There's no point calling it when _alloc() failed.

Link: http://lkml.kernel.org/r/1370585268-29169-1-git-send-email-namhyung@kernel.orgSigned-off-by: NNamhyung Kim <namhyung@kernel.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The function tracer uses preempt_disable/enable_notrace() for
synchronization between reading registered ftrace_ops and unregistering
them.

Most of the ftrace_ops are global permanent structures that do not
require this synchronization. That is, ops may be added and removed from
the hlist but are never freed, and wont hurt if a synchronization is
missed.

But this is not true for dynamically created ftrace_ops or control_ops,
which are used by the perf function tracing.

The problem here is that the function tracer can be used to trace
kernel/user context switches as well as going to and from idle.
Basically, it can be used to trace blind spots of the RCU subsystem.
This means that even though preempt_disable() is done, a
synchronize_sched() will ignore CPUs that haven't made it out of user
space or idle. These can include functions that are being traced just
before entering or exiting the kernel sections.

To implement the RCU synchronization, instead of using
synchronize_sched() the use of schedule_on_each_cpu() is performed. This
means that when a dynamically allocated ftrace_ops, or a control ops is
being unregistered, all CPUs must be touched and execute a ftrace_sync()
stub function via the work queues. This will rip CPUs out from idle or
in dynamic tick mode. This only happens when a user disables perf
function tracing or other dynamically allocated function tracers, but it
allows us to continue to debug RCU and context tracking with function
tracing.

Link: http://lkml.kernel.org/r/1369785676.15552.55.camel@gandalf.local.home

Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Commit 4f271a2a
(tracing: Add a proc file to stop tracing and free buffer)
implement a method to free up ring buffer in kernel memory
in the release code path of free_buffer's fd.

Then we don't need read/write support for free_buffer,
indeed we just have a dummy write fop, and don't implement read fop.

So the 0200 is more reasonable file mode for free_buffer than
the current file mode 0644.

Link: http://lkml.kernel.org/r/20130526085201.GA3183@udknightAcked-by: NVaibhav Nagarnaik <vnagarnaik@google.com>
Acked-by: NDavid Sharp <dhsharp@google.com>
Signed-off-by: NWang YanQing <udknight@gmail.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Consolidate the checks for !enabled and !param to return -EINVAL
in event_enable_func().

Link: http://lkml.kernel.org/r/1369380137-12452-1-git-send-email-harsh@linux.vnet.ibm.comSigned-off-by: NHarsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add the "cpudump" command to have the current CPU ftrace buffer dumped
to console if a function is hit. This is useful when debugging a
tripple fault, where you have an idea of a function that is called
just before the tripple fault occurs, and can tell ftrace to dump its
content out to the console before it continues.

This differs from the "dump" command as it only dumps the content of
the ring buffer for the currently executing CPU, and does not show
the contents of the other CPUs.

Format is:

  <function>:cpudump

echo 'bad_address:cpudump' > /debug/tracing/set_ftrace_filter

To remove this:

echo '!bad_address:cpudump' > /debug/tracing/set_ftrace_filter
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add the "dump" command to have the ftrace buffer dumped to console if
a function is hit. This is useful when debugging a tripple fault,
where you have an idea of a function that is called just before the
tripple fault occurs, and can tell ftrace to dump its content out
to the console before it continues.

Format is:

  <function>:dump

echo 'bad_address:dump' > /debug/tracing/set_ftrace_filter

To remove this:

echo '!bad_address:dump' > /debug/tracing/set_ftrace_filter
Requested-by: NLuis Claudio R. Goncalves <lclaudio@uudg.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The first_irq needs to be zero to get a linear domain and that
comes with special semantics. We want to simplify this going
forward but some documentation never hurts.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

Since irq_data may be NULL, if so, we WARN_ON(), and continue, 'hwirq'
which related with 'irq_data' has to initialize later, or it will cause
issue.
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

All other irq_domain_add_* functions are exported already, and apparently
this one got left out by mistake, which causes build errors for ARM
allmodconfig kernels:

ERROR: "irq_domain_add_simple" [drivers/gpio/gpio-rcar.ko] undefined!
ERROR: "irq_domain_add_simple" [drivers/gpio/gpio-em.ko] undefined!
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

The irqsoff tracer records the max time that interrupts are disabled.
There are hooks in the assembly code that calls back into the tracer when
interrupts are disabled or enabled.

