mac-io bus, we cannot setup FAST interrupt handlers. This because we
use spinlocks to protect the hardware and all interrupt resources are
assigned the same interrupt handler. When the interrupt handler is
invoked for interrupt X, it could be preempted for interrupt Y while
it was holding the lock (where X and Y are the interrupt resources
corresponding a single instance of this driver). This is a deadlock.
By only using a MPSAFE handler in that case we prevent preemption.
specific routines from uipc_socket2.c following repo-copy. We might
rethink the location of one or two at some point, but the division was
relatively clean. uipc_sockbuf.c is now the home of routines that
manipulate socket buffers.
take a timeval indicating when the packet was captured. Move
microtime() to the calling functions and grab the timestamp as soon
as we know that we're going to call catchpacket at least once.
This means that we call microtime() once per matched packet, as
opposed to once per matched packet per bpf listener. It also means
that we return the same timestamp to all bpf listeners, rather than
slightly different ones.
It would be more accurate to call microtime() even earlier for all
packets, as you have to grab (1+#listener) locks before you can
determine if the packet will be logged. You could always grab a
timestamp before the locks, but microtime() can be costly, so this
didn't seem like a good idea.
(I guess most ethernet interfaces will have a bpf listener these
days because of dhclient. That means that we could be doing two bpf
locks on most packets going through the interface.)
PR: 71711
soreceive(), and sopoll(), which are wrappers for pru_sosend,
pru_soreceive, and pru_sopoll, and are now used univerally by socket
consumers rather than either directly invoking the old so*() functions
or directly invoking the protocol switch method (about an even split
prior to this commit).
This completes an architectural change that was begun in 1996 to permit
protocols to provide substitute implementations, as now used by UDP.
Consumers now uniformly invoke sosend(), soreceive(), and sopoll() to
perform these operations on sockets -- in particular, distributed file
systems and socket system calls.
Architectural head nod: sam, gnn, wollman
The register layout has changed since the original NV4 - sigh.
Hotplug support has been fixed for all nVidia chipsets that supports it
(including the MCP51/55).
HW donated by: Kingsley College
the kernel malloc(9) state for vmstat -m. libmemstat is now used to
generate a machine-readable version which is converged by vmstat -m
into a human-readable version.
Not for MFC.
used to mark UNIX domain sockets as being in the process of binding or
connecting. Use these to prevent simultaneous bind or connect
operations by multiple threads or processes on the same socket at the
same time, which closes race conditions present in the UNIX domain
socket implementation since inception.
new VIA CPUs.
For older CPUs HMAC/SHA1 and HMAC/SHA256 (and others) will still be done
in software.
Move symmetric cryptography (currently only AES-CBC 128/192/256) to
padlock_cipher.c file. Move HMAC cryptography to padlock_hash.c file.
Hardware from: Centaur Technologies
them twice.
This is possible for example in situation when session is used in
authentication context, then freed and then used in encryption context
and freed - in encryption context ses_ictx and ses_octx are not touched
at newsession time, but padlock_freesession could still try to free them
when they are not NULL.
Remove the README file which warns against cosmetic or local only
changes. FreeBSD committers should now feel free to work on the
IPv6 and IPSec code without fetters. The KAME mailing lists still
exist and it is always a good idea to ask questions about this code
on the snap-users@kame.net mailing list.
Reviewed by: rwatson, brooks
locked.
- Move all the svr4 socket cache code into svr4_socket.c, specifically
move svr4_delete_socket() over from streams.c. Make the socket cache
entry structure and svr4_head private to svr4_socket.c as a result.
- Add a mutex to protect the svr4 socket cache.
- Change svr4_find_socket() to copy the sockaddr_un struct into a
caller-supplied sockaddr_un rather than giving the caller a pointer to
our internal one. This removes the one case where code outside of
svr4_socket.c could access data in the cache.
- Add an eventhandler for process_exit and process_exec to purge the cache
of any entries for the exiting or execing process.
- Add methods to init and destroy the socket cache and call them from the
svr4 ABI module's event handler.
- Conditionally grab Giant around socreate() in streamsopen().
- Use fdclose() instead of inlining it in streamsopen() when handling
socreate() failure.
