Arrange to update cached LWP credentials in userret() rather than during
syscall/trap entry, eliminating a test+branch on every syscall/trap.

This wasn't possible in the 3.99.x timeframe when l->l_cred came about
because there wasn't a reliable/timely way to force an ONPROC LWP running on
a remote CPU into the kernel (which is just about the only new thing in
this scheme).

Support save/restore of AST levels in the PCB for context switching.

Code written by ragge@ , tested by oster@.

mi_userret(): take care of calling preempt(), set spc_curpriority directly,
and remove MD code that does the same.

branches: 1.135.10;
Update copyright notice for Ludd (remove clause 3 & 4).

KNF. Remove extra spaces. No functional change.

Handle EINVAL in the fault path and send SIGBUS on mmap'd access past EOF

branches: 1.132.6;
Mark a diagnostic-only variable

branches: 1.131.2; 1.131.4;
Supress print fatal traps if the process is being debugged of it the signal
will be caught by a signal handler.

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

On a kernel segfault, print the registers from the trapframe.

branches: 1.128.2; 1.128.6;
Cleanup trapframe handling. Instead of keeping a trapframe pointer in the
pcb, put in the mdlwp instead. We had a dummy field so it didn't grow in
size. This also follows the practice that mips and powerpc follow that a
pointer to the user trapframe is in l->l_md.md_utf. Make trapframe members
start with tf_

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.

branches: 1.126.2; 1.126.4;
Move counting of faults, traps, intrs, soft[intr]s, syscalls, and nswtch
from uvmexp to per-cpu cpu_data and move them to 64bits. Remove unneeded
includes of <uvm/uvm_extern.h> and/or <uvm/uvm.h>.

Implement CAS using a RAS for non-MP VAX systems. This technique uses the
atomicity of indirect addressing for correctness. It also uses the knowledge
of dereferencing an address outside the page table length will cause a PTELEN
trap. [Tested on netbsd-5]

Remove lwp_uc_pool, replace it with kmem(9), plus add some consistency.
As discussed, a while ago, with ad@.

fix copy{in,out}{,str}() to return the error returned by uvm_fault().
fixes PR 41813.

branches: 1.122.2; 1.122.4;
One semicolon only (;; -> ;)

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

- Use lwp_getpcb() on VAX, clean from struct user usage.
- Include sys/user.h in MD proc.h .

The ci_want_resched check and preempt() call had been removed from
userret() which resulted in no process preemption (and probably
contributed to the signal trap loop locking up the machine that was
recently fixed). Put the check and preempt() call in the AST trap
handler to restore process preemption.

On the vax, the trapsignal() call will change frame->sp to point to a
callg on the user's stack that calls the user's signal handler, so do
the skip_opcode() before calling trapsignal(). A floating point
overflow no longer causes a signal loop. This should stop the native
compile hangs trying to compile src/lib/libm/complex/catan.ln.

- add siginfo translation for all arithmetic faults and traps.
- skip the current instruction for all faults, to avoid infinite loops on
SIGFPE (from OpenBSD)
Info from: http://bitsavers.vt100.net/pdf/dec/vax/archSpec/EK-VAXAR-RM-001_Arch_May82.pdf

branches: 1.116.2; 1.116.4; 1.116.8;
Merge wrstuden-revivesa into HEAD.

For ARITH traps, set the siginfo code appropriately for FP related traps.

branches: 1.114.4;
Remove unneeded playing about with kernel_lock.

branches: 1.113.2; 1.113.4; 1.113.6;
Rototill the vax code. Switch to devicet/PRIV_ALLOC. Cleanup vax autoconf
code. Move to prototype definitions. staticfy, constify, avoid casting.
Use device_* accessors.

expand some printfs. Don't bother checking for curlwp == NULL; it can't
happen anymore. Convert some variables to bool.

branches: 1.111.2; 1.111.6;
Make NetBSD/vax work again. Add support for __HAVE_FAST_SOFTINTS.
Add a few small optimizations.

Merge the ppcoea-renovation branch to HEAD.

This branch was a major cleanup and rototill of many of the various OEA
cpu based PPC ports that focused on sharing as much code as possible
between the various ports to eliminate near-identical copies of files in
every tree. Additionally there is a new PIC system that unifies the
interface to interrupt code for all different OEA ppc arches. The work
for this branch was done by a variety of people, too long to list here.

TODO:
bebox still needs work to complete the transition to -renovation.
ofppc still needs a bunch of work, which I will be looking at.
ev64260 still needs to be renovated
amigappc was not attempted.

NOTES:
pmppc was removed as an arch, and moved to a evbppc target.

branches: 1.109.2;
Changes to make ktrace LKM friendly and reduce ifdef KTRACE. Proposed
on tech-kern.

branches: 1.108.2; 1.108.10; 1.108.14; 1.108.18;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.107.2;
More MD changes to get vax compiling.

Merge newlock2 to head.

branches: 1.105.4;
Use the LWP cached credentials where sane.

- 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.

include kauth.h for kauth_cred_geteuid.

integrate kauth.

branches: 1.101.2;
adapt to uvm_fault() interface cleanup: kill the useless 3rd argument

welcome to syscall_intern.

branches: 1.99.2;
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.

branches: 1.98.4; 1.98.6; 1.98.8;
Remove leading __ from __(const|inline|signed|volatile) -- it is obsolete.

merge ktrace-lwp.

branches: 1.96.2;
PR/29607: Christian Biere systrace doesn't handle interrupted syscalls properly
Instead of jumping to the default "bad" case, jump to the error handling
switch, so that we can deal with ERESTART/EJUSTRETURN properly.

Make this compile again.

use uvm_grow() to update stack segment size on stack page fault instead
of MD code

add kernel part of concurrency support for SA on MP systems
- move per VP data into struct sadata_vp referenced from l->l_savp
* VP id
* lock on VP data
* LWP on VP
* recently blocked LWP on VP
* queue of LWPs woken which ran on this VP before sleep
* faultaddr
* LWP cache for upcalls
* upcall queue
- add current concurrency and requested concurrency variables
- make process exit run LWP on all VPs
- make signal delivery consider all VPs
- make timer events consider all VPs
- add sa_newsavp to allocate new sadata_vp structure
- add sa_increaseconcurrency to prepare new VP
- make sys_sa_setconcurrency request new VP or wakeup idle VP
- make sa_yield lower current concurrency
- set sa_cpu = VP id in upcalls
- maintain cached LWPs per VP

plug obvious kernel lock leaks
(untested)

kernel part of no-syscall upcall stack return: libpthread registers
an offset between ss_sp and struct sa_stackinfo_t (located in struct
__pthread_st) when calling sa_register. The kernel increments the
sast_gen counter in struct sastack when an upcall stack is used.
libpthread increments the sasi_stackgen counter in struct
sa_stackinfo_t when an upcall stack is freed. The kernel compares the
two counters to decide if a stack is free or in use.

