MFC r304928:
Do not obliterate errno value in the main thread during ptrace(2) call on x86.

MFC r304931:
Follow ABI when calling __error from the ptrace(2) wrapper.

MFC r305012:
Rewrite ptrace(2) wrappers in C.

MFC r305022:
Restore the requirement of setting errno to zero before calling ptrace(2).

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

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

The getcontext() from the __fillcontextx() call in the
check_deferred_signal() returns twice, since handle_signal() emulates
the return from the normal signal handler by sigreturn(2)ing the
passed context. Second return is performed on the destroyed stack
frame, because __fillcontextx() has already returned. This causes
undefined and bad behaviour, usually the victim thread gets SIGSEGV.

Avoid nested frame and the need to return from it by doing direct call
to getcontext() in the check_deferred_signal() and using a new private
libc helper __fillcontextx2() to complement the context with the
extended CPU state if the deferred signal is still present.

The __fillcontextx() is now unused, but is kept to allow older
libthr.so to be used with the new libc.

Mark __fillcontextx() as returning twice [1].

Reported by: pgj
Pointy hat to: kib
Discussed with: dim
Tested by: pgj, dim
Suggested by: jilles [1]
MFC after: 1 week

Rework the __vdso_* symbols attributes to only make the symbols weak,
but use normal references instead of weak. This makes the statically
linked binaries to use fast gettimeofday(2) by forcing the linker to
resolve references and providing the neccessary functions.

Reported by: bde
Tested by: marius (sparc64)
MFC after: 2 weeks

Make the sys/ucontext.h self-contained by changing the return type
of __getcontextx_size(3) from size_t to int.

PR: ports/164654
MFC after: 1 month

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.

Fix typos - remove duplicate "the".

PR: bin/154928
Submitted by: Eitan Adler <lists at eitanadler.com>
MFC after: 3 days

Remove unneeded stdlib directories.

It's not necessary to add stdlib directories for each architecture, even
if the architecture doesn't implement any files of its own.

Submitted by: Christoph Mallon

Mark uname(), getdomainname() and setdomainname() with COMPAT_FREEBSD4.

Looking at our source code history, it seems the uname(),
getdomainname() and setdomainname() system calls got deprecated
somewhere after FreeBSD 1.1, but they have never been phased out
properly. Because we don't have a COMPAT_FREEBSD1, just use
COMPAT_FREEBSD4.

Also fix the Linuxolator to build without the setdomainname() routine by
just making it call userland_sysctl on kern.domainname. Also replace the
setdomainname()'s implementation to use this approach, because we're
duplicating code with sysctl_domainname().

I wasn't able to keep these three routines working in our
COMPAT_FREEBSD32, because that would require yet another keyword for
syscalls.master (COMPAT4+NOPROTO). Because this routine is probably
unused already, this won't be a problem in practice. If it turns out to
be a problem, we'll just restore this functionality.

Reviewed by: rdivacky, kib

Add an alternative view of the bits in an 80-bit long double (64+16
instead of 32+32+15+1) on all arches that have such long doubles (amd64,
ia64 and i386). Large objects should be be accessed in large units,
and the 32+32+15+1[+padding] decomposition asks for almost the opposite
of that, sometimes resulting in very slow accesses depending on how
well the compiler ignores what we ask for and converts to the best
units for the given machine. E.g., on Athlons, there is a 10-20 cycle
penalty for accessing the middle 32-bit word immediately after an
80-bit store.

Whether actually using the alternative view is better is very machine-
dependent. A 32+32+16 view is probably best with old 32-bit systems
and gcc through 4.2.1. The compiler should mostly avoid the view and
generate best accesses, but gcc-4.2.1 is far from doing that. I think
64+16 is best for now. Similarly for doubles -- they should be using
64+0 especially on 64-bit machines, but fdlibm uses 32+32 extensively
for them. Fortunately, in 64-bit mode for doubles, gcc already ignores
the 32+32-bit view and generates best accesses in many cases.

Since nan() is supposed to work the same as strtod("nan(...)", NULL),
my original implementation made both use the same code. Unfortunately,
this meant libm depended on a vendor header at compile time and previously-
unexposed vendor bits in libc at runtime.

Hence, I just wrote my own version of the relevant vendor routine. As it
turns out, mine has a factor of 8 fewer of lines of code, and is a bit more
readable anyway. The strtod() and *scanf() routines still use vendor code.

Reviewed by: bde

Export gdtoa's __ULto{x,Q}_D2A routine in a private namespace so
libm can use it.