- Only allocate a stream structure and attach it to a socket in
streamsopen(). Previously, if a svr4 program performed a stream
operation on an arbitrary socket not opened via the streams device,
we would attach streams state data to it and change f_ops of the
associated struct file while it was in use. The latter was especially
not safe, and if a program wants a stream object it should open it via
the streams device anyway.
- Don't bother locking so_emuldata in the streams code now that we only
touch it right after creating a socket (in streamsopen()) or when
tearing it down when the file is closed.
- Remove D_NEEDGIANT from the streams device as it is no longer needed.
Also, call change_dir() instead of doing part of it inline (this now adds
a mac_check_vnode_chdir() call) to match fchdir() and call
mac_check_vnode_chroot() to match chroot(). Also, use the change_root()
function to do the actual change root to match chroot().
Reviewed by: rwatson
Giant VFS locking in that function.
- Remove bogus code to handle the case where namei() returns success but a
NULL vnode pointer.
- Note that this code duplicates exec_check_permissions() and annotate
where it differs.
- Hold the vnode lock longer to protect the write to set VV_TEXT in
v_vflag.
- Mark linux_uselib() MPSAFE.
Reviewed by: rwatson
function, pru_close, to notify protocols that the file descriptor or
other consumer of a socket is closing the socket. pru_abort is now a
notification of close also, and no longer detaches. pru_detach is no
longer used to notify of close, and will be called during socket
tear-down by sofree() when all references to a socket evaporate after
an earlier call to abort or close the socket. This means detach is now
an unconditional teardown of a socket, whereas previously sockets could
persist after detach of the protocol retained a reference.
This faciliates sharing mutexes between layers of the network stack as
the mutex is required during the checking and removal of references at
the head of sofree(). With this change, pru_detach can now assume that
the mutex will no longer be required by the socket layer after
completion, whereas before this was not necessarily true.
Reviewed by: gnn
fix a bug in the input sanity check of DIOCCHANGERULE (not used by pfctl,
but third-party tools). a rule must have a non-empty replacement address
list when it's a translation rule but not an anchor call (i.e. "nat ...
->" needs a replacement address, but "nat-anchor ..." doesn't). the check
confused "rule is an anchor call" with "rule is defined within an anchor".
report from Michal Mertl, Max Laier.
Obtained from: OpenBSD
MFC after: 2 weeks
The core uart code expects the receive method to actually puts the
characters read into its buffers. For AT91, it's done in the ipend routine,
so also check if we have the alternate break sequence here.
MFC after: 3 days
system's machine-dependent and machine-independent layers. Once
pmap_clear_write() is implemented on all of our supported
architectures, I intend to replace all calls to pmap_page_protect() by
calls to pmap_clear_write(). Why? Both the use and implementation of
pmap_page_protect() in our virtual memory system has subtle errors,
specifically, the management of execute permission is broken on some
architectures. The "prot" argument to pmap_page_protect() should
behave differently from the "prot" argument to other pmap functions.
Instead of meaning, "give the specified access rights to all of the
physical page's mappings," it means "don't take away the specified
access rights from all of the physical page's mappings, but do take
away the ones that aren't specified." However, owing to our i386
legacy, i.e., no support for no-execute rights, all but one invocation
of pmap_page_protect() specifies VM_PROT_READ only, when the intent
is, in fact, to remove only write permission. Consequently, a
faithful implementation of pmap_page_protect(), e.g., ia64, would
remove execute permission as well as write permission. On the other
hand, some architectures that support execute permission have
basically ignored whether or not VM_PROT_EXECUTE is passed to
pmap_page_protect(), e.g., amd64 and sparc64. This change represents
the first step in replacing pmap_page_protect() by the less subtle
pmap_clear_write() that is already implemented on amd64, i386, and
sparc64.
Discussed with: grehan@ and marcel@
renegotiation, we only initialize the hardware only when it is
absolutely required. Process SIOCGIFADDR ioctl in em(4) when we know
an IPv4 address is added. Handling SIOCGIFADDR in a driver is
layering violation but it seems that there is no easy way without
rewritting hardware initialization code to reduce settle time after
reset.
This should fix a long standing bug which didn't send ARP packet when
interface address is changed or an alias address is added. Another
effect of this fix is it doesn't need additional delays anymore when
adding an alias address to the interface.
While I'm here add a new if_flags into softc which remembers current
prgroammed interface flags and make use of it when we have to program
promiscuous mode.
