Thank you for the attention, andi let's go: On 8/8/07, Andi Kleen <ak@xxxxxxx> wrote: > > > +#define SYSRETQ \ > > + movq %gs:pda_oldrsp,%rsp; \ > > + swapgs; \ > > + sysretq; > > When the macro does more than sysret it should have a different > name That's fair. Again, suggestions are welcome. Maybe SYSCALL_RETURN ? > > */ > > .globl int_ret_from_sys_call > > int_ret_from_sys_call: > > - cli > > + DISABLE_INTERRUPTS(CLBR_ANY) > > ANY? There are certainly some registers alive at this point like rax yes, this one is wrong. Thanks for the catch > > retint_restore_args: > > - cli > > + DISABLE_INTERRUPTS(CLBR_ANY) > > Similar. I don't think so. They are live here, but restore_args follows, so we can safely clobber anything here. Right? > > > /* > > * The iretq could re-enable interrupts: > > */ > > @@ -566,10 +587,14 @@ retint_restore_args: > > restore_args: > > RESTORE_ARGS 0,8,0 > > iret_label: > > - iretq > > +#ifdef CONFIG_PARAVIRT > > + INTERRUPT_RETURN > > +ENTRY(native_iret) > > ENTRY adds alignment. Why do you need that export anyways? Just went on the flow. Will change. > > +#endif > > +1: iretq > > > > .section __ex_table,"a" > > - .quad iret_label,bad_iret > > + .quad 1b, bad_iret > > iret_label seems more expressive to me than 1 fair. > > + ENABLE_INTERRUPTS(CLBR_NONE) > > In many of the CLBR_NONEs there are actually some registers free; > but it might be safer to keep it this way. But if some client can get > significantly better code with one or two free registers it might > be worthwhile to investigate. That's exactly what I had in mind. I'd highly prefer to keep it this way until it is merged, and we are sure all the rest is stable > > - swapgs > > + SWAPGS_NOSTACK > > There's still stack here Yes, but it is not safe to use. I think Roasted addressed it later on. > > paranoid_restore\trace: > > RESTORE_ALL 8 > > - iretq > > + INTERRUPT_RETURN > > I suspect Xen will need much more changes anyways because of its > ring 3 guest. Are these changes sufficient for lguest? Yes, they are sufficient for lguest. Does any xen folks have any comment? -- Glauber de Oliveira Costa. "Free as in Freedom" http://glommer.net "The less confident you are, the more serious you have to act." _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
