On 08/10/2015 06:59, Richard Henderson wrote: > +/* Address space support. > + > + This is not "far pointers" in the 16-bit sense, but an easy way > + to use %fs and %gs segment prefixes. Therefore: > + > + (a) All address spaces have the same modes, > + (b) All address spaces have the same addresss forms, > + (c) While %fs and %gs are technically subsets of the generic > + address space, they are probably not subsets of each other. > + (d) Since we have no access to the segment base register values > + without resorting to a system call, we cannot convert a > + non-default address space to a default address space. > + Therefore we do not claim %fs or %gs are subsets of generic.
rdfsbase and rdgsbase are potentially accessible to userspace too, so I think %fs or %gs should be considered subsets of generic. Paolo > + Therefore, we need not override any of the address space hooks. */