Tested by: Atanas <atanas AT asd DOT aplus DOT net>
Analyzed by: rwatson
Discussed with: -stable
- If the WNOWAIT flag isn't specified and either of WEXITED or WTRAPPED is
set, then just call kern_wait() and let it do all the work. This means
that this function no longer has to duplicate the work to teardown
zombies that is done in kern_wait(). Instead, if the above conditions
aren't true, then it uses a simpler loop to implement WNOWAIT and/or
tracing for only stopped or continued processes. This function still
has to duplicate code from kern_wait() for the latter two cases, but
those are much simpler.
- Sync the code to handle the WCONTINUED and WSTOPPED cases with the
equivalent code in kern_wait().
- Fix several places that would return with the proctree lock still held.
- Lock the current process to prevent lost wakeup races when blocking.
that the only remove hook operation that can occur while processing the
hooks is to remove the currently executing hook. This should be safe as
the existing code has assumed this already for a long time now.
Reviewed by: scottl
MFC after: 1 week
( and where appropriate the destruction) of the pcb mutex to the init/finit
functions of the pcb zones.
This allows locking of the pcb entries and race condition free comparison
of the generation count.
Rearrange locking a bit to avoid extra locking operation to update the generation
count in in_pcballoc(). (in_pcballoc now returns the pcb locked)
I am planning to convert pcb list handling from a type safe to a reference count
model soon. ( As this allows really freeing the PCBs)
Reviewed by: rwatson@, mohans@
MFC after: 1 week
the sysctls. This saves a lot of space in the resulting kernel which is
important for embedded systems. This change was done in a ABI compatible
way. The pointer is still there, it just points to an empty string instead
of the description.
MFC After: 3 days
pmap_clear_ptes() is already convoluted. This will worsen with the
implementation of superpages. Eliminate it and add pmap_clear_write().
There are no functional changes. Checked by: md5
- Copy ethernet firmware down in small chunks so as to avoid bugs
in early versions of the bootstrap firmware.
- Attempt to "adopt" the running firmware if we cannot load a suitable
firmware image via firmware(9).
- Separate firmware validation into its own routine, and check the
major/minor driver/firmware ABI version.
instead of doing the first load with the BUS_DMA_NOWAIT flag. On 4.x with
PAE and > 4gb of RAM this proved disastrous if there weren't enough bounce
pages as amr_mapcmd() would return failure but the callback would later
fire once enough bounce pages were available and would then overwrite
another command's S/G list.
MFC after: 3 days
Submitted by: scottl (4.x version)
Reviewed by: scottl (port from 4.x to HEAD)
than only locking it if INVARIANTS is enabled. All the callers expect
smb_co_init() to return with the lock held.
Tested by: "Jiawei Ye" <leafy7382 at gmail>
pointer: When vm_object_deallocate() sleeps because of a non-zero
paging in progress count on either object or object's shadow,
vm_object_deallocate() must ensure that object is still the shadow's
backing object when it reawakens. In fact, object may have been
deallocated while vm_object_deallocate() slept. If so, reacquiring
the lock on object can lead to a deadlock.
Submitted by: ups@
MFC after: 3 weeks
precedence uart. With my last change, it became a tie, and uart seems
to always win on my amd64. This was not my intention, so have sio be
just a tiny bit more preferred than uart.
Note: I'm not making any judgement on the merits of uart winning. I'm
just saying that if we want to change it, we do it on purpose.
pmap_remove_all() before rather than after the pmap is unlocked. At
present, the page queues lock provides sufficient sychronization. In the
future, the page queues lock may not always be held when free_pv_entry() is
called.
libmemstat(3) is used by vmstat (and friends) to produce more accurate
and more detailed statistics information in a machine-readable way,
and vmstat continues to provide the same text-based front-end.
This change should not be MFC'd.
Make three simplifications to pmap_ts_referenced():
Eliminate an initialized but otherwise unused variable.
Eliminate an unnecessary test.
Exit the loop in a shorter way.
FreeBSD repository and to clean up the license header so as to
not pollute the license with file function.
Zero all mailbox structures prior to use (just in case). Change
the outgoing mailbox count for INIT_FIRMWARE to be correct.
from a semantic point of view, but I notified the author of the driver
for confirmation. So far it at least fixes the build and should only
lead to not identifying or wrongly identifying a soundcard in the worst
case.
touch data outside the packet (previously we might touch 1 byte); it
also has the happy side effect of working around broken orinoco/agere
firmware that sends malformed association response frames
Help by: Vladimir Egorin
mark it as timed out. Don't try and free the config
request for read_cfg_header that times out because
it's still active. Put in code for the config reply
handler that will then free up timed out requests.
