Once x86 exports its do_signal(), the prototypes will clash.

Fix the clash and also improve the code a bit: remove the
unnecessary kern_do_signal() indirection. This allows
interrupt_end() to share the 'regs' parameter calculation.

Also remove the unused return code to match x86.

Minimally build and boot tested.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard.weinberger@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/67c57eac09a589bac3c6c5ff22f9623ec55a184a.1435952415.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

As we got rid of the __KERNEL__ abuse, we can directly
include linux/compiler.h now.
This also allows gcc 5 to build UML.

Reported-by: Hans-Werner Hilse <hwhilse@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Currently UML is abusing __KERNEL__ to distinguish between
kernel and host code (os-Linux). It is better to use a custom
define such that existing users of __KERNEL__ don't get confused.

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

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

atomic_notifier_chain_register() and uml_postsetup() do call kernel code
that rely on the "current" kernel macro and a valid task_struct resp.
thread_info struct. Give those functions a valid stack by moving
uml_postsetup() in the init_thread stack. This moves enables a panic()
call in this early code to generate a valid stacktrace, instead of
crashing.
E.g. when an UML kernel is started with an initrd but too few physical
memory the panic() call get's actually processed.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>

Before we had SKAS0 UML had two modes of operation
TT (tracing thread) and SKAS3/4 (separated kernel address space).
TT was known to be insecure and got removed a long time ago.
SKAS3/4 required a few (3 or 4) patches on the host side which never went
mainline. The last host patch is 10 years old.

With SKAS0 mode (separated kernel address space using 0 host patches),
default since 2005, SKAS3/4 is obsolete and can be removed.

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

1) uml kernel bootmem managed through bootmem_data->node_bootmem_map,
not the struct page array, so the array is unnecessary.

2) the bootmem struct page array has been pointed by a *local* pointer,
struct page *map, in init_maps function. The array can be accessed only
in init_maps's scope. As a result, uml kernel wastes about 1% of total
memory.

Signed-off-by: Honggang Li <enjoymindful@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Use the more generic functions get_signal() signal_setup_done()
for signal delivery.

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

The reverse case of this race (you must msync before read) is
well known. This is the not so common one.

It can be triggered only on systems which do a lot of task
switching and only at UML startup. If you are starting 200+ UMLs
~ 0.5% will always die without this fix.

Signed-off-by: Anton Ivanov <antivano@cisco.com>
[rw: minor whitespace fixes]
Signed-off-by: Richard Weinberger <richard@nod.at>

_end is used, but it's already provided by <asm/sections.h>, so use that.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Signed-off-by: Richard Weinberger <richard@nod.at>