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

branches: 1.56.2;
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>

branches: 1.55.2;
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.

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

branches: 1.53.8; 1.53.12;
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.

branches: 1.52.6; 1.52.8;
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

branches: 1.51.12; 1.51.16; 1.51.22; 1.51.24;
Remove all the __P

branches: 1.50.44; 1.50.46; 1.50.52; 1.50.56;
merge ktrace-lwp.

Add a sunos_machdep include file to deal with MD implementations of
sunos_syscall_intern.

More syscall_intern lossage.

branches: 1.47.2;
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.

branches: 1.46.2;
nuke trailing whitespace

branches: 1.45.8; 1.45.10;
Put back Emmanuel's sigfilter hooks, as decided by Core.

Introduce lwp_emuldata and the associated hooks. No hook is provided for the
exec case, as the emulation already has the ability to intercept that
with the e_proc_exec hook. It is the responsability of the emulation to
take appropriaye action about lwp_emuldata in e_proc_exec.

Patch reviewed by Christos.

back the sigfilter emulation hook change off

Add a sigfilter emulation hook. It is used at the beginning of kpsignal2()
so that a specific emulation has the oportunity to filter out some signals.

if sigfilter returns 0, then no signal is sent by kpsignal2().

There is another place where signals can be generated: trapsignal. Since this
function is already an emulation hook, no call to the sigfilter hook was
introduced in trapsignal.

This is needed to emulate the softsignal feature in COMPAT_DARWIN (signals
sent as Mach exception messages)

add support for non-executable mappings (where the hardware allows this)
and make the stack and heap non-executable by default. the changes
fall into two basic catagories:

- pmap and trap-handler changes. these are all MD:
= alpha: we already track per-page execute permission with the (software)
PG_EXEC bit, so just have the trap handler pay attention to it.
= i386: use a new GDT segment for %cs for processes that have no
executable mappings above a certain threshold (currently the
bottom of the stack). track per-page execute permission with
the last unused PTE bit.
= powerpc/ibm4xx: just use the hardware exec bit.
= powerpc/oea: we already track per-page exec bits, but the hardware only
implements non-exec mappings at the segment level. so track the
number of executable mappings in each segment and turn on the no-exec
segment bit iff the count is 0. adjust the trap handler to deal.
= sparc (sun4m): fix our use of the hardware protection bits.
fix the trap handler to recognize text faults.
= sparc64: split the existing unified TSB into data and instruction TSBs,
and only load TTEs into the appropriate TSB(s) for the permissions.
fix the trap handler to check for execute permission.
= not yet implemented: amd64, hppa, sh5

- changes in all the emulations that put a signal trampoline on the stack.
instead, we now put the trampoline into a uvm_aobj and map that into
the process separately.

originally from openbsd, adapted for netbsd by me.

branches: 1.40.6;
handle __HAVE_MINIMAL_EMUL

set struct emul's nsysent to compat SYS_NSYSENT, not SYS_MAXSYSCALL

- Introduce a e_fault field in struct proc to provide emulation specific
memory fault handler. IRIX uses irix_vm_fault, and all other emulation
use NULL, which means to use uvm_fault.

- While we are there, explicitely set to NULL the uninitialized fields in
struct emul: e_fault and e_sysctl on most ports

- e_fault is used by the trap handler, for now only on mips. In order to avoid
intrusive modifications in UVM, the function pointed by e_fault does not
has exactly the same protoype as uvm_fault:
int uvm_fault __P((struct vm_map *, vaddr_t, vm_fault_t, vm_prot_t));
int e_fault __P((struct proc *, vaddr_t, vm_fault_t, vm_prot_t));

- In IRIX share groups, all the VM space is shared, except one page.
This bounds us to have different VM spaces and synchronize modifications
to the VM space accross share group members. We need an IRIX specific hook
to the page fault handler in order to propagate VM space modifications
caused by page faults.

m68k syscall rototill:

- Switch all m68k-based ports over to __HAVE_SYSCALL_INTERN.
- Add systrace glue.
- Define struct mdproc in <m68k/proc.h> instead of <machine/proc.h>.
(They were all defined exactly the same anyway, other than a couple
of the MDP_* flags.)

branches: 1.36.8;
add RCSIDs (including regeneration of files as appropriate)

Make the setregs hook emulation-specific, rather than executable
format specific.
Struct emul has a e_setregs hook back, which points to emulation-specific
setregs function. es_setregs of struct execsw now only points to
optional executable-specific setup function (this is only used for
ECOFF).

branches: 1.34.2; 1.34.4;
Add an e_trapsignal member to struct emul, so that emulated processes can
send the appropriate signal depending on the trap type.

Removed obsoletes EMUL_NO_BSD_ASYNCIO_PIPE and EMUL_NO_SIGIO_ON_READ flags.
Async I/O OS specifities should now handled in OS specific code. Linux
has been done, but other emulation should be handled. See case LINUX_F_SETFL
in sys/compat/linux/common/linux_file.c:linux_sys_fcntl() for more details.

