signal.h: add linux/signal.h and asm/signal.h to UAPI compile-test coverage

linux/signal.h and asm/signal.h are currently excluded from the UAPI
compile-test because of the errors like follows:

HDRTEST usr/include/asm/signal.h
In file included from <command-line>:
./usr/include/asm/signal.h:103:9: error: unknown type name ‘size_t’
103 | size_t ss_size;
| ^~~~~~

The errors can be fixed by replacing size_t with __kernel_size_t.

Then, remove the no-header-test entries from user/include/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch: move SA_* definitions to generic headers

Most architectures with the exception of alpha, mips, parisc and
sparc use the same values for these flags. Move their definitions into
asm-generic/signal-defs.h and allow the architectures with non-standard
values to override them. Also, document the non-standard flag values
in order to make it easier to add new generic flags in the future.

A consequence of this change is that on powerpc and x86, the constants'
values aside from SA_RESETHAND change signedness from unsigned
to signed. This is not expected to impact realistic use of these
constants. In particular the typical use of the constants where they
are or'ed together and assigned to sa_flags (or another int variable)
would not be affected.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://linux-review.googlesource.com/id/Ia3849f18b8009bf41faca374e701cdca36974528
Link: https://lkml.kernel.org/r/b6d0d1ec34f9ee93e1105f14f288fba5f89d1f24.1605235762.git.pcc@google.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

License cleanup: add SPDX license identifier to uapi header files with no license

Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.

By default are files without license information under the default
license of the kernel, which is GPLV2. Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:

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".

otherwise syscall usage would not be possible.

Update the files which contain no license information with an SPDX
license identifier. The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception. SPDX license identifiers are a legally binding
shorthand, which can be used instead of the full boiler plate text.

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>

arm64: Fix MINSIGSTKSZ and SIGSTKSZ

MINSIGSTKSZ and SIGSTKSZ for ARM64 are not correctly set in latest kernel.
This patch fixes this issue.

This issue is reported in LTP (testcase: sigaltstack02.c).
Testcase failed when sigaltstack() called with stack size "MINSIGSTKSZ - 1"
Since in Glibc-2.22, MINSIGSTKSZ is set to 5120 but in kernel
it is set to 2048 so testcase gets failed.

Testcase Output:
sigaltstack02 1 TPASS : stgaltstack() fails, Invalid Flag value,errno:22
sigaltstack02 2 TFAIL : sigaltstack() returned 0, expected -1,errno:12

Reported Issue in Glibc Bugzilla:
Bugfix in Glibc-2.22: [Bug 16850]
https://sourceware.org/bugzilla/show_bug.cgi?id=16850

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Akhilesh Kumar <akhilesh.k@samsung.com>
Signed-off-by: Manjeet Pawar <manjeet.p@samsung.com>
Signed-off-by: Rohit Thapliyal <r.thapliyal@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

consolidate kernel-side struct sigaction declarations

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

consolidate declarations of k_sigaction

Only alpha and sparc are unusual - they have ka_restorer in it.
And nobody needs that exposed to userland.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

unify SS_ONSTACK/SS_DISABLE definitions

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

UAPI: (Scripted) Disintegrate include/asm-generic

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>