From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A33015687C; Mon, 16 Sep 2024 12:00:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726488021; cv=none; b=X1oX2vCGOEYFdyHrMghVAHml7NrtFlBc221K+0WiUiBzGBC9MpQyoiIK1i9t2MUPC8656HDPtPWXIzkH98Ks3mhgjGyQLo449P+bLYt4VKcgkEcjw0G5gZ8UsNKFIGGPbB8oeFDoM7cH0qaGUpksbyJxGjJBNkEcyxns3lgWp/E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726488021; c=relaxed/simple; bh=tvsPvwa1bIHOx2x/9VaEeRpd8JwUg7mfyIgdMx1N+Fo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Hb4MhsnXsu7SPDIlNXPeIpRSB5o12NslWf43doC/v7mm0mmeDPEywvgE/RN2R/6MO+CPdRy4gN4EslX2UFVh4dKu0cLL8nT0qs6JlhMK11abL83k5GLXyb/a8RZ4eXsWhrbEhtDLqBRK5HB09x4C5Y9LTIdyVhvCZqvlKvRnjBI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=iGHk7VyW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="iGHk7VyW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD177C4CEC7; Mon, 16 Sep 2024 12:00:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1726488020; bh=tvsPvwa1bIHOx2x/9VaEeRpd8JwUg7mfyIgdMx1N+Fo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iGHk7VyWf/Nayw0omPtj4aIqoRe6OywH+cF0HFZT6RaVdIJNTzHxz+gyBs9apN5IL I7/cWTHge/z+W+YAYhWubtf24dQSRMiDWgSEHzQ6NdU9MEMRtFvls0Yaqq9tUF3RBy x1F5xO4epkXo33VXfjwYEhjp3Olk/UsSITRy+WS4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sean Anderson , Jakub Kicinski Subject: [PATCH 6.1 30/63] net: xilinx: axienet: Fix race in axienet_stop Date: Mon, 16 Sep 2024 13:44:09 +0200 Message-ID: <20240916114222.137598743@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240916114221.021192667@linuxfoundation.org> References: <20240916114221.021192667@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Anderson commit 858430db28a5f5a11f8faa3a6fa805438e6f0851 upstream. axienet_dma_err_handler can race with axienet_stop in the following manner: CPU 1 CPU 2 ====================== ================== axienet_stop() napi_disable() axienet_dma_stop() axienet_dma_err_handler() napi_disable() axienet_dma_stop() axienet_dma_start() napi_enable() cancel_work_sync() free_irq() Fix this by setting a flag in axienet_stop telling axienet_dma_err_handler not to bother doing anything. I chose not to use disable_work_sync to allow for easier backporting. Signed-off-by: Sean Anderson Fixes: 8a3b7a252dca ("drivers/net/ethernet/xilinx: added Xilinx AXI Ethernet driver") Link: https://patch.msgid.link/20240903175141.4132898-1-sean.anderson@linux.dev Signed-off-by: Jakub Kicinski [ Adjusted to apply before dmaengine support ] Signed-off-by: Sean Anderson Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/xilinx/xilinx_axienet.h | 3 +++ drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 8 ++++++++ 2 files changed, 11 insertions(+) --- a/drivers/net/ethernet/xilinx/xilinx_axienet.h +++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h @@ -419,6 +419,8 @@ struct axidma_bd { * @tx_bytes: TX byte count for statistics * @tx_stat_sync: Synchronization object for TX stats * @dma_err_task: Work structure to process Axi DMA errors + * @stopping: Set when @dma_err_task shouldn't do anything because we are + * about to stop the device. * @tx_irq: Axidma TX IRQ number * @rx_irq: Axidma RX IRQ number * @eth_irq: Ethernet core IRQ number @@ -481,6 +483,7 @@ struct axienet_local { struct u64_stats_sync tx_stat_sync; struct work_struct dma_err_task; + bool stopping; int tx_irq; int rx_irq; --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -1161,6 +1161,7 @@ static int axienet_open(struct net_devic phylink_start(lp->phylink); /* Enable worker thread for Axi DMA error handling */ + lp->stopping = false; INIT_WORK(&lp->dma_err_task, axienet_dma_err_handler); napi_enable(&lp->napi_rx); @@ -1216,6 +1217,9 @@ static int axienet_stop(struct net_devic dev_dbg(&ndev->dev, "axienet_close()\n"); + WRITE_ONCE(lp->stopping, true); + flush_work(&lp->dma_err_task); + napi_disable(&lp->napi_tx); napi_disable(&lp->napi_rx); @@ -1760,6 +1764,10 @@ static void axienet_dma_err_handler(stru dma_err_task); struct net_device *ndev = lp->ndev; + /* Don't bother if we are going to stop anyway */ + if (READ_ONCE(lp->stopping)) + return; + napi_disable(&lp->napi_tx); napi_disable(&lp->napi_rx);