There is a race in pfault_interrupt. That function gets called two times for
each pfault notification. Once with a subcode of 0 to indicate that a real
page is not available and once with a subcode of 0x80 to indicate that the
page is present again.
Since the two external interrupts can be delivered on two different cpus the
order in which the two calls are made is unpredictable. It is possible that
the subcode 0x80 interrupt is completed before the subcode 0x00 interrupt has
done the wake_up() call.
To avoid calling wake_up() on an already removed task structure proper task
structure reference counting is needed. Increase the reference counter in the
subcode 0x00 interrupt before setting pfault_wait to zero and return the
reference after the wake_up call.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add interface to issue VM control program commands.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make cmm module parameter "sender" visible in sysfs.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The condition for no context in do_exception checks for hard and soft
interrupts by using in_interrupt() but not for preemption. This is bad for
the users of __copy_from/to_user_inatomic because the fault handler might call
schedule although the preemption count is != 0. Use in_atomic() instead
in_interrupt().
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
An arbitrary guest must not be allowed to trigger cmm actions. Only one
specific guest namely the one that serves as the resource monitor may send cmm
messages. Add a parameter that allows to specify the guest that may send
messages. z/VMs resource manager has the name 'VMRMSVM' which is the default.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The memory setup didn't take care of memory holes and this makes the memory
management think there would be more memory available than there is in
reality. That causes the OOM killer to kill processes even if there is enough
memory left that can be written to the swap space.
The patch fixes this by using free_area_init_node with an array of memory
holes instead of free_area_init. Further the patch cleans up the code in
setup.c by splitting setup_arch into smaller pieces.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Martin Schwidefsky