Re: [PATCH v3] kasan: add memory corruption identification for software tag-based mode

Walter Wu
2019-07-26T13:19:36Z

On Fri, 2019-07-26 at 15:52 +0300, Andrey Ryabinin wrote:
>
> On 7/26/19 3:28 PM, Walter Wu wrote:
> > On Fri, 2019-07-26 at 15:00 +0300, Andrey Ryabinin wrote:
> >>
> >
> >>>
> >>>
> >>> I remember that there are already the lists which you concern. Maybe we
> >>> can try to solve those problems one by one.
> >>>
> >>> 1. deadlock issue? cause by kmalloc() after kfree()?
> >>
> >> smp_call_on_cpu()
> >
> >>> 2. decrease allocation fail, to modify GFP_NOWAIT flag to GFP_KERNEL?
> >>
> >> No, this is not gonna work. Ideally we shouldn't have any allocations there.
> >> It's not reliable and it hurts performance.
> >>
> > I dont know this meaning, we need create a qobject and put into
> > quarantine, so may need to call kmem_cache_alloc(), would you agree this
> > action?
> >
>
> How is this any different from what you have now?

I originally thought you already agreed the free-list(tag-based
quarantine) after fix those issue. If no allocation there, i think maybe
only move generic quarantine into tag-based kasan, but its memory
consumption is more bigger our patch. what do you think?