On 01/29/2015 05:33 PM, Rik van Riel wrote: >> > Hmm, if the the thread was not using the FPU, and this fails to >> > save anything in to the xsave_buf, what will bndcsr point to? > If the thread was not using the FPU, can we reach the > bound range exception? > > I believe the MPX feature uses information in the xstate.
There are really two kinds of bounds exceptions. There is an "old" 'BOUND' instruction that will generate #BR's as well as the new MPX instructions. The new ones require xstate and poking the FPU, etc... The old one did not. So, we _can_ as far as I know get in to do_bounds() without using the FPU. -- 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/