Arrange so that the NaN returned by strtod("nan", NULL) is the same as
the NaN returned by strtod("nan()", NULL).

In scanf, round according to the current rounding mode.

The fork symbols aren't MD, they already live in sys/.

Found by: version_gen.awk
Tested by: md5(1) (libc.so hasn't changed at all)

Classify mmap, lseek, pread, pwrite, truncate, ftruncate as pseudo
syscalls, unless WITHOUT_SYSCALL_COMPAT is defined. The default case
will have the .c wrappers still. If you define WITHOUT_SYSCALL_COMPAT,
the .c wrappers will go away and libc will make direct syscalls.

After 7-stable starts, the direct syscall method will be default.

Approved by: re (kensmith)

Adjust the syscall stub macros to be consistent in their meaning. In
particular:
SYSCALL() makes a syscall, with errno handling, and continues execution
directly after the macro in the non-error case.
RSYSCALL() is just like SYSCALL(), but returns after success.
Both SYSCALL(name) and RSYSCALL(name) export "__sys_name" as a strong
symbol, with "_name" and "name" as weak aliases.
PSEUDO() is just like RSYSCALL(), but skipping the "name" weak alias. It
still does "__sys_name" and "_name".

Change i386 to add errno handling to PSEUDO. The same for amd64 and
sparc64, with appear to have copied the behavior.
ia64 was correct (as was alpha). Just remove some apparently unused
variants of the macros. (untested!)
I believe powerpc is correct.
Fix arm to not export "name" from the PSEUDO case. Remove apparently
extra unused variants. (untested!)

The errno problem manifested on i386/amd64/sparc64 by having "PSEUDO"
classified syscalls return without setting errno. eg: "addr = mmap()"
could return with "addr" = 22 instead of setting errno to 22 and
returning -1.

Approved by: re (kensmith)

Some libc symbol map cleanups.

net: endhostdnsent is named _endhostdnsent and is
private to netdb family of functions.

posix1e: acl_size.c has been never compiled in,
so there's no "acl_size".

rpc: "getnetid" is a static function.

stdtime: "gtime" is #ifdef'ed out in the source.

some symbols are specific only to some architectures,
e.g., ___tls_get_addr is only defined on i386.

__htonl, __htons, __ntohl and __ntohs are no longer
functions, they are now (internal) defines in
<machine/endian.h>.

Submitted by: ru

Use C comments since we now preprocess these files with CPP.

The distinction between quiet and signaling NaN formats is
machine-dependent; these files tell the latest version of gdtoa
what to do.

Instead of re-implementing hton[ls] and friends for each arch, add a new MI
file, net/ntoh.c, which just implement them using the inline functions from
<sys/endian.h>.

Suggested by: bde

Prevent dead code elimination for the TP assignmient by using inline
assembly.

Fix comment.

Desupport the undocumented NO_QUAD option, just don't compile
the quad support on 64-bit platforms.

Add each directory's symbol map file to SYM_MAPS.

Add symbol maps and initial symbol version definitions to libc.

Reviewed by: davidxu

- Define LDBL_NBIT to be a mask indicating the position of the integer
bit in a long double. For architectures that don't have such a bit,
LDBL_NBIT is 0. This makes it possible to say `mantissa & ~LDBL_NBIT'
in places that previously used an #ifdef to select the right expression.
The optimizer should dispense with the extra arithmetic when LDBL_NBIT
is 0 anyway.
- Add an XXX comment for the big endian case.

Update my email address.

Replace the ldexp() implementation in libc with a renamed copy of the
scalbn() implementation from libm. (The two functions are defined to
be identical, but ldexp() lives in libc for backwards compatibility.)
The old ldexp() implementation...
- was more complicated than this one
- set errno instead of raising FP exceptions
- got some corner cases wrong
(e.g. ldexp(1.0, 2000) in round-to-zero mode)

The new implementation lives in libc/gen instead of
libc/$MACHINE_ARCH/gen, since we don't need N copies of a
machine-independent file. The amd64 and i386 platforms
retain their fast and correct MD implementations and
override this one.

Eliminate gdtoa.mk and move its contents to ${MACHINE_ARCH}/Makefile.inc.
The purpose of having a separate file involved an abandoned scheme that
would have kept contrib/gdtoa out of the include path for the rest of libc.

For variables that are only checked with defined(), don't provide
any fake value.

Unbreak memmove(). Return the dst argument. While here, fix the END
macro to actually reference memmove, not memcpy.