Fix the FC_PRIMITIVE_SEND completion to not try
and free a command twice. Dunno how this possibly
could have been working for awhile.
MFC after: 2 weeks
out ELS buffers but *don't* hang out commands,
we hang folks on the SAN because the LSI-Logic
f/w apparently sends back BUSY or QFULL or some
darn thing.
If we add command buffers, we have to respond to
them sensibly even if we don't have any upstream
listeners (scsi_targ or scsi_targ_bh), so put in
some local command reponse stuff.
MFC after: 2 weeks
sound cards with optional pseudo-multichannel playback.
It's based on snd_emu10k1 sound driver. Single channel version is available
from audio/emu10kx port since some time.
The two new ALSA header files (GPLed), which contain Audigy 2 ("p16v") and
Audigy 2 Value ("p17v") specific interfaces, are latest versions from ALSA
Mercurial repository.
This is not connected to the build yet.
Submitted by: Yuriy Tsibizov <Yuriy.Tsibizov@gfk.ru>
latest version from Mercurial repository. It brings definition of some
additional Audigy 2 / Audigy 2 Value registers.
- Use new #defines from ALSA emu10k1.h
- Remove unused include files:
+ emu10k1-ac97.h was imported from ALSA and never used,
+ emu10k1.h was imported from Creative Linux emu10k1 driver, but only
AUDIGY_CODEBASE was used from it.
Submitted by: Yuriy Tsibizov <Yuriy.Tsibizov@gfk.ru>
forcing all transfers to do the start read/write stop by hand. Some
smart bridges prefer this sort of operation, and this allows us to
support their features more easily. When bridges don't support it, we
fall back to using the old-style opertaions. Expand the ioctl
interface to expose this function. Unlike the old-style interface,
this interface is thread safe, even on old bridges.
Introduce framework to configure the multiplexed pins on boot.
Since the USART supprots RS-485 multidrop mode, it allows the
TX pins to float. However, for RS-232 operations, we don't
want these pins to float. Instead, they should be pulled up
to avoid mismatches. Linux does something similar when it
configures the TX lines. This implies that we also allow the
RX lines to float rather than be in the state they are left in
by the boot loader. Since they are input pins, I think that
this is the right thing to do.
Plus minor for our board.
protocol of a socket close event distinct from a detach event, which
will (in a future commit) become aligned with pru_abort, which will
also be a notification of close prior to detach. Add prurequests event
for close, as well as patch up some existing missing ones.
Add MEMORY_BARRIER for the few scratch dma ops that were missing
them plus add a couple of hi 32 bit dma ops (we could probably
allow 64 bit scratch and request/response queue dma now).
don't want to mix process and thread scheduling options together in these
functions, now the thread scheduling option is implemented in new thr
syscalls.
these syscalls are designed to set thread's scheduling parameters and
policy, because each syscall contains a size parameter, it is possible
to support future scheduling option, e.g SCHED_SPORADIC, this option
needs other fields in structure sched_param, current they are not
avaiblable.
install custom pager functions didn't actually happen in practice (they
all just used the simple pager and passed in a local quit pointer). So,
just hardcode the simple pager as the only pager and make it set a global
db_pager_quit flag that db commands can check when the user hits 'q' (or a
suitable variant) at the pager prompt. Also, now that it's easy to do so,
enable paging by default for all ddb commands. Any command that wishes to
honor the quit flag can do so by checking db_pager_quit. Note that the
pager can also be effectively disabled by setting $lines to 0.
Other fixes:
- 'show idt' on i386 and pc98 now actually checks the quit flag and
terminates early.
- 'show intr' now actually checks the quit flag and terminates early.
in nfs_strategy. Otherwise, for some buffers, signals would be ignored
at the intr mounts.
Reviewed by: mohan, cel
MFC after: 1 month
Approved by: pjd (mentor)
actually go write the config page. This fixes the long standing
problem about updating NVRAM on Fibre Channel cards and seems
so far to not break SPI config page writes.
