CVS log for src/sys/sys/proc.h

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Default branch: MAIN

p->p_stat is actually locked by proc_lock so document it that way and
shuffle some fields around so it's not next to p->p_trace_enabled (that
needs some attention too, in a later change).

Pull up following revision(s) (requested by maya in ticket #316):

	sys/arch/m68k/include/mutex.h: revision 1.13
	sys/arch/arm/include/cpu.h: revision 1.125
	sys/arch/sun68k/include/intr.h: revision 1.21
	sys/arch/arm/include/mutex.h: revision 1.28
	sys/sys/rwlock.h: revision 1.18
	sys/arch/powerpc/include/mutex.h: revision 1.7
	sys/arch/arm/include/mutex.h: revision 1.29
	sys/arch/powerpc/include/mutex.h: revision 1.8
	sys/uvm/uvm_param.h: revision 1.42
	sys/sys/ksem.h: revision 1.16
	sys/arch/x86/include/mutex.h: revision 1.10
	sys/sys/proc.h: revision 1.372
	sys/sys/ksem.h: revision 1.17
	sys/arch/ia64/include/mutex.h: revision 1.8
	sys/arch/evbarm/include/intr.h: revision 1.29
	sys/sys/lua.h: revision 1.9
	sys/arch/next68k/include/intr.h: revision 1.23
	sys/arch/ia64/include/mutex.h: revision 1.9
	sys/arch/hp300/include/intr.h: revision 1.35
	sys/arch/hp300/include/intr.h: revision 1.36
	sys/arch/sparc/include/cpu.h: revision 1.111
	sys/arch/hppa/include/mutex.h: revision 1.16
	sys/arch/vax/include/intr.h: revision 1.31
	sys/arch/hppa/include/mutex.h: revision 1.17
	sys/arch/news68k/include/intr.h: revision 1.28
	sys/arch/hppa/include/mutex.h: revision 1.18
	sys/arch/hppa/include/intr.h: revision 1.3
	sys/arch/hppa/include/mutex.h: revision 1.19
	sys/arch/hppa/include/intr.h: revision 1.4
	sys/sys/sched.h: revision 1.92
	sys/opencrypto/cryptodev.h: revision 1.51
	sys/arch/vax/include/mutex.h: revision 1.20
	sys/arch/sparc64/include/mutex.h: revision 1.10
	sys/arch/ia64/include/sapicvar.h: revision 1.2
	sys/arch/riscv/include/mutex.h: revision 1.5
	sys/arch/amiga/dev/grfabs_cc.c: revision 1.39
	sys/external/bsd/drm2/include/linux/idr.h: revision 1.11
	sys/arch/riscv/include/mutex.h: revision 1.6
	sys/ddb/files.ddb: revision 1.16
	sys/arch/mac68k/include/intr.h: revision 1.32
	share/man/man4/ddb.4: revision 1.203
	sys/ddb/db_command.c: revision 1.183
	sys/arch/mips/include/mutex.h: revision 1.10
	sys/ddb/db_command.c: revision 1.184
	sys/arch/x68k/include/intr.h: revision 1.22
	sys/arch/sparc/include/psl.h: revision 1.51
	sys/arch/or1k/include/mutex.h: revision 1.4
	sys/arch/mips/include/mutex.h: revision 1.11
	sys/arch/arm/xscale/pxa2x0_intr.h: revision 1.16
	sys/arch/sparc64/include/cpu.h: revision 1.134
	sys/arch/sparc/include/psl.h: revision 1.52
	sys/arch/or1k/include/mutex.h: revision 1.5
	sys/arch/mvme68k/include/intr.h: revision 1.22
	sys/arch/luna68k/include/intr.h: revision 1.16
	external/cddl/osnet/sys/sys/kcondvar.h: revision 1.6
	sys/arch/sparc/include/mutex.h: revision 1.12
	sys/arch/sparc/include/mutex.h: revision 1.13
	sys/arch/usermode/include/mutex.h: revision 1.5
	sys/arch/usermode/include/mutex.h: revision 1.6
	sys/kern/kern_core.c: revision 1.38
	usr.sbin/crash/Makefile: revision 1.49
	sys/arch/amiga/include/intr.h: revision 1.23
	sys/arch/alpha/include/mutex.h: revision 1.12
	sys/arch/alpha/include/mutex.h: revision 1.13
	sys/arch/evbarm/lubbock/sacc_obio.c: revision 1.16
	sys/ddb/ddb.h: revision 1.6
	sys/arch/sparc64/include/mutex.h: revision 1.8
	sys/arch/sh3/include/mutex.h: revision 1.12
	sys/arch/evbarm/lubbock/sacc_obio.c: revision 1.17
	sys/ddb/db_syncobj.c: revision 1.1
	sys/arch/vax/include/mutex.h: revision 1.18
	sys/arch/sparc64/include/psl.h: revision 1.63
	sys/arch/sparc64/include/mutex.h: revision 1.9
	sys/arch/sh3/include/mutex.h: revision 1.13
	sys/arch/evbarm/lubbock/obio.c: revision 1.13
	sys/arch/atari/include/intr.h: revision 1.23
	sys/ddb/db_syncobj.c: revision 1.2
	sys/arch/vax/include/mutex.h: revision 1.19
	sys/arch/evbarm/g42xxeb/obio.c: revision 1.14
	sys/arch/evbarm/g42xxeb/obio.c: revision 1.15
	sys/arch/cesfic/include/intr.h: revision 1.14
	sys/ddb/db_syncobj.h: revision 1.1
	sys/arch/x86/include/cpu.h: revision 1.134
	sys/arch/evbarm/g42xxeb/obio.c: revision 1.16
	sys/arch/cesfic/include/intr.h: revision 1.15
	sys/arch/arm/xscale/pxa2x0_intr.c: revision 1.26
	sys/sys/cpu_data.h: revision 1.54
	sys/arch/m68k/include/mutex.h: revision 1.12
	sys/arch/ia64/acpi/madt.c: revision 1.6

sys/rwlock.h: Make this more self-contained for bool.

machine/mutex.h: Sprinkle includes so this can be used by crash(8).

ddb: New `show all tstiles' command.
Shows who's waiting for which locks and what the owner is up to.

Include psl.h for ipl_cookie_t if __MUTEX_PRIVATE

sys: Rip <sys/resourcevar.h> out of <uvm/uvm_param.h>.

And thus out of <sys/param.h>, which is exceedingly overused and
fragile and delenda est.

Should fix (some) issues with the recent inclusion of machine/lock.h
in various machine/mutex.h files.

arm/mutex.h: Need machine/intr.h, machine/lock.h.

For ipl_cookie_t and __cpu_simple_lock_t.
evbarm/intr.h: Define ipl_cookie_t before including ARM_INTR_IMPL.

Otherwise arm/mutex.h doesn't work, due to a cyclic dependency which
should really be fixed.
opencrypto/cryptodev.h: Fix includes.
- Move sys/condvar.h under #ifdef _KERNEL.
- Add some other necessary includes and forward declarations.
- Sort.

hp300/intr.h: Fix missing includes.
linux/idr.h: Need <sys/mutex.h> for kmutex_t.
amiga/intr.h: Don't define spl*() functions if !_KERNEL.

This is used by crash(8) now, and what's important is ipl_cookie_t.
cesfic/intr.h: Expose ipl_cookie_t to userland for crash(8).
cesfic/intr.h: Expose ipl_cookie_t to userland only with _KMEMUSER.

Probably not necessary but let's be a little more cautious about
this.

atari/intr.h: Expose ipl_cookie_t with _KMEMUSER for crash(8).

arm/cpu.h: Need sys/param.h for COHERENCY_UNIT.

Nix machine/param.h -- not meant to be used directly, pulled in by
sys/param.h.

Move the definition of ipl_cookie_t out of the kernel-only sections,
some _KMEMUSER applications need it.

ddb: Cast pointer to uintptr_t first before db_expr_t.

hppa/intr.h: Expose ipl_cookie_t to _KMEMUSER for crash(8).

luna68k/intr.h: Expose ipl_cookie_t to _KMEMUSER for crash(8).

mvme68k/intr.h: Expose ipl_cookie_t to _KMEMUSER for crash(8).

news68k/intr.h: Fix includes.  Put some definitions under _KERNEL.

next68k/intr.h: Expose ipl_cookie_t to _KMEMUSER for crash(8).

sys/ksem.h: Hack around fstat(8) abuse of _KERNEL.

sun68k/intr.h: Expose ipl_cookie_t to _KMEMUSER for crash(8).

vax/intr.h: Expose ipl_cookie_t to _KMEMUSER for crash(8).

x68k/intr.h: Put functions under _KERNEL so crash(8) can use this.

Make ipl_cookie_t visible for _KMEMUSER userland applications.

fix editor mishap in previous

Explicitly include <sys/mutex.h> for kmutex_t.

Replace kmutex_t * (which may be undefined here) with struct kmutex *,
suggested by Taylor.

hp300/intr.h: Put most of this under #ifdef _KERNEL.
Only ipl_cookie_t really needs to be exposed now, for crash(8).

mac68k/intr.h: Expose ipl_cookie_t to _KMEMUSER for crash(8).
Make inclusion of sys/intr.h explicit for spl*.

fix hppa and vax builds.

machine/lock.h isn't necessary for __cpu_simple_lock_t, it's in
sys/types.h.  avoids cpu_data.h vs sched.h include order issues.

move the hppa ipl_t typedef with the moved usage of it.
machine/mutex.h: Sprinkle sys/types.h, omit machine/lock.h.

Turns out machine/lock.h is not needed for __cpu_simple_lock_t, which
always comes from sys/types.h.  And, really, sys/types.h (or at least
sys/stdint.h) is needed for uintN_t and uintptr_t.

ddb: Cast pointer to uintptr_t, then to db_expr_t.
Avoids warnings about conversion between pointer and integer of
different size on some architectures.

re-fix hppa builds.

this file uses __cpu_simple_lock(), not just the underlying type,
so it does need machine/lock.h.

