On Fri, Jan 26, 2018 at 07:11:47PM +0000, Hansen, Dave wrote: > The need for RSB stuffing in all the various scenarios and what the heck it actually mitigates is freakishly complicated. I've tried to write it all down in one place: https://goo.gl/pXbvBE Thank you for sharing that. One question on the third from the top (' RSB Stuff (16) After irq/nmi/#PF/...'). It says that :"Return from interrupt path (more than 16 deep) can empty RSB". Just to clarify - you mean all the returns ('ret') that are happening after we call do_IRQ and the stack unwinds - but before we do an 'iret' correct? I am 99% sure that is what you mean, but just confirming as one could read this as: 'Need to do RSB after an iret' (say you are in the kernel and then get an interrupt and iret back to kernel).