When they are enabled, the tracer checks if the amount of time they
were disabled is larger than the previous recorded max interrupts off
time. If it is, it creates a snapshot of the currently running trace
to store where the last largest interrupts off time was held and how
it happened.

During testing, this RCU lockdep dump appeared:

[ 1257.829021] ===============================
[ 1257.829021] [ INFO: suspicious RCU usage. ]
[ 1257.829021] 3.10.0-rc1-test+ #171 Tainted: G        W
[ 1257.829021] -------------------------------
[ 1257.829021] /home/rostedt/work/git/linux-trace.git/include/linux/rcupdate.h:780 rcu_read_lock() used illegally while idle!
[ 1257.829021]
[ 1257.829021] other info that might help us debug this:
[ 1257.829021]
[ 1257.829021]
[ 1257.829021] RCU used illegally from idle CPU!
[ 1257.829021] rcu_scheduler_active = 1, debug_locks = 0
[ 1257.829021] RCU used illegally from extended quiescent state!
[ 1257.829021] 2 locks held by trace-cmd/4831:
[ 1257.829021]  #0:  (max_trace_lock){......}, at: [<ffffffff810e2b77>] stop_critical_timing+0x1a3/0x209
[ 1257.829021]  #1:  (rcu_read_lock){.+.+..}, at: [<ffffffff810dae5a>] __update_max_tr+0x88/0x1ee
[ 1257.829021]
[ 1257.829021] stack backtrace:
[ 1257.829021] CPU: 3 PID: 4831 Comm: trace-cmd Tainted: G        W    3.10.0-rc1-test+ #171
[ 1257.829021] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007
[ 1257.829021]  0000000000000001 ffff880065f49da8 ffffffff8153dd2b ffff880065f49dd8
[ 1257.829021]  ffffffff81092a00 ffff88006bd78680 ffff88007add7500 0000000000000003
[ 1257.829021]  ffff88006bd78680 ffff880065f49e18 ffffffff810daebf ffffffff810dae5a
[ 1257.829021] Call Trace:
[ 1257.829021]  [<ffffffff8153dd2b>] dump_stack+0x19/0x1b
[ 1257.829021]  [<ffffffff81092a00>] lockdep_rcu_suspicious+0x109/0x112
[ 1257.829021]  [<ffffffff810daebf>] __update_max_tr+0xed/0x1ee
[ 1257.829021]  [<ffffffff810dae5a>] ? __update_max_tr+0x88/0x1ee
[ 1257.829021]  [<ffffffff811002b9>] ? user_enter+0xfd/0x107
[ 1257.829021]  [<ffffffff810dbf85>] update_max_tr_single+0x11d/0x12d
[ 1257.829021]  [<ffffffff811002b9>] ? user_enter+0xfd/0x107
[ 1257.829021]  [<ffffffff810e2b15>] stop_critical_timing+0x141/0x209
[ 1257.829021]  [<ffffffff8109569a>] ? trace_hardirqs_on+0xd/0xf
[ 1257.829021]  [<ffffffff811002b9>] ? user_enter+0xfd/0x107
[ 1257.829021]  [<ffffffff810e3057>] time_hardirqs_on+0x2a/0x2f
[ 1257.829021]  [<ffffffff811002b9>] ? user_enter+0xfd/0x107
[ 1257.829021]  [<ffffffff8109550c>] trace_hardirqs_on_caller+0x16/0x197
[ 1257.829021]  [<ffffffff8109569a>] trace_hardirqs_on+0xd/0xf
[ 1257.829021]  [<ffffffff811002b9>] user_enter+0xfd/0x107
[ 1257.829021]  [<ffffffff810029b4>] do_notify_resume+0x92/0x97
[ 1257.829021]  [<ffffffff8154bdca>] int_signal+0x12/0x17

What happened was entering into the user code, the interrupts were enabled
and a max interrupts off was recorded. The trace buffer was saved along with
various information about the task: comm, pid, uid, priority, etc.

The uid is recorded with task_uid(tsk). But this is a macro that uses rcu_read_lock()
to retrieve the data, and this happened to happen where RCU is blind (user_enter).

As only the preempt and irqs off tracers can have this happen, and they both
only have the tsk == current, if tsk == current, use current_uid() instead of
task_uid(), as current_uid() does not use RCU as only current can change its uid.

This fixes the RCU suspicious splat.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The branch selftest calls trace_test_buffer(), but with the new code
it expects the first parameter to be a pointer to a struct trace_buffer.
All self tests were changed but the branch selftest was missed.

