arch: sembuf.h: make uapi asm/sembuf.h self-contained

Userspace cannot compile <asm/sembuf.h> due to some missing type
definitions. For example, building it for x86 fails as follows:

CC usr/include/asm/sembuf.h.s
In file included from <command-line>:32:0:
usr/include/asm/sembuf.h:17:20: error: field `sem_perm' has incomplete type
struct ipc64_perm sem_perm; /* permissions .. see ipc.h */
^~~~~~~~
usr/include/asm/sembuf.h:24:2: error: unknown type name `__kernel_time_t'
__kernel_time_t sem_otime; /* last semop time */
^~~~~~~~~~~~~~~
usr/include/asm/sembuf.h:25:2: error: unknown type name `__kernel_ulong_t'
__kernel_ulong_t __unused1;
^~~~~~~~~~~~~~~~
usr/include/asm/sembuf.h:26:2: error: unknown type name `__kernel_time_t'
__kernel_time_t sem_ctime; /* last change time */
^~~~~~~~~~~~~~~
usr/include/asm/sembuf.h:27:2: error: unknown type name `__kernel_ulong_t'
__kernel_ulong_t __unused2;
^~~~~~~~~~~~~~~~
usr/include/asm/sembuf.h:29:2: error: unknown type name `__kernel_ulong_t'
__kernel_ulong_t sem_nsems; /* no. of semaphores in array */
^~~~~~~~~~~~~~~~
usr/include/asm/sembuf.h:30:2: error: unknown type name `__kernel_ulong_t'
__kernel_ulong_t __unused3;
^~~~~~~~~~~~~~~~
usr/include/asm/sembuf.h:31:2: error: unknown type name `__kernel_ulong_t'
__kernel_ulong_t __unused4;
^~~~~~~~~~~~~~~~

It is just a matter of missing include directive.

Include <asm/ipcbuf.h> to make it self-contained, and add it to
the compile-test coverage.

Link: http://lkml.kernel.org/r/20191030063855.9989-3-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

y2038: ipc: remove __kernel_time_t reference from headers

There are two structures based on time_t that conflict between libc and
kernel: timeval and timespec. Both are now renamed to __kernel_old_timeval
and __kernel_old_timespec.

For time_t, the old typedef is still __kernel_time_t. There is nothing
wrong with that name, but it would be nice to not use that going forward
as this type is used almost only in deprecated interfaces because of
the y2038 overflow.

In the IPC headers (msgbuf.h, sembuf.h, shmbuf.h), __kernel_time_t is only
used for the 64-bit variants, which are not deprecated.

Change these to a plain 'long', which is the same type as __kernel_time_t
on all 64-bit architectures anyway, to reduce the number of users of the
old type.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

y2038: powerpc: Extend sysvipc data structures

powerpc, uses a nonstandard variation of the generic sysvipc
data structures, intended to have the padding moved around
so it can deal with big-endian 32-bit user space that has
64-bit time_t.

powerpc has the same definition as parisc and sparc, but now also
supports little-endian mode, which is now wrong because the
padding is made for big-endian user space.

This takes just take the same approach here that we have for
the asm-generic headers and adds separate 32-bit fields for the
upper halves of the timestamps, to let libc deal with the mess
in user space.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

License cleanup: add SPDX license identifier to uapi header files with a license

Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be. This makes it hard for
compliance tools to determine the correct license.

Update these files with an SPDX license identifier. The identifier was
chosen based on the license information in the file.

GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:

NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".

This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.

Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier. The format
is:
((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)

SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text. The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

UAPI: (Scripted) Disintegrate arch/powerpc/include/asm

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>