Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Add section .note.GNU-stack for assembly files used by 386 and amd64.

Per Regents of the University of Calfornia letter, remove advertising
clause.

# If I've done so improperly on a file, please let me know.

Do not try to store 64 bits into 32 bit errno variable. With the changed libc
data layout, this was corrupting _PathLocale variable leading to programs
dumping core in non-default locales.

Update for AMD64 after repocopy from i386/sys/*. This means:
- strip out the nasty PIC_PROLOGUE/EPILOGUE stuff, since we dont have
to lose a register in PIC mode anymore (we use %rip-relative addressing).
- update for C register argument passing conventions.
- convert 32 bit to 64 bit register sizes etc.

Restore CSRG ID's lost in January 1995.

Removed duplicate VCS ID tags, as per style(9).

$Id$ -> $FreeBSD$

Make cerror thread aware by calling __error() to get a pointer to the
thread-specific error variable. This change make libc use the same cerror
code that libc_r has been using.

Revert $FreeBSD$ to $Id$

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.

Fix a bogon in the pic + threadsafe version of cerror, it was missing
a PIC_EPILOGUE (leaving an extra long on the stack).

Submitted by: John Polstra <jdp@polstra.com>

Add support to enable libc to be compiled in ELF format. (#ifdef __ELF__)
In a nutshell, this macroizes the local/global symbol scoping rules
that are different in a.out and ELF. It also makes the i386 assembler
stubs conform to i386 PIC calling conventions - the a.out ld.so didn't
object, but the ELF one needs it as it implements PIC jumps via PLT's as
well as calls. The a.out rtld only worked because it was accidently
snooping the grandparent calling function's return address off the stack..

This also affects the libc_r code a little, because of cpp macro nesting.

Reviewed by: julian and (hsu?)
Submitted by: John Birrel(L?)

changes for threadsafe operations

First round of changes to clean up the RCSID mess in libc:

1) Changed LIB_SCCS and SYSLIB_SCCS to LIB_RCS and SYSLIB_RCS.
2) Changed sccsid[] variables to rcsid[]
3) Moved all RCSID strings into .text
4) Converted all SCCSID's to RCS $Id$'s
5) Added missing $Id$'s after copyright.

Fixed problem with returning -1 on error when the return value is a
long long. Done by plugging both eax and edx with -1. This will clobber
edx unnecessarily when the return value is only 32bit...though probably
always an okay thing to do, it could stand a better fix.
This was the cause of gawk being broken (boy was THAT ever a subtle
bug!!!).

First crack at making libc work with the new make macros. It compiles on
my machine, and a simple static (genassym) and shared (sysctl) executable
both work. Still to be done: RPCand YP merge.