Break cycle by using `struct kmutex *' instead of `kmutex_t *'.
sys/sched.h included sys/mutex.h
which includes sys/intr.h
which includes machine/intr.h
which on cats includes arm/footbridge/footbridge_intr.h
which includes arm/cpu.h
which includes sys/cpu_data.h
which includes sys/sched.h

But there was never any real need for sys/mutex.h in sys/sched.h,
because it only uses pointers to the opaque struct kmutex.  Cycle
broken by using `struct kmutex *' instead of pulling in sys/mutex.h
for the definition of kmutex_t.

Side effect: This revealed that sys/cpu_data.h needed sys/intr.h
(which was pulled in accidentally by sys/mutex.h via sys/sched.h) for
SOFTINT_COUNT.  Also revealed some other machine/cpu.h header files
were missing includes of sys/mutex.h for kmutex_t.

ia64: Need sys/types.h for u_int, vaddr_t; sys/mutex.h for kmutex_t.

explicitly include no longer implicitly included sys/mutex.h.

arm/xscale: Use sys/bitops.h fls32 - 1 instead of 31 - __builtin_clz.
Sidesteps namespace collision with `#define bits ...' in net/zlib.c.

complete the previous - there were two calls to find_first_bit() to fix.

arm/xscale: Missed a spot with previous find_first_bit commit.

evbarm/g42xxeb: Fix off-by-one in previous.

The original find_first_bit(x) was 31 - __builtin_clz((uint32_t)x),
which is equivalent to fls32(x) - 1, not to fls32(x).

Note that fls32 is 1-based and returns 0 for x=0.

sys: Rip <sys/resourcevar.h> out of <uvm/uvm_param.h>.

And thus out of <sys/param.h>, which is exceedingly overused and
fragile and delenda est.

Should fix (some) issues with the recent inclusion of machine/lock.h
in various machine/mutex.h files.

Pull up following revision(s) (requested by gutteridge in ticket #175):

	sys/sys/proc.h: revision 1.371
	sys/kern/vfs_lookup.c: revision 1.234

Default PROC_MACHINE_ARCH to machine_arch and use this for magic
symlinks to resolve "@machine_arch".

This keeps behaviour of magic symlinks and 'uname -p' output the same.
Fixes PR 57320.

Default PROC_MACHINE_ARCH to machine_arch and use this for magic
symlinks to resolve "@machine_arch".

This keeps behaviour of magic symlinks and 'uname -p' output the same.
Fixes PR 57320.

fix typo in comment

Changes to make EVFILT_PROC MP-safe:

Because the locking protocol around processes is somewhat complex
compared to other events that can be posted on kqueues, introduce
new functions for posting NOTE_EXEC, NOTE_EXIT, and NOTE_FORK,
rather than just using the generic knote() function.  These functions
KASSERT() their locking expectations, and deal with other complexities
for each situation.

knote_proc_fork(), in particiular, needs to handle NOTE_TRACK, which
requires allocation of a new knote to attach to the child process.  We
don't want to be allocating memory while holding the parent's p_lock.
Furthermore, we also have to attach the tracking note to the child
process, which means we have to acquire the child's p_lock.

So, to handle all this, we introduce some additional synchronization
infrastructure around the 'knote' structure:

- Add the ability to mark a knote as being in a state of flux.  Knotes
  in this state are guaranteed not to be detached/deleted, thus allowing
  a code path drop other locks after putting a knote in this state.

- Code paths that wish to detach/delete a knote must first check if the
  knote is in-flux.  If so, they must wait for it to quiesce.  Because
  multiple threads of execution may attempt this concurrently, a mechanism
  exists for a single LWP to claim the detach responsibility; all other
  threads simply wait for the knote to disappear before they can make
  further progress.

- When kqueue_scan() encounters an in-flux knote, it simply treats the
  situation just like encountering another thread's queue marker -- wait
  for the flux to settle and continue on.

(The "in-flux knote" idea was inspired by FreeBSD, but this works differently
from their implementation, as the two kqueue implementations have diverged
quite a bit.)

knote_proc_fork() uses this infrastructure to implement NOTE_TRACK like so:

- Attempt to put the original tracking knote into a state of flux; if this
  fails (because the note has a detach pending), we skip all processing
  (the original process has lost interest, and we simply won the race).

- Once the note is in-flux, drop the kq and forking process's locks, and
  allocate 2 knotes: one to post the NOTE_CHILD event, and one to attach
  a new NOTE_TRACK to the child process.  Notably, we do NOT go through
  kqueue_register() to do this, but rather do all of the work directly
  and KASSERT() our assumptions; this allows us to directly control our
  interaction with locks.  All memory allocations here are performed with
  KM_NOSLEEP, in order to prevent holding the original knote in-flux
  indefinitely.

- Because the NOTE_TRACK use case adds knotes to kqueues through a
  sort of back-door mechanism, we must serialize with the closing of
  the destination kqueue's file descriptor, so steal another bit from
  the kq_count field to notify other threads that a kqueue is on its
  way out to prevent new knotes from being enqueued while the close
  path detaches them.

In addition to fixing EVFILT_PROC's reliance on KERNEL_LOCK, this also
fixes a long-standing bug whereby a NOTE_CHILD event could be dropped
if the child process exited before the interested process received the
NOTE_CHILD event (the same knote would be used to deliver the NOTE_EXIT
event, and would clobber the NOTE_CHILD's 'data' field).

Add a bunch of comments to explain what's going on in various critical
sections, and sprinkle additional KASSERT()s to validate assumptions
in several more locations.

Sync w/ HEAD.

Refactor interval timers to make it possible to support types other than
the BSD/POSIX per-process timers:

- "struct ptimer" is split into "struct itimer" (common interval timer
  data) and "struct ptimer" (per-process timer data, which contains a
  "struct itimer").

- Introduce a new "struct itimer_ops" that supplies information about
  the specific kind of interval timer, including it's processing
  queue, the softint handle used to schedule processing, the function
  to call when the timer fires (which adds it to the queue), and an
  optional function to call when the CLOCK_REALTIME clock is changed by
  a call to clock_settime() or settimeofday().

- Rename some fuctions to clearly identify what they're operating on
  (ptimer vs itimer).

- Use kmem(9) to allocate ptimer-related structures, rather than having
  dedicated pools for them.

Welcome to NetBSD 9.99.77.

Move proc_lock into the data segment.  It was dynamically allocated because
at the time we had mutex_obj_alloc() but not __cacheline_aligned.

- Replace pid_table_lock with a lockless lookup covered by pserialize, with
  the "writer" side being pid_table expansion.  The basic idea is that when
  doing an LWP lookup there is usually already a lock held (p->p_lock), or a
  spin mutex that needs to be taken (l->l_mutex), and either can be used to
  get the found LWP stable and confidently determine that all is correct.

- For user processes LSLARVAL implies the same thing as LSIDL ("not visible
  by ID"), and lookup by ID in proc0 doesn't really happen.  In-tree the new
  state should be understood by top(1), the tty subsystem and so on, and
  would attract the attention of 3rd party kernel grovellers in time, so
  remove it and just rely on LSIDL.

On debugger attach to a prestarted process don't report SIGTRAP

Introduce PSL_TRACEDCHILD that indicates tracking of birth of a process.
A freshly forked process checks whether it is traced and if so, reports
SIGTRAP + TRAP_CHLD event to a debugger as a result of tracking forks-like
events. There is a time window when a debugger can attach to a newly
created process and receive SIGTRAP + TRAP_CHLD instead of SIGSTOP.

Fixes races in t_ptrace_wait* tests when a test hangs or misbehaves,
especially the ones reported in tracer_sysctl_lookup_without_duplicates.

- proc_find() retains traditional semantics of requiring the canonical
  PID to look up a proc.  Add a separate proc_find_lwpid() to look up a
  proc by the ID of any of its LWPs.
- Add proc_find_lwp_acquire_proc(), which enables looking up the LWP
  *and* a proc given the ID of any LWP.  Returns with the proc::p_lock
  held.
- Rewrite lwp_find2() in terms of proc_find_lwp_acquire_proc(), and add
  allow the proc to be wildcarded, rather than just curproc or specific
  proc.
- lwp_find2() now subsumes the original intent of lwp_getref_lwpid(), but
  in a much nicer way, so garbage-collect the remnants of that recently
  added mechanism.

Sync with bouyer-xenpvh-base2 (HEAD)

Overhaul the way LWP IDs are allocated.  Instead of each LWP having it's
own LWP ID space, LWP IDs came from the same number space as PIDs.  The
lead LWP of a process gets the PID as its LID.  If a multi-LWP process's
lead LWP exits, the PID persists for the process.

In addition to providing system-wide unique thread IDs, this also lets us
eliminate the per-process LWP radix tree, and some associated locks.

Remove the separate "global thread ID" map added previously; it is no longer
needed to provide this functionality.

Nudged in this direction by ad@ and chs@.

Mostly merge changes from HEAD upto 20200411

Reintroduce struct proc::p_oppid

Relying on p_opptr is not safe as there is a race between:
 - spawner giving a birth to a child process and being killed
 - spawnee accessng p_opptr and reporting TRAP_CHLD

PR kern/54786 by Andreas Gustafsson

There is no "s" lock.

Make page waits (WANTED vs BUSY) interlocked by pg->interlock.  Gets RW
locks out of the equation for sleep/wakeup, and allows observing+waiting
for busy pages when holding only a read lock.  Proposed on tech-kern.

Sync with head.

UVM locking changes, proposed on tech-kern:

- Change the lock on uvm_object, vm_amap and vm_anon to be a RW lock.
- Break v_interlock and vmobjlock apart.  v_interlock remains a mutex.
- Do partial PV list locking in the x86 pmap.  Others to follow later.

- Track LWPs in a per-process radixtree.  It uses no extra memory in the
  single threaded case.  Replace scans of p->p_lwps with lookups in the
  tree.  Find free LIDs for new LWPs in the tree.  Replace the hashed sleep
  queues for park/unpark with lookups in the tree under cover of a RW lock.

- lwp_wait(): if waiting on a specific LWP, find the LWP via tree lookup and
  return EINVAL if it's detached, not ESRCH.

- Group the locks in struct proc at the end of the struct in their own cache
  line.

