Re: [PATCH 10/24] x86/mm/kaiser: Map the entry stack variables

Thomas Gleixner
2017-11-27T17:32:19Z

On Mon, 27 Nov 2017, Peter Zijlstra wrote:

> On Mon, Nov 27, 2017 at 11:49:09AM +0100, Ingo Molnar wrote:
> > diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
> > index 157f81816915..631e229ab428 100644
> > --- a/arch/x86/kernel/process_64.c
> > +++ b/arch/x86/kernel/process_64.c
> > @@ -59,7 +59,7 @@
> > #include <asm/unistd_32_ia32.h>
> > #endif
> >
> > -__visible DEFINE_PER_CPU(unsigned long, rsp_scratch);
> > +__visible DEFINE_PER_CPU_USER_MAPPED(unsigned long, rsp_scratch);
> >
> > /* Prints also some state that isn't saved in the pt_regs */
> > void __show_regs(struct pt_regs *regs, int all)
>
> Do we still need this one? It appears to me we'll never actually execute
> that part of entry_SYSCALL_64 anymore, due to
> entry_SYSCALL_64_trampoline.

Unless we use entry_SYSCALL_64 when kaiser is disabled at boottime

Thanks,

tglx