linux-kernel - Re: [PATCH v1] platform/x86: wmi: Replace kmalloc + sprintf() with kasprintf()

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Date:   Fri, 16 Feb 2018 21:30:03 +0200
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     David Laight <David.Laight@...lab.com>
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Darren Hart <dvhart@...radead.org>,
        "platform-driver-x86@...r.kernel.org" 
        <platform-driver-x86@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v1] platform/x86: wmi: Replace kmalloc + sprintf() with kasprintf()

On Fri, Feb 16, 2018 at 5:55 PM, David Laight <David.Laight@...lab.com> wrote:

>> kasprintf() does the job of two: kmalloc() and sprintf().
>> Replace two calls with one.
> ...
>> -             buf = kmalloc(strlen(wdriver->driver.name) + 5, GFP_KERNEL);
>> +             buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
> ...
>
> Except that kasprintf() has no idea how long a buffer is needed.

Hmm...

> It might even do the printf twice just to get the length.

It does exactly that. So what?

-- 
With Best Regards,
Andy Shevchenko