The uprobe syntax requires an offset after a file path not a symbol.
Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>

The filter field of the event_trigger_data structure is protected under
RCU sched locks. It was not annotated as such, and after doing so,
sparse pointed out several locations that required fix ups.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Tested-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Acked-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Trace event triggers added a lseek that uses the ftrace_filter_lseek()
function. Unfortunately, when function tracing is not configured in
that function is not defined and the kernel fails to build.

This is the second time that function was added to a file ops and
it broke the build due to requiring special config dependencies.

Make a generic tracing_lseek() that all the tracing utilities may
use.

Also, modify the old ftrace_filter_lseek() to return 0 instead of
1 on WRONLY. Not sure why it was a 1 as that does not make sense.

This also changes the old tracing_seek() to modify the file pos
pointer on WRONLY as well.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Tested-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Acked-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add a generic event_command.set_trigger_filter() op implementation and
have the current set of trigger commands use it - this essentially
gives them all support for filters.

Syntactically, filters are supported by adding 'if <filter>' just
after the command, in which case only events matching the filter will
invoke the trigger.  For example, to add a filter to an
enable/disable_event command:

    echo 'enable_event:system:event if common_pid == 999' > \
              .../othersys/otherevent/trigger

The above command will only enable the system:event event if the
common_pid field in the othersys:otherevent event is 999.

As another example, to add a filter to a stacktrace command:

    echo 'stacktrace if common_pid == 999' > \
                   .../somesys/someevent/trigger

The above command will only trigger a stacktrace if the common_pid
field in the event is 999.

The filter syntax is the same as that described in the 'Event
filtering' section of Documentation/trace/events.txt.

Because triggers can now use filters, the trigger-invoking logic needs
to be moved in those cases - e.g. for ftrace_raw_event_calls, if a
trigger has a filter associated with it, the trigger invocation now
needs to happen after the { assign; } part of the call, in order for
the trigger condition to be tested.

There's still a SOFT_DISABLED-only check at the top of e.g. the
ftrace_raw_events function, so when an event is soft disabled but not
because of the presence of a trigger, the original SOFT_DISABLED
behavior remains unchanged.

There's also a bit of trickiness in that some triggers need to avoid
being invoked while an event is currently in the process of being
logged, since the trigger may itself log data into the trace buffer.
Thus we make sure the current event is committed before invoking those
triggers.  To do that, we split the trigger invocation in two - the
first part (event_triggers_call()) checks the filter using the current
trace record; if a command has the post_trigger flag set, it sets a
bit for itself in the return value, otherwise it directly invoks the
trigger.  Once all commands have been either invoked or set their
return flag, event_triggers_call() returns.  The current record is
then either committed or discarded; if any commands have deferred
their triggers, those commands are finally invoked following the close
of the current event by event_triggers_post_call().

To simplify the above and make it more efficient, the TRIGGER_COND bit
is introduced, which is set only if a soft-disabled trigger needs to
use the log record for filter testing or needs to wait until the
current log record is closed.

The syscall event invocation code is also changed in analogous ways.

Because event triggers need to be able to create and free filters,
this also adds a couple external wrappers for the existing
create_filter and free_filter functions, which are too generic to be
made extern functions themselves.

Link: http://lkml.kernel.org/r/7164930759d8719ef460357f143d995406e4eead.1382622043.git.tom.zanussi@linux.intel.comSigned-off-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Now that event triggers use ftrace_event_file(), it needs to be outside
the #ifdef CONFIG_DYNAMIC_FTRACE, as it can now be used when that is
not defined.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add 'enable_event' and 'disable_event' event_command commands.

enable_event and disable_event event triggers are added by the user
via these commands in a similar way and using practically the same
syntax as the analagous 'enable_event' and 'disable_event' ftrace
function commands, but instead of writing to the set_ftrace_filter
file, the enable_event and disable_event triggers are written to the
per-event 'trigger' files:

    echo 'enable_event:system:event' > .../othersys/otherevent/trigger
    echo 'disable_event:system:event' > .../othersys/otherevent/trigger

The above commands will enable or disable the 'system:event' trace
events whenever the othersys:otherevent events are hit.

This also adds a 'count' version that limits the number of times the
command will be invoked:

    echo 'enable_event:system:event:N' > .../othersys/otherevent/trigger
    echo 'disable_event:system:event:N' > .../othersys/otherevent/trigger

Where N is the number of times the command will be invoked.

The above commands will will enable or disable the 'system:event'
trace events whenever the othersys:otherevent events are hit, but only
N times.

This also makes the find_event_file() helper function extern, since
it's useful to use from other places, such as the event triggers code,
so make it accessible.

