linux-toradex.git/arch/um/os-Linux, branch v3.12.6

um: Run UML in it's own session.

2013-09-07T08:57:07+00:00

If UML is not run by a shell it can happen that UML
will kill unrelated proceses upon a fatal exit because
it issues a kill(0, ...).
To prevent such oddities we create a new session in main().

Reported-and-tested-by: Richard W.M. Jones 
Signed-off-by: Richard Weinberger

um: Cleanup SIGTERM handling

2013-09-07T08:56:58+00:00

Richard reported that some UML processes survive if the UML
main process receives a SIGTERM.
This issue was caused by a wrongly placed signal(SIGTERM, SIG_DFL)
in init_new_thread_signals().
It disabled the UML exit handler accidently for some processes.
The correct solution is to disable the fatal handler for all
UML helper threads/processes.
Such that last_ditch_exit() does not get called multiple times
and all processes can exit due to SIGTERM.

Reported-and-tested-by: Richard W.M. Jones 
Signed-off-by: Richard Weinberger

um: ubd: Add REQ_FLUSH suppport

2013-09-07T08:56:49+00:00

UML's block device driver does not support write barriers,
to support this this patch adds REQ_FLUSH suppport.
Every time the block layer sends a REQ_FLUSH we fsync() now
our backing file to guarantee data consistency.

Reported-and-tested-by: Richard W.M. Jones 
Signed-off-by: Richard Weinberger

um: Implement probe_kernel_read()

2013-09-07T08:38:34+00:00

UML needs it's own probe_kernel_read() to handle kernel
mode faults correctly.
The implementation uses mincore() on the host side to detect
whether a page is owned by the UML kernel process.

This fixes also a possible crash when sysrq-t is used.
Starting with 3.10 sysrq-t calls probe_kernel_read() to
read details from the kernel workers. As kernel worker are
completely async pointers may turn NULL while reading them.

Cc: 
Cc: 
Cc:  # 3.10.x
Signed-off-by: Richard Weinberger

um: siginfo cleanup

2013-07-19T09:31:36+00:00

Currently we use both struct siginfo and siginfo_t.
Let's use struct siginfo internally to avoid ongoing
compiler warning. We are allowed to do so because
struct siginfo and siginfo_t are equivalent.

Signed-off-by: Richard Weinberger

uml: Fix which_tmpdir failure when /dev/shm is a symlink, and in other edge cases

2013-07-19T08:45:18+00:00

which_tmpdir did the wrong thing if /dev/shm was a symlink (e.g., to /run/shm),
if there were multiple mounts on top of each other, if the mount(s) were
obscured by a later mount, or if /dev/shm was a prefix of another mount point.
This fixes these cases. Applies to 3.9.6.

Signed-off-by: Tristan Schmelcher 
Signed-off-by: Richard Weinberger

um: Fix wait_stub_done() error handling

2013-07-19T08:45:18+00:00

If we die within a stub handler we only way to reliable
kill the (obviously) dying uml guest process is killing
it's host twin on the host side.

Signed-off-by: Richard Weinberger

Merge commit '8700c95adb03' into timers/nohz

2013-05-02T15:54:19+00:00

The full dynticks tree needs the latest RCU and sched
upstream updates in order to fix some dependencies.

Merge a common upstream merge point that has these
updates.

Conflicts:
	include/linux/perf_event.h
	kernel/rcutree.h
	kernel/rcutree_plugin.h

Signed-off-by: Frederic Weisbecker

nohz: Rename CONFIG_NO_HZ to CONFIG_NO_HZ_COMMON

2013-04-03T11:56:03+00:00

We are planning to convert the dynticks Kconfig options layout
into a choice menu. The user must be able to easily pick
any of the following implementations: constant periodic tick,
idle dynticks, full dynticks.

As this implies a mutual exclusion, the two dynticks implementions
need to converge on the selection of a common Kconfig option in order
to ease the sharing of a common infrastructure.

It would thus seem pretty natural to reuse CONFIG_NO_HZ to
that end. It already implements all the idle dynticks code
and the full dynticks depends on all that code for now.
So ideally the choice menu would propose CONFIG_NO_HZ_IDLE and
CONFIG_NO_HZ_EXTENDED then both would select CONFIG_NO_HZ.

On the other hand we want to stay backward compatible: if
CONFIG_NO_HZ is set in an older config file, we want to
enable CONFIG_NO_HZ_IDLE by default.

But we can't afford both at the same time or we run into
a circular dependency:

1) CONFIG_NO_HZ_IDLE and CONFIG_NO_HZ_EXTENDED both select
   CONFIG_NO_HZ
2) If CONFIG_NO_HZ is set, we default to CONFIG_NO_HZ_IDLE

We might be able to support that from Kconfig/Kbuild but it
may not be wise to introduce such a confusing behaviour.

So to solve this, create a new CONFIG_NO_HZ_COMMON option
which gathers the common code between idle and full dynticks
(that common code for now is simply the idle dynticks code)
and select it from their referring Kconfig.

Then we'll later create CONFIG_NO_HZ_IDLE and map CONFIG_NO_HZ
to it for backward compatibility.

Signed-off-by: Frederic Weisbecker 
Cc: Andrew Morton 
Cc: Chris Metcalf 
Cc: Christoph Lameter 
Cc: Geoff Levand 
Cc: Gilad Ben Yossef 
Cc: Hakan Akkan 
Cc: Ingo Molnar 
Cc: Kevin Hilman 
Cc: Li Zhong 
Cc: Namhyung Kim 
Cc: Paul E. McKenney 
Cc: Paul Gortmaker 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: Thomas Gleixner

um: fix build failure due to mess-up of sig_info protorype

2013-03-11T09:08:03+00:00

arch/um/os-Linux/signal.c:18:8: error: conflicting types for 'sig_info'
In file included from /home/slyfox/linux-2.6/arch/um/os-Linux/signal.c:12:0:
arch/um/include/shared/as-layout.h:64:15: note: previous declaration of 'sig_info' was here

Signed-off-by: Sergei Trofimovich 
CC: Jeff Dike 
CC: Richard Weinberger 
CC: "Martin Pärtel" 
CC: Al Viro 
CC: user-mode-linux-devel@lists.sourceforge.net
CC: user-mode-linux-user@lists.sourceforge.net
CC: linux-kernel@vger.kernel.org
Signed-off-by: Richard Weinberger