On Mon, 2023-07-31 at 14:43 +0100, Mark Brown wrote: > +SYSCALL_DEFINE3(map_shadow_stack, unsigned long, addr, unsigned > long, size, unsigned int, flags) > +{ > + unsigned long alloc_size; > + unsigned long __user *cap_ptr; > + unsigned long cap_val; > + int ret; > + > + if (!system_supports_gcs()) > + return -EOPNOTSUPP; > + > + if (flags) > + return -EINVAL; Any thoughts on the questions at the end of this mail? https://lore.kernel.org/lkml/7a4c97f68347d4188286c543cdccaa12577cdb9e.camel@xxxxxxxxx/