- Add some comments.

Remove now unused p_oppid from struct proc

Move TRAP_CHLD/TRAP_LWP ptrace information from struct proc to siginfo

Storing struct ptrace_state information inside struct proc was vulnerable
to synchronization bugs, as multiple events emitted in the same time were
overwritting other ones.

Cache the original parent process id in p_oppid. Reusing here p_opptr is
in theory prone to slight race codition.

Change the semantics of PT_GET_PROCESS_STATE, reutning EINVAL for calls
prompting for the value in cases when there wasn't registered an
appropriate event.

Add an alternative approach to check the ptrace_state information, directly
from the siginfo_t value returned from PT_GET_SIGINFO. The original
PT_GET_PROCESS_STATE approach is kept for compat with older NetBSD and
OpenBSD. New code is recommended to keep using PT_GET_PROCESS_STATE.

Add a couple of compile-time asserts for assumptions in the code.

No functional change intended in existing ptrace(2) software.

All ATF ptrace(2) and ATF GDB tests pass.

This change improves reliability of the threading ptrace(2) code.

Move a comment line get it next to the line it describes, avoiding
intervening unrelated text.

NFCI

Eliminate PS_NOTIFYSTOP remnants from the kernel

This flag used to be useful in /proc (BSD4.4-style) debugging semantics.
Traced child events were notified without signaling the parent.

This property was removed in NetBSD-8.0 and had no users.

This change simplifies the signal code, removing dead branches.

NFCI

Add support for PTRACE_POSIX_SPAWN to report posix_spawn(3) events

posix_spawn(3) is a first class syscall in NetBSD, different to
(V)FORK+EXEC as these operations are executed in one go. This differs to
Linux and FreeBSD, where posix_spawn(3) is implemented with existing kernel
primitives (clone(2), vfork(2), exec(3)) inside libc.

Typically LLDB and GDB software is aware of FORK/VFORK events. As discussed
with the LLDB community, instead of slicing the posix_spawn(3) operation
into phases emulating (V)FORK+EXEC(+VFORK_DONE) and returning intermediate
state to the debugger, that might have abnormal state, introduce new event
type: PTRACE_POSIX_SPAWN.

A debugger implementor can easily map it into existing fork+exec semantics
or treat as a distinct event.

There is no functional change for existing debuggers as there was no
support for reporting posix_spawn(3) events on the kernel side.

Sync with HEAD

Centralized shared part of child_return() into MI part

Add a new function md_child_return() for MD specific bits only.

New child_return() is now part of MI and central code that handles
uniformly tracing code (KTR and ptrace(2)).

Synchronize value passed to ktrsysret() among ports to SYS_fork. This is
a traditional value and accessing p_lflag to check for PL_PPWAIT shall
use locking against proc_lock. Returning SYS_fork vs SYS_vfork still isn't
correct enough as there are more entry points to forking code. Instead of
making it too good, just settle with plain SYS_fork for all ports.

PR/53998: Joel Bertrand:  Limit the number of semaphores on a
per-user basis not a per-process.  We cannot really keep track on
a per-process basis because a parent process can create the semaphore
and a child can free it taking credit for it.  There is also a
similar issue about resource exhaustion if we limited the number
of lwps per process as opposed to per user (which we don't).

Sync with HEAD, resolve a few conflicts

As discussed in tech-kern:

- make sysctl kern.expose_address tri-state:
	0: no access
	1: access to processes with open /dev/kmem
	2: access to everyone
  defaults:
	0: KASLR kernels
	1: non-KASLR kernels

- improve efficiency by calling get_expose_address() per sysctl, not per
  process.

- don't expose addresses for linux procfs

- welcome to 8.99.27, changes to fill_*proc ABI

Sync with HEAD

Resolve a couple of conflicts (result of the uimin/uimax changes)

Allow syscall_establish() to install new syscalls when the existing
entry-point is either sys_nomodule or sys_nosys.  Update the
makesyscalls.sh script to create a const array of bits to allow
syscall_disestablish() to properly restore the original entry-point.
Update all the initializers of struct emul to initialize the pointer
to the bit array struct emul.

XXX Regen of all files created by makesyscalls.sh will come soon,
XXX followed by a kernel version bump (since struct emul is being
XXX modified).

This commit should address PR kern/45781 and also removes the need
for the work-around for that PR in file

	sys/arch/usermode/modules/syscallemu/syscallemu.c

Sync with HEAD

Cause a process's user and system times to become non-decreasing.

This alters the invented values (ie: statistically calculated)
that are returned - for small values, the values are likely going to
be different than they were, but that's largely nonsense anyway
(except that the sum of utime & stime does equal cpu time consumed
by the process).   Once the values get large enough to be meaningful
the difference made by this change will be in the noise, and irrelevant.

This needs a couple of additions to struct proc, so we are now into 8.99.17

Remove an element from struct emul: e_tracesig

e_tracesig used to be implemented for Darwin compat. Nowadays the Darwin
compatiblity layer is gone and there are no other users.

This functionality isn't used where it shall be used in the existing
codebase.

If we want to emulate debugging interfaces in compat layers we would need
to implement that from scratch anyway. We would need to be bug compatible
with other OSes too.

Proposed on tech-kern@.

Welcome to NetBSD 8.99.16!

Sponsored by <The NetBSD Foundation>

Sync with HEAD

s/static inline/static __inline/g for consistency with other include
headers.

Remove the rnewprocp argument from fork1(9)

It's now unused and it can cause use-after-free scenarios as noted by
<Mateusz Guzik>.

Reference: http://mail-index.netbsd.org/tech-kern/2017/09/08/msg022267.html

Sponsored by <The NetBSD Foundation>

Pull up following revision(s) (requested by kamil in ticket #713):

	sys/modules/procfs/Makefile: revision 1.4
	sys/miscfs/procfs/procfs_vfsops.c: revision 1.98
	bin/ps/ps.1: revision 1.108
	sys/compat/linux/arch/i386/linux_ptrace.c: revision 1.32
	sys/miscfs/procfs/procfs_vnops.c: revision 1.198
	sys/kern/sys_ptrace_common.c: revision 1.23
	sys/kern/sys_ptrace_common.c: revision 1.24
	sbin/mount_procfs/mount_procfs.8: revision 1.36
	sys/kern/sys_ptrace_common.c: revision 1.25
	sys/kern/sys_ptrace.c: revision 1.5
	sys/compat/linux/arch/powerpc/linux_ptrace.c: revision 1.30
	sys/sys/proc.h: revision 1.342
	sys/kern/sys_ptrace_common.c: revision 1.26
	sys/miscfs/procfs/procfs_ctl.c: file removal
	sys/kern/sys_ptrace_common.c: revision 1.27
	sys/miscfs/procfs/procfs_subr.c: revision 1.109
	sys/kern/sys_ptrace_common.c: revision 1.28
	sys/secmodel/extensions/secmodel_extensions.c: revision 1.8
	sys/kern/sys_ptrace_common.c: revision 1.29
	sys/sys/ptrace.h: revision 1.62
	sys/compat/netbsd32/netbsd32_signal.c: revision 1.45
	share/man/man9/kauth.9: revision 1.109
	sys/miscfs/procfs/files.procfs: revision 1.12
	sys/compat/netbsd32/netbsd32.h: revision 1.115
	sys/miscfs/procfs/procfs.h: revision 1.72
	sys/compat/netbsd32/netbsd32_ptrace.c: revision 1.5
	sys/kern/kern_sig.c: revision 1.337
	sys/sys/kauth.h: revision 1.75
	sys/sys/sysctl.h: revision 1.224
	sys/kern/sys_ptrace_common.c: revision 1.30
	sys/kern/sys_ptrace_common.c: revision 1.31
	sys/kern/sys_ptrace_common.c: revision 1.32
	sys/kern/sys_ptrace_common.c: revision 1.33
	sys/compat/linux/arch/arm/linux_ptrace.c: revision 1.20
	sys/kern/sys_ptrace_common.c: revision 1.34
	sys/kern/sys_ptrace_common.c: revision 1.36
	sys/kern/kern_proc.c: revision 1.207
	sys/kern/kern_exit.c: revision 1.269
	doc/TODO.ptrace: revision 1.29

Make {s,g}et{db,fp,}regs work again for PK_32 processes
XXX: pullup-8

add disgusting magic to handle compat_netbsd32 as a module.

use process_*reg32 instead of struct *reg32.

Remove the filesystem tracing feature

This is a legacy interface from 4.4BSD, and it was
introduced to overcome shortcomings of ptrace(2) at that time, which are
no longer relevant (performance). Today /proc/#/ctl offers a narrow
subset of ptrace(2) commands and is not applicable for modern
applications use beyond simplistic tracing scenarios.

This removal will simplify kernel internals. Users will still be able to
use all the other /proc files.

This change won't affect other procfs files neither Linux compat
features within mount_procfs(8). /proc/#/ctl isn't available on Linux.

Remove:
 - /proc/#/ctl from mount_procfs(8)
 - P_FSTRACE note from the documentation of ps(1)
 - /proc/#/ctl and filesystem tracing documentation from mount_procfs(8)
 - KAUTH_REQ_PROCESS_PROCFS_CTL documentation from kauth(9)
 - source code file miscfs/procfs/procfs_ctl.c
 - PFSctl and procfs_doctl() from sys/miscfs/procfs/procfs.h
 - KAUTH_REQ_PROCESS_PROCFS_CTL from sys/sys/kauth.h
 - PSL_FSTRACE (0x00010000) from sys/sys/proc.h
 - P_FSTRACE (0x00010000) from sys/sys/sysctl.h

Reduce code complexity after removal of this functionality.

Update TODO.ptrace accordingly: remove two entries about /proc tracing.

Do not keep legacy notes as comments in the headers about removed

PSL_FSTRACE / P_FSTRACE, as this interface had little number of users
(close or equal to zero).
Proposed on tech-kern@.

All filesystem tracing utility users are encouraged to switch to ptrace(2).

