Messages in this thread | | | Subject | Re: [PATCH 12/32] kmsan: Allow disabling KMSAN checks for the current task | From | Ilya Leoshkevich <> | Date | Thu, 16 Nov 2023 10:17:20 +0100 |
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On Thu, 2023-11-16 at 09:56 +0100, Alexander Potapenko wrote: > On Wed, Nov 15, 2023 at 9:34 PM Ilya Leoshkevich <iii@linux.ibm.com> > wrote: > > > > Like for KASAN, it's useful to temporarily disable KMSAN checks > > around, > > e.g., redzone accesses. > > This example is incorrect, because KMSAN does not have redzones. > You are calling these functions from "mm: slub: Let KMSAN access > metadata", which mentiones redzones in kfree(), but the description > is > still somewhat unclear. > Can you provide more insight about what is going on? Maybe we can fix > those accesses instead of disabling KMSAN?
It's about SLUB redzones, which appear when compiling with CONFIG_DEBUG_SLAB.
I think that from KMSAN's point of view they should be considered poisoned, but then the question is what to do with functions that check them. I noticed that there was special handling for KASAN there already, so I figured that the best solution would be to do the same thing for KMSAN.
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