Link: http://lkml.kernel.org/r/f825f3048c3f6b026ee37ae5825f9fc373451828.1382622043.git.tom.zanussi@linux.intel.comSigned-off-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add 'stacktrace' event_command.  stacktrace event triggers are added
by the user via this command in a similar way and using practically
the same syntax as the analogous 'stacktrace' ftrace function command,
but instead of writing to the set_ftrace_filter file, the stacktrace
event trigger is written to the per-event 'trigger' files:

    echo 'stacktrace' > .../tracing/events/somesys/someevent/trigger

The above command will turn on stacktraces for someevent i.e. whenever
someevent is hit, a stacktrace will be logged.

This also adds a 'count' version that limits the number of times the
command will be invoked:

    echo 'stacktrace:N' > .../tracing/events/somesys/someevent/trigger

Where N is the number of times the command will be invoked.

The above command will log N stacktraces for someevent i.e. whenever
someevent is hit N times, a stacktrace will be logged.

Link: http://lkml.kernel.org/r/0c30c008a0828c660aa0e1bbd3255cf179ed5c30.1382622043.git.tom.zanussi@linux.intel.comSigned-off-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add 'snapshot' event_command.  snapshot event triggers are added by
the user via this command in a similar way and using practically the
same syntax as the analogous 'snapshot' ftrace function command, but
instead of writing to the set_ftrace_filter file, the snapshot event
trigger is written to the per-event 'trigger' files:

    echo 'snapshot' > .../somesys/someevent/trigger

The above command will turn on snapshots for someevent i.e. whenever
someevent is hit, a snapshot will be done.

This also adds a 'count' version that limits the number of times the
command will be invoked:

    echo 'snapshot:N' > .../somesys/someevent/trigger

Where N is the number of times the command will be invoked.

The above command will snapshot N times for someevent i.e. whenever
someevent is hit N times, a snapshot will be done.

Also adds a new tracing_alloc_snapshot() function - the existing
tracing_snapshot_alloc() function is a special version of
tracing_snapshot() that also does the snapshot allocation - the
snapshot triggers would like to be able to do just the allocation but
not take a snapshot; the existing tracing_snapshot_alloc() in turn now
also calls tracing_alloc_snapshot() underneath to do that allocation.

Link: http://lkml.kernel.org/r/c9524dd07ce01f9dcbd59011290e0a8d5b47d7ad.1382622043.git.tom.zanussi@linux.intel.comSigned-off-by: NTom Zanussi <tom.zanussi@linux.intel.com>
[ fix up from kbuild test robot <fengguang.wu@intel.com report ]
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add 'traceon' and 'traceoff' event_command commands.  traceon and
traceoff event triggers are added by the user via these commands in a
similar way and using practically the same syntax as the analagous
'traceon' and 'traceoff' ftrace function commands, but instead of
writing to the set_ftrace_filter file, the traceon and traceoff
triggers are written to the per-event 'trigger' files:

    echo 'traceon' > .../tracing/events/somesys/someevent/trigger
    echo 'traceoff' > .../tracing/events/somesys/someevent/trigger

The above command will turn tracing on or off whenever someevent is
hit.

This also adds a 'count' version that limits the number of times the
command will be invoked:

    echo 'traceon:N' > .../tracing/events/somesys/someevent/trigger
    echo 'traceoff:N' > .../tracing/events/somesys/someevent/trigger

Where N is the number of times the command will be invoked.

The above commands will will turn tracing on or off whenever someevent
is hit, but only N times.

Some common register/unregister_trigger() implementations of the
event_command reg()/unreg() callbacks are also provided, which add and
remove trigger instances to the per-event list of triggers, and
arm/disarm them as appropriate.  event_trigger_callback() is a
general-purpose event_command func() implementation that orchestrates
command parsing and registration for most normal commands.

Most event commands will use these, but some will override and
possibly reuse them.

The event_trigger_init(), event_trigger_free(), and
event_trigger_print() functions are meant to be common implementations
of the event_trigger_ops init(), free(), and print() ops,
respectively.

Most trigger_ops implementations will use these, but some will
override and possibly reuse them.

Link: http://lkml.kernel.org/r/00a52816703b98d2072947478dd6e2d70cde5197.1382622043.git.tom.zanussi@linux.intel.comSigned-off-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add a 'trigger' file for each trace event, enabling 'trace event
triggers' to be set for trace events.

'trace event triggers' are patterned after the existing 'ftrace
function triggers' implementation except that triggers are written to
per-event 'trigger' files instead of to a single file such as the
'set_ftrace_filter' used for ftrace function triggers.

The implementation is meant to be entirely separate from ftrace
function triggers, in order to keep the respective implementations
relatively simple and to allow them to diverge.

