On Sun, Jul 22, 2018 at 7:52 PM, Andy Lutomirski <l...@kernel.org> wrote: > Hi all- > > It would be really nice to make KASAN compatible with VMAP_STACK. > Both are valuable memory debugging features, and the fact that you > can't use both is disappointing. > > As far as I know, there are only two problems: > > 1. The KASAN shadow population code is a mess, and adding *anything* > to the KASAN shadow requires magical, fragile incantations. It should > be cleaned up so that ranges can be easily populated without needing > to very carefully align things, call helpers in the right order, etc. > The core KASAN code should figure it out by itself. > > 2. The vmalloc area is potentially extremely large. It might be > necessary to have a way to *depopulate* shadow space when stacks get > freed or, more generally, when vmap areas are freed. Ideally KASAN > would integrate with the core vmalloc/vmap code and it would Just Work > (tm). And, as a bonus, we'd get proper KASAN protection of vmalloced > memory. > > Any volunteers to fix this?
Hi Andy, I understand that having most configs as orthogonal settings that can be enabled independently is generally good in intself, but I would like to understand what does VMAP_STACK add on top of KASAN in terms of debugging capabilities?