The data that has been collected yet:

Net Free Open Linux SunOS AIX OSF1 Darwin
send SIGIO to write end of pipe Y N N N N N Y Y
send SIGIO to read end of pipe Y Y N N N ? Y ?
send SIGIO to write end of socket Y Y Y N N Y Y Y
send SIGIO to read end of socket Y Y Y Y Y ? Y ?

use _KERNEL_OPT.

Changed EMUL_BSD_ASYNCIO_PIPE to EMUL_NO_BSD_ASYNCIO_PIPE, so that
the native emulation (NetBSD) does not have a flag.

Added two flags to emulation packages:

EMUL_BSD_ASYNCIO_PIPE notes that the emulated binaries expect the original
BSD pipe behavior for asynchronous I/O, which is to fire SIGIO on read() and
write(). OSes without this flag do not expect any SIGIO to be fired on
read() and write() for pipes, even when async I/O was requested. As far as
we know, the OSes that need EMUL_BSD_ASYNCIO_PIPE are NetBSD, OSF/1 and
Darwin.

EMUL_NO_SIGIO_ON_READ notes that the emulated binaries that requested
asynchrnous I/O expect the reader process to be notified by a SIGIO, but
not the writer process. OSes without this flag expect the reader and the
writer to be notified when some data has arrived or when some data have been
read. As far as we know, the OSes that need EMUL_NO_SIGIO_ON_READ are Linux
and SunOS.

branches: 1.29.2;
Introduce 2 new flags in types.h:
* __HAVE_SYSCALL_INTERN. If this is defined, e_syscall is replaced by
e_syscall_intern, which is called at key places in the kernel. This can be
used to set a MD syscall handler pointer. This obsoletes and replaces the
*_HAS_SEPARATED_SYSCALL flags.
* __HAVE_MINIMAL_EMUL. If this is defined, certain (deprecated) elements in
struct emul are omitted.

always fill in e_syscall in respective emul_*; if the emulation doesn't
have it's own separated *_syscall() function, use syscall()

Get rid of the damn EMUL_GET* flags.

put aout specific sunos code from sunos_exec.c to separate file
sunos_exec_aout.c
make LKM safe
add EMUL_GETPID_PASS_PPID|EMUL_GETID_PASS_EID to emul_sunos flags

fix the emulation path

add e_path (emulation path) to struct emul, which replaces emulation-specific
*_emul_path variables

change macros CHECK_ALT_{CREAT|EXIST} to use that, 'root' doesn't need
to be passed explicitly any more and *_CHECK_ALT_{CREAT|EXIST} are removed
change explicit emul_find() calls in probe functions to get the emulation
path from the checked exec switch entry's emulation

remove no longer needed header files

add e_flags and e_syscall to struct emul; these are unsed and empty for now

Make these compile with the latest execsw[] changes. Someone with
SunOS binaries needs to test this...

restructure struct emul and execsw, in preparation to make emulations LKMable:
* move all exec-type specific information from struct emul to execsw[] and
provide single struct emul per emulation
* elf:
- kern/exec_elf32.c:probe_funcs[] is gone, execsw[] how has one entry
per emulation and contains pointer to respective probe function
- interp is allocated via MALLOC() rather than on stack
- elf_args structure is allocated via MALLOC() rather than malloc()
* ecoff: the per-emulation hooks moved from alpha and mips specific code
to OSF1 and Ultrix compat code as appropriate, execsw[] has one entry per
emulation supporting ecoff with appropriate probe function
* the makecmds/probe functions don't set emulation, pointer to emulation is
part of appropriate execsw[] entry
* constify couple of structures

change the type of *syscallnames[] array to 'const char * const foo[]'

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

defopt SYSCALL_DEBUG.

branches: 1.18.2;
add a new function vn_marktext() for exec code to let others know
that the vnode is now being used as process text.

branches: 1.17.2;
Need sunos_sigcode and sunos_esigcode now that our sigreturn is
different.

branches: 1.16.2;
remove unneeded <vm/*> includes

Everyone uses sunos_sendsig().

use __sparc__ not sparc

Standardize COMPAT_SUNOS -- remove all references to
sunos_exec_aout_makecmds() in machdep.c for various architectures and put
it in exec_conf.c like the other emulations; rename exec.h to
sunos_exec.h.

don't include <machine/exec.h> explicitly. No other changes needed, since
<sys/exec.h> was already being included.

Put prototype for sunos_sendsig() in sunos.h as suggested by veego.

Bring prototypes into scope and fix compiler warnings.

Add sunos_emul_path (/emul/sunos). I don't know if this is correct, but
this will at least aid the compilation step and is similar to the
others.

- added struct emul to all emulations.
- removed all setup functions.
- added copyargs() functions where needed.

rename, new syscall interface, etc.

Avoid some macro redefinitions that have appeared since exec.h
now includes exec_aout.h

branches: 1.5.2;
New RCS ID's, take two. they're more aesthecially pleasant, and use 'NetBSD'

Fix spelling error in Copyright notice

for new exec, from mw

m68k/sparc sunos binary compatibility code, pulled down from magnum branch
for consumption by the m68k masses

branches: 1.1.2;
compat exec() stuff is done more sensibly now
(hpux and ultrix compat stuff will be done the same way)