* hurd/hurdfchdir.c (_hurd_change_directory_port_from_fd): Rewrite
without HURD_DPORT_USE to clean up warnings.
* hurd/dtable.c (get_dtable_port): Likewise.
* hurd/hurdioctl.c (rectty_dtable): Renamed to install_ctty.
(install_ctty): Do the changing of the cttyid port cell here, inside
the critical section while we holding the dtable lock.
(_hurd_setcttyid, tiocsctty, tiocnotty): Use that instead of changing
the port cell and calling rectty_dtable.
(_hurd_locked_install_cttyid): New function, split out of install_ctty.
(install_ctty): Use it inside a critical section, with the lock held.
* sysdeps/mach/hurd/setsid.c (__setsid): Use
_hurd_locked_install_cttyid to effect the cttyid and dtable changes
after proc_setsid, having held the dtable lock throughout.
* hurd/dtable.c (ctty_new_pgrp): With the dtable lock held, check the
cttyid port for null and bail out early if so. The dtable lock
serializes us after any cttyid change and its associated dtable update.
* hurd/hurdfchdir.c (_hurd_change_directory_port_from_fd): Rewrite
without HURD_DPORT_USE to clean up warnings.
* hurd/dtable.c (get_dtable_port): Likewise.
* hurd/hurdioctl.c (rectty_dtable): Renamed to install_ctty.
(install_ctty): Do the changing of the cttyid port cell here, inside
the critical section while we holding the dtable lock.
(_hurd_setcttyid, tiocsctty, tiocnotty): Use that instead of changing
the port cell and calling rectty_dtable.
(_hurd_locked_install_cttyid): New function, split out of install_ctty.
(install_ctty): Use it inside a critical section, with the lock held.
* sysdeps/mach/hurd/setsid.c (__setsid): Use
_hurd_locked_install_cttyid to effect the cttyid and dtable changes
after proc_setsid, having held the dtable lock throughout.
* hurd/dtable.c (ctty_new_pgrp): With the dtable lock held, check the
cttyid port for null and bail out early if so. The dtable lock
serializes us after any cttyid change and its associated dtable update.
contents of memory that is reallocated after decrementing the break
value first. Update comment about MORECORE_CLEARS, explaining the
meaning of the values it can be set to.