On 27.04.2020 11:59, Roger Pau Monné wrote: > On Mon, Apr 27, 2020 at 10:03:05AM +0200, Jan Beulich wrote: >> --- a/xen/include/asm-x86/regs.h >> +++ b/xen/include/asm-x86/regs.h >> @@ -10,9 +10,10 @@ >> /* Frame pointer must point into current CPU stack. */ >> \ >> ASSERT(diff < STACK_SIZE); >> \ >> /* If not a guest frame, it must be a hypervisor frame. */ >> \ >> - ASSERT((diff == 0) || (r->cs == __HYPERVISOR_CS)); >> \ >> + if ( diff < PRIMARY_STACK_SIZE ) >> \ >> + ASSERT(!diff || ((r)->cs == __HYPERVISOR_CS)); >> \ > > Why not use: > > ASSERT(diff >= PRIMARY_STACK_SIZE || !diff || ((r)->cs == __HYPERVISOR_CS));
Except for the longer (without being helpful imo) string reported if the assertion triggers, I see not difference. > I'm not sure I fully understand this layout, is it possible that you > also need to account for the size of cpu_info? Depends on how paranoid we want the checking here to be, but in going further I wouldn't want this to become sub-page fine-grained if we aren't first doing e.g. what I'm mentioning in the post-commit-message remark. Jan
