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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B35EFC2BA1A for ; Mon, 6 Apr 2020 04:27:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F50820753 for ; Mon, 6 Apr 2020 04:27:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726545AbgDFE15 (ORCPT ); Mon, 6 Apr 2020 00:27:57 -0400 Received: from mx2.suse.de ([195.135.220.15]:42118 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726050AbgDFE15 (ORCPT ); Mon, 6 Apr 2020 00:27:57 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id A7755AC24; Mon, 6 Apr 2020 04:27:53 +0000 (UTC) Subject: Re: [PATCH] tty: serial: fsl_lpuart: make coverity happy To: Michael Walle , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Cc: Greg Kroah-Hartman , Colin Ian King , NXP Linux Team References: <20200403174942.9594-1-michael@walle.cc> From: Jiri Slaby Autocrypt: addr=jslaby@suse.cz; prefer-encrypt=mutual; keydata= mQINBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABtBtKaXJpIFNsYWJ5 IDxqc2xhYnlAc3VzZS5jej6JAjgEEwECACIFAk6S6NgCGwMGCwkIBwMCBhUIAgkKCwQWAgMB Ah4BAheAAAoJEL0lsQQGtHBJgDsP/j9wh0vzWXsOPO3rDpHjeC3BT5DKwjVN/KtP7uZttlkB duReCYMTZGzSrmK27QhCflZ7Tw0Naq4FtmQSH8dkqVFugirhlCOGSnDYiZAAubjTrNLTqf7e 5poQxE8mmniH/Asg4KufD9bpxSIi7gYIzaY3hqvYbVF1vYwaMTujojlixvesf0AFlE4x8WKs wpk43fmo0ZLcwObTnC3Hl1JBsPujCVY8t4E7zmLm7kOB+8EHaHiRZ4fFDWweuTzRDIJtVmrH LWvRDAYg+IH3SoxtdJe28xD9KoJw4jOX1URuzIU6dklQAnsKVqxz/rpp1+UVV6Ky6OBEFuoR 613qxHCFuPbkRdpKmHyE0UzmniJgMif3v0zm/+1A/VIxpyN74cgwxjhxhj/XZWN/LnFuER1W zTHcwaQNjq/I62AiPec5KgxtDeV+VllpKmFOtJ194nm9QM9oDSRBMzrG/2AY/6GgOdZ0+qe+ 4BpXyt8TmqkWHIsVpE7I5zVDgKE/YTyhDuqYUaWMoI19bUlBBUQfdgdgSKRMJX4vE72dl8BZ +/ONKWECTQ0hYntShkmdczcUEsWjtIwZvFOqgGDbev46skyakWyod6vSbOJtEHmEq04NegUD al3W7Y/FKSO8NqcfrsRNFWHZ3bZ2Q5X0tR6fc6gnZkNEtOm5fcWLY+NVz4HLaKrJuQINBE6S 54YBEADPnA1iy/lr3PXC4QNjl2f4DJruzW2Co37YdVMjrgXeXpiDvneEXxTNNlxUyLeDMcIQ K8obCkEHAOIkDZXZG8nr4mKzyloy040V0+XA9paVs6/ice5l+yJ1eSTs9UKvj/pyVmCAY1Co SNN7sfPaefAmIpduGacp9heXF+1Pop2PJSSAcCzwZ3PWdAJ/w1Z1Dg/tMCHGFZ2QCg4iFzg5 Bqk4N34WcG24vigIbRzxTNnxsNlU1H+tiB81fngUp2pszzgXNV7CWCkaNxRzXi7kvH+MFHu2 1m/TuujzxSv0ZHqjV+mpJBQX/VX62da0xCgMidrqn9RCNaJWJxDZOPtNCAWvgWrxkPFFvXRl t52z637jleVFL257EkMI+u6UnawUKopa+Tf+R/c+1Qg0NHYbiTbbw0pU39olBQaoJN7JpZ99 T1GIlT6zD9FeI2tIvarTv0wdNa0308l00bas+d6juXRrGIpYiTuWlJofLMFaaLYCuP+e4d8x rGlzvTxoJ5wHanilSE2hUy2NSEoPj7W+CqJYojo6wTJkFEiVbZFFzKwjAnrjwxh6O9/V3O+Z XB5RrjN8hAf/4bSo8qa2y3i39cuMT8k3nhec4P9M7UWTSmYnIBJsclDQRx5wSh0Mc9Y/psx9 