Messages in this thread | | | Date | Sat, 20 Mar 2021 12:46:06 +1100 | From | Balbir Singh <> | Subject | Re: [PATCH v11 1/6] kasan: allow an architecture to disable inline instrumentation |
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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?
> > Add a Kconfig flag to allow an arch to disable inline. (It's a bit > annoying to be 'backwards', but I'm not aware of any way to have > an arch force a symbol to be 'n', rather than 'y'.) > > We also disable stack instrumentation in this case as it does things that > are functionally equivalent to inline instrumentation, namely adding > code that touches the shadow directly without going through a C helper. > > Signed-off-by: Daniel Axtens <dja@axtens.net> > --- > lib/Kconfig.kasan | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan > index cffc2ebbf185..7e237dbb6df3 100644 > --- a/lib/Kconfig.kasan > +++ b/lib/Kconfig.kasan > @@ -12,6 +12,9 @@ config HAVE_ARCH_KASAN_HW_TAGS > config HAVE_ARCH_KASAN_VMALLOC > bool > > +config ARCH_DISABLE_KASAN_INLINE > + def_bool n > +
Some comments on what arch's want to disable kasan inline would be helpful and why.
Balbir Singh.
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