- add struct sa_stackinfo_t with sasi_stackgen to count stack use in
userland
- add sast_gen to struct sastack to count stack use in kernel
- add SA_FLAG_STACKINFO to enable the stackinfo_offset argument in the
sa_register syscall
- add sa_stackinfo_offset to struct sadata for offset between ss_sp
and struct sa_stackinfo_t
- add ssize_t stackinfo_offset argument to sa_register, initialize
struct sadata's sa_stackinfo_offset from it if SA_FLAG_STACKINFO is
set
- add sa_getstack, sa_getstack0, sa_stackused and sa_setstackfree
functions to find/use/free upcall stacks and use these where
appropriate
- don't record stack for upcall in sa_upcall0
- pass sau to sa_switchcall instead of l2 (l2 = curlwp in sa_switchcall)
- add sa_vp_blocker to struct sadata to pass recently blocked lwp to
sa_switchcall
- delay finding a stack for blocked upcalls to sa_switchcall
- add sa_stacknext to struct sadata pointing to next most likely free
upcall stack; also g/c sa_stackslist in struct sadata and sast_list
in struct sastack
- add L_SA_WOKEN flag: LWP is on sa_woken queue
- add L_SA_RECYCLE flag: LWP should be recycled in sa_setwoken
- replace l_upcallstack with L_SA_WOKEN/L_SA_RECYCLE/L_SA_BLOCKING
flags
- g/c now unused sast_blocker in struct sastack
- make sa_switchcall, sa_upcall0 and sa_upcall_getstate static in
kern_sa.c
- call sa_upcall_userret only once in userret
- split sa_makeupcalls out of sa_upcall_userret and use to process
the sa_upcalls queue
- on process exit: mark LWPs sleeping in saunblock interruptible; also
there are no LWPs sleeping on l->l_upcallstack anymore; also clear
sa_wokenq_head to prevent unblocked upcalls

additional changes:
- cleanup timerupcall sa_vp == curlwp check
- add check in sa_yield if we didn't block on our way here and we
wouldn't any longer be the LWP on the VP
- invalidate sa_vp_ofaultaddr after resolving pagefault

Initialize 'p' to NULL, to work around that the compiler otherwise
can't know that 'p' is initialized before it's being used.

Reviewed by ragge.

Avoid sneaking past signal delivery in sa_upcall_userret():
generate unblocked upcalls in sa_unblock_userret(), before signal
delivery/p_userret handling in userret().

Also defer getting state for preempted upcalls because on some ports
preemption can happen between sa_unblock_userret() and sa_upcall_userret().

Don't pass the (unused) return value args to the
trace_enter()/systrace_enter() functions.

Do not try to fetch the current proc if curlwp == NULL. This caused
DDB to fail if no process were running.

* Shuffle some data structures so, and add a flags word to ksiginfo_t.
Right now the only flag is used to indicate if a ksiginfo_t is a
result of a trap. Add a predicate macro to test for this flag.
* Add initialization macros for ksiginfo_t's.
* Add accssor macro for ksi_trap. Expands to 0 if the ksiginfo_t was
not the result of a trap. This matches the sigcontext trapcode semantics.
* In kpsendsig(), use KSI_TRAP_P() to select the lwp that gets the signal.
Inspired by Matthias Drochner's fix to kpsendsig(), but correctly handles
the case of non-trap-generated signals that have a > 0 si_code.

This patch fixes a signal delivery problem with threaded programs noted by
Matthias Drochner on tech-kern.

As discussed on tech-kern. Reviewed and OK's by Christos.

trap.c: Set ksi.ksi_trap to frame->trap.
sig_machdep.c: Use ksi->ksi_addr in compat code to supply the
'code' argument to the old signal routines.

Set ksi_addr to frame->code.

Add SA_SIGINFO support for VAX.

add MD part of SA/pthread pagefault handling on vax

__KERNEL_RCSID()

branches: 1.80.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

Add machdep sysctl support. Support booted_device, consdev, and
printfataltraps.

Fix some SA lossage.

Merge the nathanw_sa branch.

Pass the system call table to trace_enter() and ktrsys() so that it is
possible to use alternate system call tables. This is usefull for
displaying correctly the arguments in Mach binaries traces.

If NULL is given, then the regular systam call table for the process is used.

branches: 1.74.2;
Fix compilation errors introduced by recent trace_enter()/ktrsyscall() changes.

Provided by FUKAUMI Naoki <naoki at fukaumi dot org> in kern/19070.

Record stack growth, done inline to avoid another function call on
every user page fault.

XXX Should make uvm_grow() an inline.

finish previous; it would be nice if people were to use the lovely
cross compiling mechanisms we have when making sweeping changes...

MD systrace gluons.

branches: 1.70.2; 1.70.4;
Only print console messages about SIGSEGV and SIGILL if the
kernel was built with DEBUG.

kill remaining PS_STRINGS instances.

Major update of the vax pmap:
- Reinstall the "dynamic page table length" that was removed some
years ago.
- Limit the user page table submap to max 5% of available memory.
- Free the page table space when a process is swapped out.
- If the UPT submap runs out of space, throw away pmap mappings
using the same algorithm as for swapping processes.

As a result of this, 4MB machines are useable again and it's even possible
to compile a kernel for 2MB machines (but it will be slow... :-)

Still to do:
- Multiprocessor fixes.
- More profiling.

allow writing to write-only mappings. fixes PR 3493.

branches: 1.66.2; 1.66.8;
Panic if page fault on interrupt stack, per request from Jason Thorpe.

Move some locks closer to the important point.

A bunch of fixes:
- Make generic console routines not relying on running on master cpu.
- Add routine to start console transmitter (after IPI).
- Use real IPIs instead of the "console doorbell".
- Add routines cpu_send_ipi()/cpu_handle_ipi().

replace vm_map{,_entry}_t with struct vm_map{,_entry} *.

Add a bunch of locking code for MP systems.

eliminate the KERN_* error codes in favor of the traditional E* codes.
the mapping is:

KERN_SUCCESS 0
KERN_INVALID_ADDRESS EFAULT
KERN_PROTECTION_FAILURE EACCES
KERN_NO_SPACE ENOMEM
KERN_INVALID_ARGUMENT EINVAL
KERN_FAILURE various, mostly turn into KASSERTs
KERN_RESOURCE_SHORTAGE ENOMEM
KERN_NOT_RECEIVER <unused>
KERN_NO_ACCESS <unused>
KERN_PAGES_LOCKED <unused>

branches: 1.60.2;
de-__P. cleanup the whitespace a bit. add a very small optimization.

Rename arithflt to trap. Change trap label to Xtrap. This is due to that
arithflt is really the trap handler so call it that.

Make this compile again.

Changes so that the kernel can be compiled under __ELF__.

remove include of <vm/vm.h>. <vm/vm.h> -> <uvm/uvm_extern.h>

remove/move more mach vm header files:

<vm/pglist.h> -> <uvm/uvm_pglist.h>
<vm/vm_inherit.h> -> <uvm/uvm_inherit.h>
<vm/vm_kern.h> -> into <uvm/uvm_extern.h>
<vm/vm_object.h> -> nothing
<vm/vm_pager.h> -> into <uvm/uvm_pager.h>

also includes a bunch of <vm/vm_page.h> include removals (due to redudancy
with <vm/vm.h>), and a scattering of other similar headers.

Use the cpu_info struct to store cpu-specific data in the same way in
both uniprocessor and multiprocessor environments. Use the otherwise
unused internal CPU register SSP to store the cpu_info pointer.
The macros curcpu(), curproc, cpu_number() and need_resched() are now the
same in both uniprocessor and multiprocessor environments.

Rewrite cpu_fork(), it now looks like and works as other ports' cpu_fork()
(calling child_return() etc...). Have fun, Jason!

branches: 1.52.2;
Reduce use of curproc in several places:

- Change ktrace interface to pass in the current process, rather than
p->p_tracep, since the various ktr* function need curproc anyway.

- Add curproc as a parameter to mi_switch() since all callers had it
handy anyway.

- Add a second proc argument for inferior() since callers all had
curproc handy.

Also, miscellaneous cleanups in ktrace:

- ktrace now always uses file-based, rather than vnode-based I/O
(simplifies, increases type safety); eliminate KTRFLAG_FD & KTRFAC_FD.
Do non-blocking I/O, and yield a finite number of times when receiving
EWOULDBLOCK before giving up.

- move code duplicated between sys_fktrace and sys_ktrace into ktrace_common.

- simplify interface to ktrwrite()

First sweep at scheduler state cleanup. Collect MI scheduler
state into global and per-CPU scheduler state:

- Global state: sched_qs (run queues), sched_whichqs (bitmap
of non-empty run queues), sched_slpque (sleep queues).
NOTE: These may collectively move into a struct schedstate
at some point in the future.

- Per-CPU state, struct schedstate_percpu: spc_runtime
(time process on this CPU started running), spc_flags
(replaces struct proc's p_schedflags), and
spc_curpriority (usrpri of processes on this CPU).

