Re: [PATCH v2] sparc64: Add support for Application Data Integrity (ADI)

[James Morris]

On 03/08/2016 07:58 AM, David Miller wrote:
> From: Khalid Aziz <khalid.aziz@xxxxxxxxxx>
> Date: Mon, 7 Mar 2016 13:41:39 -0700
>
> > Shared data may not always be backed by a file. My understanding is
> > one of the use cases is for in-memory databases. This shared space
> > could also be used to hand off transactions in flight to other
> > processes. These transactions in flight would not be backed by a
> > file. Some of these use cases might not use shmfs even. Setting ADI
> > bits at virtual address level catches all these cases since what backs
> > the tagged virtual address can be anything - a mapped file, mmio
> > space, just plain chunk of memory.
>
> Frankly the most interesting use case to me is simply finding bugs
> and memory scribbles, and for that we're want to be able to ADI
> arbitrary memory returned from malloc() and friends.
>
> I personally see ADI more as a debugging than a security feature,
> but that's just my view.

This is certainly a major use of the feature. The Solaris folks have 
made some interesting use of it here:

https://docs.oracle.com/cd/E37069_01/html/E37085/gphwb.html