Put back role setting into mpt. That is, you can set a desired role
for mpt as a hint. On the next reboot, it'll pick that up and redo
the NVRAM settings appropriately and warn you that this won't take
effect until the next reboot. This saves people the step of having
to find a BIOS utilities disk to set target and/or initiator role
for the MPT cards.
SCHED_OTHER, the same range as rtprio() is using. In old code,
it returns nice range -20 .. 20, nice should be treated as process
weight, it is really managed by getpriority() and setpriority()
syscalls, they are different.
significantly reduces booting time when there is broken floppy disk drive,
controller, cable, BIOS, etc.
When the floppy controller interface is correctly implemented, disk change
signal (DSKCHG) is reflected in the Digital Input Register (DIR) at 0x3f7.
However, there are many cases that the signal is unusable. Moreover, some
BIOS does not reserve the port at all. In those cases, the register may not
function.
address is in the userland address space. The proper thing is either to choose
a virtual address in the kernel address space beyond the KVA, or to use
pmap_mapdev().
using sorele() and the full tear-down path. Since protocol state
allocation failed, this is not required (and is arguably undesirable).
This matches the behavior of sonewconn() under the same circumstances.
locks and the unplock during uipc_rcvd() and uipc_send() by caching
certain values from one structure while its locks are held, and
applying them to a second structure while its locks are held. If
done carefully, this should be correct, and will reduce the amount
of work done with the global unp lock held.
Tested by: kris (earlier version)
ibcs2_getdents(), ibcs2_read(), ogetdirentries(), svr4_sys_getdents(),
and svr4_sys_getdents64() similar to that in getdirentries().
- Mark ibcs2_getdents(), ibcs2_read(), linux_getdents(), linux_getdents64(),
linux_readdir(), ogetdirentries(), svr4_sys_getdents(), and
svr4_sys_getdents64() MPSAFE.
process. UFS must check a whiteout name when it uses the
whiteout, but the current implementation does not check
the whileout name, so sometimes UFS writes over a wrong
whtieout. UFS *MUST* check the whiteout name to use a
corrent whiteout. This bug leads unionfs. panic.
This commit fixes this trouble.
Submitted by: Masanori Ozawa <ozawa@ongs.co.jp> (unionfs developer)
Reviewed by: tegge & rodrigc (mentor)
Approved by: rodrigc (mentor)
MFC after: 2 weeks
we're unable to allocate the memory for a PTE, we'll wait until we can. If not,
we'll just return.
Use M_NOWAIT|M_USE_RESERVE to allocate PTEs, it is less aggressive than
M_NOWAIT alone.
Suggested by: alc
done this in ptrace syscall, when a pid is large than PID_MAX, the syscall
will search a thread in current process. It permits 1:1 thread library to
get and set a thread's scheduler attributes.
unless current thread is realtime thread, in such case, we set a new zero
priority for it, notice we don't have per-thread nice, the priority
passed by userland is ignored here.
use by ABI emulators.
- Alter the interface of kern_recvit() somewhat. Specifically, go ahead
and hard code UIO_USERSPACE in the uio as that's what all the callers
specify. In place, add a new uioseg to indicate what type of pointer
is in mp->msg_name. Previously it was always a userland address, but
ABI emulators may pass in kernel-side sockaddrs. Also, remove the
namelenp field and instead require the two places that used it to
explicitly copy mp->msg_namelen out to userland.
- Use the patched kern_recvit() to replace svr4_recvit() and the stock
kern_sendit() to replace svr4_sendit().
- Use kern_bind() instead of stackgap use in ti_bind().
- Use kern_getpeername() and kern_getsockname() instead of stackgap in
svr4_stream_ti_ioctl().
- Use kern_connect() instead of stackgap in svr4_do_putmsg().
- Use kern_getpeername() and kern_accept() instead of stackgap in
svr4_do_getmsg().
- Retire the stackgap from SVR4 compat as it is no longer used.
we will initialize the label to biba/low for files that have been created
through an NFS RPC. This is a safe default given the default nature of our
NFS implementation, there is not a whole lot of data integrity there by
default. This also fixes kernel panics associated with file creation over NFS
while creating files on filesystems which have multilabel enabled with BIBA
enabled.
MFC after: 2 weeks
Discussed with: rwatson
loading for the QLogic cards.
Because isp(4) exists before the root is mounted, it's not really
possible for us to use the kernel's linker to load modules directly
from disk- that's really too bad.
