Re: [Xen-devel] [PATCH v2 2/7] x86/traps: Poison unused stack pointers in the TSS

2017-05-03 Thread Jan Beulich
>>> On 03.05.17 at 15:29, wrote: > This is for additional defence-in-depth following LDT/GDT/IDT corruption. > > It causes attempted control transfers to ring 1 or 2 (via a call gate), or > attempts to use IST 3 through 7 to yield #SS, rather than executing with a > stack starting at the top of v

[Xen-devel] [PATCH v2 2/7] x86/traps: Poison unused stack pointers in the TSS

2017-05-03 Thread Andrew Cooper
This is for additional defence-in-depth following LDT/GDT/IDT corruption. It causes attempted control transfers to ring 1 or 2 (via a call gate), or attempts to use IST 3 through 7 to yield #SS, rather than executing with a stack starting at the top of virtual address space. Express the TSS setup