Unbreak memcpy(). memcpy() is defined to return the dst argument.
By using r8 instead of r14 to do the swap, we put the dst argument
in the return register. Since bcopy() doesn't clobber r8, we don't
have to do anything else. This fixes ports/textproc/aspell.

Make profiling actually work. The gcc compiler emits a call to the
_mcount() stub when profiling is enabled. Emit this code sequence
for assembly routines as welli (MCOUNT definition in <machine/asm.h>.
We do not pass the GOT entry however as the 4th argument, because it's
not used. The _mcount() stub calls __mcount(), which does the actual
work. Define _MCOUNT_DECL to define __mcount. We do not have an
implementation of mcount(), so we define MCOUNT as empty, but have a
weak alias to _mcount() in _mcount.S.
Note that the _mcount() stub in the kernel is slightly different from
the stub in userland. This is because we do not have to worry about
nested routines in the kernel.

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

Fix some aliasing problems.

style cleanup: Remove duplicate $FreeBSD$ tags.

These files had tags after teh copyright notice,
inside the comment block (incorrect, removed),
and outside the comment block (correct).

Approved by: rwatson (mentor)

Define LDBL_MANH_SIZE and LDBL_MANL_SIZE to be the sizes of the
high and low words of the mantissa in bits, respectively.

Add required headers.

Virtual addresses in headers of ELF files for dynamic objects need
to be relocated before they can be used as pointers.

The FP status register allows for 6 traps to be masked. One of them,
the denormal/unnormal trap, is not a standard IEEE trap. We did
not exclude it from being returned by fpgetmask(), nor did we make
sure that fpsetmask() didn't clobber it. Since the non-IEEE trap
is not part of fp_except_t, users of ifpgetmask()/fpsetmask() would
be confronted with unexpected behaviour, one of which is a SIGFPE
for denormal/unnormal FP results.

This commit makes sure that we don't leak the denormal/unnormal mask
bit in fp_except_t and also that we don't clobber it.

Add the mlockall() and munlockall() system calls.
- All those diffs to syscalls.master for each architecture *are*
necessary. This needed clarification; the stub code generation for
mlockall() was disabled, which would prevent applications from
linking to this API (suggested by mux)
- Giant has been quoshed. It is no longer held by the code, as
the required locking has been pushed down within vm_map.c.
- Callers must specify VM_MAP_WIRE_HOLESOK or VM_MAP_WIRE_NOHOLES
to express their intention explicitly.
- Inspected at the vmstat, top and vm pager sysctl stats level.
Paging-in activity is occurring correctly, using a test harness.
- The RES size for a process may appear to be greater than its SIZE.
This is believed to be due to mappings of the same shared library
page being wired twice. Further exploration is needed.
- Believed to back out of allocations and locks correctly
(tested with WITNESS, MUTEX_PROFILING, INVARIANTS and DIAGNOSTIC).

PR: kern/43426, standards/54223
Reviewed by: jake, alc
Approved by: jake (mentor)
MFC after: 2 weeks

o There are 6 trap disable bits in ar.fpsr, not five. Even though we
didn't provide a constant for one of them (non-IEEE denormal trap),
in an attempt to not support it probably, it's not we are left with
the lower 5 bits.
o Properly mask the passed or returned fp_except_t. Not doing so
causes instant core dumps by trying to write an invalid value to
ar.fpsr. Now that we're masking, stop using exclusive-or to invert
bits.

This fixes the illegal instruction fault encountered when building
mozilla.

Override the default stubs for getcontext(2) and swapcontext(2) so
that we can flush the register stack prior to entering the kernel.
This avoids having dirty registers and saves us from having to
manually write them to the backing store from within the kernel.
In that respect, flushing the RSE is both functionally required as
well as performance optimal.

On average we had 18 dirty registers when getcontext(2) was called
from libthr. Since libthr does not switch back to a context created
by getcontext(2), not having dealt with the dirty registers was
harmless.

The END() must expand to the .endp directive with the same name as
on the corresponding .proc directive, or the .endp must not have a
name at all.
While here, remove an artificial dependency in Ovfork.S by performing
manual register renaming.

Revert previous commit. We don't use setjmp()/longjmp() for context
switching anymore, so there's no need to save and restore GP. This
change breaks threaded applications linked against libc_r. Pull the
tier 2 card again: relink. This will link against libthr instead.

Implement signalcontext(). Needed by libpthread (aka libkse).

o Fix a cut-n-paste bug. We were clobbering rp with gp...
o Make sure the arguments to ctx_wrapper() are loaded from the
backing store by forcing an underflow. Do this by making all
registers in the register frame local.