This caused either a crash or failed test when the branch selftest was
enabled.

Link: http://lkml.kernel.org/r/20130529141333.GA24064@localhostReported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

As rcu_dereference_raw() under RCU debug config options can add quite a
bit of checks, and that tracing uses rcu_dereference_raw(), these checks
happen with the function tracer. The function tracer also happens to trace
these debug checks too. This added overhead can livelock the system.

Have the function tracer use the new RCU _notrace equivalents that do
not do the debug checks for RCU.

Link: http://lkml.kernel.org/r/20130528184209.467603904@goodmis.orgAcked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

With the new __DEVEL__sane_behavior mount option was introduced,
if the root cgroup is alive with no xattr function, to mount a
new cgroup with xattr will be rejected in terms of design which
just fine.  However, if the root cgroup does not mounted with
__DEVEL__sane_hehavior, to create a new cgroup with xattr option
will succeed although after that the EA function does not works
as expected but will get ENOTSUPP for setting up attributes under
either cgroup. e.g.

setfattr: /cgroup2/test: Operation not supported

Instead of keeping silence in this case, it's better to drop a log
entry in warning level.  That would be helpful to understand the
reason behind the scene from the user's perspective, and this is
essentially an improvement does not break the backward compatibilities.

With this fix, above mount attemption will keep up works as usual but
the following line cound be found at the system log:

[ ...] cgroup: new mount options do not match the existing superblock

tj: minor formatting / message updates.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reported-by: NAlexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org

Since commit 31ade306, timekeeping_init()
checks for presence of persistent clock by attempting to read a non-zero
time value. This is an issue on platforms where persistent_clock (instead
is implemented as a free-running counter (instead of an RTC) starting
from zero on each boot and running during suspend. Examples are some ARM
platforms (e.g. PandaBoard).

An attempt to read such a clock during timekeeping_init() may return zero
value and falsely declare persistent clock as missing. Additionally, in
the above case suspend times may be accounted twice (once from
timekeeping_resume() and once from rtc_resume()), resulting in a gradual
drift of system time.

This patch does a run-time correction of the issue by doing the same check
during timekeeping_suspend().

A better long-term solution would have to return error when trying to read
non-existing clock and zero when trying to read an uninitialized clock, but
that would require changing all persistent_clock implementations.

This patch addresses the immediate breakage, for now.

Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NZoran Markovic <zoran.markovic@linaro.org>
[jstultz: Tweaked commit message and subject]
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

kernel/time/ntp.c: In function ‘__hardpps’:
kernel/time/ntp.c:877: warning: unused variable ‘flags’

commit a076b214 ("ntp: Remove ntp_lock,
using the timekeeping locks to protect ntp state") removed its users,
but not the actual variable.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

The tracing infrastructure sets up for possible CPUs, but it uses
the ring buffer polling, it is possible to call the ring buffer
polling code with a CPU that hasn't been allocated. This will cause
a kernel oops when it access a ring buffer cpu buffer that is part
of the possible cpus but hasn't been allocated yet as the CPU has never
been online.
Reported-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

commit 26517f3e (tick: Avoid programming the local cpu timer if
broadcast pending) added a warning if the cpu enters broadcast mode
again while the pending bit is still set. Meelis reported that the
warning triggers. There are two corner cases which have been not
considered:

1) cpuidle calls clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER)
   twice. That can result in the following scenario

   CPU0                    CPU1
                           cpuidle_idle_call()
                             clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER)
                               set cpu in tick_broadcast_oneshot_mask

   broadcast interrupt
     event expired for cpu1
     set pending bit

                             acpi_idle_enter_simple()
                               clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER)
                                 WARN_ON(pending bit)

  Move the WARN_ON into the section where we enter broadcast mode so
  it wont provide false positives on the second call.

2) safe_halt() enables interrupts, so a broadcast interrupt can be
   delivered befor the broadcast mode is disabled. That sets the
   pending bit for the CPU which receives the broadcast
   interrupt. Though the interrupt is delivered right away from the
   broadcast handler and leaves the pending bit stale.

