Re: net: xfrm: Deletion of an unnecessary check before the function call "ipcomp_free_tfms"

Julia Lawall
2014-11-19T09:58:21Z

On Wed, 19 Nov 2014, SF Markus Elfring wrote:

> >> The ipcomp_free_tfms() function tests whether its argument is NULL and then
> >> returns immediately. Thus the test around the call is not needed.
> >
> > It doesn't though...
>
> You are right that this function implementation does a bit more before
> returning because of a detected null pointer.
> https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/net/xfrm/xfrm_ipcomp.c?id=394efd19d5fcae936261bd48e5b33b21897aacf8#n247
>
> Can you agree that input parameter validation is also performed there?
> Do you want that I resend my patch with a corrected commit message?

This is completely crazy. The function performs a side effect on a data
structure. If the call site doesn't want that done in a certain case,
then it should not be done.

julia