Please it together w/ other definitions

* 'master' of github.com:cloudius-systems/osv:
  main: minimal nanosleep() test
  libc: implement nanosleep()
  sched: add sleep_until()
  sched: fix segfault switching a thread back to itself
  kvmclock: fix for physical mapping changes
  build: disable the x86-64 redzone for now
  implement dup3()

Longer term it should be nice not to allocate the bars at all

Since we don't have an idle thread yet, if a thread is woken up that was
last running, we end up calling switch_to() for the current thread, which
breaks badly.  Add a test for this case.

virt_to_phys() no longer works on static variables, so update the code to
allocate kvmclock structures from the heap.

Using the redzone means any interrupt can clobber local variables, so disable
it.  This isn't a full solution since the payload is not built this way,
but it's better than nothing for now.

* 'master' of github.com:cloudius-systems/osv:
  libc: implement putenv()
  libc: implement getpwuid()
  libc: implement uname()
  pthread: increase default stack size
  pthread: fix pthread_self()
  main: switch payload loading to be in a pthread

Pretend we're another OS to avoid confusing the payload.

Java stomps all over a 64k stack.

The pthread_self() implementation was inconsistent with pthread_create(),
leading to corruption.  Switch to a simpler implementation using
thread-local storage.

This way, the payload may use the pthread APIs in the thread it started in.

* 'master' of github.com:cloudius-systems/osv: (30 commits)
  elf: relocate R_X86_64_64 correctly
  sched: make thread stack be controlled by the thread creator
  main: don't destroy DriverFactory for now
  bootfs: disable read01.so temporarily
  mmu: don't map NULL
  libc: fix confstr(NULL, ...)
  elf: fix segfault on unmatched symbol
  mmu: move physical memory map to ffff800000000000
  implement positional I/O (pread/pwrite/preadv/pwritev)
  implement vectored I/O (readv/writev)
  uio-ify the read/write path
  clean up the vnode operation defintion a bit
  import basic uio support code from FreeBSD
  add a real strerror() implementation from musl
  add misc routines from musl
  more stat variants
  add getuid/getgid stubs
  implement lxstat
  implement a real console layer
  simplify the console abstractions
  ...

host side reset calls

Fixes generated code going nuts over incorrect JVM_NanoTime.

Needed for pthread_attr_*() (and in general to make sure the stack is
a regular vma as expected by the payload).

segfaults.

breaks the build

Keep the first 2MB unmapped for null pointer refernences.

confstr(NULL) is defined to return the size of required storage; use a
temporary string to make it not fault.

lookup_symbol() checks if the symbol is undefined, before checking if we
actually looked it up.  Check for a missing symbol first.

This allows us to clear the area around the null pointer, and so trap errors.

The switch is tricky wrt setting up memory, since we need the memory to
be mapped in order to free it, but we need free memory to map (for the page
tables).  What we do is set up a temporart 1:1 map at ffff800000000000
that mirrors the first 1G map we already have from bootstreap, use that
to free all of memory under 1G, then map and free everything else.

This will allow for easy addition of the vectored and positional I/O
syscalls, as well as making the structure of the I/O path more similar
to *BSD and Solaris.