* Avi Kivity <avi@qumranet.com> wrote:

quoted text
> The list macros use LIST_POISON1 and LIST_POISON2 as undereferencable 
> pointers in order to trap erronous use of freed list_heads.  
> Unfortunately userspace can arrange for those pointers to actually be 
> dereferencable, potentially turning an oops to an expolit.
> 
> To avoid this allow architectures (currently x86_64 only) to override 
> the default values for these pointers with truly-undereferncable 
> values. This is easy on x86_64 as the virtual address space is large 
> and contains unmapped ranges.

looks good - thanks Avi - i've added your patch to the -tip tree. I have 
opened a separate topic for it: tip/safe-poison-pointers. (because it 
affects other architectures as well)

	Ingo
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