__set_errno returns -1 exactly so that callers don't need to bother.
The other architectures were already taking advantage of this, but
no one had ever fixed x86 and x86_64.
Change-Id: Ie131494be664f6c4a1bbf8c61bbbed58eac56122
We only need it for MAX_ERRNO, and it's time we had somewhere to put
the little assembler utility macros we've been putting off writing.
Change-Id: I9354d2e0dc47c689296a34b5b229fc9ba75f1a83
I've left the exit_group syscall as _exit because otherwise we'd have to
convince the compiler that our _exit (which just calls __exit_group) is
actually "noreturn", and it seems like that would be less clean than just
cutting out the middleman.
We'll just have to trust ourselves not to add anything to SYSCALLS.TXT
that ought to be private but that only has a single leading underscore.
Hopefully we can manage that.
Change-Id: Iac47faea9f516186e1774381846c54cafabc4354