The event trigger functionality is built on top of SOFT_DISABLE
functionality.  It adds a TRIGGER_MODE bit to the ftrace_event_file
flags which is checked when any trace event fires.  Triggers set for a
particular event need to be checked regardless of whether that event
is actually enabled or not - getting an event to fire even if it's not
enabled is what's already implemented by SOFT_DISABLE mode, so trigger
mode directly reuses that.  Event trigger essentially inherit the soft
disable logic in __ftrace_event_enable_disable() while adding a bit of
logic and trigger reference counting via tm_ref on top of that in a
new trace_event_trigger_enable_disable() function.  Because the base
__ftrace_event_enable_disable() code now needs to be invoked from
outside trace_events.c, a wrapper is also added for those usages.

The triggers for an event are actually invoked via a new function,
event_triggers_call(), and code is also added to invoke them for
ftrace_raw_event calls as well as syscall events.

The main part of the patch creates a new trace_events_trigger.c file
to contain the trace event triggers implementation.

The standard open, read, and release file operations are implemented
here.

The open() implementation sets up for the various open modes of the
'trigger' file.  It creates and attaches the trigger iterator and sets
up the command parser.  If opened for reading set up the trigger
seq_ops.

The read() implementation parses the event trigger written to the
'trigger' file, looks up the trigger command, and passes it along to
that event_command's func() implementation for command-specific
processing.

The release() implementation does whatever cleanup is needed to
release the 'trigger' file, like releasing the parser and trigger
iterator, etc.

A couple of functions for event command registration and
unregistration are added, along with a list to add them to and a mutex
to protect them, as well as an (initially empty) registration function
to add the set of commands that will be added by future commits, and
call to it from the trace event initialization code.

also added are a couple trigger-specific data structures needed for
these implementations such as a trigger iterator and a struct for
trigger-specific data.

A couple structs consisting mostly of function meant to be implemented
in command-specific ways, event_command and event_trigger_ops, are
used by the generic event trigger command implementations.  They're
being put into trace.h alongside the other trace_event data structures
and functions, in the expectation that they'll be needed in several
trace_event-related files such as trace_events_trigger.c and
trace_events.c.

The event_command.func() function is meant to be called by the trigger
parsing code in order to add a trigger instance to the corresponding
event.  It essentially coordinates adding a live trigger instance to
the event, and arming the triggering the event.

Every event_command func() implementation essentially does the
same thing for any command:

   - choose ops - use the value of param to choose either a number or
     count version of event_trigger_ops specific to the command
   - do the register or unregister of those ops
   - associate a filter, if specified, with the triggering event

The reg() and unreg() ops allow command-specific implementations for
event_trigger_op registration and unregistration, and the
get_trigger_ops() op allows command-specific event_trigger_ops
selection to be parameterized.  When a trigger instance is added, the
reg() op essentially adds that trigger to the triggering event and
arms it, while unreg() does the opposite.  The set_filter() function
is used to associate a filter with the trigger - if the command
doesn't specify a set_filter() implementation, the command will ignore
filters.

Each command has an associated trigger_type, which serves double duty,
both as a unique identifier for the command as well as a value that
can be used for setting a trigger mode bit during trigger invocation.

The signature of func() adds a pointer to the event_command struct,
used to invoke those functions, along with a command_data param that
can be passed to the reg/unreg functions.  This allows func()
implementations to use command-specific blobs and supports code
re-use.

The event_trigger_ops.func() command corrsponds to the trigger 'probe'
function that gets called when the triggering event is actually
invoked.  The other functions are used to list the trigger when
needed, along with a couple mundane book-keeping functions.

This also moves event_file_data() into trace.h so it can be used
outside of trace_events.c.

Link: http://lkml.kernel.org/r/316d95061accdee070aac8e5750afba0192fa5b9.1382622043.git.tom.zanussi@linux.intel.comSigned-off-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Idea-by: NSteve Rostedt <rostedt@goodmis.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

When debugging the read-only hugepage case, I was confused by the fact
that get_futex_key() did an access_ok() only for the non-shared futex
case, since the user address checking really isn't in any way specific
to the private key handling.

Now, it turns out that the shared key handling does effectively do the
equivalent checks inside get_user_pages_fast() (it doesn't actually
check the address range on x86, but does check the page protections for
being a user page).  So it wasn't actually a bug, but the fact that we
treat the address differently for private and shared futexes threw me
for a loop.

Just move the check up, so that it gets done for both cases.  Also, use
the 'rw' parameter for the type, even if it doesn't actually matter any
more (it's a historical artifact of the old racy i386 "page faults from
kernel space don't check write protections").

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

The hugepage code had the exact same bug that regular pages had in
commit 7485d0d3 ("futexes: Remove rw parameter from
get_futex_key()").

