4b039671de
The read/write system calls return ssize_t because -1 is used to indicate error, therefore the transfer size MUST be limited to SSIZE_MAX, otherwise garbage can be returned to the user. There is NO change from existing behavior here, only a more precise definition of that the semantics are, except in the Alpha case, where the full SSIZE_MAX transfer size can now be realized (ssize_t is 64-bit on the Alpha).