Don't explicitly zero p_intr_nesting_level and p_aioinfo in fork.

Use mtx_intr_enable() on sched_lock to ensure child processes always start
with interrupts enabled rather than calling the no-longer MI function
enable_intr(). This is bogus anyways and in theory sh

Use mtx_intr_enable() on sched_lock to ensure child processes always start
with interrupts enabled rather than calling the no-longer MI function
enable_intr(). This is bogus anyways and in theory shouldn't even be
needed.

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Fix mtx_legal2block. The only time that it is bad to block on a mutex is
if we hold a spin mutex, since we can trivially get into deadlocks if we
start switching out of processes that hold spinlocks

Fix mtx_legal2block. The only time that it is bad to block on a mutex is
if we hold a spin mutex, since we can trivially get into deadlocks if we
start switching out of processes that hold spinlocks. Checking to see if
interrupts were disabled was a sort of cheap way of doing this since most
of the time interrupts were only disabled when holding a spin lock. At
least on the i386. To fix this properly, use a per-process counter
p_spinlocks that counts the number of spin locks currently held, and
instead of checking to see if interrupts are disabled in the witness code,
check to see if we hold any spin locks. Since child processes always
start up with the sched lock magically held in fork_exit(), we initialize
p_spinlocks to 1 for child processes. Note that proc0 doesn't go through
fork_exit(), so it starts with no spin locks held.

Consulting from: cp

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- Don't hold the proc lock across VREF and the fd* functions to avoid lock
order reversals.
- Add some preliminary locking in the !RF_PROC case.
- Protect p_estcpu with sched_lock.

- Lock the forklist with an sx lock.
- Add proc locking to fork1(). Always lock the child procoess (new
process) first when both processes need to be locked at the same
time.
- Remove unneeded s

- Lock the forklist with an sx lock.
- Add proc locking to fork1(). Always lock the child procoess (new
process) first when both processes need to be locked at the same
time.
- Remove unneeded spl()'s as the data they protected is now locked.
- Ensure that the proctree is exclusively locked and the new process is
locked when setting up the parent process pointer.
- Lock the check for P_KTHREAD in p_flag in fork_exit().

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Sigh. Try to get priorities sorted out. Don't bother trying to
update native priority, it is diffcult to get right and likely
to end up horribly wrong. Use an honestly wrong fixed value
that seems

Sigh. Try to get priorities sorted out. Don't bother trying to
update native priority, it is diffcult to get right and likely
to end up horribly wrong. Use an honestly wrong fixed value
that seems to work; PUSER for user threads, and the interrupt
priority for ithreads. Set it once when the process is created
and forget about it.

Suggested by: bde
Pointy hat: me

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Initialize native priority to PRI_MAX. It was usually 0 which made a
process's priority go through the roof when it released a (contested)
mutex. Only set the native priority in mtx_lock if hasn't

Initialize native priority to PRI_MAX. It was usually 0 which made a
process's priority go through the roof when it released a (contested)
mutex. Only set the native priority in mtx_lock if hasn't already
been set.

Reviewed by: jhb

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Quiet a warning with a uintptr_t cast.

Noticed by: bde

o Move per-process jail pointer (p->pr_prison) to inside of the subject
credential structure, ucred (cr->cr_prison).
o Allow jail inheritence to be a function of credential inheritence.
o Abstract

o Move per-process jail pointer (p->pr_prison) to inside of the subject
credential structure, ucred (cr->cr_prison).
o Allow jail inheritence to be a function of credential inheritence.
o Abstract prison structure reference counting behind pr_hold() and
pr_free(), invoked by the similarly named credential reference
management functions, removing this code from per-ABI fork/exit code.
o Modify various jail() functions to use struct ucred arguments instead
of struct proc arguments.
o Introduce jailed() function to determine if a credential is jailed,
rather than directly checking pointers all over the place.
o Convert PRISON_CHECK() macro to prison_check() function.
o Move jail() function prototypes to jail.h.
o Emulate the P_JAILED flag in fill_kinfo_proc() and no longer set the
flag in the process flags field itself.
o Eliminate that "const" qualifier from suser/p_can/etc to reflect
mutex use.

Notes:

o Some further cleanup of the linux/jail code is still required.
o It's now possible to consider resolving some of the process vs
credential based permission checking confusion in the socket code.
o Mutex protection of struct prison is still not present, and is
required to protect the reference count plus some fields in the
structure.