The regular page case was fixed by commit 9ea71503 ("futex: Fix
regression with read only mappings"), but the transparent hugepage case
(added in a5b338f2: "thp: update futex compound knowledge") case
remained broken.

Found by Dave Jones and his trinity tool.
Reported-and-tested-by: NDave Jones <davej@fedoraproject.org>
Cc: stable@kernel.org # v2.6.38+
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Apart from data-type specific alignment constraints, there are also
architecture-specific alignment requirements.
For example, on s390 symbols must be on even addresses implying a 2-byte
alignment.  If the system_certificate_list_end symbol is on an odd address
and if this address is loaded, the least-significant bit is ignored.  As a
result, the load_system_certificate_list() fails to load the certificates
because of a wrong certificate length calculation.

To be safe, align system_certificate_list on an 8-byte boundary.  Also improve
the length calculation of the system_certificate_list content.  Introduce a
system_certificate_list_size (8-byte aligned because of unsigned long) variable
that stores the length.  Let the linker calculate this size by introducing
a start and end label for the certificate content.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

$ git status
# On branch pending-rebases
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#	kernel/x509_certificate_list
nothing added to commit but untracked files present (use "git add" to track)
$
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Add a flag to tell the PCI subsystem that kernel is shutting down in
preparation to kexec a kernel.  Add code in PCI subsystem to use this flag
to clear Bus Master bit on PCI devices only in case of kexec reboot.

This fixes a power-off problem on Acer Aspire V5-573G and likely other
machines and avoids any other issues caused by clearing Bus Master bit on
PCI devices in normal shutdown path.  The problem was introduced by
b566a22c ("PCI: disable Bus Master on PCI device shutdown").

This patch is based on discussion at
http://marc.info/?l=linux-pci&m=138425645204355&w=2

Link: https://bugzilla.kernel.org/show_bug.cgi?id=63861Reported-by: NChang Liu <cl91tp@gmail.com>
Signed-off-by: NKhalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NKonstantin Khlebnikov <koct9i@gmail.com>
Cc: stable@vger.kernel.org	# v3.5+

It has been reported that boot up with FTRACE_SELFTEST enabled can take a
very long time. There can be stalls of over a minute.

This was tracked down to the synchronize_sched() called when a system call
event is disabled. As the self tests enable and disable thousands of events,
this makes the synchronize_sched() get called thousands of times.

The synchornize_sched() was added with d562aff9 "tracing: Add support
for SOFT_DISABLE to syscall events" which caused this regression (added
in 3.13-rc1).

The synchronize_sched() is to protect against the events being accessed
when a tracer instance is being deleted. When an instance is being deleted
all the events associated to it are unregistered. The synchronize_sched()
makes sure that no more users are running when it finishes.

Instead of calling synchronize_sched() for all syscall events, we only
need to call it once, after the events are unregistered and before the
instance is deleted. The event_mutex is held during this action to
prevent new users from enabling events.

Link: http://lkml.kernel.org/r/20131203124120.427b9661@gandalf.local.homeReported-by: NPetr Mladek <pmladek@suse.cz>
Acked-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Acked-by: NPetr Mladek <pmladek@suse.cz>
Tested-by: NPetr Mladek <pmladek@suse.cz>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

If CONFIG_NO_HZ=n tick_nohz_get_sleep_length() returns NSEC_PER_SEC/HZ.

If CONFIG_NO_HZ=y and the nohz functionality is disabled via the
command line option "nohz=off" or not enabled due to missing hardware
support, then tick_nohz_get_sleep_length() returns 0. That happens
because ts->sleep_length is never set in that case.

Set it to NSEC_PER_SEC/HZ when the NOHZ mode is inactive.
Reported-by: NMichal Hocko <mhocko@suse.cz>
Reported-by: NBorislav Petkov <bp@alien8.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The init_kernel_text() and core_kernel_text() functions should not
include the labels _einittext and _etext when checking if an address is
inside the .text or .init sections.
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If a cgroup file implements either read_map() or read_seq_string(),
such file is served using seq_file by overriding file->f_op to
cgroup_seqfile_operations, which also overrides the release method to
single_release() from cgroup_file_release().

Because cgroup_file_open() didn't use to acquire any resources, this
used to be fine, but since f7d58818 ("cgroup: pin
cgroup_subsys_state when opening a cgroupfs file"), cgroup_file_open()
pins the css (cgroup_subsys_state) which is put by
cgroup_file_release().  The patch forgot to update the release path
for seq_files and each open/release cycle leaks a css reference.

