um: Cleanup compiler warning in arch/x86/um/tls_32.c

arch.tls_array is statically allocated so checking for NULL doesn't
make sense. This causes the compiler warning below.

Remove the checks to silence these warnings.

../arch/x86/um/tls_32.c: In function 'get_free_idx':
../arch/x86/um/tls_32.c:68:13: warning: the comparison will always evaluate as 'true' for the address of 'tls_array' will never be NULL [-Waddress]
68 | if (!t->arch.tls_array)
| ^
In file included from ../arch/x86/um/asm/processor.h:10,
from ../include/linux/rcupdate.h:30,
from ../include/linux/rculist.h:11,
from ../include/linux/pid.h:5,
from ../include/linux/sched.h:14,
from ../arch/x86/um/tls_32.c:7:
../arch/x86/um/asm/processor_32.h:22:31: note: 'tls_array' declared here
22 | struct uml_tls_struct tls_array[GDT_ENTRY_TLS_ENTRIES];
| ^~~~~~~~~
../arch/x86/um/tls_32.c: In function 'get_tls_entry':
../arch/x86/um/tls_32.c:243:13: warning: the comparison will always evaluate as 'true' for the address of 'tls_array' will never be NULL [-Waddress]
243 | if (!t->arch.tls_array)
| ^
../arch/x86/um/asm/processor_32.h:22:31: note: 'tls_array' declared here
22 | struct uml_tls_struct tls_array[GDT_ENTRY_TLS_ENTRIES];
| ^~~~~~~~~

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Implement copy_thread_tls

This is required for clone3 which passes the TLS value through a
struct rather than a register.

Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: linux-um@lists.infradead.org
Cc: <stable@vger.kernel.org> # 5.3.x
Link: https://lore.kernel.org/r/20200104123928.1048822-1-amanieu@gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Replace <asm/uaccess.h> with <linux/uaccess.h> globally

This was entirely automated, using the script by Al:

PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

um: Don't pollute kernel namespace with uapi

Don't include ptrace uapi stuff in arch headers, it will
pollute the kernel namespace and conflict with existing
stuff.
In this case it fixes clashes with common names like R8.

Signed-off-by: Richard Weinberger <richard@nod.at>

make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect

... and switch i386 to HAVE_SYSCALL_WRAPPERS, killing open-coded
uses of asmlinkage_protect() in a bunch of syscalls.

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

um: get rid of pointless include "..." where include <...> will do

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

um/x86: merge (and trim) 32- and 64-bit variants of ptrace.h

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

um: take arch/um/sys-x86 to arch/x86/um

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>