As tracefs may be mounted instead of debugfs to get to the event
directories, have perf know about tracefs, and use that file system over
debugfs if it is present.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20150202193553.340946602@goodmis.org
[ Fixed up error messages about tracefs pointed out by Namhyung ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add tracefs_configured() to return true if tracefs is configured in the
kernel (succeeds to find tracefs), and debugfs_configured() if debugfs
is configured in the kernel (succeeds to find debugfs).
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20150202193553.190606690@goodmis.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Instead of hard coding "/sys/kernel/debug" everywhere, create a macro to
hold where the default path exists.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20150202193553.032117017@goodmis.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Since tracefs will now hold the event directory for perf, and even
though by default, debugfs still mounts tracefs on the debugfs/tracing
directory, the system admin may now choose to not mount debugfs and
instead just mount tracefs instead.

Having tracefs helper functions will facilitate having perf look for
tracefs first, and then try debugfs as a fallback.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20150202193552.898934751@goodmis.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

In preparation for adding tracefs for perf to use, create a findfs
helper utility that find_debugfs uses instead of hard coding the search
in the code. This will allow for a find_tracefs to be used as well.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20150202193552.735023362@goodmis.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

It's rather strange to be checking the debugfs MAGIC number for the
tracing directory. A system admin may want to have a custom set of
events to trace and it should be allowed to let the admin make a temp
file (even for tracing virtual boxes, this is useful).

Also with the coming tracefs, the files may not even be under debugfs,
so checking the debugfs MAGIC number is pointless.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20150202193552.546175764@goodmis.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Link: http://lkml.kernel.org/n/tip-qzg2qrdgta6dmcrxqdeexthu@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

As they will have perf_event_attr.enable_on_exec set, starting as soon
as we exec() the workload.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-vmj3f6o3vxrg7mrdipts09li@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The existing one, event_format__print() uses stdout unconditionally,
and 'perf trace' needs to use it to format into a file that may have
been set by the user, i.e. 'trace -o file.output'.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-7l0mgm91hwg0bby00s5pse8r@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

So that we can specify a FILE object where to direct the formatted
output.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-a49bhdrx8851f04hppn8bqxq@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Currently code that tries to read corresponding debug symbol file from
.gnu_debuglink section (DSO_BINARY_TYPE__DEBUGLINK) does not take in
account symfs option, so filename__read_debuglink function cannot open
ELF file, if symfs option is used.

Fix is to add proper handling of symfs as it is done in other places:
use __symbol__join_symfs function to get real file name of target ELF
file.
Signed-off-by: NVictor Kamensky <victor.kamensky@linaro.org>
Tested-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Avi Kivity <avi@cloudius-systems.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1422340442-4673-3-git-send-email-victor.kamensky@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Aarch64 ELF files use mapping symbols with special names $x, $d
to identify regions of Aarch64 code (see Aarch64 ELF ABI - "ARM
IHI 0056B", section "4.5.4 Mapping symbols").

The patch filters out these symbols at load time, similar to
"696b97a5 perf symbols: Ignore mapping symbols on ARM" changes
done for ARM before V8.

Also added handling of mapping symbols that has format
"$d.<any>" and similar for both cases.

Note we are not making difference between EM_ARM and
EM_AARCH64 mapping symbols instead code handles superset
of both.
Signed-off-by: NVictor Kamensky <victor.kamensky@linaro.org>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Avi Kivity <avi@cloudius-systems.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Russell King <linux@arm.linux.org.uk>
Link: http://lkml.kernel.org/r/1422340442-4673-2-git-send-email-victor.kamensky@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Update Documentation/perf-probe.txt to add descriptions of some newer
options.
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150130093746.30575.8571.stgit@localhost.localdomainSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Fix to handle optimized no-inline functions which have only function
definition but no actual instance at that point.

To fix this problem, we need to find actual instance of the function.

