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.

branches: 1.24.32; 1.24.44;
Switch to ANSI style declaration.

branches: 1.23.2;
Add a hook for freeing an ep_emul_arg. Add a wrapper routine
(exec_free_emul_arg) to call the hook and then clear the ep_emul_arg
and ep_emul_arg_free members in the exec_package.
Change users/accessors to use these routines.
Approved by releng.

branches: 1.22.8; 1.22.12;
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: 1.21.20; 1.21.22;
Remove clause 3 and 4 from TNF licenses

branches: 1.20.54; 1.20.56; 1.20.58;
Use the LWP cached credentials where sane.

include kauth.h for kauth_cred_getegid, etc.

integrate kauth.

branches: 1.17.4; 1.17.6; 1.17.8; 1.17.10; 1.17.12;
merge ktrace-lwp.

branches: 1.16.4;
nuke trailing whitespace

branches: 1.15.4; 1.15.6;
remove the LINUX_SP_WRAP hack since it doesn't seem to be needed anymore,
and removing it lets us go back to mapping the stack non-executable again.

include <sys/resourcevar.h>. It is not required for building -current,
but it is for -netbsd-2-0. Next step is to pull up the change...

COMPAT_LINUX/powerpc used the native stack setup routine, but now the
native version does non executable mappings on the stack. This is a
showstopper for Linux binaries.

To fix that we supply a copy f the native stack setup function for Linux
binaries, with the executable bit set.

branches: 1.12.2; 1.12.4;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

'struct proc *' -> 'struct lwp *' as required to get GENERIC for macppc built

Use PAGE_SIZE rather than NBPG.

Merge the nathanw_sa branch.

branches: 1.8.2;
use generic ELF AuxInfo, no need to define a 'linux' variant here
simplify LINUX_ELF_AUX_ARGSIZ definition, LINUX_SP_WRAP is always defined here

Implement passing AT_{E,R}{U,G}ID in the elf aux vector, like solaris.
- pass struct proc to copyargs.
- eliminate svr4_copyargs, since it is the same as ours now.

branches: 1.6.8; 1.6.10;
add RCSIDs (including regeneration of files as appropriate)

PR/13652: Katsuomi Hamajima: Fix compile error.

Adjust to the new copyargs() footprint.

branches: 1.3.2;
It's "extern int", not "extern".
Macppc kernels with LINUX_COMPAT now compile again.

branches: 1.2.2; 1.2.4;
cosmetic fixes.

Added powerpc specific code for Linux compatibility on powerpc ports