Sponsored by <The NetBSD Foundation>

untangle the mess:
- factor out common code
- break each ptrace subcall to its own sub-function
  .. more to come ...
- reduce ifdef ugliness by moving it up top.
- factor out PT_IO and make PT_{READ,WRITE}_{I,D} use it
- factor out PT_DUMPCORE
- factor out sendsig code
  .. more to come ...

handle siginfo requests for ptrace32

ptrace: Partially undo PT_{READ,WRITE}_{I,D} and unbreak these commands

The refactored code did not work and was generating EFAULT.

Sponsored by <The NetBSD Foundation>

Merge the code back; the problem was that since we are reading/writing
to a kernel address for PT_{READ,WRITE}_{I,D} we need the kernel vmspace.
provide separate read and write functions to accomodate register functions
that need a size argument.

don't ignore error from copyout_piod

Use the proper process (the tracee) to get information about lwps and
registers and the tracer for vmspace.

Add new sysctl(3) entry: security.models.extensions.user_set_dbregs

Model this new sysctl(3) entry after "user_set_cpu_affinity" in the same
level of sysctl(3) switches.

Allow to read unconditionally Debug Registers (no change here). This is
convenient as even if a user of a debugger does not use hardware assisted
watchpoints/breakpoints, a debugger can still prompt these values to store
in an internal cache with context of registers. Reading them should have
no security concerns.

Add a paranoid MI switch that prohibits by default setting these registers
by a regular user (non-superuser). Make this switch disabled by default.
There are enough reserved bits out there to allow using them
unconditionally on hardened hosts.

Features shipped with Debug Registers are optional features in debuggers.
There is no reduction in elementary functionality.

Reviewed by <christos>

Sponsored by <The NetBSD Foundation>

remove struct emul's e_fault.

It used to be used by COMPAT_IRIX for the purpose of overriding
uvm_fault (only implemented in MIPS), now removed.

Ride 8.99.12 version bump.

update from HEAD

Store full executable path in p->p_path as discussed in tech-kern.
This means that the full executable path is always available.

- exec_elf.c: use p->path to set AT_SUN_EXECNAME, and since this is
  always set, do so unconditionally.
- kern_exec.c: simplify pathexec, use kmem_strfree where appropriate
  and set p->p_path
- kern_exit.c: free p->p_path
- kern_fork.c: set p->p_path for the child.
- kern_proc.c: use p->p_path to return the executable pathname; the
  NULL check for p->p_path, should be a KASSERT?
- exec.h: gc ep_path, it is not used anymore
- param.h: bump version, 'struct proc' size change

TODO:
1. reference count the path string, to save copy at fork and free
   just before exec?
2. canonicalize the pathname by changing namei() to LOCKPARENT
   vnode and then using getcwd() on the parent directory?

Sync with HEAD

Remove the filesystem tracing feature

This is a legacy interface from 4.4BSD, and it was
introduced to overcome shortcomings of ptrace(2) at that time, which are
no longer relevant (performance). Today /proc/#/ctl offers a narrow
subset of ptrace(2) commands and is not applicable for modern
applications use beyond simplistic tracing scenarios.

This removal will simplify kernel internals. Users will still be able to
use all the other /proc files.

This change won't affect other procfs files neither Linux compat
features within mount_procfs(8). /proc/#/ctl isn't available on Linux.

Remove:
 - /proc/#/ctl from mount_procfs(8)
 - P_FSTRACE note from the documentation of ps(1)
 - /proc/#/ctl and filesystem tracing documentation from mount_procfs(8)
 - KAUTH_REQ_PROCESS_PROCFS_CTL documentation from kauth(9)
 - source code file miscfs/procfs/procfs_ctl.c
 - PFSctl and procfs_doctl() from sys/miscfs/procfs/procfs.h
 - KAUTH_REQ_PROCESS_PROCFS_CTL from sys/sys/kauth.h
 - PSL_FSTRACE (0x00010000) from sys/sys/proc.h
 - P_FSTRACE (0x00010000) from sys/sys/sysctl.h

Reduce code complexity after removal of this functionality.

Update TODO.ptrace accordingly: remove two entries about /proc tracing.

Do not keep legacy notes as comments in the headers about removed
PSL_FSTRACE / P_FSTRACE, as this interface had little number of users
(close or equal to zero).

Proposed on tech-kern@.

All filesystem tracing utility users are encouraged to switch to ptrace(2).

Sponsored by <The NetBSD Foundation>

Typo

Sync with HEAD

Sync with HEAD

factor out getauxv code.

Instead of copying parts of sigswitch to process_stoptrace, use it directly.
Rename process_stoptrace -> proc_stoptrace and put it in kern_sig.c so we
don't need to expose any more functions from it.

Sync with HEAD

Introduce PT_GETDBREGS and PT_SETDBREGS in ptrace(2) on i386 and amd64

This interface is modeled after FreeBSD API with the usage.

This replaced previous watchpoint API. The previous one was introduced
recently in NetBSD-current and remove its spurs without any
backward-compatibility.

Design choices for Debug Register accessors:
 - exec() (TRAP_EXEC event) must remove debug registers from LWP
 - debug registers are only per-LWP, not per-process globally
 - debug registers must not be inherited after (v)forking a process
 - debug registers must not be inherited after forking a thread
 - a debugger is responsible to set global watchpoints/breakpoints with the
   debug registers, to achieve this PTRACE_LWP_CREATE/PTRACE_LWP_EXIT event
   monitoring function is designed to be used
 - debug register traps must generate SIGTRAP with si_code TRAP_DBREG
 - debugger is responsible to retrieve debug register state to distinguish
   the exact debug register trap (DR6 is Status Register on x86)
 - kernel must not remove debug register traps after triggering a trap event
   a debugger is responsible to detach this trap with appropriate PT_SETDBREGS
   call (DR7 is Control Register on x86)
 - debug registers must not be exposed in mcontext
 - userland must not be allowed to set a trap on the kernel

Implementation notes on i386 and amd64:
 - the initial state of debug register is retrieved on boot and this value is
   stored in a local copy (initdbregs), this value is used to initialize dbreg
   context after PT_GETDBREGS
 - struct dbregs is stored in pcb as a pointer and by default not initialized
 - reserved registers (DR4-DR5, DR9-DR15) are ignored

Further ideas:
 - restrict this interface with securelevel

Tested on real hardware i386 (Intel Pentium IV) and amd64 (Intel i7).

This commit enables 390 debug register ATF tests in kernel/arch/x86.
All tests are passing.

This commit does not cover netbsd32 compat code. Currently other interface
PT_GET_SIGINFO/PT_SET_SIGINFO is required in netbsd32 compat code in order to
validate reliably PT_GETDBREGS/PT_SETDBREGS.

This implementation does not cover FreeBSD specific defines in their
<x86/reg.h>: DBREG_DR7_LOCAL_ENABLE, DBREG_DR7_GLOBAL_ENABLE, DBREG_DR7_LEN_1
etc. These values tend to be reinvented by each tracer on its own. GNU
Debugger (GDB) works with NetBSD debug registers after adding this patch:

--- gdb/amd64bsd-nat.c.orig	2016-02-10 03:19:39.000000000 +0000
+++ gdb/amd64bsd-nat.c
@@ -167,6 +167,10 @@ amd64bsd_target (void)

 #ifdef HAVE_PT_GETDBREGS

+#ifndef DBREG_DRX
+#define	DBREG_DRX(d,x)	((d)->dr[(x)])
+#endif
+
 static unsigned long
 amd64bsd_dr_get (ptid_t ptid, int regnum)
 {


Another reason to stop introducing unpopular defines covering machine
specific register macros is that these value varies across generations of
the same CPU family.

GDB demo:
  (gdb) c
  Continuing.

  Watchpoint 2: traceme

  Old value = 0
  New value = 16
  main (argc=1, argv=0x7f7fff79fe30) at test.c:8
  8               printf("traceme=%d\n", traceme);

(Currently the GDB interface is not reliable due to NetBSD support bugs)

Sponsored by <The NetBSD Foundation>

Sync with HEAD

Introduce PTRACE_LWP_{CREATE,EXIT} in ptrace(2) and TRAP_LWP in siginfo(5)

Add interface in ptrace(2) to track thread (LWP) events:
 - birth,
 - termination.

The purpose of this thread is to keep track of the current thread state in
a tracee and apply e.g. per-thread designed hardware assisted watchpoints.

This interface reuses the EVENT_MASK and PROCESS_STATE interface, and
shares it with PTRACE_FORK, PTRACE_VFORK and PTRACE_VFORK_DONE.

Change the following structure:

typedef struct ptrace_state {
        int     pe_report_event;
        pid_t   pe_other_pid;
} ptrace_state_t;

to

typedef struct ptrace_state {
        int     pe_report_event;
        union {
                pid_t   _pe_other_pid;
                lwpid_t _pe_lwp;
        } _option;
} ptrace_state_t;

#define pe_other_pid    _option._pe_other_pid
#define pe_lwp          _option._pe_lwp

This keeps size of ptrace_state_t unchanged as both pid_t and lwpid_t are
defined as int32_t-like integer. This change does not break existing
prebuilt software and has minimal effect on necessity for source-code
changes. In summary, this change should be binary compatible and shouldn't
break build of existing software.


Introduce new siginfo(5) type for LWP events under the SIGTRAP signal:
TRAP_LWP. This change will help debuggers to distinguish exact source of
SIGTRAP.


Add two basic t_ptrace_wait* tests:
lwp_create1:
    Verify that 1 LWP creation is intercepted by ptrace(2) with
    EVENT_MASK set to PTRACE_LWP_CREATE

lwp_exit1:
    Verify that 1 LWP creation is intercepted by ptrace(2) with
    EVENT_MASK set to PTRACE_LWP_EXIT

All tests are passing.


Surfing the previous kernel ABI bump to 7.99.59 for PTRACE_VFORK{,_DONE}.

Sponsored by <The NetBSD Foundation>

Add support for PTRACE_VFORK_DONE and stub for PTRACE_VFORK in ptrace(2)

PTRACE_VFORK is supposed to be used to track vfork(2)-like events, when
parent gives birth to new process child and stops till it exits or calls
exec().
Currently PTRACE_VFORK is a stub.