   Clear the pending bit for the current cpu in the broadcast handler.
Reported-and-tested-by: NMeelis Roos <mroos@linux.ee>
Cc: Len Brown <lenb@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305271841130.4220@ionosSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Fix kernel-doc warnings in kernel/auditfilter.c:

  Warning(kernel/auditfilter.c:1029): Excess function parameter 'loginuid' description in 'audit_receive_filter'
  Warning(kernel/auditfilter.c:1029): Excess function parameter 'sessionid' description in 'audit_receive_filter'
  Warning(kernel/auditfilter.c:1029): Excess function parameter 'sid' description in 'audit_receive_filter'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When cgroup_next_descendant_pre() initiates a walk, it checks whether
the subtree root doesn't have any children and if not returns NULL.
Later code assumes that the subtree isn't empty.  This is broken
because the subtree may become empty inbetween, which can lead to the
traversal escaping the subtree by walking to the sibling of the
subtree root.

There's no reason to have the early exit path.  Remove it along with
the later assumption that the subtree isn't empty.  This simplifies
the code a bit and fixes the subtle bug.

While at it, fix the comment of cgroup_for_each_descendant_pre() which
was incorrectly referring to ->css_offline() instead of
->css_online().
Signed-off-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NMichal Hocko <mhocko@suse.cz>
Cc: stable@vger.kernel.org

If ftrace=<tracer> is on the kernel command line, when that tracer is
registered, it will be initiated by tracing_set_tracer() to execute that
tracer.

The nop tracer is just a stub tracer that is used to have no tracer
enabled. It is assigned at early bootup as it is the default tracer.

But if ftrace=nop is on the kernel command line, the registering of the
nop tracer will call tracing_set_tracer() which will try to execute
the nop tracer. But it expects tr->current_trace to be assigned something
as it usually is assigned to the nop tracer. As it hasn't been assigned
to anything yet, it causes the system to crash.

The simple fix is to move the tr->current_trace = nop before registering
the nop tracer. The functionality is still the same as the nop tracer
doesn't do anything anyway.
Reported-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Christian found v3.9 does not work with E350 with EFI is enabled.

[    1.658832] Trying to unpack rootfs image as initramfs...
[    1.679935] BUG: unable to handle kernel paging request at ffff88006e3fd000
[    1.686940] IP: [<ffffffff813661df>] memset+0x1f/0xb0
[    1.692010] PGD 1f77067 PUD 1f7a067 PMD 61420067 PTE 0

but early memtest report all memory could be accessed without problem.

early page table is set in following sequence:
[    0.000000] init_memory_mapping: [mem 0x00000000-0x000fffff]
[    0.000000] init_memory_mapping: [mem 0x6e600000-0x6e7fffff]
[    0.000000] init_memory_mapping: [mem 0x6c000000-0x6e5fffff]
[    0.000000] init_memory_mapping: [mem 0x00100000-0x6bffffff]
[    0.000000] init_memory_mapping: [mem 0x6e800000-0x6ea07fff]
but later efi_enter_virtual_mode try set mapping again wrongly.
[    0.010644] pid_max: default: 32768 minimum: 301
[    0.015302] init_memory_mapping: [mem 0x640c5000-0x6e3fcfff]
that means it fails with pfn_range_is_mapped.

It turns out that we have a bug in add_range_with_merge and it does not
merge range properly when new add one fill the hole between two exsiting
ranges. In the case when [mem 0x00100000-0x6bffffff] is the hole between
[mem 0x00000000-0x000fffff] and [mem 0x6c000000-0x6e7fffff].

Fix the add_range_with_merge by calling itself recursively.
Reported-by: N"Christian König" <christian.koenig@amd.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/CAE9FiQVofGoSk7q5-0irjkBxemqK729cND4hov-1QCBJDhxpgQ@mail.gmail.com
Cc: <stable@vger.kernel.org> v3.9
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

As kmemleak now scans all module sections that are allocated, writable
and non executable, there's no need to scan individual sections that
might reference data.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>

Instead of just picking data sections by name (names that start
with .data, .bss or .ref.data), use the section flags and scan all
sections that are allocated, writable and not executable. Which should
cover all sections of a module that might reference data.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
[catalin.marinas@arm.com: removed unused 'name' variable]
[catalin.marinas@arm.com: collapsed 'if' blocks]
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>

argv_split(empty_or_all_spaces) happily succeeds, it simply returns
argc == 0 and argv[0] == NULL. Change call_usermodehelper_exec() to
check sub_info->path != NULL to avoid the crash.

This is the minimal fix, todo:

 - perhaps we should change argv_split() to return NULL or change the
   callers.

