On Mon, 25 Aug 2014, Oleg Nesterov wrote: > On 08/25, Hugh Dickins wrote: > > > And I think I'll let Linus's guard page justify your 4 (to match comment) > > in place of the original's mysterious 5. > > Ah, thanks again. Yes, if we want to guarantee 4 pages we should check 5. > > Although obviously this doesn't explain the original's 5, this was > written before check_stack_guard_page().
I meant, you changed the coded 5 to 4, to match the comment above it; and if I were insistent on maximizing back-compatible-safety, I would say that 4 should go back to 5; but since Linus added the guard page gap at next->vm_start in between, I don't mind if you stick with 4 there to match the comment. Disclaimer: I may be mistaken in each clause of that paragraph, and you may prefer to ignore everything I wrote there as worthless! But I didn't understand your "to guarantee 4 we should check 5". Hugh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
