Commit Graph

290 Commits

Author SHA1 Message Date
Bjoern A. Zeeb
33553d6e99 For all files including net/vnet.h directly include opt_route.h and
net/route.h.

Remove the hidden include of opt_route.h and net/route.h from net/vnet.h.

We need to make sure that both opt_route.h and net/route.h are included
before net/vnet.h because of the way MRT figures out the number of FIBs
from the kernel option. If we do not, we end up with the default number
of 1 when including net/vnet.h and array sizes are wrong.

This does not change the list of files which depend on opt_route.h
but we can identify them now more easily.
2009-02-27 14:12:05 +00:00
John Baldwin
ea77ff0a15 Use shared vnode locks when invoking VOP_READDIR().
MFC after:	1 month
2009-02-13 18:18:14 +00:00
Ed Schouten
a4611ab612 Last step of splitting up minor and unit numbers: remove minor().
Inside the kernel, the minor() function was responsible for obtaining
the device minor number of a character device. Because we made device
numbers dynamically allocated and independent of the unit number passed
to make_dev() a long time ago, it was actually a misnomer. If you really
want to obtain the device number, you should use dev2udev().

We already converted all the drivers to use dev2unit() to obtain the
device unit number, which is still used by a lot of drivers. I've
noticed not a single driver passes NULL to dev2unit(). Even if they
would, its behaviour would make little sense. This is why I've removed
the NULL check.

Ths commit removes minor(), minor2unit() and unit2minor() from the
kernel. Because there was a naming collision with uminor(), we can
rename umajor() and uminor() back to major() and minor(). This means
that the makedev(3) manual page also applies to kernel space code now.

I suspect umajor() and uminor() isn't used that often in external code,
but to make it easier for other parties to port their code, I've
increased __FreeBSD_version to 800062.
2009-01-28 17:57:16 +00:00
Konstantin Belousov
6f3475454e Remove two remnant uses of AT_DEBUG. 2008-12-17 13:13:35 +00:00
Bjoern A. Zeeb
4b79449e2f Rather than using hidden includes (with cicular dependencies),
directly include only the header files needed. This reduces the
unneeded spamming of various headers into lots of files.

For now, this leaves us with very few modules including vnet.h
and thus needing to depend on opt_route.h.

Reviewed by:	brooks, gnn, des, zec, imp
Sponsored by:	The FreeBSD Foundation
2008-12-02 21:37:28 +00:00
Konstantin Belousov
b4cf0e62f4 Add sv_flags field to struct sysentvec with intention to provide description
of the ABI of the currently executing image. Change some places to test
the flags instead of explicit comparing with address of known sysentvec
structures to determine ABI features.

Discussed with:	dchagin, imp, jhb, peter
2008-11-22 12:36:15 +00:00
Marko Zec
8b615593fc Step 1.5 of importing the network stack virtualization infrastructure
from the vimage project, as per plan established at devsummit 08/08:
http://wiki.freebsd.org/Image/Notes200808DevSummit

Introduce INIT_VNET_*() initializer macros, VNET_FOREACH() iterator
macros, and CURVNET_SET() context setting macros, all currently
resolving to NOPs.

Prepare for virtualization of selected SYSCTL objects by introducing a
family of SYSCTL_V_*() macros, currently resolving to their global
counterparts, i.e. SYSCTL_V_INT() == SYSCTL_INT().

Move selected #defines from sys/sys/vimage.h to newly introduced header
files specific to virtualized subsystems (sys/net/vnet.h,
sys/netinet/vinet.h etc.).

All the changes are verified to have zero functional impact at this
point in time by doing MD5 comparision between pre- and post-change
object files(*).

(*) netipsec/keysock.c did not validate depending on compile time options.

Implemented by:	julian, bz, brooks, zec
Reviewed by:	julian, bz, brooks, kris, rwatson, ...
Approved by:	julian (mentor)
Obtained from:	//depot/projects/vimage-commit2/...
X-MFC after:	never
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
2008-10-02 15:37:58 +00:00
Konstantin Belousov
a8d403e102 Change the static struct sysentvec and struct Elf_Brandinfo initializers
to the C99 style. At least, it is easier to read sysent definitions
that way, and search for the actual instances of sigcode etc.

Explicitely initialize sysentvec.sv_maxssiz that was missed in most
sysvecs.

