Change register_for_each_vma() to take mm->mmap_sem for writing.
This is a bit unfortunate but hopefully not too bad, this is the
slow path anyway.

This is needed to ensure that find_active_uprobe() can not race
with uprobe_register() which adds the new bp at the same
bp_vaddr, after find_uprobe() fails and before
is_swbp_at_addr_fast() checks the memory.

IOW, this is needed to ensure that if find_active_uprobe()
returns NULL but is_swbp == true, we can safely assume that it
was the "normal" int3 and we should send SIGTRAP.

There is another reason for this change. We are going to replace
uprobes_state->count with MMF_ flags set by register/unregister
and cleared by find_active_uprobe(), and set/clear shouldn't
race with each other.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120529192928.GE8057@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

A separate patch to simplify the review, and for the
documentation.

The patch adds another "int *is_swbp" argument to
find_active_uprobe(), so far its only caller doesn't use this
info.

With this patch find_active_uprobe() additionally does:

	- if find_vma() + ->vm_start check fails, *is_swbp = -EFAULT

	- otherwise, if valid_vma() + find_uprobe() fails, it holds
	  the result of is_swbp_at_addr(), can be negative too. The
	  latter is only possible if we raced with another thread
	  which did munmap/etc after we hit this bp.

IOW. If find_active_uprobe(&is_swbp) returns NULL, the caller
can look at is_swbp to figure out whether the current insn is bp
or not, or detect the race with another thread if it is
negative.

Note: I think that performance-wise this change is fine. This
adds is_swbp_at_addr(), but only if we raced with
uprobe_unregister() or if we hit the "normal" int3 but this mm
has uprobes as well. And even in this case the slow
read_opcode() path is very unlikely, this insn recently
triggered do_int3(), __copy_from_user_inatomic() shouldn't fail
in the likely case.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120529192914.GD8057@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

No functional changes. Move the "find uprobe" code from
handle_swbp() to the new helper, find_active_uprobe().

Note: with or without this change, the find-active-uprobe logic
is not exactly right. We can race with another thread which
unmaps the memory with the valid uprobe before we take
mm->mmap_sem. We can't find this uprobe simply because
find_vma() fails. In this case we wrongly assume that this trap
was not caused by uprobe and send the erroneous SIGTRAP. See the
next changes.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120529192857.GC8057@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

set_orig_insn()->read_opcode() should not fail if the probed
task did mprotect() after uprobe_register(), change it to use
FOLL_FORCE. Without FOLL_WRITE this doesn't have any "side"
effect but allows to read the !VM_READ memory.

There is another reason for this change, we are going to use
is_swbp_at_addr() from handle_swbp() which can race with another
thread doing mprotect().
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120529192759.GB8057@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Change is_swbp_at_addr() to try to avoid the costly
read_opcode() if mm == current->mm, __copy_from_user_inatomic()
should succeed in the likely case.

Currently this optimization is not important, but we are going
to add more is_swbp_at_addr(current->mm) callers.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120529192744.GA8057@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Does block_sigmask() + tracehook_signal_handler();  called when
sigframe has been successfully built.  All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).

I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Only 3 out of 63 do not.  Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Everyone either defines it in arch thread_info.h or has TIF_RESTORE_SIGMASK
and picks default set_restore_sigmask() in linux/thread_info.h.  Kill the
ifdefs, slap #error in linux/thread_info.h to catch breakage when new ones
get merged.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

When we do restore we would like to have a way to setup a former
mm_struct::exe_file so that /proc/pid/exe would point to the original
executable file a process had at checkpoint time.

For this the PR_SET_MM_EXE_FILE code is introduced.  This option takes a
file descriptor which will be set as a source for new /proc/$pid/exe
symlink.

Note it allows to change /proc/$pid/exe if there are no VM_EXECUTABLE
vmas present for current process, simply because this feature is a special
to C/R and mm::num_exe_file_vmas become meaningless after that.

To minimize the amount of transition the /proc/pid/exe symlink might have,
this feature is implemented in one-shot manner.  Thus once changed the
symlink can't be changed again.  This should help sysadmins to monitor the
symlinks over all process running in a system.