PTRACE_VFORK_DONE is notification to notify a debugger that a parent has
resumed after vfork(2)-like action.
PTRACE_VFORK_DONE throws SIGTRAP with TRAP_CHLD.

Sponsored by <The NetBSD Foundation>

Sync with HEAD

Sync with HEAD

PR kern/51514: ptrace(2) fails for 32-bit process on 64-bit kernel

Updated from the original patch in the PR by me.

Sync with HEAD

Introduce and use PROC_PTRSZ() to handle differing pointer size 64->32
emulation.

Add netbsd32_clock_getcpuclockid2 and netbsd32_wait6 functions

Allow emulations to override the creation of ktrace records for posting
signals. In compat_netbsd32 use this to write the 32bit version of
the records, so a 32bit userland kdump is happy.

Sync with HEAD

GSoC 2016: Charles Cui: add SEM_NSEMS_MAX

Sync with HEAD

We need a flag for WCONTINUED so that we can reset it... Fixes bash issue.

Sync with HEAD

no need to pass the coredump flag to exit1() since it is set and known
in one place.

Split p_xstat (composite wait(2) status code, or signal number depending
on context) into:
1. p_xexit:		exit code
2. p_xsig:		signal number
3. p_sflag & WCOREFLAG	bit to indicated that the process core-dumped.

Fix the documentation of the flag bits in <sys/proc.h>

Sync with HEAD (as of 26th Dec)

Finish the rename from sc_auto --> sc_autoload

(Thanks, brad harder)

Rename sc_auto to sc_autoload at suggestion of christos@

Make the list of syscalls which can trigger a module autoload an
attribute of each emulation, rather than having a single global
list which applies only to the default emulation.

This changes 'struct emul' so

        Welcome to 7.99.23 !

We never exec(2) with a kernel vmspace, so do not test for that, but instead
KASSERT() that we don't.
When calculating the load address for the interpreter (e.g. ld.elf_so),
we need to take into account wether the exec'd process will run with
topdown memory or bottom up. We can not use the current vmspace's flags
to test for that, as this happens too early. Luckily the execpack already
knows what the new state will be later, so instead of testing the current
vmspace, pass the info as additional argument to struct emul
e_vm_default_addr.
Fix all such functions and adopt all callers.

Add proc_find_locked(), which returns the process locked and does the
sysctl access check.

Sync with HEAD

Make kill1 public (we'll need it from compat/netbsd32)

Sync with HEAD

add dtrace syscall glue:
- adds 2 members to sysent: these are the entry and exit probe ids
  they are non-zero only when dtrace is loaded
- add an emul specific probe for dtrace: this is NULL unless the emulation
  supports dtrace and is loaded
- adjust the syscall stub call trace_enter/exit if needed for systrace
- add more info to trace_enter and exit needed by systrace

Rebase to HEAD as of a few days ago.

sync with head.

for a reference, the tree before this commit was tagged
as yamt-pagecache-tag8.

this commit was splitted into small chunks to avoid
a limitation of cvs.  ("Protocol error: too many arguments")

sync with head

Remove struct simplelock forward declaration.

resync with head

sync with head

sync with (a bit old) head

Only expose the bulk of sys/proc.h and sys/lwp.h if _KERNEL or _KMEMUSER
is defined.
i386 and amd64 build ok.

sys/proc.h refers sizeof(struct pcb), so include <machine/pcb.h>.

sync with head

fork1: fix use-after-free problems.  Addresses PR/46128 from Andrew Doran.
Note: PL_PPWAIT should be fully replaced and modificaiton of l_pflag by
other LWP is undesirable, but this is enough for netbsd-6.

sync with head

sync to -current.

Remove COMPAT_SA / KERN_SA.  Welcome to 6.99.3!
Approved by core@.

merge to -current.

Add a posix_spawn syscall, as discussed on tech-kern.
Based on the summer of code project by Charles Zhang, heavily reworked
later by me - all bugs are likely mine.
Ok: core, releng.

Apply patch, requested by jmcneill in ticket #1668:
	sys/arch/amd64/amd64/syscall.c			patch
	sys/arch/i386/i386/syscall.c			patch
	sys/arch/i386/i386/trap.c			patch
	sys/kern/kern_sig.c				patch
	sys/kern/kern_sleepq.c				patch
	sys/kern/kern_subr.c				patch
	sys/kern/sys_process.c				patch
	sys/secmodel/bsd44/secmodel_bsd44_suser.c	patch
	sys/sys/proc.h					patch
	sys/sys/ptrace.h				patch

arch/i386/i386/machdep.c, arch/amd64/amd64/machdep.c (from
arch/x86/x86/machdep.c) by christos:
Remove code that was used to avoid register spills. setcontext(2) can change
the registers, so re-fetching will produce the wrong result for trace_exit().
arch/i386/i386/trap.c by reinoud:
Fix the illegal instruction return address. It was using the value of the
cpu's %cr2 register but thats not valid:

CR2 Contains a value called Page Fault Linear Address (PFLA). When a page
fault occurs, the address the program attempted to access is stored in the CR2
register.

And this is thus NOT the illegal instruction address!
kern/kern_sig.c by christos:
PR kern/45327: Jared McNeill: ptrace: siginfo doesn't work with traced processes
When saving the signal in p->p_xstat, clear it from the pending mask, but
don't remove it from the siginfo queue, so that next time the debugger
delivers it, the original information is found.
When posting a signal from the debugger l->l_sigpendset is not set, so we
use the process pending signal and add it back to the process pending set.
Split sigget into sigget() and siggetinfo(). When a signal comes from the
debugger (l->l_sigpendset == NULL), using siggetinfo() try to fetch the
siginfo information from l->l_sigpend and then from p->p_sigpend if it
was not found. This allows us to pass siginfo information for traps from
the debugger.
don't delete signal from the debugger.
kern/kern_sleepq.c by christos:
PR kern/40594: Antti Kantee: Don't call issignal() here to determine what errno
to set for the interrupted syscall, because issignal() will consume the signal
and it will not be delivered to the process afterwards. Instead call
sigispending() (which now returns the first pending signal) and does not
consume the signal.
We need to process SA_STOP signals immediately, and not deliver them to
the process. Instead of re-structuring the code to do that, call issignal()
like before in that case. (tail -F /file^Zfg should not get interrupted).
kern/kern_subr.c by jmcneill, christos:
PR kern/45312: ptrace: PT_SETREGS can't alter system calls

Add a new PT_SYSCALLEMU request that cancels the current syscall, for
use with PT_SYSCALL.
For PT_SYSCALLEMU, no need to stop again on syscall exit.
ifdef unused variable with -UPTRACE

kern/sys_process.c, sys/proc.h, sys/ptrace.h, secmodel/bsd44/secmodel_bsd44_suser.c by jmcneill, christos:
PR kern/43681: PT_SYSCALL appears to be broken

sys_ptrace: For PT_CONTINUE/PT_SYSCALL/PT_DETACH, modify the p_trace_enabled
flag of the target process, not the calling process.
Process the signal now, otherwise calling issignal() and ignoring
the return will lose the signal if it came from the debugger
(issignal() clears p->p_xstat)
PR kern/45312: ptrace: PT_SETREGS can't alter system calls

Add a new PT_SYSCALLEMU request that cancels the current syscall, for
use with PT_SYSCALL.
PR kern/45330: ptrace: signals can alter syscall return values

process_stoptrace: defer signal processing to userret, ok christos@

Remove obsolete ltsleep(9) and wakeup_one(9).

Revert MAP_NOSYSCALLS patch.

Add a MAP_NOSYSCALLS flag to mmap. This flag prohibits executing of system
calls from the mapped region. This can be used for emulation perposed or for
extra security in the case of generated code.

Its implemented by adding mapping-attributes to each uvm_map_entry. These can
then be queried when needed.

Currently the MAP_NOSYSCALLS is only implemented for x86 but other
architectures are easy to adapt; see the sys/arch/x86/x86/syscall.c patch.
Port maintainers are encouraged to add them for their processor ports too.
When this feature is not yet implemented for an architecture the
MAP_NOSYSCALLS is simply ignored with virtually no cpu cost..

add proc_compare prototype.

Add support for PTRACE_FORK.
- add a field in struct proc to save the forker/forkee pid, and a flag.
- add 3 new ptrace calls: PT_GET_PROCESS_STATE, PT_GET_EVENT_MASK,
  PT_SET_EVENT_MASK
Add a PT_STRINGS constant so that we don't hard-code the list of ptrace
subcalls in other programs (kdump).

PR# kern/45312: ptrace: PT_SETREGS can't alter system calls

Add a new PT_SYSCALLEMU request that cancels the current syscall, for
use with PT_SYSCALL.

Forward-declare struct vmspace to reduce dependencies on uvm/uvm_extern.h.

Sync with HEAD.

sync with head

Update few comments.

- Remove FORK_SHARELIMIT and PL_SHAREMOD, simplify lim_privatise().
- Use kmem(9) for struct plimit::pl_corename.

G/C M_EMULDATA

sync with head

Replace malloc with kmem, and remove M_SUBPROC.

expose the KSTACK_LOWEST_ADDR and KSTACK_SIZE to _KMEMUSER as well,
like the x86 versions do.  for crash(8).

Nuke all threads belonging to a process calling exec before allowing
the exec handshake to return.

In addition to being The Right Thing To Do, fixes some nasty
conditions for CLOEXEC fd's (or at least does so in theory, I
couldn't create any problems although I tried).

sync with head

Sync with HEAD

Refactor ps_strings access. Based on PK_32, write either the normal
version or the 32bit compat layout in execve1. Introduce a new function
copyin_psstrings for reading it back from userland and converting it to
the native layout. Refactor procfs to share most of the code with the
kern.proc_args sysctl handler.

This material is based upon work partially supported by
The NetBSD Foundation under a contract with Joerg Sonnenberger.

Sync with HEAD

Move sysctl routines from init_sysctl.c to kern_descrip.c (for
descriptors) and kern_proc.c (for processes).  This makes them
usable in a rump kernel, in case somebody was wondering.

Retire struct user, remove sys/user.h inclusions.  Note sys/user.h header
as obsolete.  Remove USER_TO_UAREA/UAREA_TO_USER macros.