No objection from:	jhb
MFC after:	1 month
2008-09-24 10:14:37 +00:00
Ed Schouten
7969b32c44 Allow COMPAT_SVR4 to be built without COMPAT_43.
It seems we only depend on COMPAT_43 to implement the send() and recv()
routines. We can easily implement them using sendto() and recvfrom(),
just like we do inside our very own C library.

I wasn't able to really test it, apart from simple compilation testing.
I've heard rumours that COMPAT_SVR4 is broken inside execve() anyway.
It's still worth to fix this, because I suspect we'll get rid of
COMPAT_43 somewhere in the future...

Reviewed by:	rdivacky
Discussed with:	jhb
2008-09-15 15:09:35 +00:00
Attilio Rao
0359a12ead Decontextualize the couplet VOP_GETATTR / VOP_SETATTR as the passed thread
was always curthread and totally unuseful.

Tested by: Giovanni Trematerra <giovanni dot trematerra at gmail dot com>
2008-08-28 15:23:18 +00:00
Julian Elischer
576c43c844 We left out V_static_len from ip_fw2.c
(also a whitespace diff that i'd rahter fix her ethan break in the
vimage branch.)
2008-08-25 05:38:18 +00:00
Bjoern A. Zeeb
603724d3ab Commit step 1 of the vimage project, (network stack)
virtualization work done by Marko Zec (zec@).

This is the first in a series of commits over the course
of the next few weeks.

Mark all uses of global variables to be virtualized
with a V_ prefix.
Use macros to map them back to their global names for
now, so this is a NOP change only.

We hope to have caught at least 85-90% of what is needed
so we do not invalidate a lot of outstanding patches again.

Obtained from:	//depot/projects/vimage-commit2/...
Reviewed by:	brooks, des, ed, mav, julian,
		jamie, kris, rwatson, zec, ...
		(various people I forgot, different versions)
		md5 (with a bit of help)
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
X-MFC after:	never
V_Commit_Message_Reviewed_By:	more people than the patch
2008-08-17 23:27:27 +00:00
Robert Watson
4f7d1876d5 Introduce a new lock, hostname_mtx, and use it to synchronize access
to global hostname and domainname variables.  Where necessary, copy
to or from a stack-local buffer before performing copyin() or
copyout().  A few uses, such as in cd9660 and daemon_saver, remain
under-synchronized and will require further updates.

Correct a bug in which a failed copyin() of domainname would leave
domainname potentially corrupted.

MFC after:	3 weeks
2008-07-05 13:10:10 +00:00
Roman Divacky
cabce2bf19 The vmspace->vm_daddr is constant until freed, there is no need
to hold lock while accessing it.

Approved by:	kib (mentor)
2008-04-21 21:24:08 +00:00
Konstantin Belousov
48b05c3f82 Implement the linux syscalls
openat, mkdirat, mknodat, fchownat, futimesat, fstatat, unlinkat,
    renameat, linkat, symlinkat, readlinkat, fchmodat, faccessat.

Submitted by:	rdivacky
Sponsored by:	Google Summer of Code 2007
Tested by:	pho
2008-04-08 09:45:49 +00:00
Konstantin Belousov
57b4252e45 Add the support for the AT_FDCWD and fd-relative name lookups to the
namei(9).

Based on the submission by rdivacky,
	sponsored by Google Summer of Code 2007
Reviewed by:	rwatson, rdivacky
Tested by:	pho
2008-03-31 12:01:21 +00:00
Doug Rabson
dfdcada31e Add the new kernel-mode NFS Lock Manager. To use it instead of the
user-mode lock manager, build a kernel with the NFSLOCKD option and
add '-k' to 'rpc_lockd_flags' in rc.conf.

Highlights include:

* Thread-safe kernel RPC client - many threads can use the same RPC
  client handle safely with replies being de-multiplexed at the socket
  upcall (typically driven directly by the NIC interrupt) and handed
  off to whichever thread matches the reply. For UDP sockets, many RPC
  clients can share the same socket. This allows the use of a single
  privileged UDP port number to talk to an arbitrary number of remote
  hosts.

* Single-threaded kernel RPC server. Adding support for multi-threaded
  server would be relatively straightforward and would follow
  approximately the Solaris KPI. A single thread should be sufficient
  for the NLM since it should rarely block in normal operation.

