K 10
svn:author
V 3
jhb
K 8
svn:date
V 27
2006-07-08T19:51:38.000000Z
K 7
svn:log
V 855
Rework kern_semctl a bit to always assume the UIO_SYSSPACE case.  This
mostly consists of pushing a few copyin's and copyout's up into
__semctl() as all the other callers were already doing the UIO_SYSSPACE
case.  This also changes kern_semctl() to set the return value in a passed
in pointer to a register_t rather than td->td_retval[0] directly so that
callers can only set td->td_retval[0] if all the various copyout's succeed.

As a result of these changes, kern_semctl() no longer does copyin/copyout
(except for GETALL/SETALL) so simplify the locking to acquire the semakptr
mutex before the MAC check and hold it all the way until the end of the
big switch statement.  The GETALL/SETALL cases have to temporarily drop it
while they do copyin/malloc and copyout.  Also, simplify the SETALL case to
remove handling for a non-existent race condition.

END