Various #include fixes and review by matt@.

Sync with HEAD.

sync with head.

many changes for COMPAT_LINUX:
 - update the linux syscall table for each platform.
 - support new-style (NPTL) linux pthreads on all platforms.
   clone() with CLONE_THREAD uses 1 process with many LWPs
   instead of separate processes.
 - move the contents of sys__lwp_setprivate() into a new
   lwp_setprivate() and use that everywhere.
 - update linux_release[] and linux32_release[] to "2.6.18".
 - adjust placement of emul fork/exec/exit hooks as needed
   and adjust other emul code to match.
 - convert all struct emul definitions to use named initializers.
 - change the pid allocator to allow multiple pids to refer to the same proc.
 - remove a few fields from struct proc that are no longer needed.
 - disable the non-functional "vdso" code in linux32/amd64,
   glibc works fine without it.
 - fix a race in the futex code where we could miss a wakeup after
   a requeue operation.
 - redo futex locking to be a little more efficient.

sync with head

Remove pfind() and pgfind(), fix locking in various broken uses of these.
Rename real routines to proc_find() and pgrp_find(), remove PFIND_* flags
and have consistent behaviour.  Provide proc_find_raw() for special cases.
Fix memory leak in sysctl_proc_corename().

COMPAT_LINUX: rework ptrace() locking, minimise differences between
different versions per-arch.

Note: while this change adds some formal cosmetics for COMPAT_DARWIN and
COMPAT_IRIX - locking there is utterly broken (for ages).

Fixes PR/43176.

Sync with HEAD.

sync with head

comment

Add the DTrace hooks to the kernel (KDTRACE_HOOKS config option).
DTrace adds a pointer to the lwp and proc structures which it uses to
manage its state.  These are opaque from the kernel perspective to keep
the kernel free of CDDL code. The state arenas are kmem_alloced and freed
as proccesses and threads are created and destoyed.

Also add a check for trap06 (privileged/illegal instruction) so that
DTrace can check for D scripts that may have triggered the trap so it
can clean up after them and resume normal operation.

Ok with core@.

Change u_long to vaddr_t/vsize_t in exec code where appropriate (mostly
involves setregs and vmcmds).  Should result in no code differences.

do_sys_wait(): fix previous by checking for ru != NULL.  Noticed by
Onno van der Linden.  Also, remove redundant arguments (seems that
was_zombie was not used since rev 1.177 ?).

Avoid #ifndef __NO_CPU_LWP_FREE, only ia64 is missing cpu_lwp_free
routines and it can/should provide stubs.

Move rlimit policy back to the subsystem.

For this we needed proc_uidmatch() exposed, which makes a lot of sense,
so put it back in sys_process.c for use in other places as well.

Sync with HEAD.

sync with head

add comments on KSTACK_LOWEST_ADDR/KSTACK_SIZE.

sync with head

update a comment.

Sync with HEAD.

Commit is split, to avoid a "too many arguments" protocol error.

sync with head.

Sync with HEAD.

- Rearrange pg_delete() and pg_remove() (renamed pg_free), thus
  proc_enterpgrp() with proc_leavepgrp() to free process group and/or
  session without proc_lock held.
- Rename SESSHOLD() and SESSRELE() to  to proc_sesshold() and
  proc_sessrele().  The later releases proc_lock now.

Quick OK by <ad>.

- Remove a bunch of unused declarations in proc.h header.
- Move yield() and suspendsched() to sched.h, where they should belong.

- Manage pid_table with kmem(9).
- Remove M_PROC and unused M_SESSION.

Avoid few #ifdef KSTACK_CHECK_MAGIC.

Make inferior() function static, rename to p_inferior(), return bool.

Sync with HEAD.

Sync with HEAD.

Update haad-dm branch to haad-dm-base2.

Make the emulations, exec formats, coredump, NFS, and the NFS server
into modules. By and large this commit:

- shuffles header files and ifdefs
- splits code out where necessary to be modular
- adds module glue for each of the components
- adds/replaces hooks for things that can be installed at runtime

We may want to patch emul::e_sysent[] so drop the const.

Sync with HEAD.

Merge wrstuden-revivesa into HEAD.

Sync with HEAD.

Fix merge conflicts.

Sync w/ -current. 34 merge conflicts to follow.

Sync with head.

sync with head.

- PPWAIT is need only be locked by proc_lock, so move it to proc::p_lflag.
- Remove a few needless lock acquires from exec/fork/exit.
- Sprinkle branch hints.

No functional change.

Sync with HEAD.

Also fix build.

Make sure the PAX flags are copied/zeroed correctly.

sync with head

Don't use proc specificdata. Speeds up mmap() and others.

Most contention on proc_lock is from getppid(), so cache the parent's PID.

Sync with HEAD.

Add back p_timerpend.

sync with head.

sync with head.

Initial checkin of re-adding SA. Everything except kern_sa.c
compiles in GENERIC for i386. This is still a work-in-progress, but
this checkin covers most of the mechanical work (changing signalling
to be able to accomidate SA's process-wide signalling and re-adding
includes of sys/sa.h and savar.h). Subsequent changes will be much
more interesting.

Also, kern_sa.c has received partial cleanup. There's still more
to do, though.

Move override of curlwp into lwp.h.

Remove clause 3 and 4 from TNF licenses

semexit: do nothing if the process has not used semaphores.

Merge proc::p_mutex and proc::p_smutex into a single adaptive mutex, since
we no longer need to guard against access from hardware interrupt handlers.

Additionally, if cloning a process with CLONE_SIGHAND, arrange to have the
child process share the parent's lock so that signal state may be kept in
sync. Partially addresses PR kern/37437.

Network protocol interrupts can now block on locks, so merge the globals
proclist_mutex and proclist_lock into a single adaptive mutex (proc_lock).
Implications:

- Inspecting process state requires thread context, so signals can no longer
  be sent from a hardware interrupt handler. Signal activity must be
  deferred to a soft interrupt or kthread.

- As the proc state locking is simplified, it's now safe to take exit()
  and wait() out from under kernel_lock.

- The system spends less time at IPL_SCHED, and there is less lock activity.

Sync with HEAD.

sync with head.

sync with HEAD

sync with head.

- simplify ASSERT_SLEEPABLE.
- move it from proc.h to systm.h.
- add some more checks.
- make it a little more lkm friendly.

sync with head.

Update field markings that describe which locks protect what.

Sync with HEAD.

sync with head

sync with HEAD

Sync with HEAD

Start detangling lock.h from intr.h. This is likely to cause short term
breakage, but the mess of dependencies has been regularly breaking the
build recently anyhow.

Sync with HEAD

Merge vmlocking2 to head.

Remove systrace. Ok core@.

Sync with HEAD.

- Push kernel_lock back into exit, wait and sysctl system calls, mainly
  for visibility.
- Serialize calls to brk() from within the same process.
- Mark more syscalls MPSAFE.

Add PaX ASLR (Address Space Layout Randomization) [from elad and myself]

For regular (non PIE) executables randomization is enabled for:
    1. The data segment
    2. The stack

For PIE executables(*) randomization is enabled for:
    1. The program itself
    2. All shared libraries
    3. The data segment
    4. The stack

(*) To generate a PIE executable:
    - compile everything with -fPIC
    - link with -shared-libgcc -Wl,-pie

This feature is experimental, and might change. To use selectively add
    options PAX_ASLR=0
in your kernel.

Currently we are using 12 bits for the stack, program, and data segment and
16 or 24 bits for mmap, depending on __LP64__.

Sync with head.

Merge more changes from vmlocking2, mainly:

- Locking improvements.
- Use pool_cache for more items.

Convert many of the uses of __attribute__ to equivalent
__packed, __unused and __dead macros from cdefs.h

use binuptime for l_stime/l_rtime.

- Use pool_cache for a few more items and make those caches static.
- Mark another 10 syscalls MPSAFE including execve(). A small bit of
  work is required to fix a couple of issues (tty, kqueue).

Sync with HEAD.

Sync with HEAD.

Sync with head.

sync with head

Use atomics to maintain nprocs.

Sync with HEAD.

sync with head.

Sync with HEAD.

Sync with HEAD

Add _lwp_ctl() system call: provides a bidirectional, per-LWP communication
area between processes and the kernel.

Sync with HEAD.

sync with -HEAD

Merge from vmlocking:

- pool_cache changes.
- Debugger/procfs locking fixes.
- Other minor changes.

sync with HEAD

Sync with HEAD.

Merge scheduler changes from the vmlocking branch. All discussed on
tech-kern:

- Invert priority space so that zero is the lowest priority. Rearrange
  number and type of priority levels into bands. Add new bands like
  'kernel real time'.
- Ignore the priority level passed to tsleep. Compute priority for
  sleep dynamically.
- For SCHED_4BSD, make priority adjustment per-LWP, not per-process.

Sync with HEAD.

- Fix interactivity problems under high load. Beacuse soft interrupts
  are being stacked on top of regular LWPs, more often than not aston()
  was being called on a soft interrupt thread instead of a user thread,
  meaning that preemption was not happening on EOI.

- Don't use bool in a couple of data structures. Sub-word writes are not
  always atomic and may clobber other fields in the containing word.

- For SCHED_4BSD, make p_estcpu per thread (l_estcpu). Rework how the
  dynamic priority level is calculated - it's much better behaved now.

- Kill the l_usrpri/l_priority split now that priorities are no longer
  directly assigned by tsleep(). There are three fields describing LWP
  priority:

        l_priority: Dynamic priority calculated by the scheduler.
                This does not change for kernel/realtime threads,
                and always stays within the correct band. Eg for
                timeshared LWPs it never moves out of the user
                priority range. This is basically what l_usrpri
                was before.

        l_inheritedprio: Lent to the LWP due to priority inheritance
                (turnstiles).

        l_kpriority: A boolean value set true the first time an LWP
                sleeps within the kernel. This indicates that the LWP
                should get a priority boost as compensation for blocking.
                lwp_eprio() now does the equivalent of sched_kpri() if
                the flag is set. The flag is cleared in userret().

