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Date:   Thu, 21 Apr 2022 15:57:57 +0100
From:   Aaron Tomlin <atomlin@redhat.com>
To:     Oleksandr Natalenko <oleksandr@natalenko.name>
Cc:     mcgrof@kernel.org, cl@linux.com, pmladek@suse.com, mbenes@suse.cz,
        christophe.leroy@csgroup.eu, akpm@linux-foundation.org,
        linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org,
        atomlin@atomlin.com, ghalat@redhat.com, neelx@redhat.com
Subject: Re: [PATCH v3 2/2] module: Introduce module unload taint tracking
Message-ID: <20220421145757.zfn6zxh6rx3dp75o@ava.usersys.com>
References: <20220420115257.3498300-1-atomlin@redhat.com>
 <20220420115257.3498300-3-atomlin@redhat.com>
 <2100545.irdbgypaU6@natalenko.name>
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On Thu 2022-04-21 16:28 +0200, Oleksandr Natalenko wrote:
> Hello.

Hi Oleksandr,

> Thanks for this submission. Please see one comment inline.

Thanks for your feedback!

> > @@ -150,6 +160,41 @@ int unregister_module_notifier(struct notifier_block *nb)
> >  }
> >  EXPORT_SYMBOL(unregister_module_notifier);
> >  
> > +#ifdef CONFIG_MODULE_UNLOAD_TAINT_TRACKING
> > +static int try_add_tainted_module(struct module *mod)
> > +{
> > +	struct mod_unload_taint *mod_taint;
> > +
> > +	module_assert_mutex_or_preempt();
> > +
> > +	list_for_each_entry_rcu(mod_taint, &unloaded_tainted_modules, list,
> > +				lockdep_is_held(&module_mutex)) {
> > +		size_t len = strlen(mod_taint->name);
> > +
> > +		if (len == strlen(mod->name) && !memcmp(mod_taint->name, mod->name, len) &&
> 
> Here, two strings are compared, so I'd expect to see `strncmp()` instead of `memcmp()`.

Good point. There are other examples of this throughout
kernel/module/main.c; albeit, I will use strncmp() here.


Kind regards,

-- 
Aaron Tomlin