Re: [PATCH 1/2] powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct

2020-09-17 Thread Michael Ellerman
On Mon, 7 Sep 2020 13:42:09 + (UTC), Christophe Leroy wrote: > We need r1 to be properly set before activating MMU, so > reading task_struct->stack must be done with MMU off. > > This means we need an additional register to play with MSR > bits while r11 now points to the stack. For that,

[PATCH 1/2] powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct

2020-09-07 Thread Christophe Leroy
We need r1 to be properly set before activating MMU, so reading task_struct->stack must be done with MMU off. This means we need an additional register to play with MSR bits while r11 now points to the stack. For that, move r10 back to CR (As is already done for hash MMU) and use r10. We still