From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:46138 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727141AbeHJMZ3 (ORCPT ); Fri, 10 Aug 2018 08:25:29 -0400 Subject: Re: [bcache:for-next 9/27] drivers/md/bcache/sysfs.c:271 __cached_dev_store() error: uninitialized symbol 'v'. To: kbuild test robot , kbuild@01.org, Kent Overstreet Cc: Dan Carpenter , linux-fsdevel@vger.kernel.org, kbuild-all@01.org References: <20180810081918.aygl7ck7p4nsmsyf@mwanda> From: Coly Li Message-ID: Date: Fri, 10 Aug 2018 17:56:07 +0800 MIME-Version: 1.0 In-Reply-To: <20180810081918.aygl7ck7p4nsmsyf@mwanda> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 2018/8/10 4:19 PM, kbuild test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/colyli/linux-bcache.git for-next > head: 2b04674443471465b4bdc0e52b2355bb5e128078 > commit: 9c26e5fd96446919cc77c14a09ba9b6cf2320ab5 [9/27] bcache: set max writeback rate when I/O request is idle > > smatch warnings: > drivers/md/bcache/sysfs.c:271 __cached_dev_store() error: uninitialized symbol 'v'. > > # https://git.kernel.org/pub/scm/linux/kernel/git/colyli/linux-bcache.git/commit/?id=9c26e5fd96446919cc77c14a09ba9b6cf2320ab5 > git remote add bcache https://git.kernel.org/pub/scm/linux/kernel/git/colyli/linux-bcache.git > git remote update bcache > git checkout 9c26e5fd96446919cc77c14a09ba9b6cf2320ab5 > vim +/v +271 drivers/md/bcache/sysfs.c > Oh, here is a bug, thanks for pointing out this. Very helpful! Coly Li > cafe5635 Kent Overstreet 2013-03-23 257 > cafe5635 Kent Overstreet 2013-03-23 258 sysfs_strtoul(data_csum, dc->disk.data_csum); > cafe5635 Kent Overstreet 2013-03-23 259 d_strtoul(verify); > 5ceaaad7 Kent Overstreet 2013-09-10 260 d_strtoul(bypass_torture_test); > cafe5635 Kent Overstreet 2013-03-23 261 d_strtoul(writeback_metadata); > cafe5635 Kent Overstreet 2013-03-23 262 d_strtoul(writeback_running); > cafe5635 Kent Overstreet 2013-03-23 263 d_strtoul(writeback_delay); > 16749c23 Kent Overstreet 2013-11-11 264 > cafe5635 Kent Overstreet 2013-03-23 265 sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent, 0, 40); > cafe5635 Kent Overstreet 2013-03-23 266 > 9c26e5fd Coly Li 2018-07-26 267 if (attr == &sysfs_writeback_rate) { > 9c26e5fd Coly Li 2018-07-26 268 int v; > 9c26e5fd Coly Li 2018-07-26 269 > 9c26e5fd Coly Li 2018-07-26 270 sysfs_strtoul_clamp(writeback_rate, v, 1, INT_MAX); > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > 9c26e5fd Coly Li 2018-07-26 @271 atomic_long_set(&dc->writeback_rate.rate, v); > ^ > This code is impossible to reach, so Smatch isn't supposed to generate > a warning... It doesn't warn when I build it on my system... Sometimes > Smatch takes short cuts if the system is overloaded so that might be the > reason for this warning. > > Anyway, sysfs_strtoul_clamp() returns if "attr == &sysfs_writeback_rate". > [snipped] > --- > 0-DAY kernel test infrastructure Open Source Technology Center > https://lists.01.org/pipermail/kbuild-all Intel Corporation >