* Kernel mode NLM server supporting cancel requests and granted
  callbacks. I've tested the NLM server reasonably extensively - it
  passes both my own tests and the NFS Connectathon locking tests
  running on Solaris, Mac OS X and Ubuntu Linux.

* Userland NLM client supported. While the NLM server doesn't have
  support for the local NFS client's locking needs, it does have to
  field async replies and granted callbacks from remote NLMs that the
  local client has contacted. We relay these replies to the userland
  rpc.lockd over a local domain RPC socket.

* Robust deadlock detection for the local lock manager. In particular
  it will detect deadlocks caused by a lock request that covers more
  than one blocking request. As required by the NLM protocol, all
  deadlock detection happens synchronously - a user is guaranteed that
  if a lock request isn't rejected immediately, the lock will
  eventually be granted. The old system allowed for a 'deferred
  deadlock' condition where a blocked lock request could wake up and
  find that some other deadlock-causing lock owner had beaten them to
  the lock.

* Since both local and remote locks are managed by the same kernel
  locking code, local and remote processes can safely use file locks
  for mutual exclusion. Local processes have no fairness advantage
  compared to remote processes when contending to lock a region that
  has just been unlocked - the local lock manager enforces a strict
  first-come first-served model for both local and remote lockers.

Sponsored by:	Isilon Systems
PR:		95247 107555 115524 116679
MFC after:	2 weeks
2008-03-26 15:23:12 +00:00
Antoine Brodin
afe5acff1b Simplify fcntl(SVR4_F_DUP2FD) code now that FreeBSD has F_DUP2FD.
Approved by:	rwatson (mentor)
2008-03-17 18:27:28 +00:00
Jeff Roberson
66257bc8d9 - The P_SA flag has been removed. Don't reference it in a KASSERT. 2008-03-12 22:17:06 +00:00
Attilio Rao
22db15c06f VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.

KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.

Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
Attilio Rao
cb05b60a89 vn_lock() is currently only used with the 'curthread' passed as argument.
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.

Manpage and FreeBSD_version will be updated through further commits.

As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.

Tested by:	Diego Sardina <siarodx at gmail dot com>,
		Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
Jeff Roberson
397c19d175 Remove explicit locking of struct file.
- Introduce a finit() which is used to initailize the fields of struct file
   in such a way that the ops vector is only valid after the data, type,
   and flags are valid.
 - Protect f_flag and f_count with atomic operations.
 - Remove the global list of all files and associated accounting.
 - Rewrite the unp garbage collection such that it no longer requires
   the global list of all files and instead uses a list of all unp sockets.
 - Mark sockets in the accept queue so we don't incorrectly gc them.

Tested by:	kris, pho
2007-12-30 01:42:15 +00:00
Konstantin Belousov
89b57fcf01 Fix for the panic("vm_thread_new: kstack allocation failed") and
silent NULL pointer dereference in the i386 and sparc64 pmap_pinit()
when the kmem_alloc_nofault() failed to allocate address space. Both
functions now return error instead of panicing or dereferencing NULL.

As consequence, vmspace_exec() and vmspace_unshare() returns the errno
int. struct vmspace arg was added to vm_forkproc() to avoid dealing
with failed allocation when most of the fork1() job is already done.

The kernel stack for the thread is now set up in the thread_alloc(),
that itself may return NULL. Also, allocation of the first process
thread is performed in the fork1() to properly deal with stack
allocation failure. proc_linkup() is separated into proc_linkup()
called from fork1(), and proc_linkup0(), that is used to set up the
kernel process (was known as swapper).

In collaboration with:	Peter Holm
Reviewed by:	jhb
2007-11-05 11:36:16 +00:00
Robert Watson
30d239bc4c Merge first in a series of TrustedBSD MAC Framework KPI changes
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:

  mac_<object>_<method/action>
  mac_<object>_check_<method/action>

The previous naming scheme was inconsistent and mostly
reversed from the new scheme.  Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier.  Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods.  Also simplify, slightly,
some entry point names.

All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.

Sponsored by:	SPARTA (original patches against Mac OS X)
Obtained from:	TrustedBSD Project, Apple Computer
2007-10-24 19:04:04 +00:00
Robert Watson
32f9753cfb Eliminate now-unused SUSER_ALLOWJAIL arguments to priv_check_cred(); in
some cases, move to priv_check() if it was an operation on a thread and
no other flags were present.