- Every platform must now supply a struct cpu_info and
a curcpu() macro. Simplify existing cpu_info declarations
where appropriate.

- All references to per-CPU scheduler state now made through
curcpu(). NOTE: this will likely be adjusted in the future
after further changes to struct proc are made.

Tested on i386 and Alpha. Changes are mostly mechanical, but apologies
in advance if it doesn't compile on a particular platform.

Move common return-to-userland goo into userret(), like other ports.

Use preempt(), not an open-coded equivalent (which won't be
equivalent for long).

First cut of multiprocessor support for vax. Still much to do before
other CPUs than the master can spin up.

branches: 1.47.2;
Initial VAX ELF32 support (mostly untested). It's checked primarily for
testing and archival for now. I don't expect anyone to work with it
since the binutils and gas changes are still pending. But you got to
crawl before you walk.

Rewrite the page table entry routines. Don't take a pte invalid fault for
missing pte's, instead map in pte entries in pmap_enter(). The user ptes
is no more handled by the VM system. All this made swapping start working
on VAX again.
Still to do:
- Keep refcount per pte page, so that those pages get free'd when the
process is swapped out. Right now they are only free'd when the pmap
is destroyed.

Many thanks to Chuck Silvers for all help finding the deadlock problems.

Add some small checks to avoid unwanted panic types.

branches: 1.44.2; 1.44.4; 1.44.6;
completely remove Mach VM support. all that is left is the all the
header files as UVM still uses (most of) these.

if uvm_fault() fails with KERN_RESOURCE_SHORTAGE, send a SIGKILL
and print a message about it. this will be used to recover from
out-of-swap conditions.

Change vsbus to take a locator for all devices.
Figure out interrupt vector/mask on vsbus by forcing all devices to
generate interrupts in the match routine, like on unibus.

Allocate (almost) all interrupt vectors dynamically. Simplifies much
work when adding support for new machines and devices.

Giant change: NBPG now set to 4k and CLSIZE == 1 for vax. This change
made a whole bunch of annoying bugs disappear; mostly depending on
bad use of NBPG in non-MD code. The VAX port was the only port that
used this historical "feature".

The CL* macros should probably go away totally, there is no reason
at all to keep them.

Fix (small) segv bug. Recognize in-kernel trace and breakpoint traps.

defopt DDB.

defopt KTRACE

Wall fixes.

Wall cleaning + a little better fault checking.

Support for UVM on VAXen.

Adjust for the fact that the page {0,1} base and length registers are now
stored in the pmap structure.

Optimized copy/fetch/store routines; rewritten in assembler.

Major rewriting, optimization and simplifying of the pmap code:

- Map in all physical memory first in system space. This reduces
pmap_copy_page() and pmap_zero_page to 3 resp. 2 instructions.
- Have fized position user page tables. Makes the pv_table smaller
and all reverse references faster (and simpler).
- Remove the wiring code. Nobody doesn't even know what a DR32 is anymore.
- Simulate page reference bit by setting page invalid, as suggested by
Rich Draves in a paper for 1991 Mach Usenix Symposium.

This reduced the time spent in the pmap module to between 70-75% of
the previous; and made process startup _much_ faster.

Only check for process switch if we are coming in from userspace.
Make ERESTART work for syscalls >63.
While we're here; clean up a little bit.

Fix execve(2) and *setregs() interfaces so emulations can set registers in a
more correct way. (See tech-kern.)

branches: 1.28.2;
Handle XFC instruction faults.

Remove __VM_PMAP_HACK.

Bug fixes to page fault handling system. Many thanks to Johnny Billquist
for hunting down this bug(s).

cpu_switch() should be mi_switch(). Pointed out by Johnny Billquist.
(bqt@update.uu.se)

Fix an inconsistency that came in with Lite: setrq() was renamed to
setrunqueue(), but remrq() was never renamed. Rename remrq() to
remrunqueue().

backout previous kprintf change

printf -> kprintf, sprintf -> ksprintf

Fixed all (proto)type errors. Fixes PR 2377.

Added prototypes to everything. Made all files compile with -Wall.

Do not have debugging enabled by default.

Add support for ktracing syscalls.

#ifdef a call to kdb_trap() on DDB.

Fix #includes.

Be able to handle debugger traps from kernel.

struct ivec_dsp for interrupt vector allocation added.

Null pointer were referenced if signal occurred before first
syscall. Didn't hurt on 4.3 Reno binaries.

rudimentary DDB support.

Enabled auto reboot. Fixed bug in conf.c. Started use of rpb.
Detecting kernel stack overflow. Removed local mapping of
sigtramp code. Frob kernel stack pages in cpu_swapin().
Cleaned up some code and changed to KNF.

Changed conf.c to new style. Took away double saving of regs in traps.
Changed boot() to use vfs_shutdown(). Updated setregs.

- added sunos_machdep.c for sun3, atari, amiga and mac68k.
- changed machdep.c and trap.c to use struct emul.
- remove ep_setup references.
- added struct emul to all emulations.

Speed-up of pmap and trap.
Fixes due to uVAX support.

Support for uVAXII, new tmscp driver added.

Zillions of bugfixes. Obsolete files taken away. New style config
fixed. Inline assembler commonly used.

Lots of fixes and updates.

new RCS ID format.

Lots of bug fixes; clock and mem files new.

branches: 1.2.2;
Lots of bug fixes. Generic console support added. Major changes in machdep.c.
pmap.c now supports user process mapping. Page faults handles correctly.

Initial VAX port merging.

Support save/restore of AST levels in the PCB for context switching.

Code written by ragge@ , tested by oster@.

mi_userret(): take care of calling preempt(), set spc_curpriority directly,
and remove MD code that does the same.

branches: 1.135.10;
Update copyright notice for Ludd (remove clause 3 & 4).

KNF. Remove extra spaces. No functional change.

Handle EINVAL in the fault path and send SIGBUS on mmap'd access past EOF

branches: 1.132.6;
Mark a diagnostic-only variable

branches: 1.131.2; 1.131.4;
Supress print fatal traps if the process is being debugged of it the signal
will be caught by a signal handler.

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

On a kernel segfault, print the registers from the trapframe.

branches: 1.128.2; 1.128.6;
Cleanup trapframe handling. Instead of keeping a trapframe pointer in the
pcb, put in the mdlwp instead. We had a dummy field so it didn't grow in
size. This also follows the practice that mips and powerpc follow that a
pointer to the user trapframe is in l->l_md.md_utf. Make trapframe members
start with tf_

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.

branches: 1.126.2; 1.126.4;
Move counting of faults, traps, intrs, soft[intr]s, syscalls, and nswtch
from uvmexp to per-cpu cpu_data and move them to 64bits. Remove unneeded
includes of <uvm/uvm_extern.h> and/or <uvm/uvm.h>.

Implement CAS using a RAS for non-MP VAX systems. This technique uses the
atomicity of indirect addressing for correctness. It also uses the knowledge
of dereferencing an address outside the page table length will cause a PTELEN
trap. [Tested on netbsd-5]

Remove lwp_uc_pool, replace it with kmem(9), plus add some consistency.
As discussed, a while ago, with ad@.

fix copy{in,out}{,str}() to return the error returned by uvm_fault().
fixes PR 41813.

branches: 1.122.2; 1.122.4;
One semicolon only (;; -> ;)

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

- Use lwp_getpcb() on VAX, clean from struct user usage.
- Include sys/user.h in MD proc.h .

The ci_want_resched check and preempt() call had been removed from
userret() which resulted in no process preemption (and probably
contributed to the signal trap loop locking up the machine that was
recently fixed). Put the check and preempt() call in the AST trap
handler to restore process preemption.

On the vax, the trapsignal() call will change frame->sp to point to a
callg on the user's stack that calls the user's signal handler, so do
the skip_opcode() before calling trapsignal(). A floating point
overflow no longer causes a signal loop. This should stop the native
compile hangs trying to compile src/lib/libm/complex/catan.ln.

- add siginfo translation for all arithmetic faults and traps.
- skip the current instruction for all faults, to avoid infinite loops on
SIGFPE (from OpenBSD)
Info from: http://bitsavers.vt100.net/pdf/dec/vax/archSpec/EK-VAXAR-RM-001_Arch_May82.pdf

branches: 1.116.2; 1.116.4; 1.116.8;
Merge wrstuden-revivesa into HEAD.

For ARITH traps, set the siginfo code appropriately for FP related traps.

branches: 1.114.4;
Remove unneeded playing about with kernel_lock.

branches: 1.113.2; 1.113.4; 1.113.6;
Rototill the vax code. Switch to devicet/PRIV_ALLOC. Cleanup vax autoconf
code. Move to prototype definitions. staticfy, constify, avoid casting.
Use device_* accessors.

expand some printfs. Don't bother checking for curlwp == NULL; it can't
happen anymore. Convert some variables to bool.

branches: 1.111.2; 1.111.6;
Make NetBSD/vax work again. Add support for __HAVE_FAST_SOFTINTS.
Add a few small optimizations.

Merge the ppcoea-renovation branch to HEAD.

This branch was a major cleanup and rototill of many of the various OEA
cpu based PPC ports that focused on sharing as much code as possible
between the various ports to eliminate near-identical copies of files in
every tree. Additionally there is a new PIC system that unifies the
interface to interrupt code for all different OEA ppc arches. The work
for this branch was done by a variety of people, too long to list here.

TODO:
bebox still needs work to complete the transition to -renovation.
ofppc still needs a bunch of work, which I will be looking at.
ev64260 still needs to be renovated
amigappc was not attempted.

NOTES:
pmppc was removed as an arch, and moved to a evbppc target.

branches: 1.109.2;
Changes to make ktrace LKM friendly and reduce ifdef KTRACE. Proposed
on tech-kern.

branches: 1.108.2; 1.108.10; 1.108.14; 1.108.18;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.107.2;
More MD changes to get vax compiling.

Merge newlock2 to head.

branches: 1.105.4;
Use the LWP cached credentials where sane.

- 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.

include kauth.h for kauth_cred_geteuid.

integrate kauth.

branches: 1.101.2;
adapt to uvm_fault() interface cleanup: kill the useless 3rd argument

welcome to syscall_intern.

branches: 1.99.2;
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.

branches: 1.98.4; 1.98.6; 1.98.8;
Remove leading __ from __(const|inline|signed|volatile) -- it is obsolete.

merge ktrace-lwp.

branches: 1.96.2;
PR/29607: Christian Biere systrace doesn't handle interrupted syscalls properly
Instead of jumping to the default "bad" case, jump to the error handling
switch, so that we can deal with ERESTART/EJUSTRETURN properly.

Make this compile again.

use uvm_grow() to update stack segment size on stack page fault instead
of MD code

add kernel part of concurrency support for SA on MP systems
- move per VP data into struct sadata_vp referenced from l->l_savp
* VP id
* lock on VP data
* LWP on VP
* recently blocked LWP on VP
* queue of LWPs woken which ran on this VP before sleep
* faultaddr
* LWP cache for upcalls
* upcall queue
- add current concurrency and requested concurrency variables
- make process exit run LWP on all VPs
- make signal delivery consider all VPs
- make timer events consider all VPs
- add sa_newsavp to allocate new sadata_vp structure
- add sa_increaseconcurrency to prepare new VP
- make sys_sa_setconcurrency request new VP or wakeup idle VP
- make sa_yield lower current concurrency
- set sa_cpu = VP id in upcalls
- maintain cached LWPs per VP

plug obvious kernel lock leaks
(untested)

kernel part of no-syscall upcall stack return: libpthread registers
an offset between ss_sp and struct sa_stackinfo_t (located in struct
__pthread_st) when calling sa_register. The kernel increments the
sast_gen counter in struct sastack when an upcall stack is used.
libpthread increments the sasi_stackgen counter in struct
sa_stackinfo_t when an upcall stack is freed. The kernel compares the
two counters to decide if a stack is free or in use.

- add struct sa_stackinfo_t with sasi_stackgen to count stack use in
userland
- add sast_gen to struct sastack to count stack use in kernel
- add SA_FLAG_STACKINFO to enable the stackinfo_offset argument in the
sa_register syscall
- add sa_stackinfo_offset to struct sadata for offset between ss_sp
and struct sa_stackinfo_t
- add ssize_t stackinfo_offset argument to sa_register, initialize
struct sadata's sa_stackinfo_offset from it if SA_FLAG_STACKINFO is
set
- add sa_getstack, sa_getstack0, sa_stackused and sa_setstackfree
functions to find/use/free upcall stacks and use these where
appropriate
- don't record stack for upcall in sa_upcall0
- pass sau to sa_switchcall instead of l2 (l2 = curlwp in sa_switchcall)
- add sa_vp_blocker to struct sadata to pass recently blocked lwp to
sa_switchcall
- delay finding a stack for blocked upcalls to sa_switchcall
- add sa_stacknext to struct sadata pointing to next most likely free
upcall stack; also g/c sa_stackslist in struct sadata and sast_list
in struct sastack
- add L_SA_WOKEN flag: LWP is on sa_woken queue
- add L_SA_RECYCLE flag: LWP should be recycled in sa_setwoken
- replace l_upcallstack with L_SA_WOKEN/L_SA_RECYCLE/L_SA_BLOCKING
flags
- g/c now unused sast_blocker in struct sastack
- make sa_switchcall, sa_upcall0 and sa_upcall_getstate static in
kern_sa.c
- call sa_upcall_userret only once in userret
- split sa_makeupcalls out of sa_upcall_userret and use to process
the sa_upcalls queue
- on process exit: mark LWPs sleeping in saunblock interruptible; also
there are no LWPs sleeping on l->l_upcallstack anymore; also clear
sa_wokenq_head to prevent unblocked upcalls

additional changes:
- cleanup timerupcall sa_vp == curlwp check
- add check in sa_yield if we didn't block on our way here and we
wouldn't any longer be the LWP on the VP
- invalidate sa_vp_ofaultaddr after resolving pagefault

Initialize 'p' to NULL, to work around that the compiler otherwise
can't know that 'p' is initialized before it's being used.

Reviewed by ragge.

Avoid sneaking past signal delivery in sa_upcall_userret():
generate unblocked upcalls in sa_unblock_userret(), before signal
delivery/p_userret handling in userret().

Also defer getting state for preempted upcalls because on some ports
preemption can happen between sa_unblock_userret() and sa_upcall_userret().

Don't pass the (unused) return value args to the
trace_enter()/systrace_enter() functions.

Do not try to fetch the current proc if curlwp == NULL. This caused
DDB to fail if no process were running.

* Shuffle some data structures so, and add a flags word to ksiginfo_t.
Right now the only flag is used to indicate if a ksiginfo_t is a
result of a trap. Add a predicate macro to test for this flag.
* Add initialization macros for ksiginfo_t's.
* Add accssor macro for ksi_trap. Expands to 0 if the ksiginfo_t was
not the result of a trap. This matches the sigcontext trapcode semantics.
* In kpsendsig(), use KSI_TRAP_P() to select the lwp that gets the signal.
Inspired by Matthias Drochner's fix to kpsendsig(), but correctly handles
the case of non-trap-generated signals that have a > 0 si_code.

This patch fixes a signal delivery problem with threaded programs noted by
Matthias Drochner on tech-kern.

As discussed on tech-kern. Reviewed and OK's by Christos.

trap.c: Set ksi.ksi_trap to frame->trap.
sig_machdep.c: Use ksi->ksi_addr in compat code to supply the
'code' argument to the old signal routines.

Set ksi_addr to frame->code.

