Received: by 2002:a25:8b12:0:0:0:0:0 with SMTP id i18csp1951817ybl; Thu, 15 Aug 2019 04:06:53 -0700 (PDT) X-Google-Smtp-Source: APXvYqz//5qhKQKlcL3vr8bvYDiM8cYAdCAY2rFMGJtsbOlWCRrUzqg3lLnoxIl3TLUK+onU1xxw X-Received: by 2002:a17:90a:a013:: with SMTP id q19mr1714838pjp.64.1565867213711; Thu, 15 Aug 2019 04:06:53 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1565867213; cv=none; d=google.com; s=arc-20160816; b=bCJDv3RBUnVdM+RzpgReLWR6STDcpJryabbT2rNockPxdWkCEPSTgZ32IG80wn+tJf 7ARvawPUjTNrAqbM0mHi2kqaWH3sBT0gRZUHzZgLneHM7ALsVvV/kjaCmtDrzIVfRjUm xtWyuEyWWapbDlAr4Lg2jveHZwmJX+6nXFiB8I+w92r20l051W+LIKBiLTJDuTifqqNd WpfyNDwtsKdnUoxmeIKIIjD79CResePylRIpbEvevSkx7jA1VkKIYrI+/m65FqfeUQOo H2GECZjEojRu/8LsS89Km50fzfNXsowMAh9WJn6Pcd42WGawrKgA4QxkRQ090z1zz+zE 6QiQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:mime-version:user-agent:date:message-id:subject:cc :autocrypt:openpgp:from:to; bh=O2fYiJlgwwdZe3ClcoylLLYBQXyjbUnGlIoa4QG8TNU=; b=BWDQ53eUXj751LJnNlLCIxxe6Ex/sDPX6T75StG7eg/F6PDfUDtkzxFx/IdHiXG8kc 4/ySxkUfJ5TbFiwqhw5voXGrGsU/ycjQ7RJcCjgaB9hge+AY+RQpeBMDzj3y4ua1sJfB /TZHqutgR+Nioy5FpcfBz06Vq7bMwarQdMY2s5GLxq4dzBKYDP9v6XLi/9ZePTrw8j7t dflJ6Q2dIVv8FKakXuMyuyRhEzqA7nVg3f44aZnRiyBYFji2szTxguwoDSo8upWzwtC+ tdUNCpK/2V9LdZXOvdSHoMP8eRtSGacNCvggPwNG48r2IUSksOBDNccuZHBR7kq4l2ge OcUg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=canonical.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id r8si780606pjd.64.2019.08.15.04.06.37; Thu, 15 Aug 2019 04:06:53 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=canonical.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731062AbfHOKV0 (ORCPT + 99 others); Thu, 15 Aug 2019 06:21:26 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:38553 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730646AbfHOKVZ (ORCPT ); Thu, 15 Aug 2019 06:21:25 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212]) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1hyCsl-0006b3-9t; Thu, 15 Aug 2019 10:21:23 +0000 To: Lars-Peter Clausen , Jonathan Cameron , Hartmut Knaack , Peter Meerwald-Stadler , Greg Kroah-Hartman , Michael Hennerich , Stefan Popa , linux-iio@vger.kernel.org, "devel@driverdev.osuosl.org" From: