5ATcNe3S9vsgV99TI+vxn8nS jLSUt0HTW+dqJj49pcJkj2+Q4EdHXcYZT1RFA3CBWsT0ZqGYfU/LbT+CG c3Sl/4uuNEBlKYqWjI4xfg4lVjVx09ZAqtZXxFcV7JECaBHu3tEtaySLe d3JLDsa8Z094depIph8O8ShJJcRHzyTo9qfWRlTeqQ8BruU3nORDW7a6x XFcNN0ddbwGmB538FNAdMcRgN1gpzq0ICDqX7+yvgPca+/Ag7u9HOH+kQ 1iqlFMuCSGzU4MHUIUj8otYyXF7dRgtP1TV5szOmk8iirRpjr8wTD3KX0 Q==; X-IronPort-AV: E=Sophos;i="5.93,251,1654585200"; d="scan'208";a="109911419" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa6.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 20 Aug 2022 05:58:05 -0700 Received: from chn-vm-ex02.mchp-main.com (10.10.87.72) by chn-vm-ex02.mchp-main.com (10.10.87.72) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.12; Sat, 20 Aug 2022 05:58:04 -0700 Received: from ROB-ULT-M18064N.mchp-main.com (10.10.115.15) by chn-vm-ex02.mchp-main.com (10.10.85.144) with Microsoft SMTP Server id 15.1.2507.12 via Frontend Transport; Sat, 20 Aug 2022 05:58:01 -0700 From: Tudor Ambarus To: , , , CC: , , , , , , , , , , Subject: [PATCH 12/33] dmaengine: at_hdmac: Protect atchan->status with the channel lock Date: Sat, 20 Aug 2022 15:56:56 +0300 Message-ID: <20220820125717.588722-13-tudor.ambarus@microchip.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220820125717.588722-1-tudor.ambarus@microchip.com> References: <20220820125717.588722-1-tudor.ambarus@microchip.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: dmaengine@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 b3895e5d2ae9..aeb241832c52 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -1902,12 +1902,12 @@ 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; }