Without this patch:
  ----
  # perf probe -a __up
  Failed to get entry address of __up.
    Error: Failed to add events.
  # perf probe -L __up
  Specified source line is not found.
    Error: Failed to show lines.
  ----

With this patch:
  ----
  # perf probe -a __up
  Added new event:
    probe:__up           (on __up)

  You can now use it in all perf tools, such as:

          perf record -e probe:__up -aR sleep 1

  # perf probe -L __up
  <__up@/home/fedora/ksrc/linux-3/kernel/locking/semaphore.c:0>
        0  static noinline void __sched __up(struct semaphore *sem)
           {
                  struct semaphore_waiter *waiter = list_first_entry(&sem->wait_
                                                          struct semaphore_waite
        4         list_del(&waiter->list);
        5         waiter->up = true;
        6         wake_up_process(waiter->task);
        7  }
  ----
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150130093744.30575.43290.stgit@localhost.localdomainSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

It's not related to mmap, remove it from the message.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1422585209-32742-3-git-send-email-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Do not rely on dso__data_read_offset() will always call dso__data_fd()
internally.  With multi-thread support, accessing a fd will be protected
by a lock and it'll cause a huge contention.  It can be avoided since we
can skip reading from file if there's a data in the dso cache.

If one needs to call the dso__data_read_offset(), [s]he also needs to
call dso__data_fd() (or set dso->binary_type at least) first like the
dwarf unwind code does.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1422585209-32742-2-git-send-email-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The current dso cache permits to keep dso->data.fd is open under a half
of open file limit.  But test__dso_data_cache() sets dso_cnt to limit /
2 + 1 so it'll reach the limit in the loop even though the loop count is
one less than the dso_cnt and it makes the final dso__data_fd() after
the loop meaningless.

I guess the intention was dsos[0]->data.fd is open before the last open
and gets closed after it.  So add an assert before the last open.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1422585209-32742-1-git-send-email-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Currently the adjusments made as part of perf_event_task_tick() use the
percpu rotation lists to iterate over any active PMU contexts, but these
are not used by the context rotation code, having been replaced by
separate (per-context) hrtimer callbacks. However, some manipulation of
the rotation lists (i.e. removal of contexts) has remained in
perf_rotate_context(). This leads to the following issues:

* Contexts are not always removed from the rotation lists. Removal of
  PMUs which have been placed in rotation lists, but have not been
  removed by a hrtimer callback can result in corruption of the rotation
  lists (when memory backing the context is freed).

  This has been observed to result in hangs when PMU drivers built as
  modules are inserted and removed around the creation of events for
  said PMUs.

* Contexts which do not require rotation may be removed from the
  rotation lists as a result of a hrtimer, and will not be considered by
  the unthrottling code in perf_event_task_tick.

This patch fixes the issue by updating the rotation ist when events are
scheduled in/out, ensuring that each rotation list stays in sync with
the HW state. As each event holds a refcount on the module of its PMU,
this ensures that when a PMU module is unloaded none of its CPU contexts
can be in a rotation list. By maintaining a list of perf_event_contexts
rather than perf_event_cpu_contexts, we don't need separate paths to
handle the cpu and task contexts, which also makes the code a little
simpler.

As the rotation_list variables are not used for rotation, these are
renamed to active_ctx_list, which better matches their current function.
perf_pmu_rotate_{start,stop} are renamed to
perf_pmu_ctx_{activate,deactivate}.
Reported-by: NJohannes Jensen <johannes.jensen@arm.com>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Will Deacon <Will.Deacon@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150129134511.GR17721@leverpostejSigned-off-by: NIngo Molnar <mingo@kernel.org>

When initialising an event, perf_init_event will call try_module_get() to
ensure that the PMU's module cannot be removed for the lifetime of the
event, with __free_event() dropping the reference when the event is
finally destroyed. If something fails after the event has been
initialised, but before the event is installed, perf_event_alloc will
drop the reference on the module.

However, if we fail to initialise an event for some reason (e.g. we ask
an uncore PMU to perform sampling, and it refuses to initialise the
event), we do not drop the refcount. If we try to open such a bogus
event without a precise IDR type, we will loop over each PMU in the pmus
list, incrementing each of their refcounts without decrementing them.