In particular one could make a snapshot of processes and ring alarm if
there unexpected changes of /proc/pid/exe's in a system.

Note -- this feature is available iif CONFIG_CHECKPOINT_RESTORE is set and
the caller must have CAP_SYS_RESOURCE capability granted, otherwise the
request to change symlink will be rejected.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: NOleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

During checkpoint we dump whole process memory to a file and the dump
includes process stack memory.  But among stack data itself, the stack
carries additional parameters such as command line arguments, environment
data and auxiliary vector.

So when we do restore procedure and once we've restored stack data itself
we need to setup mm_struct::arg_start/end, env_start/end, so restored
process would be able to find command line arguments and environment data
it had at checkpoint time.  The same applies to auxiliary vector.

For this reason additional PR_SET_MM_(ARG_START | ARG_END | ENV_START |
ENV_END | AUXV) codes are introduced.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Acked-by: NKees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

While doing the checkpoint-restore in the user space one need to determine
whether various kernel objects (like mm_struct-s of file_struct-s) are
shared between tasks and restore this state.

The 2nd step can be solved by using appropriate CLONE_ flags and the
unshare syscall, while there's currently no ways for solving the 1st one.

One of the ways for checking whether two tasks share e.g.  mm_struct is to
provide some mm_struct ID of a task to its proc file, but showing such
info considered to be not that good for security reasons.

Thus after some debates we end up in conclusion that using that named
'comparison' syscall might be the best candidate.  So here is it --
__NR_kcmp.

It takes up to 5 arguments - the pids of the two tasks (which
characteristics should be compared), the comparison type and (in case of
comparison of files) two file descriptors.

Lookups for pids are done in the caller's PID namespace only.

At moment only x86 is supported and tested.

[akpm@linux-foundation.org: fix up selftests, warnings]
[akpm@linux-foundation.org: include errno.h]
[akpm@linux-foundation.org: tweak comment text]
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Valdis.Kletnieks@vt.edu
Cc: Michal Marek <mmarek@suse.cz>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For those who doesn't need C/R functionality there is no need to control
last pid, ie the pid for the next fork() call.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Force SIGCHLD handling to SIG_IGN so that signals are not generated and so
that the children autoreap.  This increases the parallelize and in general
the speed of network namespace shutdown.

Note self reaping childrean can exist past zap_pid_ns_processess but they
will all be reaped before we allow the pid namespace init task with pid ==
1 to be reaped.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Louis Rilling <louis.rilling@kerlabs.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Using task_active_pid_ns is more robust because it works even after we
have called exit_namespaces.  This change allows us to have parent
processes that are zombies.  Normally a zombie parent processes is crazy
and the last thing you would want to have but in the case of not letting
the init process of a pid namespace be reaped until all of it's children
are dead and reaped a zombie parent process is exactly what we want.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Louis Rilling <louis.rilling@kerlabs.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add more comments on clear_tasks_mm_cpumask, plus adds a runtime check:
the function is only suitable for offlined CPUs, and if called
inappropriately, the kernel should scream aloud.

[akpm@linux-foundation.org: tweak comment: s/walks up/walks/, use 80 cols]
Suggested-by: NAndrew Morton <akpm@linux-foundation.org>
Suggested-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many architectures clear tasks' mm_cpumask like this:

	read_lock(&tasklist_lock);
	for_each_process(p) {
		if (p->mm)
			cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
	}
	read_unlock(&tasklist_lock);

Depending on the context, the code above may have several problems,
such as:

1. Working with task->mm w/o getting mm or grabing the task lock is
   dangerous as ->mm might disappear (exit_mm() assigns NULL under
   task_lock(), so tasklist lock is not enough).

2. Checking for process->mm is not enough because process' main
   thread may exit or detach its mm via use_mm(), but other threads
   may still have a valid mm.