Fix it by updating cgroup_file_release() to also handle seq_files and
using it for seq_file release path too.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v3.12

Juri hit the below lockdep report:

[    4.303391] ======================================================
[    4.303392] [ INFO: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected ]
[    4.303394] 3.12.0-dl-peterz+ #144 Not tainted
[    4.303395] ------------------------------------------------------
[    4.303397] kworker/u4:3/689 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
[    4.303399]  (&p->mems_allowed_seq){+.+...}, at: [<ffffffff8114e63c>] new_slab+0x6c/0x290
[    4.303417]
[    4.303417] and this task is already holding:
[    4.303418]  (&(&q->__queue_lock)->rlock){..-...}, at: [<ffffffff812d2dfb>] blk_execute_rq_nowait+0x5b/0x100
[    4.303431] which would create a new lock dependency:
[    4.303432]  (&(&q->__queue_lock)->rlock){..-...} -> (&p->mems_allowed_seq){+.+...}
[    4.303436]

[    4.303898] the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock:
[    4.303918] -> (&p->mems_allowed_seq){+.+...} ops: 2762 {
[    4.303922]    HARDIRQ-ON-W at:
[    4.303923]                     [<ffffffff8108ab9a>] __lock_acquire+0x65a/0x1ff0
[    4.303926]                     [<ffffffff8108cbe3>] lock_acquire+0x93/0x140
[    4.303929]                     [<ffffffff81063dd6>] kthreadd+0x86/0x180
[    4.303931]                     [<ffffffff816ded6c>] ret_from_fork+0x7c/0xb0
[    4.303933]    SOFTIRQ-ON-W at:
[    4.303933]                     [<ffffffff8108abcc>] __lock_acquire+0x68c/0x1ff0
[    4.303935]                     [<ffffffff8108cbe3>] lock_acquire+0x93/0x140
[    4.303940]                     [<ffffffff81063dd6>] kthreadd+0x86/0x180
[    4.303955]                     [<ffffffff816ded6c>] ret_from_fork+0x7c/0xb0
[    4.303959]    INITIAL USE at:
[    4.303960]                    [<ffffffff8108a884>] __lock_acquire+0x344/0x1ff0
[    4.303963]                    [<ffffffff8108cbe3>] lock_acquire+0x93/0x140
[    4.303966]                    [<ffffffff81063dd6>] kthreadd+0x86/0x180
[    4.303969]                    [<ffffffff816ded6c>] ret_from_fork+0x7c/0xb0
[    4.303972]  }

Which reports that we take mems_allowed_seq with interrupts enabled. A
little digging found that this can only be from
cpuset_change_task_nodemask().

This is an actual deadlock because an interrupt doing an allocation will
hit get_mems_allowed()->...->__read_seqcount_begin(), which will spin
forever waiting for the write side to complete.

Cc: John Stultz <john.stultz@linaro.org>
Cc: Mel Gorman <mgorman@suse.de>
Reported-by: NJuri Lelli <juri.lelli@gmail.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Tested-by: NJuri Lelli <juri.lelli@gmail.com>
Acked-by: NLi Zefan <lizefan@huawei.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org

Tony reported that aa0d5326 ("ia64: Use preempt_schedule_irq")
broke PREEMPT=n builds on ia64.

Ok, wrapped my brain around it. I tripped over the magic asm foo which
has a single need_resched check and schedule point for both sys call
return and interrupt return.

So you need the schedule_preempt_irq() for kernel preemption from
interrupt return while on a normal syscall preemption a schedule would
be sufficient. But using schedule_preempt_irq() is not harmful here in
any way. It just sets the preempt_active bit also in cases where it
would not be required.

Even on preempt=n kernels adding the preempt_active bit is completely
harmless. So instead of having an extra function, moving the existing
one out of the ifdef PREEMPT looks like the sanest thing to do.

It would also allow getting rid of various other sti/schedule/cli asm
magic in other archs.
Reported-and-Tested-by: NTony Luck <tony.luck@gmail.com>
Fixes: aa0d5326 ("ia64: Use preempt_schedule_irq")
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
[slightly edited Changelog]
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1311211230030.30673@ionos.tec.linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Commit 8c4f3c3f "ftrace: Check module functions being traced on reload"
fixed module loading and unloading with respect to function tracing, but
it missed the function graph tracer. If you perform the following

 # cd /sys/kernel/debug/tracing
 # echo function_graph > current_tracer
 # modprobe nfsd
 # echo nop > current_tracer

You'll get the following oops message:

