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=-7.1 required=3.0 tests=BIGNUM_EMAILS,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_MUTT autolearn=ham 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 0EAF3C43387 for ; Tue, 8 Jan 2019 20:38:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF0B920883 for ; Tue, 8 Jan 2019 20:38:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="d/Hj3S6x" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729043AbfAHUi1 (ORCPT ); Tue, 8 Jan 2019 15:38:27 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:49552 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728945AbfAHUi1 (ORCPT ); Tue, 8 Jan 2019 15:38:27 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id x08KYwI1117056; Tue, 8 Jan 2019 20:38:25 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type; s=corp-2018-07-02; bh=pJOQHOMayID1WkEHwaEl8OoJQRELeiNM+sb+FQ+wOng=; b=d/Hj3S6xcj5ywsnpobsxZpheI5k67cpHllV+KAX6PJ6Dvg1/5NH/lKIAFHELQLdRX89o dUtUmpMuKjdaV5u0NEQhzkhQJf0dmrvniOOvtujJHHj1MpMrLtNxNJWDXw5ByhCTmSFU tSzkuYM12UWFxm++CS7U+lX9iH3wf1hoTj5iOjpdttnEhdHpjl/IWskuN/zjsrMsW7du 33z27Pm3XRrrw1cpCNeOJOTH8vC/XtLG/tZCL2E3vjuZKawIJwbKW2EMPyd6DU6d+YYr G2eZifGBW/laoOv6OXpnnA2k4uJ2MW68uaOKDrBh7NvjcfkM2b4geNHcA4SVCpbVUqV2 fw== Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by userp2120.oracle.com with ESMTP id 2ptn7qwq89-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 08 Jan 2019 20:38:25 +0000 Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id x08KcOpj005930 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 8 Jan 2019 20:38:24 GMT Received: from abhmp0015.oracle.com (abhmp0015.oracle.com [141.146.116.21]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x08KcNPF007948; Tue, 8 Jan 2019 20:38:23 GMT Received: from kadam (/10.175.191.32) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 08 Jan 2019 12:38:23 -0800 Date: Tue, 8 Jan 2019 23:38:09 +0300 From: Dan Carpenter To: mkelly@xevo.com Cc: linux-iio@vger.kernel.org Subject: [bug report] tools: iio: iio_generic_buffer: allow continuous looping Message-ID: <20190108203809.GA27223@kadam> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9130 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=765 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1901080159 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Hello Martin Kelly, The patch 55dda0abcf9d: "tools: iio: iio_generic_buffer: allow continuous looping" from May 17, 2018, leads to the following static checker warning: ./tools/iio/iio_generic_buffer.c:640 main() warn: unsigned 'num_loops' is never less than zero. ./tools/iio/iio_generic_buffer.c 331 int main(int argc, char **argv) 332 { 333 unsigned long long num_loops = 2; ^^^^^^^^ 334 unsigned long timedelay = 1000000; 335 unsigned long buf_len = 128; 336 337 ssize_t i; 338 unsigned long long j; 339 unsigned long toread; 340 int ret, c; 341 int fp = -1; 342 343 int num_channels = 0; 344 char *trigger_name = NULL, *device_name = NULL; 345 346 char *data = NULL; 347 ssize_t read_size; 348 int dev_num = -1, trig_num = -1; 349 char *buffer_access = NULL; 350 int scan_size; 351 int noevents = 0; 352 int notrigger = 0; 353 char *dummy; 354 bool force_autochannels = false; 355 356 struct iio_channel_info *channels = NULL; 357 [ snip ] 632 /* Attempt to open non blocking the access dev */ 633 fp = open(buffer_access, O_RDONLY | O_NONBLOCK); 634 if (fp == -1) { /* TODO: If it isn't there make the node */ 635 ret = -errno; 636 fprintf(stderr, "Failed to open %s\n", buffer_access); 637 goto error; 638 } 639 --> 640 for (j = 0; j < num_loops || num_loops < 0; j++) { ^^^^^^^^^^^^^ If num_loops is -1 then it's supposed to loop forever. It basically does, except for the static checker warning. 641 if (!noevents) { 642 struct pollfd pfd = { 643 .fd = fp, 644 .events = POLLIN, 645 }; 646 647 ret = poll(&pfd, 1, -1); 648 if (ret < 0) { 649 ret = -errno; 650 goto error; 651 } else if (ret == 0) { 652 continue; 653 } 654 655 toread = buf_len; 656 } else { 657 usleep(timedelay); 658 toread = 64; 659 } regards, dan carpenter