Re: [PATCH 1/1] tty: vt: Remove redundant null check before kfree.

From: Greg KH
Date: Thu Nov 22 2012 - 16:10:49 EST


On Wed, Nov 21, 2012 at 11:43:34PM +0100, Jiri Slaby wrote:
> On 11/21/2012 03:46 PM, Greg KH wrote:
> > On Wed, Nov 21, 2012 at 10:49:07AM +0530, Sachin Kamat wrote:
> >> --- a/drivers/tty/vt/consolemap.c
> >> +++ b/drivers/tty/vt/consolemap.c
> >> @@ -410,10 +410,8 @@ static void con_release_unimap(struct uni_pagedir *p)
> >> kfree(p->inverse_translations[i]);
> >> p->inverse_translations[i] = NULL;
> >> }
> >> - if (p->inverse_trans_unicode) {
> >> - kfree(p->inverse_trans_unicode);
> >> - p->inverse_trans_unicode = NULL;
> >> - }
> >> + kfree(p->inverse_trans_unicode);
> >> + p->inverse_trans_unicode = NULL;
> >
> > kfree with NULL is a no-op, but the line after that just caused a kernel
> > crash if it was NULL, so I can't accept this type of thing.
>
> Greg, I'm not sure -- what do you mean here? The change actually looks
> fine to me... We do not dereference p->inverse_trans_unicode there.

If we never dereference it, why is it being set to NULL?

greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/