Rough implement of makecontext() needed to support libthr.
o Up to 8 arguments are allowed. This is the number of arguments
passed in registers. Subsequent registers are passed on the stack.
Trying to deal with this is not easy in C and likely forces us to
use assembly code. Let's avoid that for now. There's no indication
that more than 8 arguments is a strong requirement (Linux also has
an 8 argument limit).
o We expect that the stack base is 16-byte aligned and the stack
size is a multiple of 16-byte. We bomb out if this is not the case.
We probably want to be less strict by enforcing it ourselves. For
now it's better to not hide gross alignment bogons by silently
correcting it.

Revamp of the syscall path, exception and context handling. The
prime objectives are:
o Implement a syscall path based on the epc inststruction (see
sys/ia64/ia64/syscall.s).
o Revisit the places were we need to save and restore registers
and define those contexts in terms of the register sets (see
sys/ia64/include/_regset.h).

Secundairy objectives:
o Remove the requirement to use contigmalloc for kernel stacks.
o Better handling of the high FP registers for SMP systems.
o Switch to the new cpu_switch() and cpu_throw() semantics.
o Add a good unwinder to reconstruct contexts for the rare
cases we need to (see sys/contrib/ia64/libuwx)

Many files are affected by this change. Functionally it boils
down to:
o The EPC syscall doesn't preserve registers it does not need
to preserve and places the arguments differently on the stack.
This affects libc and truss.
o The address of the kernel page directory (kptdir) had to
be unstaticized for use by the nested TLB fault handler.
The name has been changed to ia64_kptdir to avoid conflicts.
The renaming affects libkvm.
o The trapframe only contains the special registers and the
scratch registers. For syscalls using the EPC syscall path
no scratch registers are saved. This affects all places where
the trapframe is accessed. Most notably the unaligned access
handler, the signal delivery code and the debugger.
o Context switching only partly saves the special registers
and the preserved registers. This affects cpu_switch() and
triggered the move to the new semantics, which additionally
affects cpu_throw().
o The high FP registers are either in the PCB or on some
CPU. context switching for them is done lazily. This affects
trap().
o The mcontext has room for all registers, but not all of them
have to be defined in all cases. This mostly affects signal
delivery code now. The *context syscalls are as of yet still
unimplemented.

Many details went into the removal of the requirement to use
contigmalloc for kernel stacks. The details are mostly CPU
specific and limited to exception_save() and exception_restore().
The few places where we create, destroy or switch stacks were
mostly simplified by not having to construct physical addresses
and additionally saving the virtual addresses for later use.

Besides more efficient context saving and restoring, which of
course yields a noticable speedup, this also fixes the dreaded
SMP bootup problem as a side-effect. The details of which are
still not fully understood.

This change includes all the necessary backward compatibility
code to have it handle older userland binaries that use the
break instruction for syscalls. Support for break-based syscalls
has been pessimized in favor of a clean implementation. Due to
the overall better performance of the kernel, this will still
be notived as an improvement if it's noticed at all.

Approved by: re@ (jhb)

Add a comment describing why it's important for the values in this
file to be correct, and how to generate them automatically.

Caused much pain and suffering for: peter

Add __ldtoa(), a wrapper around gdtoa() to make it look like dtoa().
In support of this, add some MD macros to assist in converting long
doubles to the format expected by gdtoa().

Reviewed by: silence on standards@

Replace our ancient dtoa/strtod implementation with the gdtoa
package, a more recent, generalized set of routines. Among the
changes:
- Declare strtof() and strtold() in stdlib.h.
- Add glue to libc to support these routines for all kinds
of ``long double''.
- Update printf() to reflect the fact that dtoa works slightly
differently now.

As soon as I see that nothing has blown up, I will kill
src/lib/libc/stdlib/strtod.c. Soon printf() will be able
to use the new routines to output long doubles without loss
of precision, but numerous bugs in the existing code must
be addressed first.

Reviewed by: bde (briefly), mike (mentor), obrien

Fix threaded applications on ia64 that are linked dynamicly. We did
not save (restore) the global pointer (GP) in the jmpbuf in setjmp
(longjmp) because it's not needed in general. GP is considered a
scratch register at callsites and hence is always restored after a
call (when it's possible that the call resolves to a symbol in a
different loadmodule; otherwise GP does not have to be saved and
restored at all), including calls to setjmp/longjmp. There's just
one problem with this now that we use setjmp/longjmp for context
switching: A new context must have GP defined properly for the
thread's entry point. This means that we need to put GP in the
jmpbuf and consequently that we have to restore is in longjmp.
This automaticly requires us to save it as well.