 - kill or justify ->path[0] check

 - narrow the scope of helper_lock()
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-By: NLucas De Marchi <lucas.demarchi@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since try_module_get() returns false( = 0) when it fails to
pindown a module, event_enable_func() returns 0 which means
"succeed". This can cause a kernel panic when the entry
is removed, because the event is already released.

This fixes the bug by returning -EBUSY, because the reason
why it fails is that the module is being removed at that time.

Link: http://lkml.kernel.org/r/20130516114848.13508.97899.stgit@mhiramat-M0-7522

Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

wq_numa_init() builds per-node cpumasks which are later used to make
unbound workqueues NUMA-aware.  The cpumasks are allocated using
alloc_cpumask_var_node() for all possible nodes.  Unfortunately, on
machines with off-line nodes, this leads to NUMA-aware allocations on
existing bug offline nodes, which in turn triggers BUG in the memory
allocation code.

Fix it by using NUMA_NO_NODE for cpumask allocations for offline
nodes.

  kernel BUG at include/linux/gfp.h:323!
  invalid opcode: 0000 [#1] SMP
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0+ #1
  Hardware name: ProLiant BL465c G7, BIOS A19 12/10/2011
  task: ffff880234608000 ti: ffff880234602000 task.ti: ffff880234602000
  RIP: 0010:[<ffffffff8117495d>]  [<ffffffff8117495d>] new_slab+0x2ad/0x340
  RSP: 0000:ffff880234603bf8  EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff880237404b40 RCX: 00000000000000d0
  RDX: 0000000000000001 RSI: 0000000000000003 RDI: 00000000002052d0
  RBP: ffff880234603c28 R08: 0000000000000000 R09: 0000000000000001
  R10: 0000000000000001 R11: ffffffff812e3aa8 R12: 0000000000000001
  R13: ffff8802378161c0 R14: 0000000000030027 R15: 00000000000040d0
  FS:  0000000000000000(0000) GS:ffff880237800000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: ffff88043fdff000 CR3: 00000000018d5000 CR4: 00000000000007f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Stack:
   ffff880234603c28 0000000000000001 00000000000000d0 ffff8802378161c0
   ffff880237404b40 ffff880237404b40 ffff880234603d28 ffffffff815edba1
   ffff880237816140 0000000000000000 ffff88023740e1c0
  Call Trace:
   [<ffffffff815edba1>] __slab_alloc+0x330/0x4f2
   [<ffffffff81174b25>] kmem_cache_alloc_node_trace+0xa5/0x200
   [<ffffffff812e3aa8>] alloc_cpumask_var_node+0x28/0x90
   [<ffffffff81a0bdb3>] wq_numa_init+0x10d/0x1be
   [<ffffffff81a0bec8>] init_workqueues+0x64/0x341
   [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0
   [<ffffffff819f1f31>] kernel_init_freeable+0xb7/0x1ec
   [<ffffffff815d50de>] kernel_init+0xe/0xf0
   [<ffffffff815ff89c>] ret_from_fork+0x7c/0xb0
  Code: 45  84 ac 00 00 00 f0 41 80 4d 00 40 e9 f6 fe ff ff 66 0f 1f 84 00 00 00 00 00 e8 eb 4b ff ff 49 89 c5 e9 05 fe ff ff <0f> 0b 4c 8b 73 38 44 89 ff 81 cf 00 00 20 00 4c 89 f6 48 c1 ee
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-and-Tested-by: NLingzhu Xiang <lxiang@redhat.com>

According to sparse warning, print_*probe_event static because
those functions are not directly called from outside.

Link: http://lkml.kernel.org/r/20130513115839.6545.83067.stgit@mhiramat-M0-7522

Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Fix a sparse warning about the rcu operated pointer is
defined without __rcu address space.

Link: http://lkml.kernel.org/r/20130513115837.6545.23322.stgit@mhiramat-M0-7522

Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Use rcu_dereference_raw() for accessing tp->files. Because the
write-side uses rcu_assign_pointer() for memory barrier,
the read-side also has to use rcu_dereference_raw() with
read memory barrier.

Link: http://lkml.kernel.org/r/20130513115834.6545.17022.stgit@mhiramat-M0-7522

Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Special preds are created when folding a series of preds that
can be done in serial. These are allocated in an ops field of
the pred structure. But they were never freed, causing memory
leaks.

