libc: move rfork_thread(3) to libsys

rfork_thread(3) is assembly that makes syscalls directly and uses
cerror so it belongs in libsys.

Reviewed by: kib, emaste, imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/908

lib: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

libc: Remove _get_tp() and _set_tp().

Their uses have been replaced by _tcb_get() and _tcb_set() from
<machine/tls.h>.

Reviewed by: kib, jrtc27
Sponsored by: The University of Cambridge, Google Inc.
Differential Revision: https://reviews.freebsd.org/D33354

libc: add _get_tp() private function

which returns pointer to tcb

Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29623

Unify i386 and amd64 getcontextx.c, and use ifuncs while there.

In particular, use ifuncs for __getcontextx_size(), also calculate the
size of the extended save area in resolver. Same for __fillcontextx2().

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Add API for obtaining extended machine context states that cannot be
fit into existing mcontext_t.

On i386 and amd64 do return the extended FPU states using
getcontextx(3). For other architectures, getcontextx(3) returns the
same information as getcontext(2).

Tested by: pho
MFC after: 1 month

Replace a proliferation of buggy MD implementations of modf() with a
working MI one. The MI one only needs to be overridden on machines
with non-IEEE754 arithmetic. (The last supported one was the VAX.)
It can also be overridden if someone comes up with a faster one that
actually passes the regression tests -- but this is harder than it sounds.

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

- Import the HEAD csup code which is the basis for the cvsmode work.

GC dead code. If we want to stay polite to the foreign compilers,
we can find another way to issue an #error, but using a preprocessed
assembler for that purpose and clobbering libc.a with an empty .o
just for the sake of #error reporting is way too much of a burden.

Add support for TLS in statically linked programs.

Make FLT_ROUNDS correctly reflect the dynamic rounding mode.

Replace seven nominally MD implementations of frexp() that are broken
for subnormals with one implementation that works.

Implement the classification macros isfinite(), isinf(), isnan(), and
isnormal() the hard way, rather than relying on fpclassify(). This is
a lose in the sense that we need a total of 12 functions, but it is
necessary for binary compatibility because we have never bumped libm's
major version number. In particular, isinf(), isnan(), and isnanf()
were BSD libc functions before they were C99 macros, so we can't
reimplement them in terms of fpclassify() without adding a dependency
on libc.so.5. I have tried to arrange things so that programs that
could be compiled in FreeBSD 4.X will generate the same external
references when compiled in 5.X. At the same time, the new macros
should remain C99-compliant.

The isinf() and isnan() functions remain in libc for historical
reasons; however, I have moved the functions that implement the macros
isfinite() and isnormal() to libm where they belong. Moreover,
half a dozen MD versions of isinf() and isnan() have been replaced
with MI versions that work equally well.

Prodded by: kris

Disconnect the userland get/set/swapcontext() functions from
libc. I want to keep these in some version for the thread
library/ies, but don't know whether to have them repo-copied
to libc_r or renamed and kept in libc.

Change the name of an alpha macro that was changed with the
system call commit.

Fixed editing error in previous commit (*blush*).

Fixed unsorting of SRCS.

Save and restore FPU state properly in ucontext_t's.

Reviewed by: deischen, julian
Approved by: -arch

Move swapcontext.c to the ${MACHINE_ARCH}/gen/Makefile.inc area, otherwise
it causes undefined references to getcontext() and setcontext() on
platforms other than i386 and alpha.

Fixed unsorting and splitting of SRCS in previous commit.

Add getcontext, setcontext, makecontext, and swapcontext. These
functions are defined in SUSv2 and the latest POSIX spec.

Thanks to Bernd Walter <ticso@cicely8.cicely.de> for helping debug my
alpha assembly.

Approved by: -arch

rfork(2) wrapper for simple rfork-style threads. I have lost count of
the number of times I have given this to people and got asked: why isn't
it in libc? It is impossible to do this without assembler glue to reset
the stack for the new child process.

int rfork_thread(flags, stack_addr, start_fnc, start_arg)
int flags; Flags to rfork system call. See rfork(2).
void *stack_addr; Top of stack for thread.
int (*start_fnc)(void *); Address of thread function to call in child.
void *start_arg; Argument to pass to the thread function in child.

This is deliberately not documented or prototyped in includes until the
corresponding alpha version is written.

$Id$ -> $FreeBSD$

Moved `SRCS+= frexp.c' to the correct Makefile.inc.

Sorted SRCS.

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.

remove GCC support functions from libc.
Should never have been here in the first place.

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.

Reenable sigsetjmp.S. Preserve the FP state. Rearrange offsets
to match setjmp.S.

Put __infinity back here again until someone does the right thing and
repartitions libc into something human again. I don't have that kind of
time right now myself, unfortunately.
Submitted by: jkh

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.

BSD 4.4 Lite Lib Sources