When setjmp/longjmp isn't used for context switching, this can be
reverted again.

ABI breaker: Move the J_SIGMASK field in the jmpbuf before
the J_SIG0 field. While here, rename J_SIG0 to J_SIGSET and
remove J_SIG1. The main reason for this change is that the
128-bit sigset_t is now aligned on a 16-byte boundary, which
allows us to use 16-byte atomic loads and stores on CPUs that
support it. The removal of J_SIG1 is done to avoid confusion:
it is never accessed and should not be. Renaming J_SIG0 to
J_SIGSET is the icing on the cake that's better done now than
later.

Use __FBSDID.

ia64 actually uses 80-bit long doubles and must support big and little
endian at compile-time.

Reviewed by: das

o Implement C99 classification macros isfinite(), isinf(), isnan(),
isnormal(). The current isinf() and isnan() are perserved for
binary compatibility with 5.0, but new programs will use the macros.
o Implement C99 comparison macros isgreater(), isgreaterequal(),
isless(), islessequal(), islessgreater(), isunordered().

Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU>

Implement fpclassify():
o Add a MD header private to libc called _fpmath.h; this header
contains bitfield layouts of MD floating-point types.
o Add a MI header private to libc called fpmath.h; this header
contains bitfield layouts of MI floating-point types.
o Add private libc variables to lib/libc/$arch/gen/infinity.c for
storing NaN values.
o Add __double_t and __float_t to <machine/_types.h>, and provide
double_t and float_t typedefs in <math.h>.
o Add some C99 manifest constants (FP_ILOGB0, FP_ILOGBNAN, HUGE_VALF,
HUGE_VALL, INFINITY, NAN, and return values for fpclassify()) to
<math.h> and others (FLT_EVAL_METHOD, DECIMAL_DIG) to <float.h> via
<machine/float.h>.
o Add C99 macro fpclassify() which calls __fpclassify{d,f,l}() based
on the size of its argument. __fpclassifyl() is never called on
alpha because (sizeof(long double) == sizeof(double)), which is good
since __fpclassifyl() can't deal with such a small `long double'.

This was developed by David Schultz and myself with input from bde and
fenner.

PR: 23103
Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU>
(significant portions)
Reviewed by: bde, fenner (earlier versions)

Implement missing fpgetround() and fpsetround().

Correct typos, mostly s/ a / an / where appropriate. Some whitespace cleanup,
especially in troff files.

Sort SRCS.

o Fix _longjmp() to return 1 when the return value is given as 0.
o Remove the unwanted smartness in _longjmp() where it compares
the current ar.bspstore with the saved ar.bspstore and restores
ar.rnat based on it. This either avoids saving ar.rnat in the
jmp_buf or is the consequence of not saving ar.rnat. All this
complexity breaks libc_r where we use longjmp() to switch to
different threads and the current ar.bspstore has no relation
to the saved ar.bspstore. Thus: we save ar.rnat in setjmp()
and simply restore ar.bspstore and ar.rnat in longjmp().

This code needs a cleanup.

ia64 ABI breaker:
Don't force 16-byte alignment at run-time. Do it at compile-time.
This saves us the pointer fiddling by the setjmp functions and
reduces complexity. While here, increase the jmp_buf by 16 bytes
to an even 512 bytes. Coincidentally, due to the way alignment
was handled prior to this change, the jmp_buf has not changed in
size, but only in how the space is used. Prior to this change
the 16 bytes were reserved for enforcing alignment; now they are
reserved by us for future extensions.
Therefore, this ABI breaker is relatively save: the failure is
always an alignment trap.

Re-apply the previously backed-out commit that fixes the problem where
HUGE_VAL is not properly aligned on some architectures. The previous
fix now works because the two versions of 'math.h' (include/math.h
and lib/msun/src/math.h) have since been merged into one.

PR: bin/43544

Revert previous commit to unbreak world until we figure out the
right way to do it.

Fix a problem with the definition of HUGE_VAL causing the gcc warning
"cast increases required alignment of target type" on some platforms.

Reviewed by: bde

We cannot use an alloc with only inputs and/or locals. The kernel
assumes that the parameters are passed in output registers. Remove
the alloc entirely, but don't depend on the kernel not trashing
our registers.

