in the non-MULTIPROCESSOR case (LOCKDEBUG requires it). Scheduler
lock is held upon entry to mi_switch() and cpu_switch(), and
cpu_switch() releases the lock before returning.
Largely from Bill Sommerfeld, with some minor bug fixes and
machine-dependent code hacking from me.
- Change ktrace interface to pass in the current process, rather than
p->p_tracep, since the various ktr* function need curproc anyway.
- Add curproc as a parameter to mi_switch() since all callers had it
handy anyway.
- Add a second proc argument for inferior() since callers all had
curproc handy.
Also, miscellaneous cleanups in ktrace:
- ktrace now always uses file-based, rather than vnode-based I/O
(simplifies, increases type safety); eliminate KTRFLAG_FD & KTRFAC_FD.
Do non-blocking I/O, and yield a finite number of times when receiving
EWOULDBLOCK before giving up.
- move code duplicated between sys_fktrace and sys_ktrace into ktrace_common.
- simplify interface to ktrwrite()
count is 0, wait for use count to drain before finishing the close.
This is necessary in order for multiple processes to safely share file
descriptor tables.
The read/write system calls return ssize_t because -1 is used to indicate
error, therefore the transfer size MUST be limited to SSIZE_MAX, otherwise
garbage can be returned to the user.
There is NO change from existing behavior here, only a more precise
definition of that the semantics are, except in the Alpha case, where
the full SSIZE_MAX transfer size can now be realized (ssize_t is 64-bit
on the Alpha).
and swapctl(). For the former three, they use an 'int' in their user-land
prototype which was a 'u_int' in the kernel, which screwed up automatic
generation/checking of lint syscall stubs. For the latter, the user-land
prototype uses a "const char *", but the syscall just used "char *".
From Chris Demetriou <cgd@pa.dec.com>.
automatic array rather than an array allocated with alloca().
(This was the only use of alloca() in the kernel, and it wasn't
necessary or consistent with the way other functions in this file
work.)
