The APIs link correctly but are NOPs on Intel machines. I think full testing would require Apple Silicon or emulation. Is there precedent for any other platform/feature that requires hardware specific features?
-j On Tue, Oct 13, 2020 at 7:09 AM Peter Maydell <peter.mayd...@linaro.org> wrote: > > On Tue, 13 Oct 2020 at 14:58, Paolo Bonzini <pbonz...@redhat.com> wrote: > > > > On 13/10/20 01:29, Joelle van Dyne wrote: > > > From: osy <os...@users.noreply.github.com> > > > > > > https://developer.apple.com/documentation/apple_silicon/porting_just-in-time_compilers_to_apple_silicon > > > > > > For < iOS 14, reverse engineered functions from libsystem_pthread.dylib is > > > implemented to handle APRR supported SoCs. > > > > > > The following rules apply for JIT write protect: > > > * JIT write-protect is enabled before tcg_qemu_tb_exec() > > > * JIT write-protect is disabled after tcg_qemu_tb_exec() returns > > > * JIT write-protect is disabled inside do_tb_phys_invalidate() but if it > > > is called inside of tcg_qemu_tb_exec() then write-protect will be > > > enabled again before returning. > > > * JIT write-protect is disabled by cpu_loop_exit() for interrupt > > > handling. > > > * JIT write-protect is disabled everywhere else. > > > > > > Signed-off-by: Joelle van Dyne <j...@getutm.app> > > > > Can this be emulated somehow on other platforms (such as Linux) so that > > it does not bitrot? > > Some of it is write^execute, which we could test via OpenBSD > I think if we updated our VM image not to mount the disk > with that protection disabled. Having "generically support > w^x" be separate from "iOS specifics" might be useful. > > The apple.com webpage linked above suggests also that we could > test some at least of these APIs on our OSX builds if we > enable the "hardened runtime" on x86 (though that might also > enable other stuff we don't want to deal with? no idea) > > thanks > -- PMM