Colin Ian King Openpgp: preference=signencrypt Autocrypt: addr=colin.king@canonical.com; prefer-encrypt=mutual; keydata= mQINBE6TJCgBEACo6nMNvy06zNKj5tiwDsXXS+LhT+LwtEsy9EnraKYXAf2xwazcICSjX06e fanlyhB0figzQO0n/tP7BcfMVNG7n1+DC71mSyRK1ZERcG1523ajvdZOxbBCTvTitYOy3bjs +LXKqeVMhK3mRvdTjjmVpWnWqJ1LL+Hn12ysDVVfkbtuIm2NoaSEC8Ae8LSSyCMecd22d9Pn LR4UeFgrWEkQsqROq6ZDJT9pBLGe1ZS0pVGhkRyBP9GP65oPev39SmfAx9R92SYJygCy0pPv BMWKvEZS/7bpetPNx6l2xu9UvwoeEbpzUvH26PHO3DDAv0ynJugPCoxlGPVf3zcfGQxy3oty dNTWkP6Wh3Q85m+AlifgKZudjZLrO6c+fAw/jFu1UMjNuyhgShtFU7NvEzL3RqzFf9O1qM2m uj83IeFQ1FZ65QAiCdTa3npz1vHc7N4uEQBUxyXgXfCI+A5yDnjHwzU0Y3RYS52TA3nfa08y LGPLTf5wyAREkFYou20vh5vRvPASoXx6auVf1MuxokDShVhxLpryBnlKCobs4voxN54BUO7m zuERXN8kadsxGFzItAyfKYzEiJrpUB1yhm78AecDyiPlMjl99xXk0zs9lcKriaByVUv/NsyJ FQj/kmdxox3XHi9K29kopFszm1tFiDwCFr/xumbZcMY17Yi2bQARAQABtCVDb2xpbiBLaW5n IDxjb2xpbi5raW5nQGNhbm9uaWNhbC5jb20+iQI2BBMBCAAhBQJOkyQoAhsDBQsJCAcDBRUK CQgLBRYCAwEAAh4BAheAAAoJEGjCh9/GqAImsBcP9i6C/qLewfi7iVcOwqF9avfGzOPf7CVr n8CayQnlWQPchmGKk6W2qgnWI2YLIkADh53TS0VeSQ7Tetj8f1gV75eP0Sr/oT/9ovn38QZ2 vN8hpZp0GxOUrzkvvPjpH+zdmKSaUsHGp8idfPpZX7XeBO0yojAs669+3BrnBcU5wW45SjSV nfmVj1ZZj3/yBunb+hgNH1QRcm8ZPICpjvSsGFClTdB4xu2AR28eMiL/TTg9k8Gt72mOvhf0 fS0/BUwcP8qp1TdgOFyiYpI8CGyzbfwwuGANPSupGaqtIRVf+/KaOdYUM3dx/wFozZb93Kws gXR4z6tyvYCkEg3x0Xl9BoUUyn9Jp5e6FOph2t7TgUvv9dgQOsZ+V9jFJplMhN1HPhuSnkvP 5/PrX8hNOIYuT/o1AC7K5KXQmr6hkkxasjx16PnCPLpbCF5pFwcXc907eQ4+b/42k+7E3fDA Erm9blEPINtt2yG2UeqEkL+qoebjFJxY9d4r8PFbEUWMT+t3+dmhr/62NfZxrB0nTHxDVIia u8xM+23iDRsymnI1w0R78yaa0Eea3+f79QsoRW27Kvu191cU7QdW1eZm05wO8QUvdFagVVdW Zg2DE63Fiin1AkGpaeZG9Dw8HL3pJAJiDe0KOpuq9lndHoGHs3MSa3iyQqpQKzxM6sBXWGfk EkK5Ag0ETpMkKAEQAMX6HP5zSoXRHnwPCIzwz8+inMW7mJ60GmXSNTOCVoqExkopbuUCvinN 4Tg+AnhnBB3R1KTHreFGoz3rcV7fmJeut6CWnBnGBtsaW5Emmh6gZbO5SlcTpl7QDacgIUuT v1pgewVHCcrKiX0zQDJkcK8FeLUcB2PXuJd6sJg39kgsPlI7R0OJCXnvT/VGnd3XPSXXoO4K cr5fcjsZPxn0HdYCvooJGI/Qau+imPHCSPhnX3WY/9q5/WqlY9cQA8tUC+7mgzt2VMjFft1h rp/CVybW6htm+a1d4MS4cndORsWBEetnC6HnQYwuC4bVCOEg9eXMTv88FCzOHnMbE+PxxHzW 3Gzor/QYZGcis+EIiU6hNTwv4F6fFkXfW6611JwfDUQCAHoCxF3B13xr0BH5d2EcbNB6XyQb IGngwDvnTyKHQv34wE+4KtKxxyPBX36Z+xOzOttmiwiFWkFp4c2tQymHAV70dsZTBB5Lq06v 