This patch implements a small helper function that does things
correctly, i.e.:

1. We take the task's lock while whe handle its mm (we can't use
   get_task_mm()/mmput() pair as mmput() might sleep);

2. To catch exited main thread case, we use find_lock_task_mm(),
   which walks up all threads and returns an appropriate task
   (with task lock held).

Also, Per Peter Zijlstra's idea, now we don't grab tasklist_lock in
the new helper, instead we take the rcu read lock. We can do this
because the function is called after the cpu is taken down and marked
offline, so no new tasks will get this cpu set in their mm mask.
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Child should wake up the parent from vfork() only after finishing all
operations with shared mm.  There is no sense in using
CLONE_CHILD_CLEARTID together with CLONE_VFORK, but it looks more accurate
now.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In embedded systems, sometimes the same program (busybox) is the cause of
multiple warnings.  Outputting the pid with the program name in the
warning printk helps distinguish which instances of a program are using
the stack most.

This is a small patch, but useful.
Signed-off-by: NTim Bird <tim.bird@am.sony.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 8f92054e ("CRED: Fix __task_cred()'s lockdep check and banner
comment"):

    add the following validation condition:

        task->exit_state >= 0

    to permit the access if the target task is dead and therefore
    unable to change its own credentials.

OK, but afaics currently this can only help wait_task_zombie() which calls
__task_cred() without rcu lock.

Remove this validation and change wait_task_zombie() to use task_uid()
instead.  This means we do rcu_read_lock() only to shut up the lockdep,
but we already do the same in, say, wait_task_stopped().

task_is_dead() should die, task->exit_state != 0 means that this task has
passed exit_notify(), only do_wait-like code paths should use this.

Unfortunately, we can't kill task_is_dead() right now, it has already
acquired buggy users in drivers/staging.  The fix already exists.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Warning(kernel/kmod.c:419): No description found for parameter 'depth'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If we move call_usermodehelper_fns() to kmod.c file and EXPORT_SYMBOL it
we can avoid exporting all it's helper functions:
	call_usermodehelper_setup
	call_usermodehelper_setfns
	call_usermodehelper_exec
And make all of them static to kmod.c

Since the optimizer will see all these as a single call site it will
inline them inside call_usermodehelper_fns().  So we loose the call to
_fns but gain 3 calls to the helpers.  (Not that it matters)
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Both kernel/sys.c && security/keys/request_key.c where inlining the exact
same code as call_usermodehelper_fns(); So simply convert these sites to
directly use call_usermodehelper_fns().
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

call_usermodehelper_freeinfo() is not used outside of kmod.c.  So unexport
it, and make it static to kmod.c
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NNicolas Pitre <nico@linaro.org>
Acked-by: NColin Cross <ccross@android.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the module-wide pr_fmt() mechanism rather than open-coding "genirq: "
everywhere.

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

sethostname() and setdomainname() notify userspace on failure (without
modifying uts_kern_table).  Change things so that we only notify userspace
on success, when uts_kern_table was actually modified.
Signed-off-by: NSasikantha babu <sasikanth.v19@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: WANG Cong <amwang@redhat.com>
Reviewed-by: NCyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the comment of allocate_resource(), the explanation of parameter max
and min is not correct.

Actually, these two parameters are used to specify the range of the
resource that will be allocated, not the min/max size that will be
allocated.
Signed-off-by: NWei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The @func callback was invoked twice for group leader when
perf_event_for_each() called. It seems the commit 75f937f2
("perf_counter: Fix ctx->mutex vs counter ->mutex inversion") made the
mistake during the change.
Signed-off-by: NNamhyung Kim <namhyung.kim@lge.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1338443506-25009-1-git-send-email-namhyung.kim@lge.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Remove explicit NULL assignment of static pointer
dattr_cur from init_sched_domains().
Signed-off-by: NKamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120523091411.GG5005@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

No need to have the last NULL entry.
Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4FBF29E7.5020805@ct.jp.nec.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The strings sched_feat_names are never changed.
Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4FBF29B2.9030904@ct.jp.nec.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

task_tick_rt() has an optimization to only reschedule SCHED_RR tasks
if they were the only element on their rq.  However, with cgroups
a SCHED_RR task could be the only element on its per-cgroup rq but
still be competing with other SCHED_RR tasks in its parent's
cgroup.  In this case, the SCHED_RR task in the child cgroup would
never yield at the end of its timeslice.  If the child cgroup
rt_runtime_us was the same as the parent cgroup rt_runtime_us,
the task in the parent cgroup would starve completely.