 ------------[ cut here ]------------
 WARNING: CPU: 2 PID: 2910 at /linux.git/kernel/trace/ftrace.c:1640 __ftrace_hash_rec_update.part.35+0x168/0x1b9()
 Modules linked in: nfsd exportfs nfs_acl lockd ipt_MASQUERADE sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables uinput snd_hda_codec_idt
 CPU: 2 PID: 2910 Comm: bash Not tainted 3.13.0-rc1-test #7
 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
  0000000000000668 ffff8800787efcf8 ffffffff814fe193 ffff88007d500000
  0000000000000000 ffff8800787efd38 ffffffff8103b80a 0000000000000668
  ffffffff810b2b9a ffffffff81a48370 0000000000000001 ffff880037aea000
 Call Trace:
  [<ffffffff814fe193>] dump_stack+0x4f/0x7c
  [<ffffffff8103b80a>] warn_slowpath_common+0x81/0x9b
  [<ffffffff810b2b9a>] ? __ftrace_hash_rec_update.part.35+0x168/0x1b9
  [<ffffffff8103b83e>] warn_slowpath_null+0x1a/0x1c
  [<ffffffff810b2b9a>] __ftrace_hash_rec_update.part.35+0x168/0x1b9
  [<ffffffff81502f89>] ? __mutex_lock_slowpath+0x364/0x364
  [<ffffffff810b2cc2>] ftrace_shutdown+0xd7/0x12b
  [<ffffffff810b47f0>] unregister_ftrace_graph+0x49/0x78
  [<ffffffff810c4b30>] graph_trace_reset+0xe/0x10
  [<ffffffff810bf393>] tracing_set_tracer+0xa7/0x26a
  [<ffffffff810bf5e1>] tracing_set_trace_write+0x8b/0xbd
  [<ffffffff810c501c>] ? ftrace_return_to_handler+0xb2/0xde
  [<ffffffff811240a8>] ? __sb_end_write+0x5e/0x5e
  [<ffffffff81122aed>] vfs_write+0xab/0xf6
  [<ffffffff8150a185>] ftrace_graph_caller+0x85/0x85
  [<ffffffff81122dbd>] SyS_write+0x59/0x82
  [<ffffffff8150a185>] ftrace_graph_caller+0x85/0x85
  [<ffffffff8150a2d2>] system_call_fastpath+0x16/0x1b
 ---[ end trace 940358030751eafb ]---

The above mentioned commit didn't go far enough. Well, it covered the
function tracer by adding checks in __register_ftrace_function(). The
problem is that the function graph tracer circumvents that (for a slight
efficiency gain when function graph trace is running with a function
tracer. The gain was not worth this).

The problem came with ftrace_startup() which should always be called after
__register_ftrace_function(), if you want this bug to be completely fixed.

Anyway, this solution moves __register_ftrace_function() inside of
ftrace_startup() and removes the need to call them both.
Reported-by: NDave Wysochanski <dwysocha@redhat.com>
Fixes: ed926f9b ("ftrace: Use counters to enable functions to trace")
Cc: stable@vger.kernel.org # 3.0+
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

This reverts commit c2fda509.

c2fda509 removed lockdep annotation from work_on_cpu() to work around
the PCI path that calls work_on_cpu() from within a work_on_cpu() work item
(PF driver .probe() method -> pci_enable_sriov() -> add VFs -> VF driver
.probe method).

961da7fb6b22 ("PCI: Avoid unnecessary CPU switch when calling driver
.probe() method) avoids that recursive work_on_cpu() use in a different
way, so this revert restores the work_on_cpu() lockdep annotation.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NTejun Heo <tj@kernel.org>

When the system enters suspend, it disables all interrupts in
suspend_device_irqs(), including the interrupts marked EARLY_RESUME.

On the resume side things are different. The EARLY_RESUME interrupts
are reenabled in sys_core_ops->resume and the non EARLY_RESUME
interrupts are reenabled in the normal system resume path.

When suspend_noirq() failed or suspend is aborted for any other
reason, we might omit the resume side call to sys_core_ops->resume()
and therefor the interrupts marked EARLY_RESUME are not reenabled and
stay disabled forever.

To solve this, enable all irqs unconditionally in irq_resume()
regardless whether interrupts marked EARLY_RESUMEhave been already
enabled or not.

This might try to reenable already enabled interrupts in the non
failure case, but the only affected platform is XEN and it has been
confirmed that it does not cause any side effects.

[ tglx: Massaged changelog. ]
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Acked-by-and-tested-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NHeiko Stuebner <heiko@sntech.de>
Reviewed-by: NPavel Machek <pavel@ucw.cz>
Cc: <ian.campbell@citrix.com>
Cc: <rjw@rjwysocki.net>
Cc: <len.brown@intel.com>
Cc: <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1385388587-16442-1-git-send-email-ldewangan@nvidia.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

When one work starts execution, the high bits of work's data contain
pool ID. It can represent a maximum of WORK_OFFQ_POOL_NONE. Pool ID
is assigned WORK_OFFQ_POOL_NONE when the work being initialized
indicating that no pool is associated and get_work_pool() uses it to
check the associated pool. So if worker_pool_assign_id() assigns a
ID greater than or equal WORK_OFFQ_POOL_NONE to a pool, it triggers
leakage, and it may break the non-reentrance guarantee.

