Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

In order to maximize the re-usability of kernel code in user space this
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.

Reviewed by: rwatson
Approved by: re (bz)

Backout previous change (disabling of security checks for signals delivered
in emulation layers), since it appears to be too broad.

Requested by: rwatson

Split out kill(2) syscall service routine into user-level and kernel part, the
former is callable from user space and the latter from the kernel one. Make
kernel version take additional argument which tells if the respective call
should check for additional restrictions for sending signals to suid/sugid
applications or not.

Make all emulation layers using non-checked version, since signal numbers in
emulation layers can have different meaning that in native mode and such
protection can cause misbehaviour.

As a result remove LIBTHR from the signals allowed to be delivered to a
suid/sugid application.

Requested (sorta) by: rwatson
MFC after: 2 weeks

/* -> /*- for license, add FreeBSD tag

Fix a multitude of security bugs in the iBCS2 emulator:
- Return NULL instead of returning memory outside of the stackgap
in stackgap_alloc() (FreeBSD-SA-00:42.linux)
- Check for stackgap_alloc() returning NULL in ibcs2_emul_find();
other calls to stackgap_alloc() have not been changed since they
are small fixed-size allocations.
- Replace use of strcpy() with strlcpy() in exec_coff_imgact()
to avoid buffer overflow
- Use strlcat() instead of strcat() to avoid a one byte buffer
overflow in ibcs2_setipdomainname()
- Use copyinstr() instead of copyin() in ibcs2_setipdomainname()
to ensure that the string is null-terminated
- Avoid integer overflow in ibcs2_setgroups() and ibcs2_setgroups()
by checking that gidsetsize argument is non-negative and
no larger than NGROUPS_MAX.
- Range-check signal numbers in ibcs2_wait(), ibcs2_sigaction(),
ibcs2_sigsys() and ibcs2_kill() to avoid accessing array past
the end (or before the start)

Use __FBSDID().

- Replace inline implementations of sigprocmask() with calls to
kern_sigprocmask() in the various binary compatibility emulators.
- Replace calls to sigsuspend(), sigaltstack(), sigaction(), and
sigprocmask() that used the stackgap with calls to the corresponding
kern_sig*() functions instead without using the stackgap.

- Move p->p_sigmask to td->td_sigmask. Signal masks will be per thread with
a follow on commit to kern_sig.c
- signotify() now operates on a thread since unmasked pending signals are
stored in the thread.
- PS_NEEDSIGCHK moves to TDF_NEEDSIGCHK.

SCARGS removal take II.

Backout removal SCARGS, the code freeze is only "selectively" over.

Remove SCARGS.

Reviewed by: md5

Back our kernel support for reliable signal queues.

Requested by: rwatson, phk, and many others

Add a missing include.

When working with sigset_t's, and needing to perform masking operations based
on a process's pending signals, use the signal queue flattener,
ksiginfo_to_sigset_t, on the process, and on a local sigset_t, and then work
with that as needed.

Replace various spelling with FALLTHROUGH which is lint()able

Moved signal handling and rescheduling from userret() to ast() so that
they aren't in the usual path of execution for syscalls and traps.
The main complication for this is that we have to set flags to control
ast() everywhere that changes the signal mask.

Avoid locking in userret() in most of the remaining cases.

Submitted by: luoqi (first part only, long ago, reorganized by me)
Reminded by: dillon

Remove __P.

KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after: ha ha ha ha

Undo part of the tangle of having sys/lock.h and sys/mutex.h included in
other "system" header files.

Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.

Sort sys/*.h includes where possible in affected files.

OK'ed by: bde (with reservations)

Proc locking.

Avoid using the osig* syscalls.

sigset_t change (part 4 of 5)
-----------------------------

The compatibility code and/or emulators have been updated:

iBCS2 now mostly uses the older syscalls. SVR4 now properly
handles all signals. This has been achieved by using the
new sigset_t throughout the emulator. The Linuxulator has
been severely updated. Internally the new Linux sigset_t is
made the default. These are then mapped to and from the
new FreeBSD sigset_t.

Also, rt_sigsuspend has been implemented in the Linuxulator.
Implementing this syscall basicly caused all this sigset_t
changing in the first place and the syscall has been used
throughout the change as a means for testing. It basicly is
too much work to undo the implementation so that it can
later be added again.

A special note on the use of sv_sigtbl and sv_sigsize in
struct sysentvec:
Every signal larger than sv_sigsize is not translated and is
passed on to the signal handler unmodified. Signals in the
range 1 upto and including sv_sigsize are translated.
The rationale is that only the system defined signals need to
be translated.

The emulators also have been updated so that the translation
tables are only indexed for valid (system defined) signals.
This change also fixes the translation bug already in the
SVR4 emulator.

$Id$ -> $FreeBSD$

Rename struct members sa_siginfo. POSIX reserves identifiers starting
with sa_ when <signal.h> is included. They would conflict with the
upcoming SA_SIGINFO implementation.

Reviewed by: BDE

Move the "retval" (3rd) parameter from all syscall functions and put
it in struct proc instead.

This fixes a boatload of compiler warning, and removes a lot of cruft
from the sources.

I have not removed the /*ARGSUSED*/, they will require some looking at.

libkvm, ps and other userland struct proc frobbing programs will need
recompiled.

Removed unused #includes.

Don't include <sys/ioctl.h> in the kernel. Stage 1: don't include
it when it is not used. In most cases, the reasons for including it
went away when the special ioctl headers became self-sufficient.

Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Perform special sigset() check.
Make sure signal is not blocked. If it is, return SIG_HOLD instead
of handler and unblock the signal.

In bsd_to_ibcs2_sigaction(), flag for ibcs2 system should be
IBCS2_SA_NOCLDSTOP and not SA_NOCLDSTOP.

Submitted by: bde

sigset() should have sa_flags cleared to sig is maked before calling
handler (remove SA_NODEFER).

On the other hand, signal() case should set sa_flags to SA_NODEFER as
in previous change.

In addition, added #ifdef'd code for signal() to or in SA_RESETHAND
flag for when that compatability is implemented.

Use sa_flag option SA_NODEFER in sigsys() emulation because SVR3
does not automatically mask signal upon delivery.

Remove old files no longer needed.
Add new files created for emulator.
Modify NetBSD import to work with FreeBSD and add new features and
code. The complete emulator is essentially a combination of work/code
implemented by Sean Eric Fagan, Soren Schmidt, Scott Bartram, and myself,
Steven Wallace.

Features of this new emulator system include:

o "clean" code, including strict prototyping.
o Auto-generation of ibcs2 system calls, xenix system calls, isc system
calls. Generation includes system tables, structure definitions,
and prototyping of function calls.
o ibcs2 emulator does not rely on any COMPAT_43 system calls.
o embedded socksys support
o ibcs2 msgsys, semsys, shmsys calls supported if supported in kernel
o alternate /emul/ibcs2 namespace searched first for files in ibcs2
system. Usefull to keep sysv libraries, binaries in /emul/ibcs2.
o many other finer details and functions fixed or implemented.

Remove trailing whitespace.

iBCS2 emulator core files.

This is the main files for the iBCS2 emulator. It can be use
compiled into the kernel by using:

options IBCS2
options COMPAT_IBCS2

or as a lkm module using:

options COMPAT_IBCS2

and then loading it via the ibcs2 script in /usr/bin

REMEMBER: this code is still experimental ! NO WARRENTY !

Submitted by: sef@kithrup.com, mostyn@mrl.com, sos@kmd-ac.dk