Add SA_SIGINFO support for VAX.

add MD part of SA/pthread pagefault handling on vax

__KERNEL_RCSID()

branches: 1.80.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

Add machdep sysctl support. Support booted_device, consdev, and
printfataltraps.

Fix some SA lossage.

Merge the nathanw_sa branch.

Pass the system call table to trace_enter() and ktrsys() so that it is
possible to use alternate system call tables. This is usefull for
displaying correctly the arguments in Mach binaries traces.

If NULL is given, then the regular systam call table for the process is used.

branches: 1.74.2;
Fix compilation errors introduced by recent trace_enter()/ktrsyscall() changes.

Provided by FUKAUMI Naoki <naoki at fukaumi dot org> in kern/19070.

Record stack growth, done inline to avoid another function call on
every user page fault.

XXX Should make uvm_grow() an inline.

finish previous; it would be nice if people were to use the lovely
cross compiling mechanisms we have when making sweeping changes...

MD systrace gluons.

branches: 1.70.2; 1.70.4;
Only print console messages about SIGSEGV and SIGILL if the
kernel was built with DEBUG.

kill remaining PS_STRINGS instances.

Major update of the vax pmap:
- Reinstall the "dynamic page table length" that was removed some
years ago.
- Limit the user page table submap to max 5% of available memory.
- Free the page table space when a process is swapped out.
- If the UPT submap runs out of space, throw away pmap mappings
using the same algorithm as for swapping processes.

As a result of this, 4MB machines are useable again and it's even possible
to compile a kernel for 2MB machines (but it will be slow... :-)

Still to do:
- Multiprocessor fixes.
- More profiling.

allow writing to write-only mappings. fixes PR 3493.

branches: 1.66.2; 1.66.8;
Panic if page fault on interrupt stack, per request from Jason Thorpe.

Move some locks closer to the important point.

A bunch of fixes:
- Make generic console routines not relying on running on master cpu.
- Add routine to start console transmitter (after IPI).
- Use real IPIs instead of the "console doorbell".
- Add routines cpu_send_ipi()/cpu_handle_ipi().

replace vm_map{,_entry}_t with struct vm_map{,_entry} *.

Add a bunch of locking code for MP systems.

eliminate the KERN_* error codes in favor of the traditional E* codes.
the mapping is:

KERN_SUCCESS 0
KERN_INVALID_ADDRESS EFAULT
KERN_PROTECTION_FAILURE EACCES
KERN_NO_SPACE ENOMEM
KERN_INVALID_ARGUMENT EINVAL
KERN_FAILURE various, mostly turn into KASSERTs
KERN_RESOURCE_SHORTAGE ENOMEM
KERN_NOT_RECEIVER <unused>
KERN_NO_ACCESS <unused>
KERN_PAGES_LOCKED <unused>

branches: 1.60.2;
de-__P. cleanup the whitespace a bit. add a very small optimization.

Rename arithflt to trap. Change trap label to Xtrap. This is due to that
arithflt is really the trap handler so call it that.

Make this compile again.

Changes so that the kernel can be compiled under __ELF__.

remove include of <vm/vm.h>. <vm/vm.h> -> <uvm/uvm_extern.h>

remove/move more mach vm header files:

<vm/pglist.h> -> <uvm/uvm_pglist.h>
<vm/vm_inherit.h> -> <uvm/uvm_inherit.h>
<vm/vm_kern.h> -> into <uvm/uvm_extern.h>
<vm/vm_object.h> -> nothing
<vm/vm_pager.h> -> into <uvm/uvm_pager.h>

also includes a bunch of <vm/vm_page.h> include removals (due to redudancy
with <vm/vm.h>), and a scattering of other similar headers.

Use the cpu_info struct to store cpu-specific data in the same way in
both uniprocessor and multiprocessor environments. Use the otherwise
unused internal CPU register SSP to store the cpu_info pointer.
The macros curcpu(), curproc, cpu_number() and need_resched() are now the
same in both uniprocessor and multiprocessor environments.

Rewrite cpu_fork(), it now looks like and works as other ports' cpu_fork()
(calling child_return() etc...). Have fun, Jason!

branches: 1.52.2;
Reduce use of curproc in several places:

- Change ktrace interface to pass in the current process, rather than
p->p_tracep, since the various ktr* function need curproc anyway.

- Add curproc as a parameter to mi_switch() since all callers had it
handy anyway.

- Add a second proc argument for inferior() since callers all had
curproc handy.

Also, miscellaneous cleanups in ktrace:

- ktrace now always uses file-based, rather than vnode-based I/O
(simplifies, increases type safety); eliminate KTRFLAG_FD & KTRFAC_FD.
Do non-blocking I/O, and yield a finite number of times when receiving
EWOULDBLOCK before giving up.

- move code duplicated between sys_fktrace and sys_ktrace into ktrace_common.

- simplify interface to ktrwrite()

First sweep at scheduler state cleanup. Collect MI scheduler
state into global and per-CPU scheduler state:

- Global state: sched_qs (run queues), sched_whichqs (bitmap
of non-empty run queues), sched_slpque (sleep queues).
NOTE: These may collectively move into a struct schedstate
at some point in the future.

- Per-CPU state, struct schedstate_percpu: spc_runtime
(time process on this CPU started running), spc_flags
(replaces struct proc's p_schedflags), and
spc_curpriority (usrpri of processes on this CPU).

- Every platform must now supply a struct cpu_info and
a curcpu() macro. Simplify existing cpu_info declarations
where appropriate.

- All references to per-CPU scheduler state now made through
curcpu(). NOTE: this will likely be adjusted in the future
after further changes to struct proc are made.

Tested on i386 and Alpha. Changes are mostly mechanical, but apologies
in advance if it doesn't compile on a particular platform.

Move common return-to-userland goo into userret(), like other ports.

Use preempt(), not an open-coded equivalent (which won't be
equivalent for long).

First cut of multiprocessor support for vax. Still much to do before
other CPUs than the master can spin up.

branches: 1.47.2;
Initial VAX ELF32 support (mostly untested). It's checked primarily for
testing and archival for now. I don't expect anyone to work with it
since the binutils and gas changes are still pending. But you got to
crawl before you walk.

Rewrite the page table entry routines. Don't take a pte invalid fault for
missing pte's, instead map in pte entries in pmap_enter(). The user ptes
is no more handled by the VM system. All this made swapping start working
on VAX again.
Still to do:
- Keep refcount per pte page, so that those pages get free'd when the
process is swapped out. Right now they are only free'd when the pmap
is destroyed.

Many thanks to Chuck Silvers for all help finding the deadlock problems.

Add some small checks to avoid unwanted panic types.

branches: 1.44.2; 1.44.4; 1.44.6;
completely remove Mach VM support. all that is left is the all the
header files as UVM still uses (most of) these.

if uvm_fault() fails with KERN_RESOURCE_SHORTAGE, send a SIGKILL
and print a message about it. this will be used to recover from
out-of-swap conditions.

Change vsbus to take a locator for all devices.
Figure out interrupt vector/mask on vsbus by forcing all devices to
generate interrupts in the match routine, like on unibus.

Allocate (almost) all interrupt vectors dynamically. Simplifies much
work when adding support for new machines and devices.

Giant change: NBPG now set to 4k and CLSIZE == 1 for vax. This change
made a whole bunch of annoying bugs disappear; mostly depending on
bad use of NBPG in non-MD code. The VAX port was the only port that
used this historical "feature".

The CL* macros should probably go away totally, there is no reason
at all to keep them.

Fix (small) segv bug. Recognize in-kernel trace and breakpoint traps.

defopt DDB.

defopt KTRACE

Wall fixes.

Wall cleaning + a little better fault checking.

Support for UVM on VAXen.

Adjust for the fact that the page {0,1} base and length registers are now
stored in the pmap structure.

Optimized copy/fetch/store routines; rewritten in assembler.

