From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Rusty Russell To: Lucas De Marchi , lkml , linux-modules Cc: "Kent Overstreet" Cc: Rafael J. Wysocki Cc: Viresh Kumar Cc: cpufreq@vger.kernel.org Cc: linux-pm@vger.kernel.org Subject: Re: module refcnt underflow In-Reply-To: References: Date: Mon, 01 Jul 2013 12:08:36 +0930 Message-ID: <8738rzt36b.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii List-ID: Lucas De Marchi writes: > Hi, > > While checking somethings for a next release of kmod I noticed this > strange thing: > > cat /sys/module/acpi_cpufreq/refcnt > 18446744073709551614 > > We outputs this as "-1" in lsmod because we treat the value as signed. > I was just going to change it to unsigned to make it compatible with > what module-init-tools does but... For me it looks like a bug in the > kernel since in this file we just have the output of > kernel/module.c:module_refcount() > > I have this behavior on 3.9.2 but judging by the missing commits in > kernel/module.c, this would also happen in latest head. I've never > seen such a value so I guess it might be difficult to reproduce it > again. > > Any hints on what could cause decs to be greater than incs in module_refcount()? That points to a bug in the cpufreq code. At a glance, there's nothing obvious, but there are quite a few reference counts in that code. Informed people cc'd... Thanks, Rusty.