B42WbV4xrtiiydfBtO6tH6c9mT5Ng+d1sN/VTSPyfQARAQABiQIfBBgBAgAJBQJOkueGAhsM AAoJEL0lsQQGtHBJN7UQAIDvgxaW8iGuEZZ36XFtewH56WYvVUefs6+Pep9ox/9ZXcETv0vk DUgPKnQAajG/ViOATWqADYHINAEuNvTKtLWmlipAI5JBgE+5g9UOT4i69OmP/is3a/dHlFZ3 qjNk1EEGyvioeycJhla0RjakKw5PoETbypxsBTXk5EyrSdD/I2Hez9YGW/RcI/WC8Y4Z/7FS ITZhASwaCOzy/vX2yC6iTx4AMFt+a6Z6uH/xGE8pG5NbGtd02r+m7SfuEDoG3Hs1iMGecPyV XxCVvSV6dwRQFc0UOZ1a6ywwCWfGOYqFnJvfSbUiCMV8bfRSWhnNQYLIuSv/nckyi8CzCYIg c21cfBvnwiSfWLZTTj1oWyj5a0PPgGOdgGoIvVjYXul3yXYeYOqbYjiC5t99JpEeIFupxIGV ciMk6t3pDrq7n7Vi/faqT+c4vnjazJi0UMfYnnAzYBa9+NkfW0w5W9Uy7kW/v7SffH/2yFiK 9HKkJqkN9xYEYaxtfl5pelF8idoxMZpTvCZY7jhnl2IemZCBMs6s338wS12Qro5WEAxV6cjD VSdmcD5l9plhKGLmgVNCTe8DPv81oDn9s0cIRLg9wNnDtj8aIiH8lBHwfUkpn32iv0uMV6Ae sLxhDWfOR4N+wu1gzXWgLel4drkCJcuYK5IL1qaZDcuGR8RPo3jbFO7Y Message-ID: <2971e87a-bf8e-f42e-cf8d-f90d9db9499f@suse.cz> Date: Mon, 6 Apr 2020 06:27:52 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200403174942.9594-1-michael@walle.cc> Content-Type: text/plain; charset=iso-8859-2 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03. 04. 20, 19:49, Michael Walle wrote: > Coverity reports the following: > > var_compare_op: Comparing chan to null implies that chan might be null. > > 1234 if (chan) > 1235 dmaengine_terminate_all(chan); > 1236 > > Dereference after null check (FORWARD_NULL) > var_deref_op: Dereferencing null pointer chan. > > 1237 dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); > > Technically, this is correct. But lpuart_dma_rx_free() is guarded by > lpuart_dma_rx_use which is only true if there is a dma channel, see > lpuart_rx_dma_startup(). In any way, this looks bogus. So remove > the superfluous "if (chan)" check and make coverity happy. > > Fixes: a092ab25fdaa ("tty: serial: fsl_lpuart: fix DMA mapping") > Signed-off-by: Michael Walle > Reported-by: Colin Ian King Acked-by: Jiri Slaby > --- > drivers/tty/serial/fsl_lpuart.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c > index 4cb04d8bf034..83d803729d23 100644 > --- a/drivers/tty/serial/fsl_lpuart.c > +++ b/drivers/tty/serial/fsl_lpuart.c > @@ -1210,9 +1210,7 @@ static void lpuart_dma_rx_free(struct uart_port *port) > struct lpuart_port, port); > struct dma_chan *chan = sport->dma_rx_chan; > > - if (chan) > - dmaengine_terminate_all(chan); > - > + dmaengine_terminate_all(chan); > dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); > kfree(sport->rx_ring.buf); > sport->rx_ring.tail = 0; > thanks, -- js suse labs