Major rewriting, optimization and simplifying of the pmap code:

- Map in all physical memory first in system space. This reduces
pmap_copy_page() and pmap_zero_page to 3 resp. 2 instructions.
- Have fized position user page tables. Makes the pv_table smaller
and all reverse references faster (and simpler).
- Remove the wiring code. Nobody doesn't even know what a DR32 is anymore.
- Simulate page reference bit by setting page invalid, as suggested by
Rich Draves in a paper for 1991 Mach Usenix Symposium.

This reduced the time spent in the pmap module to between 70-75% of
the previous; and made process startup _much_ faster.

Only check for process switch if we are coming in from userspace.
Make ERESTART work for syscalls >63.
While we're here; clean up a little bit.

Fix execve(2) and *setregs() interfaces so emulations can set registers in a
more correct way. (See tech-kern.)

branches: 1.28.2;
Handle XFC instruction faults.

Remove __VM_PMAP_HACK.

Bug fixes to page fault handling system. Many thanks to Johnny Billquist
for hunting down this bug(s).

cpu_switch() should be mi_switch(). Pointed out by Johnny Billquist.
(bqt@update.uu.se)

Fix an inconsistency that came in with Lite: setrq() was renamed to
setrunqueue(), but remrq() was never renamed. Rename remrq() to
remrunqueue().

backout previous kprintf change

printf -> kprintf, sprintf -> ksprintf

Fixed all (proto)type errors. Fixes PR 2377.

Added prototypes to everything. Made all files compile with -Wall.

Do not have debugging enabled by default.

Add support for ktracing syscalls.

#ifdef a call to kdb_trap() on DDB.

Fix #includes.

Be able to handle debugger traps from kernel.

struct ivec_dsp for interrupt vector allocation added.

Null pointer were referenced if signal occurred before first
syscall. Didn't hurt on 4.3 Reno binaries.

rudimentary DDB support.

Enabled auto reboot. Fixed bug in conf.c. Started use of rpb.
Detecting kernel stack overflow. Removed local mapping of
sigtramp code. Frob kernel stack pages in cpu_swapin().
Cleaned up some code and changed to KNF.

Changed conf.c to new style. Took away double saving of regs in traps.
Changed boot() to use vfs_shutdown(). Updated setregs.

- added sunos_machdep.c for sun3, atari, amiga and mac68k.
- changed machdep.c and trap.c to use struct emul.
- remove ep_setup references.
- added struct emul to all emulations.

Speed-up of pmap and trap.
Fixes due to uVAX support.

Support for uVAXII, new tmscp driver added.

Zillions of bugfixes. Obsolete files taken away. New style config
fixed. Inline assembler commonly used.

Lots of fixes and updates.

new RCS ID format.

Lots of bug fixes; clock and mem files new.

branches: 1.2.2;
Lots of bug fixes. Generic console support added. Major changes in machdep.c.
pmap.c now supports user process mapping. Page faults handles correctly.

Initial VAX port merging.

mi_userret(): take care of calling preempt(), set spc_curpriority directly,
and remove MD code that does the same.

Update copyright notice for Ludd (remove clause 3 & 4).

KNF. Remove extra spaces. No functional change.

Handle EINVAL in the fault path and send SIGBUS on mmap'd access past EOF

branches: 1.132.6;
Mark a diagnostic-only variable

branches: 1.131.2; 1.131.4;
Supress print fatal traps if the process is being debugged of it the signal
will be caught by a signal handler.

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

On a kernel segfault, print the registers from the trapframe.

branches: 1.128.2; 1.128.6;
Cleanup trapframe handling. Instead of keeping a trapframe pointer in the
pcb, put in the mdlwp instead. We had a dummy field so it didn't grow in
size. This also follows the practice that mips and powerpc follow that a
pointer to the user trapframe is in l->l_md.md_utf. Make trapframe members
start with tf_

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.

branches: 1.126.2; 1.126.4;
Move counting of faults, traps, intrs, soft[intr]s, syscalls, and nswtch
from uvmexp to per-cpu cpu_data and move them to 64bits. Remove unneeded
includes of <uvm/uvm_extern.h> and/or <uvm/uvm.h>.

Implement CAS using a RAS for non-MP VAX systems. This technique uses the
atomicity of indirect addressing for correctness. It also uses the knowledge
of dereferencing an address outside the page table length will cause a PTELEN
trap. [Tested on netbsd-5]

Remove lwp_uc_pool, replace it with kmem(9), plus add some consistency.
As discussed, a while ago, with ad@.

fix copy{in,out}{,str}() to return the error returned by uvm_fault().
fixes PR 41813.

branches: 1.122.2; 1.122.4;
One semicolon only (;; -> ;)

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

- Use lwp_getpcb() on VAX, clean from struct user usage.
- Include sys/user.h in MD proc.h .

The ci_want_resched check and preempt() call had been removed from
userret() which resulted in no process preemption (and probably
contributed to the signal trap loop locking up the machine that was
recently fixed). Put the check and preempt() call in the AST trap
handler to restore process preemption.

On the vax, the trapsignal() call will change frame->sp to point to a
callg on the user's stack that calls the user's signal handler, so do
the skip_opcode() before calling trapsignal(). A floating point
overflow no longer causes a signal loop. This should stop the native
compile hangs trying to compile src/lib/libm/complex/catan.ln.

- add siginfo translation for all arithmetic faults and traps.
- skip the current instruction for all faults, to avoid infinite loops on
SIGFPE (from OpenBSD)
Info from: http://bitsavers.vt100.net/pdf/dec/vax/archSpec/EK-VAXAR-RM-001_Arch_May82.pdf

branches: 1.116.2; 1.116.4; 1.116.8;
Merge wrstuden-revivesa into HEAD.

For ARITH traps, set the siginfo code appropriately for FP related traps.

branches: 1.114.4;
Remove unneeded playing about with kernel_lock.

branches: 1.113.2; 1.113.4; 1.113.6;
Rototill the vax code. Switch to devicet/PRIV_ALLOC. Cleanup vax autoconf
code. Move to prototype definitions. staticfy, constify, avoid casting.
Use device_* accessors.

expand some printfs. Don't bother checking for curlwp == NULL; it can't
happen anymore. Convert some variables to bool.

branches: 1.111.2; 1.111.6;
Make NetBSD/vax work again. Add support for __HAVE_FAST_SOFTINTS.
Add a few small optimizations.

Merge the ppcoea-renovation branch to HEAD.

This branch was a major cleanup and rototill of many of the various OEA
cpu based PPC ports that focused on sharing as much code as possible
between the various ports to eliminate near-identical copies of files in
every tree. Additionally there is a new PIC system that unifies the
interface to interrupt code for all different OEA ppc arches. The work
for this branch was done by a variety of people, too long to list here.

TODO:
bebox still needs work to complete the transition to -renovation.
ofppc still needs a bunch of work, which I will be looking at.
ev64260 still needs to be renovated
amigappc was not attempted.

NOTES:
pmppc was removed as an arch, and moved to a evbppc target.

branches: 1.109.2;
Changes to make ktrace LKM friendly and reduce ifdef KTRACE. Proposed
on tech-kern.

branches: 1.108.2; 1.108.10; 1.108.14; 1.108.18;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.107.2;
More MD changes to get vax compiling.

Merge newlock2 to head.

branches: 1.105.4;
Use the LWP cached credentials where sane.

- 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.

include kauth.h for kauth_cred_geteuid.

integrate kauth.

branches: 1.101.2;
adapt to uvm_fault() interface cleanup: kill the useless 3rd argument

welcome to syscall_intern.

branches: 1.99.2;
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.

branches: 1.98.4; 1.98.6; 1.98.8;
Remove leading __ from __(const|inline|signed|volatile) -- it is obsolete.

merge ktrace-lwp.

branches: 1.96.2;
PR/29607: Christian Biere systrace doesn't handle interrupted syscalls properly
Instead of jumping to the default "bad" case, jump to the error handling
switch, so that we can deal with ERESTART/EJUSTRETURN properly.