This patch adds a module_put when pmu->event_init(event) fails, ensuring
that the refcounts are balanced in failure cases. As the innards of the
precise and search based initialisation look very similar, this logic is
hoisted out into a new helper function. While the early return for the
failed try_module_get is removed from the search case, this is handled
by the remaining return when ret is not -ENOENT.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1420642611-22667-1-git-send-email-mark.rutland@arm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Currently we flag available data (via poll syscall) on perf fd with
POLL_IN macro, which is normally used for SIGIO interface.

We've been lucky, because POLLIN (0x1) is subset of POLL_IN (0x20001)
and sys_poll (do_pollfd function) cut the extra bit out (0x20000).
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1422467678-22341-1-git-send-email-jolsa@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

So what I suspect; but I'm in zombie mode today it seems; is that while
I initially thought that it was impossible for ctx to change when
refcount dropped to 0, I now suspect its possible.

Note that until perf_remove_from_context() the event is still active and
visible on the lists. So a concurrent sys_perf_event_open() from another
task into this task can race.
Reported-by: NVince Weaver <vincent.weaver@maine.edu>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Stephane Eranian <eranian@gmail.com>
Cc: mark.rutland@arm.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150129134434.GB26304@twins.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

Jiri reported triggering the new WARN_ON_ONCE in event_sched_out over
the weekend:

  event_sched_out.isra.79+0x2b9/0x2d0
  group_sched_out+0x69/0xc0
  ctx_sched_out+0x106/0x130
  task_ctx_sched_out+0x37/0x70
  __perf_install_in_context+0x70/0x1a0
  remote_function+0x48/0x60
  generic_exec_single+0x15b/0x1d0
  smp_call_function_single+0x67/0xa0
  task_function_call+0x53/0x80
  perf_install_in_context+0x8b/0x110

I think the below should cure this; if we install a group leader it
will iterate the (still intact) group list and find its siblings and
try and install those too -- even though those still have the old
event->ctx -- in the new ctx.

Upon installing the first group sibling we'd try and schedule out the
group and trigger the above warn.

Fix this by installing the group leader last, installing siblings
would have no effect, they're not reachable through the group lists
and therefore we don't schedule them.

Also delay resetting the state until we're absolutely sure the events
are quiescent.
Reported-by: NJiri Olsa <jolsa@redhat.com>
Reported-by: vincent.weaver@maine.edu
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150126162639.GA21418@twins.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

There have been a few reported issues wrt. the lack of locking around
changing event->ctx. This patch tries to address those.

It avoids the whole rwsem thing; and while it appears to work, please
give it some thought in review.

What I did fail at is sensible runtime checks on the use of
event->ctx, the RCU use makes it very hard.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150123125834.209535886@infradead.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Add a few WARN()s to catch things that should never happen.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150123125834.150481799@infradead.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Signed-off-by: NIngo Molnar <mingo@kernel.org>

Pull ARM SoC fixes from Olof Johansson:
 "One more week's worth of fixes.  Worth pointing out here are:

   - A patch fixing detaching of iommu registrations when a device is
     removed -- earlier the ops pointer wasn't managed properly
   - Another set of Renesas boards get the same GIC setup fixup as
     others have in previous -rcs
   - Serial port aliases fixups for sunxi.  We did the same to tegra but
     we caught that in time before the merge window due to more machines
     being affected.  Here it took longer for anyone to notice.
   - A couple more DT tweaks on sunxi
   - A follow-up patch for the mvebu coherency disabling in last -rc
     batch"

* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  arm: dma-mapping: Set DMA IOMMU ops in arm_iommu_attach_device()
  ARM: shmobile: r8a7790: Instantiate GIC from C board code in legacy builds
  ARM: shmobile: r8a73a4: Instantiate GIC from C board code in legacy builds
  ARM: mvebu: don't set the PL310 in I/O coherency mode when I/O coherency is disabled
  ARM: sunxi: dt: Fix aliases
  ARM: dts: sun4i: Add simplefb node with de_fe0-de_be0-lcd0-hdmi pipeline
  ARM: dts: sun6i: ippo-q8h-v5: Fix serial0 alias
  ARM: dts: sunxi: Fix usb-phy support for sun4i/sun5i

Pull input layer updates from Dmitry Torokhov:
 "Just a few quirks for PS/2 this time"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: elantech - add more Fujtisu notebooks to force crc_enabled
  Input: i8042 - add noloop quirk for Medion Akoya E7225 (MD98857)
  Input: synaptics - adjust min/max for Lenovo ThinkPad X1 Carbon 2nd

Commit 8eb23b9f ("sched: Debug nested sleeps") added code to report
on nested sleep conditions, which we generally want to avoid because the
inner sleeping operation can re-set the thread state to TASK_RUNNING,
but that will then cause the outer sleep loop not actually sleep when it
calls schedule.

However, that's actually valid traditional behavior, with the inner
sleep being some fairly rare case (like taking a sleeping lock that
normally doesn't actually need to sleep).

And the debug code would actually change the state of the task to
TASK_RUNNING internally, which makes that kind of traditional and
working code not work at all, because now the nested sleep doesn't just
sometimes cause the outer one to not block, but will cause it to happen
every time.

In particular, it will cause the cardbus kernel daemon (pccardd) to
basically busy-loop doing scheduling, converting a laptop into a heater,
as reported by Bruno Prémont.  But there may be other legacy uses of
that nested sleep model in other drivers that are also likely to never
get converted to the new model.

This fixes both cases:

 - don't set TASK_RUNNING when the nested condition happens (note: even
   if WARN_ONCE() only _warns_ once, the return value isn't whether the
   warning happened, but whether the condition for the warning was true.
   So despite the warning only happening once, the "if (WARN_ON(..))"
   would trigger for every nested sleep.

 - in the cases where we knowingly disable the warning by using
   "sched_annotate_sleep()", don't change the task state (that is used
   for all core scheduling decisions), instead use '->task_state_change'
   that is used for the debugging decision itself.

(Credit for the second part of the fix goes to Oleg Nesterov: "Can't we
avoid this subtle change in behaviour DEBUG_ATOMIC_SLEEP adds?" with the
suggested change to use 'task_state_change' as part of the test)
Reported-and-bisected-by: NBruno Prémont <bonbons@linux-vserver.org>
Tested-by: NRafael J Wysocki <rjw@rjwysocki.net>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Cc: Ilya Dryomov <ilya.dryomov@inktank.com>,
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Hurley <peter@hurleysoftware.com>,
Cc: Davidlohr Bueso <dave@stgolabs.net>,
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add two more Fujitsu LIFEBOOK models that also ship with the Elantech
touchpad and don't work with crc_disabled to the quirk list.
Signed-off-by: NRainer Koenig <Rainer.Koenig@ts.fujitsu.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Merge tag 'renesas-soc-fixes3-for-v3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into fixes

Merge "Third Round of Renesas ARM Based SoC Fixes for v3.19" from Simon Horman:

* Instantiate GIC from C board code in legacy builds on r8a7790 and r8a73a4

* tag 'renesas-soc-fixes3-for-v3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  ARM: shmobile: r8a7790: Instantiate GIC from C board code in legacy builds
  ARM: shmobile: r8a73a4: Instantiate GIC from C board code in legacy builds
Signed-off-by: NOlof Johansson <olof@lixom.net>

Pull i2c fixes from Wolfram Sang:
 "i2c driver bugfixes (s3c2410, slave-eeprom, sh_mobile), size
  regression "bugfix" (i2c slave), documentation bugfix (st).

