Who broke cb8f488c33 patch? (was Re: [PATCH 1/1] USBHID: correct start/stop cycle)

[Jiri Kosina <jkosina@suse.cz>]

On Wed, 12 Nov 2008, Denys Vlasenko wrote:

> > > > I fully bisected it, and the final "buggy" patch seems to have been 
> > > > Denys Vlasenko's patch: cb8f488c33539f096580e202f5438a809195008f (see 
> > > > http://github.com/jonsmirl/digispeaker/commit/cb8f488c33539f096580e202f5438a809195008f) 
> > > > Denys: Any reason you removed "!prev" in front of "expand_stack"?
> > > Looks like I erroneously thought it can't be NULL,
> > > or that expand_upwards() is ok with getting NULL vma parameter.
> > > I looked again and neither is true.
> > > Sorry, looks like I indeed broke this.
> > Hmm, so ... ? Seems like this didn't get fixed in Linus' tree yet?
> I found my original email in "sent" folder. The patch in that mail does 
> NOT remove !prev. That change had beed added by someone else. See 
> attached file with original email.
> Ok, I think we are not much interested in who did it, 

Hmm, I in fact think we would like to know who removed the check and 
folded it into your original patch. I have added all the Signoffs and CCs 
to the recepient list.

Andrew usually puts

	[someone@somewhere.com: added this and that to the patch]

marker into the changelog, but it's not the case here. 

Having your name in Signed-off-by field of something you are not aware of 
should make you feel at least a little bit nervous IMHO.

> let's fix it for good.
> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
> --- linux-2.6.28-rc4/mm/mmap.c	Mon Nov 10 01:36:15 2008
> +++ linux-2.6.28-rc4.fix/mm/mmap.c	Wed Nov 12 01:21:39 2008
> @@ -1704,7 +1704,7 @@
>  	vma = find_vma_prev(mm, addr, &prev);
>  	if (vma && (vma->vm_start <= addr))
>  		return vma;
> -	if (expand_stack(prev, addr))
> +	if (!prev || expand_stack(prev, addr))
>  		return NULL;
>  	if (prev->vm_flags & VM_LOCKED) {
>  		if (mlock_vma_pages_range(prev, addr, prev->vm_end) < 0)

Thanks,

-- 
Jiri Kosina
SUSE Labs