Make this compile again.

use uvm_grow() to update stack segment size on stack page fault instead
of MD code

add kernel part of concurrency support for SA on MP systems
- move per VP data into struct sadata_vp referenced from l->l_savp
* VP id
* lock on VP data
* LWP on VP
* recently blocked LWP on VP
* queue of LWPs woken which ran on this VP before sleep
* faultaddr
* LWP cache for upcalls
* upcall queue
- add current concurrency and requested concurrency variables
- make process exit run LWP on all VPs
- make signal delivery consider all VPs
- make timer events consider all VPs
- add sa_newsavp to allocate new sadata_vp structure
- add sa_increaseconcurrency to prepare new VP
- make sys_sa_setconcurrency request new VP or wakeup idle VP
- make sa_yield lower current concurrency
- set sa_cpu = VP id in upcalls
- maintain cached LWPs per VP

plug obvious kernel lock leaks
(untested)

kernel part of no-syscall upcall stack return: libpthread registers
an offset between ss_sp and struct sa_stackinfo_t (located in struct
__pthread_st) when calling sa_register. The kernel increments the
sast_gen counter in struct sastack when an upcall stack is used.
libpthread increments the sasi_stackgen counter in struct
sa_stackinfo_t when an upcall stack is freed. The kernel compares the
two counters to decide if a stack is free or in use.

- add struct sa_stackinfo_t with sasi_stackgen to count stack use in
userland
- add sast_gen to struct sastack to count stack use in kernel
- add SA_FLAG_STACKINFO to enable the stackinfo_offset argument in the
sa_register syscall
- add sa_stackinfo_offset to struct sadata for offset between ss_sp
and struct sa_stackinfo_t
- add ssize_t stackinfo_offset argument to sa_register, initialize
struct sadata's sa_stackinfo_offset from it if SA_FLAG_STACKINFO is
set
- add sa_getstack, sa_getstack0, sa_stackused and sa_setstackfree
functions to find/use/free upcall stacks and use these where
appropriate
- don't record stack for upcall in sa_upcall0
- pass sau to sa_switchcall instead of l2 (l2 = curlwp in sa_switchcall)
- add sa_vp_blocker to struct sadata to pass recently blocked lwp to
sa_switchcall
- delay finding a stack for blocked upcalls to sa_switchcall
- add sa_stacknext to struct sadata pointing to next most likely free
upcall stack; also g/c sa_stackslist in struct sadata and sast_list
in struct sastack
- add L_SA_WOKEN flag: LWP is on sa_woken queue
- add L_SA_RECYCLE flag: LWP should be recycled in sa_setwoken
- replace l_upcallstack with L_SA_WOKEN/L_SA_RECYCLE/L_SA_BLOCKING
flags
- g/c now unused sast_blocker in struct sastack
- make sa_switchcall, sa_upcall0 and sa_upcall_getstate static in
kern_sa.c
- call sa_upcall_userret only once in userret
- split sa_makeupcalls out of sa_upcall_userret and use to process
the sa_upcalls queue
- on process exit: mark LWPs sleeping in saunblock interruptible; also
there are no LWPs sleeping on l->l_upcallstack anymore; also clear
sa_wokenq_head to prevent unblocked upcalls

additional changes:
- cleanup timerupcall sa_vp == curlwp check
- add check in sa_yield if we didn't block on our way here and we
wouldn't any longer be the LWP on the VP
- invalidate sa_vp_ofaultaddr after resolving pagefault

Initialize 'p' to NULL, to work around that the compiler otherwise
can't know that 'p' is initialized before it's being used.

Reviewed by ragge.

Avoid sneaking past signal delivery in sa_upcall_userret():
generate unblocked upcalls in sa_unblock_userret(), before signal
delivery/p_userret handling in userret().

Also defer getting state for preempted upcalls because on some ports
preemption can happen between sa_unblock_userret() and sa_upcall_userret().

Don't pass the (unused) return value args to the
trace_enter()/systrace_enter() functions.

Do not try to fetch the current proc if curlwp == NULL. This caused
DDB to fail if no process were running.

* Shuffle some data structures so, and add a flags word to ksiginfo_t.
Right now the only flag is used to indicate if a ksiginfo_t is a
result of a trap. Add a predicate macro to test for this flag.
* Add initialization macros for ksiginfo_t's.
* Add accssor macro for ksi_trap. Expands to 0 if the ksiginfo_t was
not the result of a trap. This matches the sigcontext trapcode semantics.
* In kpsendsig(), use KSI_TRAP_P() to select the lwp that gets the signal.
Inspired by Matthias Drochner's fix to kpsendsig(), but correctly handles
the case of non-trap-generated signals that have a > 0 si_code.

This patch fixes a signal delivery problem with threaded programs noted by
Matthias Drochner on tech-kern.

As discussed on tech-kern. Reviewed and OK's by Christos.

trap.c: Set ksi.ksi_trap to frame->trap.
sig_machdep.c: Use ksi->ksi_addr in compat code to supply the
'code' argument to the old signal routines.

Set ksi_addr to frame->code.

Add SA_SIGINFO support for VAX.

add MD part of SA/pthread pagefault handling on vax

__KERNEL_RCSID()

branches: 1.80.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

Add machdep sysctl support. Support booted_device, consdev, and
printfataltraps.

Fix some SA lossage.

Merge the nathanw_sa branch.

Pass the system call table to trace_enter() and ktrsys() so that it is
possible to use alternate system call tables. This is usefull for
displaying correctly the arguments in Mach binaries traces.

If NULL is given, then the regular systam call table for the process is used.

branches: 1.74.2;
Fix compilation errors introduced by recent trace_enter()/ktrsyscall() changes.

Provided by FUKAUMI Naoki <naoki at fukaumi dot org> in kern/19070.

Record stack growth, done inline to avoid another function call on
every user page fault.

XXX Should make uvm_grow() an inline.

finish previous; it would be nice if people were to use the lovely
cross compiling mechanisms we have when making sweeping changes...

MD systrace gluons.

branches: 1.70.2; 1.70.4;
Only print console messages about SIGSEGV and SIGILL if the
kernel was built with DEBUG.

kill remaining PS_STRINGS instances.

Major update of the vax pmap:
- Reinstall the "dynamic page table length" that was removed some
years ago.
- Limit the user page table submap to max 5% of available memory.
- Free the page table space when a process is swapped out.
- If the UPT submap runs out of space, throw away pmap mappings
using the same algorithm as for swapping processes.

As a result of this, 4MB machines are useable again and it's even possible
to compile a kernel for 2MB machines (but it will be slow... :-)

Still to do:
- Multiprocessor fixes.
- More profiling.

allow writing to write-only mappings. fixes PR 3493.

branches: 1.66.2; 1.66.8;
Panic if page fault on interrupt stack, per request from Jason Thorpe.

Move some locks closer to the important point.

A bunch of fixes:
- Make generic console routines not relying on running on master cpu.
- Add routine to start console transmitter (after IPI).
- Use real IPIs instead of the "console doorbell".
- Add routines cpu_send_ipi()/cpu_handle_ipi().

replace vm_map{,_entry}_t with struct vm_map{,_entry} *.

Add a bunch of locking code for MP systems.

eliminate the KERN_* error codes in favor of the traditional E* codes.
the mapping is:

KERN_SUCCESS 0
KERN_INVALID_ADDRESS EFAULT
KERN_PROTECTION_FAILURE EACCES
KERN_NO_SPACE ENOMEM
KERN_INVALID_ARGUMENT EINVAL
KERN_FAILURE various, mostly turn into KASSERTs
KERN_RESOURCE_SHORTAGE ENOMEM
KERN_NOT_RECEIVER <unused>
KERN_NO_ACCESS <unused>
KERN_PAGES_LOCKED <unused>

branches: 1.60.2;
de-__P. cleanup the whitespace a bit. add a very small optimization.

Rename arithflt to trap. Change trap label to Xtrap. This is due to that
arithflt is really the trap handler so call it that.

Make this compile again.