This was discovered using the kmemleak checker:

unreferenced object 0xffff8800797fd5e0 (size 32):
  comm "swapper/0", pid 1, jiffies 4294690605 (age 104.608s)
  hex dump (first 32 bytes):
    00 00 01 00 03 00 05 00 07 00 09 00 0b 00 0d 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff814b52af>] kmemleak_alloc+0x73/0x98
    [<ffffffff8111ff84>] kmemleak_alloc_recursive.constprop.42+0x16/0x18
    [<ffffffff81120e68>] __kmalloc+0xd7/0x125
    [<ffffffff810d47eb>] kcalloc.constprop.24+0x2d/0x2f
    [<ffffffff810d4896>] fold_pred_tree_cb+0xa9/0xf4
    [<ffffffff810d3781>] walk_pred_tree+0x47/0xcc
    [<ffffffff810d5030>] replace_preds.isra.20+0x6f8/0x72f
    [<ffffffff810d50b5>] create_filter+0x4e/0x8b
    [<ffffffff81b1c30d>] ftrace_test_event_filter+0x5a/0x155
    [<ffffffff8100028d>] do_one_initcall+0xa0/0x137
    [<ffffffff81afbedf>] kernel_init_freeable+0x14d/0x1dc
    [<ffffffff814b24b7>] kernel_init+0xe/0xdb
    [<ffffffff814d539c>] ret_from_fork+0x7c/0xb0
    [<ffffffffffffffff>] 0xffffffffffffffff

Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: stable@vger.kernel.org # 2.6.39+
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

When rcu_init() is called we already have slab working, allocating
bootmem at that point results in warnings and an allocation from
slab.  This commit therefore changes alloc_bootmem_cpumask_var() to
alloc_cpumask_var() in rcu_bootup_announce_oddness(), which is called
from rcu_init().
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Tested-by: NRobin Holt <holt@sgi.com>

[paulmck: convert to zalloc_cpumask_var(), as suggested by Yinghai Lu.]

Kay Sievers noted that the ALWAYS_USE_PERSISTENT_CLOCK config,
which enables some minor compile time optimization to avoid
uncessary code in mostly the suspend/resume path could cause
problems for userland.

In particular, the dependency for RTC_HCTOSYS on
!ALWAYS_USE_PERSISTENT_CLOCK, which avoids setting the time
twice and simplifies suspend/resume, has the side effect
of causing the /sys/class/rtc/rtcN/hctosys flag to always be
zero, and this flag is commonly used by udev to setup the
/dev/rtc symlink to /dev/rtcN, which can cause pain for
older applications.

While the udev rules could use some work to be less fragile,
breaking userland should strongly be avoided. Additionally
the compile time optimizations are fairly minor, and the code
being optimized is likely to be reworked in the future, so
lets revert this change.
Reported-by: NKay Sievers <kay@vrfy.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
Cc: stable <stable@vger.kernel.org> #3.9
Cc: Feng Tang <feng.tang@intel.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Link: http://lkml.kernel.org/r/1366828376-18124-1-git-send-email-john.stultz@linaro.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Commit 8425e3d5 ("workqueue: inline trivial wrappers") changed
schedule_work() and schedule_delayed_work() to inline wrappers,
but these rely on some symbols that are EXPORT_SYMBOL_GPL, while
the original functions were EXPORT_SYMBOL.  This has the effect of
changing the licensing requirement for these functions and making
them unavailable to non GPL modules.

Make them available again by removing the restriction on the
required symbols.
Signed-off-by: NMarc Dionne <marc.dionne@your-file-system.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

When we fail to mutex_trylock(), we release the pool spin_lock and do
mutex_lock(). After that, we should regrab the pool spin_lock, but,
regrabbing is missed in current code. So correct it.

Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Commit c0f4dfd4 (rcu: Make RCU_FAST_NO_HZ take advantage of numbered
callbacks) introduced a bug that can result in excessively long grace
periods.  This bug reverse the senes of the "if" statement checking
for lazy callbacks, so that RCU takes a lazy approach when there are
in fact non-lazy callbacks.  This can result in excessive boot, suspend,
and resume times.

This commit therefore fixes the sense of this "if" statement.
Reported-by: NBorislav Petkov <bp@alien8.de>
Reported-by: NBjørn Mork <bjorn@mork.no>
Reported-by: NJoerg Roedel <joro@8bytes.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: NBjørn Mork <bjorn@mork.no>
Tested-by: NJoerg Roedel <joro@8bytes.org>

An inactive timer's base can refer to a offline cpu's base.

