linux.git/arch/um/include/shared/os.h, branch v4.12

x86/arch_prctl/64: Rename do_arch_prctl() to do_arch_prctl_64()

2017-03-20T15:10:32+00:00

In order to introduce new arch_prctls that are not 64 bit only, rename the
existing 64 bit implementation to do_arch_prctl_64(). Also rename the
second argument of that function from 'addr' to 'arg2', because it will no
longer always be an address.

Signed-off-by: Kyle Huey 
Reviewed-by: Andy Lutomirski 
Cc: Grzegorz Andrejczuk 
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář 
Cc: Peter Zijlstra 
Cc: Dave Hansen 
Cc: Andi Kleen 
Cc: linux-kselftest@vger.kernel.org
Cc: Nadav Amit 
Cc: Robert O'Callahan 
Cc: Richard Weinberger 
Cc: "Rafael J. Wysocki" 
Cc: Borislav Petkov 
Cc: Len Brown 
Cc: Shuah Khan 
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jeff Dike 
Cc: Alexander Viro 
Cc: user-mode-linux-user@lists.sourceforge.net
Cc: David Matlack 
Cc: Boris Ostrovsky 
Cc: Dmitry Safonov 
Cc: linux-fsdevel@vger.kernel.org
Cc: Paolo Bonzini 
Link: http://lkml.kernel.org/r/20170320081628.18952-5-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner

x86/arch_prctl: Rename 'code' argument to 'option'

2017-03-20T15:10:32+00:00

The x86 specific arch_prctl() arbitrarily changed prctl's 'option' to
'code'. Before adding new options, rename it.

Signed-off-by: Kyle Huey 
Cc: Grzegorz Andrejczuk 
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář 
Cc: Peter Zijlstra 
Cc: Dave Hansen 
Cc: Andi Kleen 
Cc: linux-kselftest@vger.kernel.org
Cc: Nadav Amit 
Cc: Robert O'Callahan 
Cc: Richard Weinberger 
Cc: "Rafael J. Wysocki" 
Cc: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Len Brown 
Cc: Shuah Khan 
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jeff Dike 
Cc: Alexander Viro 
Cc: user-mode-linux-user@lists.sourceforge.net
Cc: David Matlack 
Cc: Boris Ostrovsky 
Cc: Dmitry Safonov 
Cc: linux-fsdevel@vger.kernel.org
Cc: Paolo Bonzini 
Link: http://lkml.kernel.org/r/20170320081628.18952-3-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner

um: Fix ptrace GETREGS/SETREGS bugs

2016-01-10T20:49:48+00:00

This fix two related bugs:
* PTRACE_GETREGS doesn't get the right orig_ax (syscall) value
* PTRACE_SETREGS can't set the orig_ax value (erased by initial value)

Get rid of the now useless and error-prone get_syscall().

Fix inconsistent behavior in the ptrace implementation for i386 when
updating orig_eax automatically update the syscall number as well. This
is now updated in handle_syscall().

Signed-off-by: Mickaël Salaün 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Thomas Gleixner 
Cc: Kees Cook 
Cc: Andy Lutomirski 
Cc: Will Drewry 
Cc: Thomas Meyer 
Cc: Nicolas Iooss 
Cc: Anton Ivanov 
Cc: Meredydd Luff 
Cc: David Drysdale 
Signed-off-by: Richard Weinberger 
Acked-by: Kees Cook

um: Update UBD to use pread/pwrite family of functions

2016-01-10T20:49:48+00:00

This decreases the number of syscalls per read/write by half.

Signed-off-by: Anton Ivanov 
Signed-off-by: Richard Weinberger

um: Switch clocksource to hrtimers

2015-11-06T21:54:49+00:00

UML is using an obsolete itimer call for
all timers and "polls" for kernel space timer firing
in its userspace portion resulting in a long list
of bugs and incorrect behaviour(s). It also uses
ITIMER_VIRTUAL for its timer which results in the
timer being dependent on it running and the cpu
load.

This patch fixes this by moving to posix high resolution
timers firing off CLOCK_MONOTONIC and relaying the timer
correctly to the UML userspace.

Fixes:
 - crashes when hosts suspends/resumes
 - broken userspace timers - effecive ~40Hz instead
   of what they should be. Note - this modifies skas behavior
   by no longer setting an itimer per clone(). Timer events
   are relayed instead.
 - kernel network packet scheduling disciplines
 - tcp behaviour especially under load
 - various timer related corner cases

Finally, overall responsiveness of userspace is better.

Signed-off-by: Thomas Meyer 
Signed-off-by: Anton Ivanov 
[rw: massaged commit message]
Signed-off-by: Richard Weinberger

um: Store syscall number after syscall_trace_enter()

2015-11-06T21:49:09+00:00

To support changing syscall numbers we have to store
it after syscall_trace_enter().

Signed-off-by: Richard Weinberger

um: Move syscall() declaration into os.h

2015-05-31T11:14:07+00:00

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: Memory corruption on startup

2014-04-20T21:57:21+00:00

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 
[rw: minor whitespace fixes]
Signed-off-by: Richard Weinberger

um: Make stack trace reliable against kernel mode faults

2013-11-17T10:27:30+00:00

As UML uses an alternative signal stack we cannot use
the current stack pointer for stack dumping if UML itself
dies by SIGSEGV. To bypass this issue we save regs taken
from mcontext in our segv handler into thread_struct and
use these regs to obtain the stack pointer in show_stack().

Signed-off-by: Richard Weinberger