6nJs601Qd6InlpTc2mjd5mRZUZ48/Y7i+vyuNVDXFkwhYDXzFRotO9VJqtXv8iqMtvS4xPPo 2DtJx6qOyDE7gnfmk84IbyDLzlOZ3k0p7jorXEaw0bbPN9dDpw2Sh9TJAUZVssK119DJZXv5 2BSc6c+GtMqkV8nmWdakunN7Qt/JbTcKlbH3HjIyXBy8gXDaEto5ABEBAAGJAh8EGAEIAAkF Ak6TJCgCGwwACgkQaMKH38aoAiZ4lg/+N2mkx5vsBmcsZVd3ys3sIsG18w6RcJZo5SGMxEBj t1UgyIXWI9lzpKCKIxKx0bskmEyMy4tPEDSRfZno/T7p1mU7hsM4owi/ic0aGBKP025Iok9G LKJcooP/A2c9dUV0FmygecRcbIAUaeJ27gotQkiJKbi0cl2gyTRlolKbC3R23K24LUhYfx4h pWj8CHoXEJrOdHO8Y0XH7059xzv5oxnXl2SD1dqA66INnX+vpW4TD2i+eQNPgfkECzKzGj+r KRfhdDZFBJj8/e131Y0t5cu+3Vok1FzBwgQqBnkA7dhBsQm3V0R8JTtMAqJGmyOcL+JCJAca 3Yi81yLyhmYzcRASLvJmoPTsDp2kZOdGr05Dt8aGPRJL33Jm+igfd8EgcDYtG6+F8MCBOult TTAu+QAijRPZv1KhEJXwUSke9HZvzo1tNTlY3h6plBsBufELu0mnqQvHZmfa5Ay99dF+dL1H WNp62+mTeHsX6v9EACH4S+Cw9Q1qJElFEu9/1vFNBmGY2vDv14gU2xEiS2eIvKiYl/b5Y85Q QLOHWV8up73KK5Qq/6bm4BqVd1rKGI9un8kezUQNGBKre2KKs6wquH8oynDP/baoYxEGMXBg GF/qjOC6OY+U7kNUW3N/A7J3M2VdOTLu3hVTzJMZdlMmmsg74azvZDV75dUigqXcwjE= Cc: "linux-kernel@vger.kernel.org" Subject: static analysis bug report in drivers/staging/iio/dac/ad5380.c Message-ID: Date: Thu, 15 Aug 2019 11:21:22 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Static analysis with Coverity Scan has detected a potential assignment bug in ad5380.c: 217 case IIO_CHAN_INFO_CALIBBIAS: 218 ret = regmap_read(st->regmap, AD5380_REG_OFFSET(chan->address), 219 val); 220 if (ret) 221 return ret; 222 *val >>= chan->scan_type.shift; CID 43178 (#1 of 1): Unused value (UNUSED_VALUE)assigned_pointer: Assigning value from val - (1 << chan->scan_type.realbits) / 2 to val here, but that stored value is not used. 223 val -= (1 << chan->scan_type.realbits) / 2; 224 return IIO_VAL_INT; val is a pointer and so updating it before a return is probably not the intention. I suspect the intention was probably: *val -= (1 << chan->scan_type.realbits) / 2; However, I'm not confident about this as the following case has: 225 case IIO_CHAN_INFO_SCALE: 226 *val = 2 * st->vref; 227 *val2 = chan->scan_type.realbits; 228 return IIO_VAL_FRACTIONAL_LOG2; which may imply the update maybe to *val2 instead, e.g.: *val2 -= (1 << chan->scan_type.realbits) / 2; Any ideas? Colin