In the current code, cpu_base's lock is blindly reinitialized each
time a CPU is brought up. If a CPU is brought online during the period
that another thread is trying to modify an inactive timer on that CPU
with holding its timer base lock, then the lock will be reinitialized
under its feet. This leads to following SPIN_BUG().

<0> BUG: spinlock already unlocked on CPU#3, kworker/u:3/1466
<0> lock: 0xe3ebe000, .magic: dead4ead, .owner: kworker/u:3/1466, .owner_cpu: 1
<4> [<c0013dc4>] (unwind_backtrace+0x0/0x11c) from [<c026e794>] (do_raw_spin_unlock+0x40/0xcc)
<4> [<c026e794>] (do_raw_spin_unlock+0x40/0xcc) from [<c076c160>] (_raw_spin_unlock+0x8/0x30)
<4> [<c076c160>] (_raw_spin_unlock+0x8/0x30) from [<c009b858>] (mod_timer+0x294/0x310)
<4> [<c009b858>] (mod_timer+0x294/0x310) from [<c00a5e04>] (queue_delayed_work_on+0x104/0x120)
<4> [<c00a5e04>] (queue_delayed_work_on+0x104/0x120) from [<c04eae00>] (sdhci_msm_bus_voting+0x88/0x9c)
<4> [<c04eae00>] (sdhci_msm_bus_voting+0x88/0x9c) from [<c04d8780>] (sdhci_disable+0x40/0x48)
<4> [<c04d8780>] (sdhci_disable+0x40/0x48) from [<c04bf300>] (mmc_release_host+0x4c/0xb0)
<4> [<c04bf300>] (mmc_release_host+0x4c/0xb0) from [<c04c7aac>] (mmc_sd_detect+0x90/0xfc)
<4> [<c04c7aac>] (mmc_sd_detect+0x90/0xfc) from [<c04c2504>] (mmc_rescan+0x7c/0x2c4)
<4> [<c04c2504>] (mmc_rescan+0x7c/0x2c4) from [<c00a6a7c>] (process_one_work+0x27c/0x484)
<4> [<c00a6a7c>] (process_one_work+0x27c/0x484) from [<c00a6e94>] (worker_thread+0x210/0x3b0)
<4> [<c00a6e94>] (worker_thread+0x210/0x3b0) from [<c00aad9c>] (kthread+0x80/0x8c)
<4> [<c00aad9c>] (kthread+0x80/0x8c) from [<c000ea80>] (kernel_thread_exit+0x0/0x8)

As an example, this particular crash occurred when CPU #3 is executing
mod_timer() on an inactive timer whose base is refered to offlined CPU
#2.  The code locked the timer_base corresponding to CPU #2. Before it
could proceed, CPU #2 came online and reinitialized the spinlock
corresponding to its base. Thus now CPU #3 held a lock which was
reinitialized. When CPU #3 finally ended up unlocking the old cpu_base
corresponding to CPU #2, we hit the above SPIN_BUG().

CPU #0		CPU #3				       CPU #2
------		-------				       -------
.....		 ......				      <Offline>
		mod_timer()
		 lock_timer_base
		   spin_lock_irqsave(&base->lock)

cpu_up(2)	 .....				        ......
							init_timers_cpu()
....		 .....				    	spin_lock_init(&base->lock)
.....		   spin_unlock_irqrestore(&base->lock)  ......
		   <spin_bug>

Allocation of per_cpu timer vector bases is done only once under
"tvec_base_done[]" check. In the current code, spinlock_initialization
of base->lock isn't under this check. When a CPU is up each time the
base lock is reinitialized. Move base spinlock initialization under
the check.
Signed-off-by: NTirupathi Reddy <tirupath@codeaurora.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1368520142-4136-1-git-send-email-tirupath@codeaurora.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Bjørn Mork reported the following warning when running powertop.

