to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.
I'd LOVE to do this rename in 7.0 so that we can eventually MFC the
new kthread_xxx() calls.
can more easily be used INSTEAD OF the hard-working Yarrow.
The only hardware source used at this point is the one inside
the VIA C3 Nehemiah (Stepping 3 and above) CPU. More sources will
be added in due course. Contributions welcome!
o Each source gets its own queue, which is a FIFO, not a ring buffer.
The FIFOs are implemented with the sys/queue.h macros. The separation
is so that a low entropy/high rate source can't swamp the harvester
with low-grade entropy and destroy the reseeds.
o Each FIFO is limited to 256 (set as a macro, so adjustable) events
queueable. Full FIFOs are ignored by the harvester. This is to
prevent memory wastage, and helps to keep the kernel thread CPU
usage within reasonable limits.
o There is no need to break up the event harvesting into ${burst}
sized chunks, so retire that feature.
o Break the device away from its roots with the memory device, and
allow it to get its major number automagically.
1) It is already called in init_main.c:proc0_post()
2) It is called each time read_random_phony() called, because "initialized"
variable is never set to 1.
Approved by: markm
o Separate the kernel stuff from the Yarrow algorithm. Yarrow is now
well contained in one source file and one header.
o Replace the Blowfish-based crypto routines with Rijndael-based ones.
(Rijndael is the new AES algorithm). The huge improvement in
Rijndael's key-agility over Blowfish means that this is an
extremely dramatic improvement in speed, and makes a heck of
a difference in its (lack of) CPU load.
o Clean up the sysctl's. At BDE's prompting, I have gone back to
static sysctls.
o Bug fixes. The streamlining of the crypto stuff enabled me to
find and fix some bugs. DES also found a bug in the reseed routine
which is fixed.
o Change the way reseeds clear "used" entropy. Previously, only the
source(s) that caused a reseed were cleared. Now all sources in the
relevant pool(s) are cleared.
o Code tidy-up. Mostly to make it (nearly) 80-column compliant.
mtx_enter(lock, type) becomes:
mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)
similarily, for releasing a lock, we now have:
mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.
The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.
Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:
MTX_QUIET and MTX_NOSWITCH
The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:
mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.
Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.
Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.
Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.
Finally, caught up to the interface changes in all sys code.
Contributors: jake, jhb, jasone (in no particular order)
call instead.
This makes a pretty dramatic difference to the amount of work that
the harvester needs to do - it is much friendlier on the system.
(80386 and 80486 class machines will notice little, as the new
get_cyclecounter() call is a wrapper round nanotime(9) for them).
now in dirs called sys/*/random/ instead of sys/*/randomdev/*.
Introduce blocking, but only at startup; the random device will
block until the first reseed happens to prevent clients from
using untrustworthy output.
Provide a read_random() call for the rest of the kernel so that
the entropy device does not need to be present. This means that
things like IPX no longer need to have "device random" hardcoded
into thir kernel config. The downside is that read_random() will
provide very poor output until the entropy device is loaded and
reseeded. It is recommended that developers do NOT use the
read_random() call; instead, they should use arc4random() which
internally uses read_random().
Clean up the mutex and locking code a bit; this makes it possible
to unload the module again.
from many folk.
o The reseed process is now a kthread. With SMPng, kthreads are
pre-emptive, so the annoying jerkiness of the mouse is gone.
o The data structures are protected by mutexes now, not splfoo()/splx().
o The cryptographic routines are broken out into their own subroutines.
this facilitates review, and possible replacement if that is ever
found necessary.
Thanks to: kris, green, peter, jasone, grog, jhb
Forgotten to thank: You know who you are; no offense intended.
wrong bytes.
o Improve the public interface; use void* instead of char* or u_int64_t
to pass arbitrary data around.
Submitted by: kris ("horrible bug")
o Make the comments KNF-compliant.
o Use nanotime instead of getnanotime; the manpage lies about the
kern.timecounter.method - it has been removed.
o Fix the ENTROPYSOURCE const permanently.
o Make variable names more consistent.
o Make function prototypes more consistent.
Some more needs to be done; to follow.
with splhigh(). However, the entropy-harvesting routine needs pretty
serious irq-protection, as it is called out of irq handlers etc.
Clues given by: bde