However, the this is still a net win in in that the firmware has
been split up on a per chip (and in some cases, functionality)
basis, so the amount of stuff loaded *can* be substantially less
than the 1.5MB of firmware images that ispfw now manages. That is,
each specific f/w set is now also built as a module. For example,
QLogic 2322 f/w is built as isp_2322.ko and Initiator/Target 1080
firmware is built as isp_1080_it.ko.
For compatibility purposes (i.e., to perturb folks the least), we
also still build all of the firmware as one ispfw.ko module.
This allows us to let 'ispfw_LOAD' keep on working in existing
loader.conf files. If you now want to strip this down to just
the firmware for your h/w, you can then change loader.conf to
load the f/w you specifically want.
We also still allow for ispfw to be statically built (e.g., for
PAE and sparc64).
Future changes will look at f/w unloading and also role switching
that then uses the kernel linker to load different ips f/w sets.
MFC after: 2 months
uma(9) will be used for memory allocation.
In case of problems or tracking bugs, there are more useful tools for malloc(9)
debugging than for uma(9) debugging, like memguard(9) and redzone(9).
MFC after: 1 week
parameter that can specify configuration parameters:
o rev cloner api's to add optional parameter block
o add SIOCCREATE2 that accepts parameter data
o rev vlan support to use new api (maintain old code)
Reviewed by: arch@
that the 'data' pointer is already setup to point to a valid KVM buffer
or contains the copied-in data from userland as appropriate (ioctl(2)
still does this). kern_ioctl() takes care of looking up a file pointer,
implementing FIONCLEX and FIOCLEX, and calling fi_ioctl().
- Use kern_ioctl() to implement xenix_rdchk() instead of using the stackgap
and mark xenix_rdchk() MPSAFE.
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.
to use the hinted child system. Bus drivers that use this need to
implmenet the bus_hinted_child method, where they actually add the
child to their bus, as they see fit. The bus is repsonsible for
getting the attribtues for the child, adding it in the right order,
etc. ISA hinting will be updated to use this method.
MFC After: 3 days
atkbd. Version 1.162 of GENERIC fixed this problem in April of 1999.
Subsequent to that, the hints data was removed from GENERIC and move
to hints files. All the hints file ever created have atkbd at the
right location. This should have been removed just after RELENG_4 was
branched (and likely around 4.5 in RELENG_4).
MFC After: 3 days
in nfs_strategy. Otherwise, for some buffers, signals would be ignored
at the intr mounts.
Reviewed by: mohan
MFC after: 1 month
Approved by: kan (mentor)
any modifications to make it build as part of the FreeBSD kernel.
Now that the source appears to have stabilized, local changes will
happen on HEAD and will therefore cause affected files to be pulled
from the vendor branch.
subr_acl_posix1e.c, leaving kern_acl.c containing only ACL system
calls and utility routines common across ACL types.
Add subr_acl_posix1e.c to the build.
Obtained from: TrustedBSD Project
not all known to be MPSAFE yet.
- Actually remove Giant from the kernel linker by taking it out of the
KLD_LOCK() and KLD_UNLOCK() macros.
Pointy hat to: jhb (2)
shmctl(). None of the other ABI's do this (including the native FreeBSD
ABI), and uselessly trying to do a copyin() can actually result in a
bogus EFAULT if the a process specifies NULL for the optional argument
(which is what they should do in this case).
ibcs2_[gs]etgroups() rather than using the stackgap. This also makes
ibcs2_[gs]etgroups() MPSAFE. Also, it cleans up one bit of weirdness in
the old setgroups() where it allocated an entire credential just so it had
a place to copy the group list into. Now setgroups just allocates a
NGROUPS_MAX array on the stack that it copies into and then passes to
kern_setgroups().
ABI as FreeBSD's poll(2) is ABI compatible. The ibcs2_poll() function
attempted to implement poll(2) using a wrapper around select(2). Besides
being somewhat ugly, it also had at least one bug in that instead of
allocating complete fdset's on the stack via the stackgap it just allocated
pointers to fdsets.
Use it to reset controller and to select data rate. According to Intel
80277AA datasheet, software reset behaves the same as DOR reset except
that it is self clearing. National Semiconductor PC8477B datasheet says
the same. As a side effect, we no longer use Configuration Control
Register (CCR) at 0x3f7 for these controllers, which is often missing
in modern hardware.