sys/compat: Memset zero before copyout.

Just in case of uninitialized padding which would lead to kernel
stack disclosure. If the compiler can prove the memset redundant
then it can optimize it away; otherwise better safe than sorry.

Merge the [pgoyette-compat] branch

branches: 1.20.56; 1.20.58;
Remove includes <sys/mount.h> and <sys/sched.h> added for <sys/syscallargs.h>.
Now they are handled by $sysarghdrextra in sys/kern/syscalls.conf.

branches: 1.19.2; 1.19.22; 1.19.28;
Remove clause 3 and 4 from TNF licenses

branches: 1.18.2;
Merge proc::p_mutex and proc::p_smutex into a single adaptive mutex, since
we no longer need to guard against access from hardware interrupt handlers.

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

branches: 1.17.6; 1.17.8;
Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.16.4;
ANSIfy most of the function definitions in sys/compat (but not ndis).
All by the magic of sed ...

branches: 1.15.6; 1.15.8; 1.15.16;
Modify the (recently added) compat_sigaltstack() #define to take the
values of the SS_ONSTACK and SS_DISABLE constants.
Use it to shorten the source files when this action is replicated.
Actually, given the monstrous complexity of sigaltstack1() there is
probably a much better way to do this...

branches: 1.14.6; 1.14.8;
Merge newlock2 to head.

__unused removal on arguments; approved by core.

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

branches: 1.11.20; 1.11.22;
merge ktrace-lwp.

compat code reorg.

branches: 1.9.2; 1.9.18;
Merge the nathanw_sa branch.

rename: s/sa_/<compat>sa/g

Add kernel support for having userland provide the signal trampoline:

* struct sigacts gets a new sigact_sigdesc structure, which has the
sigaction and the trampoline/version. Version 0 means "legacy kernel
provided trampoline". Other versions are coordinated with machine-
dependent code in libc.
* sigaction1() grows two more arguments -- the trampoline pointer and
the trampoline version.
* A new __sigaction_sigtramp() system call is provided to register a
trampoline along with a signal handler.
* The handler is no longer passed to sensig() functions. Instead,
sendsig() looks up the handler by peeking in the sigacts for the
process getting the signal (since it has to look in there for the
trampoline anyway).
* Native sendsig() functions now select the appropriate trampoline and
its arguments based on the trampoline version in the sigacts.

Changes to libc to use the new facility will be checked in later. Kernel
version not bumped; we will ride the 1.6C bump made recently.

branches: 1.6.8;
add RCSIDs (including regeneration of files as appropriate)

branches: 1.5.6; 1.5.8;
Kill register declarations.

branches: 1.4.12;
Put the prototypes for native_sig*_to_sig*() in one place.

Substantial signal handling changes:
* Increase the size of sigset_t to accomodate 128 signals -- adding new
versions of sys_setprocmask(), sys_sigaction(), sys_sigpending() and
sys_sigsuspend() to handle the changed arguments.
* Abstract the guts of sys_sigaltstack(), sys_setprocmask(), sys_sigaction(),
sys_sigpending() and sys_sigsuspend() into separate functions, and call them
from all the emulations rather than hard-coding everything. (Avoids uses
the stackgap crap for these system calls.)
* Add a new flag (p_checksig) to indicate that a process may have signals
pending and userret() needs to do the full (slow) check.
* Eliminate SAS_ALTSTACK; it's exactly the inverse of SS_DISABLE.
* Correct emulation bugs with restoring SS_ONSTACK.
* Make the signal mask in the sigcontext always use the emulated mask format.
* Store signals internally in sigaction structures, rather than maintaining a
bunch of little sigsets for each SA_* bit.
* Keep track of where we put the signal trampoline, rather than figuring it out
in *_sendsig().
* Issue a warning when a non-emulated sigaction bit is observed.
* Add missing emulated signals, and a native SIGPWR (currently not used).
* Implement the `not reset when caught' semantics for relevant signals.

Note: Only code touched by the i386 port has been modified. Other ports and
emulations need to be updated.

Modify the recent sigaltstack() interface change to use the __RENAME() scheme;
add __sigaltstack14().

In XPG4.2, the ss_size member of type stack_t (struct sigaltstack) is specified
to be of type size_t; since this imposes an interface change on the Alpha
(sizeof(int) != sizeof(size_t)), allocate a new system call number and make
the previous version a compatibility system call.

