Make SYSVSEM mpsafe. Each semaphore set gets its own lock, however

there is a global lock over the undo structures because of the way
they are managed.

Switch to using SLIST instead of rolling our own linked list.

Fix several races where a permission check was done before a
copyin/copyout, if the copy happened to fault it may have been
possible to race for access to a semaphore set that one shouldn't
have access to.

Requested by: rwatson
Tested by: NetBSD regression suite.

0 files changed, 0 insertions, 0 deletions