Re: [PATCH 3/3] powerpc: fix reschedule bug in KUAP-unlocked user copy

2022-10-13 Thread Guenter Roeck
On Fri, Oct 14, 2022 at 01:16:47AM +1000, Nicholas Piggin wrote: > schedule must not be explicitly called while KUAP is unlocked, because > the AMR register will not be saved across the context switch on 64s > (preemption is allowed because that is driven by interrupts which do > save the AMR). >

Re: [PATCH 3/3] powerpc: fix reschedule bug in KUAP-unlocked user copy

2022-10-13 Thread Guenter Roeck
On Fri, Oct 14, 2022 at 01:16:47AM +1000, Nicholas Piggin wrote: > schedule must not be explicitly called while KUAP is unlocked, because > the AMR register will not be saved across the context switch on 64s > (preemption is allowed because that is driven by interrupts which do > save the AMR). >

[PATCH 3/3] powerpc: fix reschedule bug in KUAP-unlocked user copy

2022-10-13 Thread Nicholas Piggin
schedule must not be explicitly called while KUAP is unlocked, because the AMR register will not be saved across the context switch on 64s (preemption is allowed because that is driven by interrupts which do save the AMR). exit_vmx_usercopy() runs inside an unlocked user access region, and it call