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

Revert r253748,253749

This WIP should not have been committed yet.

Pointyhat to: avg

remove needless inclusion of machine/cpu.h in userland

MFC after: 21 days

Remove clause 3 and 4 from TNF licenses

Per the NetBSD Foundation statement
Third parties are encouraged to change the license on any files which
have a 4-clause license contributed to the NetBSD Foundation to a
2-clause license.

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

Do not restore the register holding the TLS pointer when doing various
usermode context switches (long jumps and ucontext operations). If these
are used across threads, multiple threads can end up with the same TLS base.
Madness will then result.

This makes behavior on PPC match that on x86 systems and on Linux.

MFC after: 10 days

Properly resolve the _ctx_start function descriptor (the symbol _ctx_start
is a descriptor, not a code address), which prevents crashes when starting
a context. This fixes QEMU on powerpc64.

MFC after: 3 days

Replace the assembler macro WEAK_ALIAS with a new macro WEAK_REFERENCE which
has the same API as __weak_reference(). Give 'x' in SYS.h a more meaningful
name.

Tested on 32- and 64-bit PowerMac.

Reviewed by: bde

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

This commit adds profiling support for powerpc64. Now we can do application
profiling and kernel profiling. To enable kernel profiling one has to build
kgmon(8). I will enable the build once I managed to build and test powerpc
(32-bit) kernels with profiling support.

- add a powerpc64 PROF_PROLOGUE for _mcount.
- add macros to avoid adding the PROF_PROLOGUE in certain assembly entries.
- apply these macros where needed.
- add size information to the MCOUNT function.

MFC after: 3 weeks, together with r230291

Two other places where we can use WEAK_ALIAS.

Use the macro WEAK_ALIAS. Tested on 32 and 64-bit.

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

Turn off default generation of userland dot symbols on powerpc64 now that
we have a binutils that supports it. Kernel dot symbols remain on to assist
DDB.

Mark assembler sources from libc as working with non-executable stack.

Reviewed and tested by: nwhitehorn

Fix stack alignment (required to be to 16 bytes) instead of ptrace and
cerror on powerpc64.

Make sure to specify the alignment of minbrk and curbrk. They were correctly
aligned by accident with earlier binutils, but no longer are, causing link
failures.

Submitted by: nwhitehorn
Obtained from: projects/binutils-2.17

Provide 64-bit PowerPC support in libc.

Obtained from: projects/ppc64