On 2019-11-05 01:11, Sami Tolvanen wrote:
On Mon, Nov 4, 2019 at 1:59 PM Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote:On Mon, Nov 4, 2019 at 1:38 PM Sami Tolvanen <samitolvanen@xxxxxxxxxx> wrote:>> On Mon, Nov 4, 2019 at 5:20 AM Marc Zyngier <maz@xxxxxxxxxx> wrote:> > > ENTRY(cpu_do_suspend) > > > mrs x2, tpidr_el0 > > > @@ -73,6 +75,9 @@ alternative_endif > > > stp x8, x9, [x0, #48] > > > stp x10, x11, [x0, #64] > > > stp x12, x13, [x0, #80] > > > +#ifdef CONFIG_SHADOW_CALL_STACK > > > + str x18, [x0, #96] > > > +#endif > >> > Do we need the #ifdefery here? We didn't add that to the KVM path,> > and I'd feel better having a single behaviour, specially when > > NR_CTX_REGS is unconditionally sized to hold 13 regs. >> I'm fine with dropping the ifdefs here in v5 unless someone objects to this.Oh, yeah I guess it would be good to be consistent. Rather than dropthe ifdefs, would you (Marc) be ok with conditionally setting NR_CTX_REGS based on CONFIG_SHADOW_CALL_STACK, and doing so in KVM? (So 3 ifdefs, rather than 0)?Without any conditionals or comments, it's not clear why x18 is beingsaved and restored (unless git blame survives, or a comment is added in place of the ifdefs in v6).True. Clearing the sleep state buffer in cpu_do_resume is also pointless without CONFIG_SHADOW_CALL_STACK, so if the ifdefs are removed, some kind of an explanation is needed there.
I can't imagine the overhead being noticeable, and I certainly value
minimizing the testing space. Sticking a comment there should be
enough for people hacking on this to understand that this isn't
entirely dead code.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
