linux-stable.git/arch/um/kernel/skas/process.c, branch linux-4.2.y

um: Remove broken SMP support

2015-04-13T19:00:58+00:00

At times where UML used the TT mode to operate it had
kind of SMP support. It never got finished nor was
stable.
Let's rip out that cruft and stop confusing developers
which do tree-wide SMP cleanups.

If someone wants SMP support UML it has do be done from scratch.

Signed-off-by: Richard Weinberger

um: Remove SKAS3/4 support

2015-04-13T19:00:53+00:00

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default since 2005, SKAS3/4 is obsolete and can be removed.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

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

2012-10-09T20:28:45+00:00

Signed-off-by: Al Viro 
Signed-off-by: Richard Weinberger

remove references to cpu_*_map in arch/

2012-03-29T05:08:30+00:00

This has been obsolescent for a while; time for the final push.

In adjacent context, replaced old cpus_* with cpumask_*.

Signed-off-by: Rusty Russell 
Acked-by: David S. Miller  (arch/sparc)
Acked-by: Chris Metcalf  (arch/tile)
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Russell King 
Cc: linux-arm-kernel@lists.infradead.org
Cc: Richard Kuo 
Cc: linux-hexagon@vger.kernel.org
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Cc: Kyle McMartin 
Cc: Helge Deller 
Cc: sparclinux@vger.kernel.org

uml: kill processes instead of panicing kernel

2008-02-05T17:44:28+00:00

UML was panicing in the case of failures of libc calls which shouldn't happen.
 This is an overreaction since a failure from libc doesn't normally mean that
kernel data structures are in an unknown state.  Instead, the current process
should just be killed if there is no way to recover.

The case that prompted this was a failure of PTRACE_SETREGS restoring the same
state that was read by PTRACE_GETREGS.  It appears that when a process tries
to load a bogus value into a segment register, it segfaults (as expected) and
the value is actually loaded and is seen by PTRACE_GETREGS (not expected).

This case is fixed by forcing a fatal SIGSEGV on the process so that it
immediately dies.  fatal_sigsegv was added for this purpose.  It was declared
as noreturn, so in order to pursuade gcc that it actually does not return, I
added a call to os_dump_core (and declared it noreturn) so that I get a core
file if somehow the process survives.

All other calls in arch/um/os-Linux/skas/process.c got the same treatment,
with failures causing the process to die instead of a kernel panic, with some
exceptions.

userspace_tramp exits with status 1 if anything goes wrong there.  That will
cause start_userspace to return an error.  copy_context_skas0 and
map_stub_pages also now return errors instead of panicing.  Callers of thes
functions were changed to check for errors and do something appropriate.
Usually that's to return an error to their callers.
check_skas3_ptrace_faultinfo just exits since that's too early to do anything
else.

save_registers, restore_registers, and init_registers now return status
instead of panicing on failure, with their callers doing something
appropriate.

There were also duplicate declarations of save_registers and restore_registers
in os.h - these are gone.

I noticed and fixed up some whitespace damage.

Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: fix stub address calculations

2007-10-16T16:43:09+00:00

The calculation of CONFIG_STUB_CODE and CONFIG_STUB_DATA didn't take into
account anything but 3G/1G and 2G/2G, leaving the other vmsplits out in the
cold.

I'd rather not duplicate the four known host vmsplit cases for each of these
symbols.  I'd also like to calculate them based on the highest userspace
address.

The Kconfig language seems not to allow calculation of hex constants, so I
moved this to as-layout.h.  CONFIG_STUB_CODE, CONFIG_STUB_DATA, and
CONFIG_STUB_START are now gone.  In their place are STUB_CODE, STUB_DATA, and
STUB_START in as-layout.h.

i386 and x86_64 seem to differ as to whether an unadorned constant is an int
or a long, so I cast them to unsigned long so they can be printed
consistently.  However, they are also used in stub.S, where C types don't work
so well.  So, there are ASM_ versions of these constants for use in stub.S.  I
also ifdef-ed the non-asm-friendly portion of as-layout.h.

With this in place, most of the rest of this patch is changing CONFIG_STUB_*
to STUB_*, except in stub.S, where they are changed to ASM_STUB_*.

defconfig has the old symbols deleted.

I also print these addresses out in case there is any problem mapping them on
the host.

The two stub.S files had some trailing whitespace, so that is cleaned up here.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: fold mmu_context_skas into mm_context

2007-10-16T16:43:06+00:00

This patch folds mmu_context_skas into struct mm_context, changing all users
of these structures as needed.

Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: style fixes pass 3

2007-10-16T16:43:05+00:00

Formatting changes in the files which have been changed in the course
of folding foo_skas functions into their callers.  These include:
	copyright updates
	header file trimming
	style fixes
	adding severity to printks

These changes should be entirely non-functional.

Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: remove code made redundant by CHOOSE_MODE removal

2007-10-16T16:43:05+00:00

This patch makes a number of simplifications enabled by the removal of
CHOOSE_MODE.  There were lots of functions that looked like

	int foo(args){
		foo_skas(args);
	}

The bodies of foo_skas are now folded into foo, and their declarations (and
sometimes entire header files) are deleted.

In addition, the union uml_pt_regs, which was a union between the tt and skas
register formats, is now a struct, with the tt-mode arm of the union being
removed.

It turns out that usr2_handler was unused, so it is gone.

Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

uml: more __init annotations

2007-07-24T19:24:58+00:00

2.6.23-rc1 turned up another batch of references from non-__init code to
__init code.  In most cases, these were missing __init annotations.  In one
case (os_drop_memory), the annotation was present but wrong.

init_maps is __init, but for some reason was being very careful about the
mechanism by which it allocated memory, checking whether it was OK to use
kmalloc (at this point in the boot, it definitely isn't) and using either
alloc_bootmem_low_pages or kmalloc/vmalloc.  So, the kmalloc/vmalloc code is
removed.

Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds