Fix a security problem in sysctl() the long way round.

Use pre-emption detection to avoid the need for wiring a userland buffer
when copying opaque data structures.

sysctl_wire_old_buffer() is now a no-op. Other consumers of this
API should use pre-emption detection to notice update collisions.

vslock() and vsunlock() should no longer be called by any code
and should be retired in subsequent commits.

Discussed with:	pete, phk
MFC after:	1 week

0 files changed, 0 insertions, 0 deletions