This patch fix this issue by modifying the worker_pool_assign_id()
function calling idr_alloc() by setting @end param WORK_OFFQ_POOL_NONE.

Furthermore, in the current implementation, the BUILD_BUG_ON() in
init_workqueues makes no sense. The number of worker pools needed
cannot be determined at compile time, because the number of backing
pools for UNBOUND workqueues is dynamic based on the assigned custom
attributes. So remove it.

tj: Minor comment and indentation updates.
Signed-off-by: NLi Bin <huawei.libin@huawei.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

It seems the "dying" should be "draining" here.
Signed-off-by: NLi Bin <huawei.libin@huawei.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

An ordered workqueue implements execution ordering by using single
pool_workqueue with max_active == 1.  On a given pool_workqueue, work
items are processed in FIFO order and limiting max_active to 1
enforces the queued work items to be processed one by one.

Unfortunately, 4c16bd32 ("workqueue: implement NUMA affinity for
unbound workqueues") accidentally broke this guarantee by applying
NUMA affinity to ordered workqueues too.  On NUMA setups, an ordered
workqueue would end up with separate pool_workqueues for different
nodes.  Each pool_workqueue still limits max_active to 1 but multiple
work items may be executed concurrently and out of order depending on
which node they are queued to.

Fix it by using dedicated ordered_wq_attrs[] when creating ordered
workqueues.  The new attrs match the unbound ones except that no_numa
is always set thus forcing all NUMA nodes to share the default
pool_workqueue.

While at it, add sanity check in workqueue creation path which
verifies that an ordered workqueues has only the default
pool_workqueue.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NLibin <huawei.libin@huawei.com>
Cc: stable@vger.kernel.org
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>

Move the setting of PF_NO_SETAFFINITY up before set_cpus_allowed()
in create_worker(). Otherwise userland can change ->cpus_allowed
in between.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Since be445626 ("cgroup: remove synchronize_rcu() from
cgroup_diput()"), cgroup destruction path makes use of workqueue.  css
freeing is performed from a work item from that point on and a later
commit, ea15f8cc ("cgroup: split cgroup destruction into two
steps"), moves css offlining to workqueue too.

As cgroup destruction isn't depended upon for memory reclaim, the
destruction work items were put on the system_wq; unfortunately, some
controller may block in the destruction path for considerable duration
while holding cgroup_mutex.  As large part of destruction path is
synchronized through cgroup_mutex, when combined with high rate of
cgroup removals, this has potential to fill up system_wq's max_active
of 256.

Also, it turns out that memcg's css destruction path ends up queueing
and waiting for work items on system_wq through work_on_cpu().  If
such operation happens while system_wq is fully occupied by cgroup
destruction work items, work_on_cpu() can't make forward progress
because system_wq is full and other destruction work items on
system_wq can't make forward progress because the work item waiting
for work_on_cpu() is holding cgroup_mutex, leading to deadlock.

This can be fixed by queueing destruction work items on a separate
workqueue.  This patch creates a dedicated workqueue -
cgroup_destroy_wq - for this purpose.  As these work items shouldn't
have inter-dependencies and mostly serialized by cgroup_mutex anyway,
giving high concurrency level doesn't buy anything and the workqueue's
@max_active is set to 1 so that destruction work items are executed
one by one on each CPU.

Hugh Dickins: Because cgroup_init() is run before init_workqueues(),
cgroup_destroy_wq can't be allocated from cgroup_init().  Do it from a
separate core_initcall().  In the future, we probably want to reorder
so that workqueue init happens before cgroup_init().
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NHugh Dickins <hughd@google.com>
Reported-by: NShawn Bohrer <shawn.bohrer@gmail.com>
Link: http://lkml.kernel.org/r/20131111220626.GA7509@sbohrermbp13-local.rgmadvisors.com
Link: http://lkml.kernel.org/g/alpine.LNX.2.00.1310301606080.2333@eggly.anvils
Cc: stable@vger.kernel.org # v3.9+

Since commit 1e75fa8b (time: Condense timekeeper.xtime
into xtime_sec - merged in v3.6), there has been an problem
with the error accounting in the timekeeping code, such that
when truncating to nanoseconds, we round up to the next nsec,
but the balancing adjustment to the ntp_error value was dropped.

This causes 1ns per tick drift forward of the clock.

In 3.7, this logic was isolated to only GENERIC_TIME_VSYSCALL_OLD
architectures (s390, ia64, powerpc).

The fix is simply to balance the accounting and to subtract the
added nanosecond from ntp_error. This allows the internal long-term
clock steering to keep the clock accurate.

