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Message-ID: <1459336290.5907.39.camel@linux.intel.com>
Subject: Re: [PATCH v2 2/5] string_helpers: add kstrdup_quotable_cmdline
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Kees Cook <keescook@chromium.org>, James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Kalle Valo <kvalo@codeaurora.org>,
        Mauro Carvalho Chehab <mchehab@osg.samsung.com>,
        Joe Perches <joe@perches.com>, Guenter Roeck <linux@roeck-us.net>,
        Jiri Slaby <jslaby@suse.com>, Paul Moore <pmoore@redhat.com>,
        Stephen Smalley <sds@tycho.nsa.gov>,
        Mimi Zohar <zohar@linux.vnet.ibm.com>,
        Casey Schaufler <casey@schaufler-ca.com>,
        Andreas Gruenbacher <agruenba@redhat.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org
Date: Wed, 30 Mar 2016 14:11:30 +0300
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On Wed, 2016-03-30 at 14:07 +0300, Andy Shevchenko wrote:
> On Mon, 2016-03-28 at 14:14 -0700, Kees Cook wrote:


> > +	res = get_cmdline(task, buffer, PAGE_SIZE - 1);
> > +	buffer[res] = '\0';
> > +
> > +	/* Collapse trailing NULLs. */
> > +	for (; res > 0; res--)
> > +		if (buffer[res-1] != '\0')
> > +			break;
> /* buffer[res] is '\0', so, predecrement is safe here */
> while (buffer[--res] == '\0')
>  /* nothing */;
> 
> ?
> 

Oops, no, the following should be better

while (--res >= 0 && buffer[res] == '\0') ;

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy