[RFC][PATCH 10/24] x86/pti: Introduce per-task PTI trampoline stack

2020-11-09 Thread Alexandre Chartre
Double the size of the kernel stack when using PTI. The entire stack is mapped into the kernel address space, and the top half of the stack (the PTI stack) is also mapped into the user address space. The PTI stack will be used as a per-task trampoline stack instead of the current per-cpu trampolin

[RFC][PATCH 10/24] x86/pti: Introduce per-task PTI trampoline stack

2020-11-09 Thread Alexandre Chartre
Double the size of the kernel stack when using PTI. The entire stack is mapped into the kernel address space, and the top half of the stack (the PTI stack) is also mapped into the user address space. The PTI stack will be used as a per-task trampoline stack instead of the current per-cpu trampolin