- Keep track of scheduling class (OTHER, FIFO, RR) in struct lwp, and use
  this to make decisions in a few places where we previously tested for a
  kernel thread.

- Partially fix itimers and usr/sys/intr time accounting in the presence
  of software interrupts.

- Use kthread_create() to create idle LWPs. Move priority definitions
  from the various modules into sys/param.h.

- newlwp -> lwp_create

Use one byte of p_pad1[] for p_trace_enabled where xxx_syscall_intern()
can save the result of trace_is_enabled() so that it can be efficiently
determined on every system call without having 2 separate syscall functions.
The death of syscall_fancy() looms.

Sync with HEAD.

sync with head.

Sync with HEAD.

Follow the merge of pmap.c on i386 and amd64 and move
pmap_init_tmp_pgtbl into arch/x86/x86/pmap.c. Modify the ACPI wakeup
code to restore CR4 before jumping back into kernel space as the large
page option might cover that.

- Simplify debugger/procfs reference counting of processes. Use a per-proc
  rwlock: rw_tryenter(RW_READER) to gain a reference, and rw_enter(RW_WRITER)
  by the process itself to drain out reference holders before major changes
  like exiting.
- Fix numerous bugs and locking issues in procfs.
- Mark procfs MPSAFE.

Make ras_lookup() lockless.

sync with head.

Merge from vmlocking: fix a deadlock with (threaded) soft interrupts and
process exit.

Sync with head.

sync with head.

Sync with HEAD.

Change the way p->p_limit (and hence p->p_rlimit) is locked.
Should fix PR/36939 and make the rlimit code MP safe.
Posted for comment to tech-kern (non received!)

The p_limit field (for a process) is only be changed once (on the first
  write), and a reference to the old structure is kept (for code paths
  that have cached the pointer).
Only p->p_limit is now locked by p->p_mutex, and since the referenced memory
  will not go away, is only needed if the pointer is to be changed.
The contents of 'struct plimit' are all locked by pl_mutex, except that the
  code doesn't bother to acquire it for reads (which are basically atomic).
Add FORK_SHARELIMIT that causes fork1() to share the limits between parent
  and child, use it for the IRIX_PR_SULIMIT.
Fix borked test for both IRIX_PR_SUMASK and IRIX_PR_SDIR being set.

Sync with HEAD.

Implementation of POSIX message queues.

Reviewed by: <ad>, <tech-kern>

sync with head.

Add curlwp_set() to set curlwp.  (This is for that architectures which have
a special CPU register which could be used to store curlwp (armv6, ppc)).

Sync with HEAD.

proc_free: release proclist_lock earlier as suggested by Andrew Doran.
calling lwp_free with the lock held leads a deadlock.

    1. CPU1: do_sys_wait -> lwp_free busy-waits for an LWP exiting on CPU2,
     holding proclist_lock.

    2. CPU2: the exiting LWP is interrupted by softclock.

    3. CPU2: softclock -> sched_pstats tries to acquire proclist_lock.
     it also busy-waits because the owning LWP is running.

Sync with HEAD.

Sync with HEAD.

- Fix a bug with _lwp_park() where if the computed wakeup time was under
  1 microsecond into the future, the thread could enter an untimed sleep.
- Change the signature of _lwp_park() to accept an lwpid_t and second
  hint pointer, but do so in a way that remains compatible with older
  pthread libraries. This can be used to wake another thread before the
  calling thread goes asleep, saving at least one syscall + involuntary
  context switch. This turns out to be a fairly large win on the condvar
  benchmarks that I have tried.
- Mark some more syscalls MP safe.

Sync with head.

Merge some of the less invasive changes from the vmlocking branch:

- kthread, callout, devsw API changes
- select()/poll() improvements
- miscellaneous MT safety improvements

Adapt to callout API change.

Sync with head.

Sync with head.

Split sys__lwp_park() so that the compat/netbsd32 code can copyin and convert
its timeout then call the standard function.

merge yamt-idlelwp branch.  asked by core@.  some ports still needs work.

from doc/BRANCHES:

	idle lwp, and some changes depending on it.

	1. separate context switching and thread scheduling.
	   (cf. gmcgarry_ctxsw)
	2. implement idle lwp.
	3. clean up related MD/MI interfaces.
	4. make scheduler(s) modular.

sync with head.

mark lwp_exit() and exit1() __noreturn__.

Add the child 'rusage' of an exiting process to its own 'rusage' exactly
once, and prior to passing it to the caller of sys_wait4() and at the same
time as adding it to the parent.
Commands like:
time sh -c 'i=0; while [ $i -lt 1000 ]; do i=$(expr $i + 1); done'
now give same output.

Split sys_wait4() so that compat code can fiddle with the returned 'status'
and 'rusage' without having to copy data to/from stackgap buffers.
The old split (find_stopped_child) could be removed.
amd64 seems to run netbsd32, linux and linux32 emulations. sparc64 compiles.

sync with head.

Remove proc->p_ru and the 'rusage' pool.
I think it existed to cache the numbers in kernel memory of a zombie when
proc->p_stats was part of the 'u' area - so got freed earlier and wouldn't
(easily) be accessible from a separate process.  However since both the
p_ru and p_stats fields are freed at the same time it is no longer needed.
Ride the recent 4.99.19 version change.

Import of POSIX Asynchronous I/O.
Seems to be quite stable. Some work still left to do.

Please note, that syscalls are not yet MP-safe, because
of the file and vnode subsystems.

Reviewed by: <tech-kern>, <ad>

Some changes mainly for top/ps:

- Add an optional name field to struct lwp.
- Count the total number of context switches + involuntary,
  not voluntary + involuntary.
- Mark the idle threads as LSIDL when not running, otherwise
  they show up funny in a top(1) that shows threads.
- Make pctcpu and cpticks per-LWP attributes.
- Add to kinfo_lwp: cpticks, pctcpu, pid, name.

Allow cpu_lwp_free2 to be defined away

Apply patch (requested by chs in ticket #554):
	sys/kern/kern_exit.c	patch
	sys/kern/kern_lwp.c	patch
	sys/kern/kern_proc.c	patch
	sys/sys/proc.h		patch
Add a new SDYING process state. In exit1() release structures before curlwp is
NULL. It should fix the problem described in PR 34892.

curlwp is never NULL now.

Sync with head.

Sync with HEAD.

Put back mtsleep() temporarily. Converting everything over to condvars
at once will take too much time..

Checkpoint:

- Addition of scheduler-specific pointers in the struct proc, lwp and
  schedstate_percpu.
- Addition of sched_lwp_fork(), sched_lwp_exit() and sched_slept() hooks.
- mi_switch() now has only one argument.
- sched_nextlwp(void) becomes sched_switch(struct lwp *) and does an
  enqueueing of LWP.
- Addition of general kern.sched sysctl node.
- Remove twice called uvmexp.swtch++, other cleanups.

Discussed on tech-kern@

- Make the proclist_lock a mutex. The write:read ratio is unfavourable,
  and mutexes are cheaper use than RW locks.
- LOCK_ASSERT -> KASSERT in some places.
- Hold proclist_lock/kernel_lock longer in a couple of places.

Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

- sync with head.
- move sched_changepri back to kern_synch.c as it doesn't know PPQ anymore.

typedef pri_t and use it instead of int and u_char.

sync with head.

- introduce sys/cpu.h which has cpu_idle and cpu_need_resched.
- use it where appropriate.
- while i'm here, remove several unnecessary #include.

Pick up some additional files that were missed before due to conflicts
with newlock2 merge:

Replace the Mach-derived boolean_t type with the C99 bool type.  A
future commit will replace use of TRUE and FALSE with true and false.

General Common Scheduler Framework (CSF) patch import. Huge thanks for
Daniel Sieger <dsieger at TechFak.Uni-Bielefeld de> for this work.

Short abstract: Split the dispatcher from the scheduler in order to
make the scheduler more modular. Introduce initial API for other
schedulers' implementations.

Discussed in tech-kern@
OK: yamt@, ad@

Note: further work will go soon.

Introduce a new member to struct emul, e_startlwp, to be used by
sys__lwp_create.  It allows using the said syscall under COMPAT_NETBSD32.

The libpthread regression tests now pass on amd64 and sparc64.

The pre-kauth 'struct ucread' and 'struct pcred' are now only used in the
(depracted some time ago) 'struct kinfo_proc' returned by sysctl.
Move the definitions to sys/syctl.h and rename in order to ensure all the
users are located.

Change the process/lwp flags seen by userland via sysctl back to the
P_*/L_* naming convention, and rename the in-kernel flags to avoid
conflict. (P_ -> PK_, L_ -> LW_ ). Add back the (now unused) LSDEAD
constant.

Restores source compatibility with pre-newlock2 tools like ps or top.

Reviewed by Andrew Doran.

- separate context switching and thread scheduling.
- introduce idle lwp.
- change some related MD/MI interfaces and implement i386 version.

proc_free() was returning a NULL rusage pointer to wait() when a traced
process was reparented. Change proc_free() to copy the rusage to a buffer
on the stack if required, so it can be passed both to the debugger and
to the real parent process.

Fixes kern/35582 (kernel panics with gdb).

Restore proc::p_userret in a limited way for Linux compat. XXX

remove a forward decl of sa_emul.

Merge newlock2 to head.

Fix typo in comment.

- When clearing signals dequeue siginfo first and free later, once
  outside the lock permiter.
- Push kernel_lock back in a a couple of places.
- Adjust limcopy() to be MP safe (this needs redoing).
- Fix a couple of bugs noticed along the way.
- Catch up with condvar changes.

Remove support for SA. Ok core@.

- Remove the last use of mtsleep()
- sched_pause() -> kpause()

- Job control shouldn't affect LWPs sleeping interruptably.
- Remove another use of mtsleep().

Sync with head.

sync with head.

Checkpoint work in progress.

sync with head.

Make PaX MPROTECT use specificdata(9), freeing up two P_* flags.
While here, make more generic for upcoming PaX features.

Sync with head.

Checkpoint work in progress.

- Redo LWP locking slightly and fix some races.
- Fix some locking botches.
- Make signal mask / stack per-proc for SA processes.
- Add _lwp_kill().