  Also, one documentation update (da9063), so some devicetrees can now
  be verified"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: sh_mobile: terminate DMA reads properly
  i2c: Only include slave support if selected
  i2c: s3c2410: fix ABBA deadlock by keeping clock prepared
  i2c: slave-eeprom: fix boundary check when using sysfs
  i2c: st: Rename clock reference to something that exists
  DT: i2c: Add devices handled by the da9063 MFD driver

Pull char/misc driver fixes from Greg KH:
 "Here are two tiny patches, one fixing up the drivers/Kconfig file, and
  one adding a MAINTAINERS entry for the UIO git tree"

* tag 'char-misc-3.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  drivers/Kconfig: remove duplicate entry for soc
  MAINTAINERS: add git url entry for UIO

Pull staging tree fixes from Greg KH:
 "Here are two tiny staging tree fixes.  One for the nvec driver to
  resolve a reported problem, and one to add a MAINTAINERS entry for the
  Android drivers"

* tag 'staging-3.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  MAINTAINERS: add Android driver entries
  staging: nvec: specify a platform-device base id

Pull USB fixes from Greg KH:
 "Here are some small USB fixes and quirk additions for 3.19-rc7.

  All have been in linux-next for a while with no reported problems"

* tag 'usb-3.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: Add OTG PET device to TPL
  usb-storage/SCSI: blacklist FUA on JMicron 152d:2566 USB-SATA controller
  uas: Add no-report-opcodes quirk for Simpletech devices with id 4971:8017
  storage: Revise/fix quirk for 04E6:000F SCM USB-SCSI converter
  usb: phy: never defer probe in non-OF case
  usb: dwc2: call dwc2_is_controller_alive() under spinlock

Pull perf fixes from Ingo Molnar:
 "Mostly tooling fixes, but also an event groups fix, two PMU driver
  fixes and a CPU model variant addition"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Tighten (and fix) the grouping condition
  perf/x86/intel: Add model number for Airmont
  perf/rapl: Fix crash in rapl_scale()
  perf/x86/intel/uncore: Move uncore_box_init() out of driver initialization
  perf probe: Fix probing kretprobes
  perf symbols: Introduce 'for' method to iterate over the symbols with a given name
  perf probe: Do not rely on map__load() filter to find symbols
  perf symbols: Introduce method to iterate symbols ordered by name
  perf symbols: Return the first entry with a given name in find_by_name method
  perf annotate: Fix memory leaks in LOCK handling
  perf annotate: Handle ins parsing failures
  perf scripting perl: Force to use stdbool
  perf evlist: Remove extraneous 'was' on error message

Pull btrfs fix from Chris Mason:
 "We have one more fix for btrfs in my for-linus branch - this was a bug
  in the new raid5/6 scrubbing support"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: fix raid56 scrub failed in xfstests btrfs/072

Pull quota and UDF fix from Jan Kara:
 "A fix for UDF to properly free preallocated blocks and a fix for quota
  so that Q_GETQUOTA quotactl reports correct numbers for XFS filesystem
  (and similarly Q_XGETQUOTA quotactl works properly for other
  filesystems)"

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  quota: Switch ->get_dqblk() and ->set_dqblk() to use bytes as space units
  udf: Release preallocation on last writeable close

Pull KVM fixes from Paolo Bonzini:
 "The ARM changes are largish, but not too scary.  And a simple fix for
  x86 (bug introduced in 3.19)"

(Paolo sayus these are the "Final" fixes. We'll see).

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: check LAPIC presence when building apic_map
  arm/arm64: KVM: Use kernel mapping to perform invalidation on page fault
  arm/arm64: KVM: Invalidate data cache on unmap
  arm/arm64: KVM: Use set/way op trapping to track the state of the caches

Pull IOMMU fixes from Joerg Roedel:
 "Two small fixes for the Tegra GART IOMMU driver:

   - provide a .map_sg function for iommu_ops
   - do not register Tegra GART driver as a workaround because of issues
     with it when used from DRM code"

* tag 'iommu-fixes-v3.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/tegra: gart: Provide default ->map_sg() callback
  iommu/tegra: gart: Do not register with bus