While this fix removes the regression added in 1e75fa8b, the
ideal solution is to move away from GENERIC_TIME_VSYSCALL_OLD
and use the new VSYSCALL method, which avoids entirely the
nanosecond granular rounding, and the resulting short-term clock
adjustment oscillation needed to keep long term accurate time.

[ jstultz: Many thanks to Martin for his efforts identifying this
  	   subtle bug, and providing the fix. ]

Originally-from: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Paul Turner <pjt@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable <stable@vger.kernel.org>  #v3.6+
Link: http://lkml.kernel.org/r/1385149491-20307-1-git-send-email-john.stultz@linaro.orgSigned-off-by: NJohn Stultz <john.stultz@linaro.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

<linux/spinlock.h> has heavy dependencies on other header files.
It triggers circular dependencies in generated headers on IA64, at
least:

  CC      kernel/bounds.s
In file included from /home/space/kas/git/public/linux/arch/ia64/include/asm/thread_info.h:9:0,
                 from include/linux/thread_info.h:54,
                 from include/asm-generic/preempt.h:4,
                 from arch/ia64/include/generated/asm/preempt.h:1,
                 from include/linux/preempt.h:18,
                 from include/linux/spinlock.h:50,
                 from kernel/bounds.c:14:
/home/space/kas/git/public/linux/arch/ia64/include/asm/asm-offsets.h:1:35: fatal error: generated/asm-offsets.h: No such file or directory
compilation terminated.

Let's replace <linux/spinlock.h> with <linux/spinlock_types.h>, it's
enough to find out size of spinlock_t.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-and-Tested-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

As suggested by David Miller, make genl_register_family_with_ops()
a macro and pass only the array, evaluating ARRAY_SIZE() in the
macro, this is a little safer.

The openvswitch has some indirection, assing ops/n_ops directly in
that code. This might ultimately just assign the pointers in the
family initializations, saving the struct genl_family_and_ops and
code (once mcast groups are handled differently.)
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix a trivial typo in rq_attach_root().
Signed-off-by: NShigeru Yoshida <shigeru.yoshida@gmail.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131117.121236.1990617639803941055.shigeru.yoshida@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Commit 37dc6b50 ("sched: Remove unnecessary iteration over sched
domains to update nr_busy_cpus") forgot to clear 'sd_busy' under some
conditions leading to a possible NULL deref in set_cpu_sd_state_idle().
Reported-by: NAnton Blanchard <anton@samba.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131118113701.GF3866@twins.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

After commit 863bffc8 ("sched/fair: Fix group power_orig
computation"), we can dereference rq->sd before it is set.

Fix this by falling back to power_of() in this case and add a comment
explaining things.
Signed-off-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
[ Added comment and tweaked patch. ]
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: mikey@neuling.org
Link: http://lkml.kernel.org/r/20131113151718.GN21461@twins.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

The 64-bit attr.config value for perf trace events was being copied into
an "int" before doing a comparison, meaning the top 32 bits were
being truncated.

As far as I can tell this didn't cause any errors, but it did mean
it was possible to create valid aliases for all the tracepoint ids
which I don't think was intended.  (For example, 0xffffffff00000018
and 0x18 both enable the same tracepoint).
Signed-off-by: NVince Weaver <vincent.weaver@maine.edu>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1311151236100.11932@vincent-weaver-1.um.maine.eduSigned-off-by: NIngo Molnar <mingo@kernel.org>

Currently we only allocate a single cpu hashtable for per-cpu
swevents; do away with this optimization for it is fragile in the face
of things like perf_pmu_migrate_context().

The easiest thing is to make sure all CPUs are consistent wrt state.
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130913111447.GN31370@twins.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

Vince's perf-trinity fuzzer found yet another 'interesting' problem.

When we sample the irq_work_exit tracepoint with period==1 (or
PERF_SAMPLE_PERIOD) and we add an fasync SIGNAL handler we create an
infinite event generation loop:

  ,-> <IPI>
  |     irq_work_exit() ->
  |       trace_irq_work_exit() ->
  |         ...
  |           __perf_event_overflow() -> (due to fasync)
  |             irq_work_queue() -> (irq_work_list must be empty)
  '---------      arch_irq_work_raise()

Similar things can happen due to regular poll() wakeups if we exceed
the ring-buffer wakeup watermark, or have an event_limit.

To avoid this, dis-allow sampling this particular tracepoint.

In order to achieve this, create a special perf_perm function pointer
for each event and call this (when set) on trying to create a
tracepoint perf event.

[ roasted: use expr... to allow for ',' in your expression ]
Reported-by: NVince Weaver <vincent.weaver@maine.edu>
Tested-by: NVince Weaver <vincent.weaver@maine.edu>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20131114152304.GC5364@laptop.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

Taken straight from a tglx email ;)
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Use the helper function instead of __GFP_ZERO.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>