Eliminate caller-side jail exception checking (also now-unused); jail
privilege exception code now goes solely in kern_jail.c.

We can't yet eliminate suser() due to some cases in the KAME code where
a privilege check is performed and then used in many different deferred
paths.  Do, however, move those prototypes to priv.h.

Reviewed by:	csjp
Obtained from:	TrustedBSD Project
2007-06-12 00:12:01 +00:00
Attilio Rao
a1fe14bc33 rufetch and calcru sometimes should be called atomically together.
This patch fixes places where they should be called atomically changing
their locking requirements (both assume per-proc spinlock held) and
introducing rufetchcalc which wrappers both calls to be performed in
atomic way.

Reviewed by: jeff
Approved by: jeff (mentor)
2007-06-09 21:48:44 +00:00
Attilio Rao
a140976eb4 The current rusage code show peculiar problems:
- Unsafeness on ruadd() in thread_exit()
- Unatomicity of thread_exiit() in the exit1() operations

This patch addresses these problems allocating p_fd as part of the
process and modifying the way it is accessed.

A small chunk of this patch, resolves a race about p_state in kern_wait(),
since we have to be sure about the zombif-ing process.

Submitted by: jeff
Approved by: jeff (mentor)
2007-06-09 18:56:11 +00:00
Jeff Roberson
982d11f836 Commit 14/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
   sychronization.
 - Use the per-process spinlock rather than the sched_lock for per-process
   scheduling synchronization.

Tested by:      kris, current@
Tested on:      i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-05 00:00:57 +00:00
Attilio Rao
2feb50bf7d Revert VMCNT_* operations introduction.
Probabilly, a general approach is not the better solution here, so we should
solve the sched_lock protection problems separately.

Requested by: alc
Approved by: jeff (mentor)
2007-05-31 22:52:15 +00:00
Jeff Roberson
222d01951f - define and use VMCNT_{GET,SET,ADD,SUB,PTR} macros for manipulating
vmcnts.  This can be used to abstract away pcpu details but also changes
   to use atomics for all counters now.  This means sched lock is no longer
   responsible for protecting counts in the switch routines.

Contributed by:		Attilio Rao <attilio@FreeBSD.org>
2007-05-18 07:10:50 +00:00
Robert Watson
5e3f7694b1 Replace custom file descriptor array sleep lock constructed using a mutex
and flags with an sxlock.  This leads to a significant and measurable
performance improvement as a result of access to shared locking for
frequent lookup operations, reduced general overhead, and reduced overhead
in the event of contention.  All of these are imported for threaded
applications where simultaneous access to a shared file descriptor array
occurs frequently.  Kris has reported 2x-4x transaction rate improvements
on 8-core MySQL benchmarks; smaller improvements can be expected for many
workloads as a result of reduced overhead.

- Generally eliminate the distinction between "fast" and regular
  acquisisition of the filedesc lock; the plan is that they will now all
  be fast.  Change all locking instances to either shared or exclusive
  locks.

- Correct a bug (pointed out by kib) in fdfree() where previously msleep()
  was called without the mutex held; sx_sleep() is now always called with
  the sxlock held exclusively.

- Universally hold the struct file lock over changes to struct file,
  rather than the filedesc lock or no lock.  Always update the f_ops
  field last. A further memory barrier is required here in the future
  (discussed with jhb).

- Improve locking and reference management in linux_at(), which fails to
  properly acquire vnode references before using vnode pointers.  Annotate
  improper use of vn_fullpath(), which will be replaced at a future date.

In fcntl(), we conservatively acquire an exclusive lock, even though in
some cases a shared lock may be sufficient, which should be revisited.
The dropping of the filedesc lock in fdgrowtable() is no longer required
as the sxlock can be held over the sleep operation; we should consider
removing that (pointed out by attilio).

Tested by:	kris
Discussed with:	jhb, kris, attilio, jeff
2007-04-04 09:11:34 +00:00
Ruslan Ermilov
9f70620442 Regen.
Forgotten by:	trhodes
2006-11-11 21:49:08 +00:00
Robert Watson
acd3428b7d Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges.  These may
require some future tweaking.

Sponsored by:           nCircle Network Security, Inc.
Obtained from:          TrustedBSD Project
Discussed on:           arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
                        Alex Lyashkov <umka at sevcity dot net>,
                        Skip Ford <skip dot ford at verizon dot net>,
                        Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:42:10 +00:00
Robert Watson
aed5570872 Complete break-out of sys/sys/mac.h into sys/security/mac/mac_framework.h
begun with a repo-copy of mac.h to mac_framework.h.  sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.

