From: Jann Horn <jannh@xxxxxxxxxx> Date: Sat, 23 Feb 2019 00:11:58 +0100 > I think what Linus is saying is: There are some scenarios (like a > system with the old 4G/4G X86 patch) where *the same* address can > refer to two different pieces of memory, depending on whether you > interpret it as a kernel pointer or a user pointer. Exactly. On sparc64 the kernel is mapped exactly at the same virtual addresses as userspace processes usually are mapped, even 32-bit ones. The difference is the MMU context only.