Changes so that the kernel can be compiled under __ELF__.

remove include of <vm/vm.h>. <vm/vm.h> -> <uvm/uvm_extern.h>

remove/move more mach vm header files:

<vm/pglist.h> -> <uvm/uvm_pglist.h>
<vm/vm_inherit.h> -> <uvm/uvm_inherit.h>
<vm/vm_kern.h> -> into <uvm/uvm_extern.h>
<vm/vm_object.h> -> nothing
<vm/vm_pager.h> -> into <uvm/uvm_pager.h>

also includes a bunch of <vm/vm_page.h> include removals (due to redudancy
with <vm/vm.h>), and a scattering of other similar headers.

Use the cpu_info struct to store cpu-specific data in the same way in
both uniprocessor and multiprocessor environments. Use the otherwise
unused internal CPU register SSP to store the cpu_info pointer.
The macros curcpu(), curproc, cpu_number() and need_resched() are now the
same in both uniprocessor and multiprocessor environments.

Rewrite cpu_fork(), it now looks like and works as other ports' cpu_fork()
(calling child_return() etc...). Have fun, Jason!

branches: 1.52.2;
Reduce use of curproc in several places:

- Change ktrace interface to pass in the current process, rather than
p->p_tracep, since the various ktr* function need curproc anyway.

- Add curproc as a parameter to mi_switch() since all callers had it
handy anyway.

- Add a second proc argument for inferior() since callers all had
curproc handy.

Also, miscellaneous cleanups in ktrace:

- ktrace now always uses file-based, rather than vnode-based I/O
(simplifies, increases type safety); eliminate KTRFLAG_FD & KTRFAC_FD.
Do non-blocking I/O, and yield a finite number of times when receiving
EWOULDBLOCK before giving up.

- move code duplicated between sys_fktrace and sys_ktrace into ktrace_common.

- simplify interface to ktrwrite()

First sweep at scheduler state cleanup. Collect MI scheduler
state into global and per-CPU scheduler state:

- Global state: sched_qs (run queues), sched_whichqs (bitmap
of non-empty run queues), sched_slpque (sleep queues).
NOTE: These may collectively move into a struct schedstate
at some point in the future.

- Per-CPU state, struct schedstate_percpu: spc_runtime
(time process on this CPU started running), spc_flags
(replaces struct proc's p_schedflags), and
spc_curpriority (usrpri of processes on this CPU).

- Every platform must now supply a struct cpu_info and
a curcpu() macro. Simplify existing cpu_info declarations
where appropriate.

- All references to per-CPU scheduler state now made through
curcpu(). NOTE: this will likely be adjusted in the future
after further changes to struct proc are made.

Tested on i386 and Alpha. Changes are mostly mechanical, but apologies
in advance if it doesn't compile on a particular platform.

Move common return-to-userland goo into userret(), like other ports.

Use preempt(), not an open-coded equivalent (which won't be
equivalent for long).

First cut of multiprocessor support for vax. Still much to do before
other CPUs than the master can spin up.

branches: 1.47.2;
Initial VAX ELF32 support (mostly untested). It's checked primarily for
testing and archival for now. I don't expect anyone to work with it
since the binutils and gas changes are still pending. But you got to
crawl before you walk.

Rewrite the page table entry routines. Don't take a pte invalid fault for
missing pte's, instead map in pte entries in pmap_enter(). The user ptes
is no more handled by the VM system. All this made swapping start working
on VAX again.
Still to do:
- Keep refcount per pte page, so that those pages get free'd when the
process is swapped out. Right now they are only free'd when the pmap
is destroyed.

Many thanks to Chuck Silvers for all help finding the deadlock problems.

Add some small checks to avoid unwanted panic types.

branches: 1.44.2; 1.44.4; 1.44.6;
completely remove Mach VM support. all that is left is the all the
header files as UVM still uses (most of) these.

if uvm_fault() fails with KERN_RESOURCE_SHORTAGE, send a SIGKILL
and print a message about it. this will be used to recover from
out-of-swap conditions.

Change vsbus to take a locator for all devices.
Figure out interrupt vector/mask on vsbus by forcing all devices to
generate interrupts in the match routine, like on unibus.

Allocate (almost) all interrupt vectors dynamically. Simplifies much
work when adding support for new machines and devices.

Giant change: NBPG now set to 4k and CLSIZE == 1 for vax. This change
made a whole bunch of annoying bugs disappear; mostly depending on
bad use of NBPG in non-MD code. The VAX port was the only port that
used this historical "feature".

The CL* macros should probably go away totally, there is no reason
at all to keep them.

Fix (small) segv bug. Recognize in-kernel trace and breakpoint traps.

defopt DDB.

defopt KTRACE

Wall fixes.

Wall cleaning + a little better fault checking.

Support for UVM on VAXen.

Adjust for the fact that the page {0,1} base and length registers are now
stored in the pmap structure.

Optimized copy/fetch/store routines; rewritten in assembler.

Major rewriting, optimization and simplifying of the pmap code:

- Map in all physical memory first in system space. This reduces
pmap_copy_page() and pmap_zero_page to 3 resp. 2 instructions.
- Have fized position user page tables. Makes the pv_table smaller
and all reverse references faster (and simpler).
- Remove the wiring code. Nobody doesn't even know what a DR32 is anymore.
- Simulate page reference bit by setting page invalid, as suggested by
Rich Draves in a paper for 1991 Mach Usenix Symposium.

This reduced the time spent in the pmap module to between 70-75% of
the previous; and made process startup _much_ faster.

Only check for process switch if we are coming in from userspace.
Make ERESTART work for syscalls >63.
While we're here; clean up a little bit.

Fix execve(2) and *setregs() interfaces so emulations can set registers in a
more correct way. (See tech-kern.)

branches: 1.28.2;
Handle XFC instruction faults.

Remove __VM_PMAP_HACK.

Bug fixes to page fault handling system. Many thanks to Johnny Billquist
for hunting down this bug(s).

cpu_switch() should be mi_switch(). Pointed out by Johnny Billquist.
(bqt@update.uu.se)

Fix an inconsistency that came in with Lite: setrq() was renamed to
setrunqueue(), but remrq() was never renamed. Rename remrq() to
remrunqueue().

backout previous kprintf change

printf -> kprintf, sprintf -> ksprintf

Fixed all (proto)type errors. Fixes PR 2377.

Added prototypes to everything. Made all files compile with -Wall.

Do not have debugging enabled by default.

Add support for ktracing syscalls.

#ifdef a call to kdb_trap() on DDB.

Fix #includes.

Be able to handle debugger traps from kernel.

struct ivec_dsp for interrupt vector allocation added.

Null pointer were referenced if signal occurred before first
syscall. Didn't hurt on 4.3 Reno binaries.

rudimentary DDB support.

Enabled auto reboot. Fixed bug in conf.c. Started use of rpb.
Detecting kernel stack overflow. Removed local mapping of
sigtramp code. Frob kernel stack pages in cpu_swapin().
Cleaned up some code and changed to KNF.

Changed conf.c to new style. Took away double saving of regs in traps.
Changed boot() to use vfs_shutdown(). Updated setregs.

- added sunos_machdep.c for sun3, atari, amiga and mac68k.
- changed machdep.c and trap.c to use struct emul.
- remove ep_setup references.
- added struct emul to all emulations.

Speed-up of pmap and trap.
Fixes due to uVAX support.

Support for uVAXII, new tmscp driver added.

Zillions of bugfixes. Obsolete files taken away. New style config
fixed. Inline assembler commonly used.

Lots of fixes and updates.

new RCS ID format.

Lots of bug fixes; clock and mem files new.

branches: 1.2.2;
Lots of bug fixes. Generic console support added. Major changes in machdep.c.
pmap.c now supports user process mapping. Page faults handles correctly.

Initial VAX port merging.

Update copyright notice for Ludd (remove clause 3 & 4).

KNF. Remove extra spaces. No functional change.