On Wed, Sep 28, 2011 at 06:43:04PM -0400, David Miller wrote:
> From: Mike Stump <mikest...@comcast.net>
> Date: Wed, 28 Sep 2011 15:19:10 -0700
>
> > If Android is safe in this respect, then, they can just turn it on,
> > and then force anyone porting software to their platform to `fix'
> > their code.
>
> They'd have to then know to turn this option off when building the kernel,
> which does use such constructs extensively.
>
> I think this whole idea has too many downsides to be considered seriously.
>
> People write problems like this, lots of people. It's a pervasive
> technique to encode boolean state into the low bits of a pointer or to
> represent special "token" pointers using integers such as "-1".
Or "1". Just do
grep '\*)[[:blank:]]*1' *.[chS]
to see how often an integer value is stored into a pointer.
And it is not just void * pointers, it is struct cgraph_node *
or struct varpool_node * too and the pointed types there certainly
have higher alignment than 1.
Now repeat the same with google codesearch.
Jakub
