Re: [PATCH] core: dev: don't call BUG() on bad input

From: Vasiliy Kulikov
Date: Mon Feb 14 2011 - 07:23:28 EST


Hi Nicolas,

On Mon, Feb 14, 2011 at 13:16 +0100, Nicolas de Pesloüan wrote:
> >- BUG_ON(strlen(name)>= sizeof(dev->name));
> >+ if (strnlen(name, sizeof(dev->name))>= sizeof(dev->name)) {

Ehh... Space after ")" is needed :)

> "size_t strnlen(const char *s, size_t maxlen) : The strnlen()
> function returns strlen(s), if that is less than maxlen, or maxlen
> if there is no '\0' character among the first maxlen characters
> pointed to by s."
>
> How can strnlen(name, sizeof(dev->name)) be greater than sizeof(dev->name)?
>
> Shouldn't it be "if (strnlen(name, sizeof(dev->name)) == sizeof(dev->name))" instead?

Not a big deal, but MO it's better to guard from everything that
is not a good input by negating the check. strnlen() < sizeof() is OK,
strnlen() >= sizeof() is bad. Is "==" more preferable for net/ coding style?


--
Vasiliy Kulikov
http://www.openwall.com - bringing security into open computing environments
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