Generate the normal asm stubs for all sysv system calls. Use these instead
of C wrappers for the *sys indirect system calls. The indirect system calls
are horribly broken on sparc64.

Submitted by: tmm

Our default syscall.S is identical to what was explicitly being done for
Alpha and IA-64. So there is no need for special handling.

Implement _Unwind_FindTableEntry(). This function is part of GCC
for some configurations, but not for FreeBSD (yet?). Have one in
libc in the mean time.

Fix the style of the SCM ID's.
I believe have made all of libc .h's as consistent as possible.

Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

Remove 'register' keyword.

o Move NTOHL() and associated macros into <sys/param.h>. These are
deprecated in favor of the POSIX-defined lowercase variants.
o Change all occurrences of NTOHL() and associated marcros in the
source tree to use the lowercase function variants.
o Add missing license bits to sparc64's <machine/endian.h>.
Approved by: jake
o Clean up <machine/endian.h> files.
o Remove unused __uint16_swap_uint32() from i386's <machine/endian.h>.
o Remove prototypes for non-existent bswapXX() functions.
o Include <machine/endian.h> in <arpa/inet.h> to define the
POSIX-required ntohl() family of functions.
o Do similar things to expose the ntohl() family in libstand, <netinet/in.h>,
and <sys/param.h>.
o Prepend underscores to the ntohl() family to help deal with
complexities associated with having MD (asm and inline) versions, and
having to prevent exposure of these functions in other headers that
happen to make use of endian-specific defines.
o Create weak aliases to the canonical function name to help deal with
third-party software forgetting to include an appropriate header.
o Remove some now unneeded pollution from <sys/types.h>.
o Add missing <arpa/inet.h> includes in userland.

Tested on: alpha, i386
Reviewed by: bde, jake, tmm

Implement fpsetmask() and fpgetmask().

Compensate for the way that _setjmp aligns the start of jmp_buf.

Fix WAW dependency. p6 is written in the syscall epilogue.

Fix a few more dependancy violations.

Implement setjmp, longjmp, sigsetjmp and siglongjmp.

Add __divdf3(), __divsf3() and __infinity[].

Obtained from: Intel (for the divide code)

Adjust so that we don't use relocations which can't exist in a shared
library.

Shorter versions of the byte swapping code.

Fix a load of dependancy violations.

Fix a whole bunch of dependancy bugs and make it actually work when the
size is not a multiple of eight.

Fix byte swapping - it was totally broken.

Implement _setjmp()/_longjmp().

Obtained from: Intel's EFI toolkit

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

Use relative paths to find byte_swap_*.S to make it easier to use these
from libstand.

Make this compile. Still need to write/borrow a working setjmp.

Correct a comment.

Clean up syscall generation in libc by removing HIDDEN_SYSCALLS
and treating (almost) all system calls the same way:

__sys_foo - actual syscall
foo, _foo - weak definitions to __sys_foo

Change PSEUDO syscalls (currently only _exit and _getlogin) to
be __sys_foo (T) and _foo (W).

Add $FreeBSD$ to a few files to satisfy commitprep.

Suggested by: bde

Comment only change; s/_thread_sys_/__sys_/

Remove _THREAD_SAFE and make libc thread-safe by default by
adding (weak definitions to) stubs for some of the pthread
functions. If the threads library is linked in, the real
pthread functions will pulled in.

Use the following convention for system calls wrapped by the
threads library:
__sys_foo - actual system call
_foo - weak definition to __sys_foo
foo - weak definition to __sys_foo

Change all libc uses of system calls wrapped by the threads
library from foo to _foo. In order to define the prototypes
for _foo(), we introduce namespace.h and un-namespace.h
(suggested by bde). All files that need to reference these
system calls, should include namespace.h before any standard
includes, then include un-namespace.h after the standard
includes and before any local includes. <db.h> is an exception
and shouldn't be included in between namespace.h and
un-namespace.h namespace.h will define foo to _foo, and
un-namespace.h will undefine foo.

Try to eliminate some of the recursive calls to MT-safe
functions in libc/stdio in preparation for adding a mutex
to FILE. We have recursive mutexes, but would like to avoid
using them if possible.

Remove uneeded includes of <errno.h> from a few files.

Add $FreeBSD$ to a few files in order to pass commitprep.

Approved by: -arch

Remove last vestiges of thr_sleep and thr_wakeup from libc.

Return zero from setjmp() and _setjmp() for now.

Fix a couple of dumb mistakes.

Fix RAW dependency violation on p6 between cmp and mov.

Initial libc port for ia64.