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: 12949683 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 22E07C25B08 for ; Sat, 20 Aug 2022 13:02:57 +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=/aGSY2xql9j8qM3bkAI2pXha7IBnfPxmEZ+TDFkYCTE=; b=js3I00qjK2H1Ar /7XznSlT87VrW3gAhq3RRDTKr+qfM5X1HQyUzXSLdnu6maqitUfMfwp5PY5gUx80mVQM1GmUq2Kxp pJNreMWkDwE4xcxZ4flYTIqs8EdcEg0QoQtBsOGWhvhx+dNA8O/e6pNWskQ88nK/gutVfE9c5P/1d V2FugjZT56snfDN2N8Q0Igyh8v1r74k563rjxRvFL6qOra+m233QpXylK/s2v8fHwJHQUO0Rz6DRP itmr3DmDhT0860Baa4tsHLUw817Lv+flhpOeLLJ1m4/lxND52GWor3/bop3bRBux4ggse+iXAX5U7 /I8lNYBCQYzyG+zcALxw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oPO6s-00AEbZ-1P; Sat, 20 Aug 2022 13:01:54 +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 1oPO3B-00ACWd-Rq for linux-arm-kernel@lists.infradead.org; Sat, 20 Aug 2022 12:58:10 +0000 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: , , , 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220820_055806_031436_5AE5B11B X-CRM114-Status: GOOD ( 10.66 ) 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@microchip.com, linux-kernel@vger.kernel.org, maciej.sosnowski@intel.com, mripard@kernel.org, torfl6749@gmail.com, ludovic.desroches@microchip.com, stable@vger.kernel.org, dmaengine@vger.kernel.org, dan.j.williams@intel.com, linux-arm-kernel@lists.infradead.org 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 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; }