Messages in this thread | | | Date | Wed, 10 Apr 2013 11:52:12 +0200 | From | Ingo Molnar <> | Subject | Re: [kernel-hardening] Re: [PATCH] x86: make IDT read-only |
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* H. Peter Anvin <hpa@zytor.com> wrote:
> On 04/09/2013 11:22 AM, Kees Cook wrote: > > > > Can we create a RO fixed per-cpu area? > > > > "Fixed" and "percpu" are mutually exclusive...
There's a fixmap area that holds kmap_atomic() percpu mappings:
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
In a similar fashion we could use a per CPU high-mapped read-only alias as well (assuming it fits, memory is pretty tight there).
Thanks,
Ingo
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