Modify task_tick_rt() to check that the task is the only task on its
rq, and that the each of the scheduling entities of its ancestors
is also the only entity on its rq.
Signed-off-by: NColin Cross <ccross@android.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337229266-15798-1-git-send-email-ccross@android.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Since nr_cpus_allowed is used outside of sched/rt.c and wants to be
used outside of there more, move it to a more natural site.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-kr61f02y9brwzkh6x53pdptm@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

We could re-read rq->rt_avg after we validated it was smaller than
total, invalidating the check and resulting in an unintended negative.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/1337688268.9698.29.camel@twinsSigned-off-by: NIngo Molnar <mingo@kernel.org>

SD_OVERLAP exists to allow overlapping groups, overlapping groups
appear in NUMA topologies that aren't fully connected.

The typical result of not fully connected NUMA is that each cpu (or
rather node) will have different spans for a particular distance.
However due to how sched domains are traversed -- only the first cpu
in the mask goes one level up -- the next level only cares about the
spans of the cpus that went up.

Due to this two things were observed to be broken:

 - build_overlap_sched_groups() -- since its possible the cpu we're
   building the groups for exists in multiple (or all) groups, the
   selection criteria of the first group didn't ensure there was a cpu
   for which is was true that cpumask_first(span) == cpu. Thus load-
   balancing would terminate.

 - update_group_power() -- assumed that the cpu span of the first
   group of the domain was covered by all groups of the child domain.
   The above explains why this isn't true, so deal with it.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/1337788843.9783.14.camel@laptopSigned-off-by: NIngo Molnar <mingo@kernel.org>

Allocators don't appreciate it when you try and allocate memory from
offline nodes.
Reported-and-tested-by: NTony Luck <tony.luck@intel.com>
Reported-and-tested-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-epfc1io9whb7o22bcujf31vn@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Follow up on commit 556061b0 ("sched/nohz: Fix rq->cpu_load[]
calculations") since while that fixed the busy case it regressed the
mostly idle case.

Add a callback from the nohz exit to also age the rq->cpu_load[]
array. This closes the hole where either there was no nohz load
balance pass during the nohz, or there was a 'significant' amount of
idle time between the last nohz balance and the nohz exit.

So we'll update unconditionally from the tick to not insert any
accidental 0 load periods while busy, and we try and catch up from
nohz idle balance and nohz exit. Both these are still prone to missing
a jiffy, but that has always been the case.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: pjt@google.com
Cc: Venkatesh Pallipadi <venki@google.com>
Link: http://lkml.kernel.org/n/tip-kt0trz0apodbf84ucjfdbr1a@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

lglocks and brlocks are currently generated with some complicated macros
in lglock.h.  But there's no reason to not just use common utility
functions and put all the data into a common data structure.

Since there are at least two users it makes sense to share this code in a
library.  This is also easier maintainable than a macro forest.

This will also make it later possible to dynamically allocate lglocks and
also use them in modules (this would both still need some additional, but
now straightforward, code)

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Using %ps in a printk format will sometimes fail silently and print the
empty string if the address passed in does not match a symbol that
kallsyms knows about.  But using %pS will fall back to printing the full
address if kallsyms can't find the symbol.  Make %ps act the same as %pS
by falling back to printing the address.

While we're here also make %ps print the module that a symbol comes from
so that it matches what %pS already does.  Take this simple function for
example (in a module):

	static void test_printk(void)
	{
		int test;
		pr_info("with pS: %pS\n", &test);
		pr_info("with ps: %ps\n", &test);
	}

Before this patch:

 with pS: 0xdff7df44
 with ps:

After this patch:

 with pS: 0xdff7df44
 with ps: 0xdff7df44
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>