Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: [PATCH v11 1/6] kasan: allow an architecture to disable inline instrumentation | Date | Mon, 22 Mar 2021 22:08:05 +1100 |
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Daniel Axtens <dja@axtens.net> writes: > Balbir Singh <bsingharora@gmail.com> writes: > >> On Sat, Mar 20, 2021 at 01:40:53AM +1100, Daniel Axtens wrote: >>> For annoying architectural reasons, it's very difficult to support inline >>> instrumentation on powerpc64. >> >> I think we can expand here and talk about how in hash mode, the vmalloc >> address space is in a region of memory different than where kernel virtual >> addresses are mapped. Did I recollect the reason correctly? > > I think that's _a_ reason, but for radix mode (which is all I support at > the moment), the reason is a bit simpler.
Actually Aneesh fixed that in:
0034d395f89d ("powerpc/mm/hash64: Map all the kernel regions in the same 0xc range")
The problem we had prior to that was that the linear mapping was at (0xc << 60), vmalloc was at (0xd << 60), and vmemap was at (0xf << 60).
Meaning our shadow region would need to be more than (3 << 60) in size.
cheers
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