* Ingo Molnar <mi...@kernel.org> wrote: > > * Linus Torvalds <torva...@linux-foundation.org> wrote: > > > On Aug 6, 2015 10:15 AM, "Ingo Molnar" <mi...@kernel.org> wrote: > > > > > > What sense does it make to have a blob we don't know the exact layout of? > > > How > > > will debuggers or user-space in general be able to print (and change) the > > > register values if they don't know the layout? > > > > The usage model is that you only use this for saving and restoring state. > > > > If you look at the state, you restore the state and then you look at the > > registers. You never look at the blob itself. > > So we are relying on the saved structure already in a couple of cases, such > as MPX > exception handling: > > /* > * We need to look at BNDSTATUS to resolve this exception. > * A NULL here might mean that it is in its 'init state', > * which is all zeros which indicates MPX was not > * responsible for the exception. > */ > bndcsr = get_xsave_field_ptr(XSTATE_BNDCSR); > if (!bndcsr) > goto exit_trap; > > trace_bounds_exception_mpx(bndcsr); > > get_xsave_field_ptr() very much knows about the structure.
Correction: get_xsave_field_ptr() users very much know about the structure. Thanks, Ingo -- 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/