This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.

Obtained from:	TrustedBSD Project
Sponsored by:	SPARTA
2006-10-22 11:52:19 +00:00
Robert Watson
0ee913128d Remove two hypothetical calls to suser() in ifdef'd (and uncompilable)
svr4 code: this code would call centralized sysctl code that does
these checks also.

MFC after:	1 week
Obtained from:	TrustedBSD Project
Sponsored by:	nCircle Network Security, Inc.
2006-09-02 08:18:22 +00:00
John Baldwin
f8f1f7fb85 Regen to propogate <prefix>_AUE_<mumble> changes as well as the earlier
systrace changes.
2006-08-15 17:37:01 +00:00
John Baldwin
df78f6d313 - Remove unused sysvec variables from various syscalls.conf.
- Send the systrace_args files for all the compat ABIs to /dev/null for
  now.  Right now makesyscalls.sh generates a file with a hardcoded
  function name, so it wouldn't work for any of the ABIs anyway.  Probably
  the function name should be configurable via a 'systracename' variable
  and the functions should be stored in a function pointer in the sysvec
  structure.
2006-08-15 17:25:55 +00:00
Robert Watson
3d0685834f With socket code no longer in svr4_stream.c, MAC includes are no longer
required, so GC.
2006-08-05 22:04:21 +00:00
Brooks Davis
012759b743 Use TAILQ_EMPTY instead of checking if TAILQ_FIRST is NULL. 2006-08-04 21:15:09 +00:00
John Baldwin
91ce2694d1 Regen for MPSAFE flag removal. 2006-07-28 19:08:37 +00:00
John Baldwin
af5bf12239 Now that all system calls are MPSAFE, retire the SYF_MPSAFE flag used to
mark system calls as being MPSAFE:
- Stop conditionally acquiring Giant around system call invocations.
- Remove all of the 'M' prefixes from the master system call files.
- Remove support for the 'M' prefix from the script that generates the
  syscall-related files from the master system call files.
- Don't explicitly set SYF_MPSAFE when registering nfssvc.
2006-07-28 19:05:28 +00:00
John Baldwin
78371ec202 Regen. 2006-07-28 16:56:44 +00:00
John Baldwin
95e7d19dfa - Explicitly lock Giant to protect the fields in the svr4_strm structure
except for s_family (which is read-only once after it is set when the
  structure is created).
- Mark svr4_sys_ioctl(), svr4_sys_getmsg(), and svr4_sys_putmsg() MPSAFE.
2006-07-28 16:56:17 +00:00
John Baldwin
f30e89ced3 Fix a file descriptor race I reintroduced when I split accept1() up into
kern_accept() and accept1().  If another thread closed the new file
descriptor and the first thread later got an error trying to copyout the
socket address, then it would attempt to close the wrong file object.  To
fix, add a struct file ** argument to kern_accept().  If it is non-NULL,
then on success kern_accept() will store a pointer to the new file object
there and not release any of the references.  It is up to the calling code
to drop the references appropriately (including a call to fdclose() in case
of error to safely handle the aforementioned race).  While I'm at it, go
ahead and fix the svr4 streams code to not leak the accept fd if it gets an
error trying to copyout the streams structures.
2006-07-27 19:54:41 +00:00
John Baldwin
3ce72960e8 Regen. 2006-07-21 20:41:33 +00:00
John Baldwin
e0569c0798 Clean up the svr4 socket cache and streams code some to make it more easily
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.
2006-07-21 20:40:13 +00:00
John Baldwin
52d639a953 Add conditional VFS Giant locking to svr4_sys_fchroot() and mark it MPSAFE.
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
2006-07-21 20:28:56 +00:00
John Baldwin
7cf6a457ea Regen. 2006-07-19 19:03:21 +00:00
John Baldwin
a1ca3e0ba7 Add conditional VFS Giant locking to svr4_sys_resolvepath() and mark it
MPSAFE.
2006-07-19 19:03:03 +00:00
John Baldwin
a3616b117c Make svr4_sys_waitsys() a lot less ugly and mark it MPSAFE.
- 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.
2006-07-19 19:01:10 +00:00