Merge the [pgoyette-compat] branch

branches: 1.20.56;
Remove includes <sys/mount.h> and <sys/sched.h> added for <sys/syscallargs.h>.
Now they are handled by $sysarghdrextra in sys/kern/syscalls.conf.

branches: 1.19.2; 1.19.22; 1.19.28;
Remove clause 3 and 4 from TNF licenses

branches: 1.18.2;
Merge proc::p_mutex and proc::p_smutex into a single adaptive mutex, since
we no longer need to guard against access from hardware interrupt handlers.

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

branches: 1.17.6; 1.17.8;
Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.16.4;
ANSIfy most of the function definitions in sys/compat (but not ndis).
All by the magic of sed ...

branches: 1.15.6; 1.15.8; 1.15.16;
Modify the (recently added) compat_sigaltstack() #define to take the
values of the SS_ONSTACK and SS_DISABLE constants.
Use it to shorten the source files when this action is replicated.
Actually, given the monstrous complexity of sigaltstack1() there is
probably a much better way to do this...

branches: 1.14.6; 1.14.8;
Merge newlock2 to head.

__unused removal on arguments; approved by core.

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

branches: 1.11.20; 1.11.22;
merge ktrace-lwp.

compat code reorg.

branches: 1.9.2; 1.9.18;
Merge the nathanw_sa branch.

rename: s/sa_/<compat>sa/g

Add kernel support for having userland provide the signal trampoline:

* struct sigacts gets a new sigact_sigdesc structure, which has the
sigaction and the trampoline/version. Version 0 means "legacy kernel
provided trampoline". Other versions are coordinated with machine-
dependent code in libc.
* sigaction1() grows two more arguments -- the trampoline pointer and
the trampoline version.
* A new __sigaction_sigtramp() system call is provided to register a
trampoline along with a signal handler.
* The handler is no longer passed to sensig() functions. Instead,
sendsig() looks up the handler by peeking in the sigacts for the
process getting the signal (since it has to look in there for the
trampoline anyway).
* Native sendsig() functions now select the appropriate trampoline and
its arguments based on the trampoline version in the sigacts.

Changes to libc to use the new facility will be checked in later. Kernel
version not bumped; we will ride the 1.6C bump made recently.

branches: 1.6.8;
add RCSIDs (including regeneration of files as appropriate)

branches: 1.5.6; 1.5.8;
Kill register declarations.

branches: 1.4.12;
Put the prototypes for native_sig*_to_sig*() in one place.

Substantial signal handling changes:
* Increase the size of sigset_t to accomodate 128 signals -- adding new
versions of sys_setprocmask(), sys_sigaction(), sys_sigpending() and
sys_sigsuspend() to handle the changed arguments.
* Abstract the guts of sys_sigaltstack(), sys_setprocmask(), sys_sigaction(),
sys_sigpending() and sys_sigsuspend() into separate functions, and call them
from all the emulations rather than hard-coding everything. (Avoids uses
the stackgap crap for these system calls.)
* Add a new flag (p_checksig) to indicate that a process may have signals
pending and userret() needs to do the full (slow) check.
* Eliminate SAS_ALTSTACK; it's exactly the inverse of SS_DISABLE.
* Correct emulation bugs with restoring SS_ONSTACK.
* Make the signal mask in the sigcontext always use the emulated mask format.
* Store signals internally in sigaction structures, rather than maintaining a
bunch of little sigsets for each SA_* bit.
* Keep track of where we put the signal trampoline, rather than figuring it out
in *_sendsig().
* Issue a warning when a non-emulated sigaction bit is observed.
* Add missing emulated signals, and a native SIGPWR (currently not used).
* Implement the `not reset when caught' semantics for relevant signals.

Note: Only code touched by the i386 port has been modified. Other ports and
emulations need to be updated.

Modify the recent sigaltstack() interface change to use the __RENAME() scheme;
add __sigaltstack14().

In XPG4.2, the ss_size member of type stack_t (struct sigaltstack) is specified
to be of type size_t; since this imposes an interface change on the Alpha
(sizeof(int) != sizeof(size_t)), allocate a new system call number and make
the previous version a compatibility system call.