[   49.289034] ------------[ cut here ]------------
[   49.289055] WARNING: at kernel/rcutree.c:502 rcu_eqs_exit_common.isra.48+0x3d/0x125()
[   49.289244] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.10.0-bisect-rcu-warn+ #107
[   49.289251]  ffffffff8157d8c8 ffffffff81801e28 ffffffff8137e4e3 ffffffff81801e68
[   49.289260]  ffffffff8103094f ffffffff81801e68 0000000000000000 ffff88023afcd9b0
[   49.289268]  0000000000000000 0140000000000000 ffff88023bee7700 ffffffff81801e78
[   49.289276] Call Trace:
[   49.289285]  [<ffffffff8137e4e3>] dump_stack+0x19/0x1b
[   49.289293]  [<ffffffff8103094f>] warn_slowpath_common+0x62/0x7b
[   49.289300]  [<ffffffff8103097d>] warn_slowpath_null+0x15/0x17
[   49.289306]  [<ffffffff810a9006>] rcu_eqs_exit_common.isra.48+0x3d/0x125
[   49.289314]  [<ffffffff81079b49>] ? trace_hardirqs_off_caller+0x37/0xa6
[   49.289320]  [<ffffffff810a9692>] rcu_idle_exit+0x85/0xa8
[   49.289327]  [<ffffffff8107076e>] trace_cpu_idle_rcuidle+0xae/0xff
[   49.289334]  [<ffffffff810708b1>] cpu_startup_entry+0x72/0x115
[   49.289341]  [<ffffffff813689e5>] rest_init+0x149/0x150
[   49.289347]  [<ffffffff8136889c>] ? csum_partial_copy_generic+0x16c/0x16c
[   49.289355]  [<ffffffff81a82d34>] start_kernel+0x3f0/0x3fd
[   49.289362]  [<ffffffff81a8274c>] ? repair_env_string+0x5a/0x5a
[   49.289368]  [<ffffffff81a82481>] x86_64_start_reservations+0x2a/0x2c
[   49.289375]  [<ffffffff81a82550>] x86_64_start_kernel+0xcd/0xd1
[   49.289379] ---[ end trace 07a1cc95e29e9036 ]---

The warning is that 'rdtp->dynticks' has an unexpected value, which roughly
translates to - the calls to rcu_idle_enter() and rcu_idle_exit() were not
made in the correct order, or otherwise messed up.

And Bjørn's painstaking debugging indicated that this happens when the idle
loop enters the poll mode. Looking at the poll function cpu_idle_poll(), and
the implementation of trace_cpu_idle_rcuidle(), the problem becomes very clear:
cpu_idle_poll() lacks calls to rcu_idle_enter/exit(), and trace_cpu_idle_rcuidle()
calls them in the reverse order - first rcu_idle_exit(), and then rcu_idle_enter().
Hence the even/odd alternative sequencing of rdtp->dynticks goes for a toss.

And powertop readily triggers this because powertop uses the idle-tracing
infrastructure extensively.

So, to fix this, wrap the code in cpu_idle_poll() within rcu_idle_enter/exit(),
so that it blends properly with the calls inside trace_cpu_idle_rcuidle() and
thus get the function ordering right.
Reported-and-tested-by: NBjørn Mork <bjorn@mork.no>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/519169BF.4080208@linux.vnet.ibm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

commit 5b39939a (nohz: Move ts->idle_calls incrementation into strict
idle logic) moved code out of tick_nohz_stop_sched_tick() and missed
to bail out when the cpu is offline. That's causing subsequent
failures as an offline CPU is supposed to die and not to fiddle with
nohz magic.

Return false in can_stop_idle_tick() if the cpu is offline.
Reported-and-tested-by: NJiri Kosina <jkosina@suse.cz>
Reported-and-tested-by: NPrarit Bhargava <prarit@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305132138160.2863@ionosSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

cgroup_create_file() calls d_instantiate(), which may decide to look
at the xattrs on the file. Smack always does this and SELinux can be
configured to do so.

But cgroup_add_file() didn't initialize xattrs before calling
cgroup_create_file(), which finally leads to dereferencing NULL
dentry->d_fsdata.

This bug has been there since cgroup xattr was introduced.

Cc: <stable@vger.kernel.org> # 3.8.x
Reported-by: NIvan Bulatovic <combuster@archlinux.us>
Reported-by: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NLi Zefan <lizefan@huawei.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Prarit reported a crash on CPU offline/online. The reason is that on
CPU down the NOHZ related per cpu data of the dead cpu is not cleaned
up. If at cpu online an interrupt happens before the per cpu tick
device is registered the irq_enter() check potentially sees stale data
and dereferences a NULL pointer.

Cleanup the data after the cpu is dead.
Reported-by: NPrarit Bhargava <prarit@redhat.com>
Cc: stable@vger.kernel.org
Cc: Mike Galbraith <bitbucket@online.de>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305031451561.2886@ionosSigned-off-by: NThomas Gleixner <tglx@linutronix.de>