Reviewed by: freebsd-arch
Obtained from: TrustedBSD Project

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- Don't call clear_resched() in userret(), instead, clear the resched flag
in mi_switch() just before calling cpu_switch() so that the first switch
after a resched request will satisfy the reques

- Don't call clear_resched() in userret(), instead, clear the resched flag
in mi_switch() just before calling cpu_switch() so that the first switch
after a resched request will satisfy the request.
- While I'm at it, move a few things into mi_switch() and out of
cpu_switch(), specifically set the p_oncpu and p_lastcpu members of
proc in mi_switch(), and handle the sched_lock state change across a
context switch in mi_switch().
- Since cpu_switch() no longer handles the sched_lock state change, we
have to setup an initial state for sched_lock in fork_exit() before we
release it.

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o Export the nextpid variable via SYSCTL as kern.lastpid, decreasing by
one the number of variables needed for top and other setgid kmem
utilities that could only be accessed via /dev/kmem previo

o Export the nextpid variable via SYSCTL as kern.lastpid, decreasing by
one the number of variables needed for top and other setgid kmem
utilities that could only be accessed via /dev/kmem previously.

Submitted by: Thomas Moestl <tmoestl@gmx.net>
Reviewed by: freebsd-audit

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Change and clean the mutex lock interface.

mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

simil

Change and clean the mutex lock interface.

mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)

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Fix fork_exit() to take a pointer to a function that returns void as its
first argument rather than a function that returns a void *.

Noticed by: jake

- Change fork_exit() to take a pointer to a trapframe as its 3rd argument
instead of a trapframe directly. (Requested by bde.)
- Convert the alpha switch_trampoline to call fork_exit() and use the

- Change fork_exit() to take a pointer to a trapframe as its 3rd argument
instead of a trapframe directly. (Requested by bde.)
- Convert the alpha switch_trampoline to call fork_exit() and use the MI
fork_return() instead of child_return().
- Axe child_return().

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- Catch up to proc flag changes.
- Add new fork_exit() and fork_return() MI C functions.

Add mibs to hold the number of forks since boot. New mibs are:

vm.stats.vm.v_forks
vm.stats.vm.v_vforks
vm.stats.vm.v_rforks
vm.stats.vm.v_kthreads
vm.stats.vm.v_forkpages
vm.stats.vm.v_vfork

Add mibs to hold the number of forks since boot. New mibs are:

vm.stats.vm.v_forks
vm.stats.vm.v_vforks
vm.stats.vm.v_rforks
vm.stats.vm.v_kthreads
vm.stats.vm.v_forkpages
vm.stats.vm.v_vforkpages
vm.stats.vm.v_rforkpages
vm.stats.vm.v_kthreadpages

Submitted by: Paul Herman <pherman@frenchfries.net>
Reviewed by: alfred

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Make intr_nesting_level per-process, rather than per-cpu. Setup
interrupt threads to run with it always >= 1, so that malloc can
detect M_WAITOK from "interrupt" context. This is also necessary
in

Make intr_nesting_level per-process, rather than per-cpu. Setup
interrupt threads to run with it always >= 1, so that malloc can
detect M_WAITOK from "interrupt" context. This is also necessary
in order to context switch from sched_ithd() directly.

Reviewed By: peter

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Protect proc.p_pptr and proc.p_children/p_sibling with the
proctree_lock.

linprocfs not locked pending response from informal maintainer.

Reviewed by: jhb, -smp@

- Change the allproc_lock to use a macro, ALLPROC_LOCK(how), instead
of explicit calls to lockmgr. Also provides macros for the flags
pased to specify shared, exclusive or release which map to t

- Change the allproc_lock to use a macro, ALLPROC_LOCK(how), instead
of explicit calls to lockmgr. Also provides macros for the flags
pased to specify shared, exclusive or release which map to the
lockmgr flags. This is so that the use of lockmgr can be easily
replaced with optimized reader-writer locks.
- Add some locking that I missed the first time.

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Whitespace. Fix indentation, align comments.

- Add a mutex to the proc structure p_mtx that will be used to lock accesses
to each individual proc.
- Initialize the lock during fork1(), and destroy it in wait1().

Remove thr_sleep and thr_wakeup. Remove fields p_nthread and p_wakeup
from struct proc, which are now unused (p_nthread already was).
Remove process flag P_KTHREADP which was untested and only set
i

Remove thr_sleep and thr_wakeup. Remove fields p_nthread and p_wakeup
from struct proc, which are now unused (p_nthread already was).
Remove process flag P_KTHREADP which was untested and only set
in vfs_aio.c (it should use kthread_create). Move the yield
system call to kern_synch.c as kern_threads.c has been removed
completely.

moral support from: alfred, jhb

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Use an mp-safe callout for endtsleep.

Use callout_reset instead of timeout(9). Most callouts are statically
allocated, 2 have been added to struct proc for setitimer and sleep.

Reviewed by: jhb, jlemon

Protect the following with a lockmgr lock:

allproc
zombproc
pidhashtbl
proc.p_list
proc.p_hash
nextpid

Reviewed by: jhb
Obtained from: BSD/OS and netbsd