Remove chooselwp - it doesn't exist.

sync with head

Checkpoint work in progress on locking and per-LWP signals. Very much a
a work in progress and there is still a lot to do.

Don't free specificdata in lwp_exit2(); it's not safe to block there.
Instead, free an LWP's specificdata from lwp_exit() (if it is not the
last LWP) or exit1() (if it is the last LWP).  For consistency, free the
proc's specificdata from exit1() as well.  Add lwp_finispecific() and
proc_finispecific() functions to make this more convenient.

add {proc,lwp}_initspecific and use them to init proc0 and lwp0.

Add specificdata support to procs and lwps, each providing their own
wrappers around the speicificdata subroutines.  Also:
- Call the new lwpinit() function from main() after calling procinit().
- Move some pool initialization out of kern_proc.c and into files that
  are directly related to the pools in question (kern_lwp.c and kern_ras.c).
- Convert uipc_sem.c to proc_{get,set}specific(), and eliminate the p_ksems
  member from struct proc.

Back out previous (p_flag2).

In 30 minutes from now Jason Thorpe will come up with an implementation
of a proplib dictionary in struct proc, so adding an int doesn't really
make any sense.

Until we figure out the Perfect Way of adding flags to processes, add
a p_flag2. No objections on tech-kern@.

Input from simonb@, thanks!

- Allocate and free turnstiles where needed.
- Split proclist_mutex and alllwp_mutex out of the proclist_lock,
  and use in interrupt context.
- Fix an MP race in enterpgrp()/setsid().
- Acquire proclist_lock and p_crmutex in some obvious places.

sync with head

sync with head

Single-thread updates to the process credential.

add ASSERT_SLEEPABLE() macro to assert we can sleep.

- Hold a reference to the process credentials in each struct lwp.
- Update the reference on syscall and user trap if p_cred has changed.
- Collect accounting flags in the LWP, and collate on LWP exit.

sync with head.

Sync with head.

Merge 2006-05-24 NetBSD-current into the "peter-altq" branch.

sync with head.

Introduce PaX MPROTECT -- mprotect(2) restrictions used to strengthen
W^X mappings.

Disabled by default.

First proposed in:

	http://mail-index.netbsd.org/tech-security/2005/12/18/0000.html

More information in:

	http://pax.grsecurity.net/docs/mprotect.txt

Read relevant parts of options(4) and sysctl(3) before using!

Lots of thanks to the PaX author and Matt Thomas.

integrate kauth.

sync with head

cleanup user.h.
- remove several #include which are not directly related to
  this header anymore.  tweak *.c accordingly.
- update comments.
- move some !_KERNEL #include to proc.h because it's more appropriate
  place these days.
- whitespace.

Sync with head.

Avoid using <sys/kauth.h>

sync with head.

Pull up following revision(s) (requested by pavel in ticket #1244):
	sys/sys/lwp.h: revision 1.36 via patch
	sys/sys/proc.h: revision 1.219 via patch
	sys/kern/init_sysctl.c: revision 1.65 via patch
PR/32809: Pavel Cahyna: Conflicting flags in l_flag and p_flag are causing
ps(1) to print incorrect information. Annotate the flags in the header files
to make sure that flags are not being re-used and move flags so that there
are no conflicts.

sync with head.

PR/32809: Pavel Cahyna: Conflicting flags in l_flag and p_flag are causing
ps(1) to print incorrect information. Annotate the flags in the header files
to make sure that flags are not being re-used and move flags so that there
are no conflicts.

Merge 2006-03-31 NetBSD-current into the "peter-altq" branch.

Get rid of some stuff we no longer need here:

  - suser()
  - groupmember()
  - pcred/ucred memory pools
  - crget(), crfree(), crcmp(), crcopy(), crdup(), crcvt()

Rework the _lwp* and sa_* families of syscalls so some details can be
handled differently depending on the emulation.  This paves the way for
COMPAT_NETBSD32 support of our pthread system.

Merge 2006-03-28 NetBSD-current into the "peter-altq" branch.

kill the last use of vm_fault_t, from Havard Eidnes

Adapt to kernel authorization changes.

file proc.h was added on branch elad-kernelauth on 2006-03-08 01:01:13 +0000

Clean up fallout proc_is_traced_p() change:
- proc_is_traced_p() -> trace_is_enabled(), to match trace_enter() and
  trace_exit().
- trace_is_enabled() becomes a real function.
- Remove unnecessary include files from various files that used to care
  about KTRACE and SYSTRACE, but do no more.

Add a proc_is_traced_p() macro and use it, instead of copying the same code
in many places. Idea from thorpej.

file proc.h was added on branch yamt-pdpolicy on 2006-04-01 12:07:51 +0000

implement PT_SYSCALL

merge yamt-uio_vmspace branch.

- use vmspace rather than proc or lwp where appropriate.
  the latter is more natural to specify an address space.
  (and less likely to be abused for random purposes.)
- fix a swdmover race.

sync with head.

Change "inline" back to "__inline" in .h files -- C99 is still too
new, and some apps compile things in C89 mode. C89 keywords stay.

As per core@.

define vmspace_kernel() rather than using proc0 directly.

uio_segflg/uio_lwp -> uio_vmspace.

Remove leading __ from __(const|inline|signed|volatile) -- it is obsolete.

fix a long-standing scheduler problem that p_estcpu is doubled
for each fork-wait cycles.

- updatepri: factor out the code to decay estcpu so that it can be used
  by scheduler_wait_hook.
- scheduler_fork_hook: record how much estcpu is inherited from
  the parent process.
- scheduler_wait_hook: don't add back inherited estcpu to the parent.

merge ktrace-lwp.

Sync with head.

sync with head.

Note that M_SUBPROC is only used on sparc/sparc64.

Sync with HEAD. Here we go again...

sync with head.

make scheduler work better when a system has many runnable processes
by making p_estcpu fixpt_t.  PR/31542.

1. schedcpu() decreases p_estcpu of all processes
   every seconds, by at least 1 regardless of load average.
2. schedclock() increases p_estcpu of curproc by 1,
   at about 16 hz.

in the consequence, if a system has >16 processes
with runnable lwps, their p_estcpu are not likely increased.

by making p_estcpu fixpt_t, we can decay it more slowly
when loadavg is high.  (ie. solve #1.)

i left kinfo_proc2::p_estcpu (ie. ps -O cpu) scaled because i have
no idea about its absolute value's usage other than debugging,
for which raw values are more valuable.

Pull up following revision(s) (requested by yamt in ticket #842):
	sys/sys/proc.h: revision 1.206
	sys/kern/kern_lwp.c: revision 1.30
	sys/kern/kern_exit.c: revision 1.151
protect p_nrlwps by sched_lock.  no objection on tech-kern@.  PR/29652.

Pull up following revision(s) (requested by fvdl in ticket #798):
	sys/compat/sunos/sunos_exec.c: revision 1.47
	sys/compat/pecoff/pecoff_emul.c: revision 1.11
	sys/arch/sparc64/sparc64/netbsd32_machdep.c: revision 1.45
	sys/arch/amd64/amd64/netbsd32_machdep.c: revision 1.12
	sys/sys/proc.h: revision 1.198
	sys/compat/mach/mach_exec.c: revision 1.56
	sys/compat/freebsd/freebsd_exec.c: revision 1.27
	sys/arch/sparc64/include/vmparam.h: revision 1.27
	sys/kern/kern_resource.c: revision 1.91
	sys/compat/netbsd32/netbsd32_netbsd.c: revision 1.88
	sys/compat/osf1/osf1_exec.c: revision 1.39
	sys/compat/svr4_32/svr4_32_resource.c: revision 1.5
	sys/compat/ultrix/ultrix_misc.c: revision 1.99
	sys/compat/svr4_32/svr4_32_exec.h: revision 1.9
	sys/kern/exec_elf32.c: revision 1.103
	sys/compat/aoutm68k/aoutm68k_exec.c: revision 1.19
	sys/compat/sunos32/sunos32_exec.c: revision 1.20
	sys/compat/hpux/hpux_exec.c: revision 1.46
	sys/compat/darwin/darwin_exec.c: revision 1.40
	sys/kern/sysv_shm.c: revision 1.83
	sys/uvm/uvm_extern.h: revision 1.99
	sys/uvm/uvm_mmap.c: revision 1.89
	sys/kern/kern_exec.c: revision 1.195
	sys/compat/netbsd32/netbsd32.h: revision 1.31
	sys/arch/sparc64/sparc64/svr4_32_machdep.c: revision 1.20
	sys/compat/svr4/svr4_exec.c: revision 1.56
	sys/compat/irix/irix_exec.c: revision 1.41
	sys/compat/ibcs2/ibcs2_exec.c: revision 1.63
	sys/compat/svr4_32/svr4_32_exec.c: revision 1.16
	sys/arch/amd64/include/vmparam.h: revision 1.8
	sys/compat/linux/common/linux_exec.c: revision 1.73
Fix some things regarding COMPAT_NETBSD32 and limits/VM addresses.
* For sparc64 and amd64, define *SIZ32 VM constants.
* Add a new function pointer to struct emul, pointing at a function
  that will return the default VM map address. The default function
  is uvm_map_defaultaddr, which just uses the VM_DEFAULT_ADDRESS
  macro. This gives emulations control over the default map address,
  and allows things to be mapped at the right address (in 32bit range)
  for COMPAT_NETBSD32.
* Add code to adjust the data and stack limits when a COMPAT_NETBSD32
  or COMPAT_SVR4_32 binary is executed.
* Don't use USRSTACK in kern_resource.c, use p_vmspace->vm_minsaddr
  instead (emulations might have set it differently)
* Since this changes struct emul, bump kernel version to 3.99.2
Tested on amd64, compile-tested on sparc64.

protect p_nrlwps by sched_lock.  no objection on tech-kern@.  PR/29652.

Correct typo in comments found by Roland Illig.

Move proc0 initialization from main() in init_main.c and proc0_insert() in
kern_proc.c into a new function proc0_init() in kern_proc.c, as suggested
on tech-kern@ days ago.