Currently lockdep will print the 1st circle detected if it
exists when acquiring a new (next) lock.

This patch prints the shortest path from the next lock to be
acquired to the previous held lock if a circle is found.

The patch still uses the current method to check circle, and
once the circle is found, breadth-first search algorithem is
used to compute the shortest path from the next lock to the
previous lock in the forward lock dependency graph.

Printing the shortest path will shorten the dependency chain,
and make troubleshooting for possible circular locking easier.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1246201486-7308-2-git-send-email-tom.leiming@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Merge branch 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  genirq: Fix UP compile failure caused by irq_thread_check_affinity

Merge branch 'lockdep-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-lockdep

* 'lockdep-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-lockdep:
  lockdep: Fix lockdep annotation for pipe_double_lock()

Since genirq: Delegate irq affinity setting to the irq thread
(591d2fb0) compilation with
CONFIG_SMP=n fails with following error:

/usr/src/linux-2.6/kernel/irq/manage.c:
   In function 'irq_thread_check_affinity':
/usr/src/linux-2.6/kernel/irq/manage.c:475:
   error: 'struct irq_desc' has no member named 'affinity'
make[4]: *** [kernel/irq/manage.o] Error 1

That commit adds a new function irq_thread_check_affinity() which
uses struct irq_desc.affinity which is only available for CONFIG_SMP=y.
Move that function under #ifdef CONFIG_SMP.

[ tglx@brownpaperbag: compile and boot tested on UP and SMP ]
Signed-off-by: Bruno Premont <bonbons@linux-vserver.org>
LKML-Reference: <20090722222232.2eb3e1c4@neptune.home>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The presumed use of the pipe_double_lock() routine is to lock 2 locks in
a deadlock free way by ordering the locks by their address. However it
fails to keep the specified lock classes in order and explicitly
annotates a deadlock.

Rectify this.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Miklos Szeredi <mszeredi@suse.cz>
LKML-Reference: <1248163763.15751.11098.camel@twins>

Merge branch 'perf-counters-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-perf

* 'perf-counters-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-perf: (31 commits)
  perf_counter tools: Give perf top inherit option
  perf_counter tools: Fix vmlinux symbol generation breakage
  perf_counter: Detect debugfs location
  perf_counter: Add tracepoint support to perf list, perf stat
  perf symbol: C++ demangling
  perf: avoid structure size confusion by using a fixed size
  perf_counter: Fix throttle/unthrottle event logging
  perf_counter: Improve perf stat and perf record option parsing
  perf_counter: PERF_SAMPLE_ID and inherited counters
  perf_counter: Plug more stack leaks
  perf: Fix stack data leak
  perf_counter: Remove unused variables
  perf_counter: Make call graph option consistent
  perf_counter: Add perf record option to log addresses
  perf_counter: Log vfork as a fork event
  perf_counter: Synthesize VDSO mmap event
  perf_counter: Make sure we dont leak kernel memory to userspace
  perf_counter tools: Fix index boundary check
  perf_counter: Fix the tracepoint channel to perfcounters
  perf_counter, x86: Extend perf_counter Pentium M support
  ...

Merge branch 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  softirq: introduce tasklet_hrtimer infrastructure

Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  clocksource: Prevent NULL pointer dereference
  timer: Avoid reading uninitialized data

Merge branch 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  genirq: Delegate irq affinity setting to the irq thread

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: fix nr_uninterruptible accounting of frozen tasks really
  sched: fix load average accounting vs. cpu hotplug
  sched: Account for vruntime wrapping

* 'tj-block-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc:
  virtio_blk: mark virtio_blk with __refdata to kill spurious section mismatch
  block: sysfs fix mismatched queue_var_{store,show} in 64bit kernel
  ataflop: adjust NULL test
  block: fix failfast merge testing in elv_rq_merge_ok()
  z2ram: Small cleanup for z2ram.c

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  fs/Kconfig: move nilfs2 out

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6:
  ide-tape: Don't leak kernel stack information
  ide: fix memory leak when flush command is issued

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (37 commits)
  sky2: Avoid races in sky2_down
  drivers/net/mlx4: Adjust constant
  drivers/net: Move a dereference below a NULL test
  drivers/net: Move a dereference below a NULL test
  connector: maintainer/mail update.
  USB host CDC Phonet network interface driver
  macsonic, jazzsonic: fix oops on module unload
  macsonic: move probe function to .devinit.text
  can: switch carrier on if device was stopped while in bus-off state
  can: restart device even if dev_alloc_skb() fails
  can: sja1000: remove duplicated includes
  New device ID for sc92031 [1088:2031]
  3c589_cs: re-initialize the multicast in the tc589_reset
  Fix error return for setsockopt(SO_TIMESTAMPING)
  netxen: fix thermal check and shutdown
  netxen: fix deadlock on dev close
  netxen: fix context deletion sequence
  net: Micrel KS8851 SPI network driver
  tcp: Use correct peer adr when copying MD5 keys
  tcp: Fix MD5 signature checking on IPv4 mapped sockets
  ...

* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  NFSv4: Fix a problem whereby a buggy server can oops the kernel
  NFSv4: Fix an NFSv4 mount regression
  NFSv4: Fix an Oops in nfs4_free_lock_state

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: ctxfi: Swapped SURROUND-SIDE channels on emu20k2
  ALSA: ca0106 - Fix the max capture buffer size
  ALSA: hda - Fix pin-setup for Sony VAIO with STAC9872 codecs
  ALSA: hda - Add quirk for Gateway T6834c laptop
  ALSA: OSS sequencer should be initialized after snd_seq_system_client_init
  ALSA: sound/isa: convert nested spin_lock_irqsave to spin_lock
  ALSA: hda_codec: Check for invalid zero connections

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: Move dereferences below a NULL test
  HID: hiddev, fix lock imbalance

the "reserved" field was not initialized to zero, resulting in 4 bytes
of stack data leaking to userspace....
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'linux-next' of git://git.infradead.org/ubi-2.6:
  UBI: fix bug in image sequence number handling
  UBI: gluebi: initialize ubi_num field

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: atkbd - add force relese key quirk for Soltech TA12
  Input: fix EVIOCGNAME/JSIOCGNAME regression
  Input: atkbd - add forced release keys quirk for FSC Amilo Pi 3525
  Input: pcspkr - switch driver to dev_pm_ops
  Input: xpad - don't resend successfully sent outgoing requests
  Input: wistron_btns - recognize Maxdata Pro 7000 notebooks

Currently, perf top -p only tracks the pid provided, which isn't very useful
for watching forky loads, so give it an inherit option.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1248165036.9795.10.camel@marge.simson.net>

vmlinux meets the criteria for symbol adjustment, which breaks vmlinux generated symbols.
Fix this by exempting vmlinux.  This is a bit fragile in that someone could change the
kernel dso's name, but currently that name is also hardwired.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1248091298.18702.18.camel@marge.simson.net>

If "/sys/kernel/debug" is not a debugfs mount point, search for the debugfs
filesystem in /proc/mounts, but also allows the user to specify
'--debugfs-dir=blah' or set the environment variable: 'PERF_DEBUGFS_DIR'
Signed-off-by: Jason Baron <jbaron@redhat.com>
[ also made it probe "/debug" by default ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090721181629.GA3094@redhat.com>

Add support to 'perf list' and 'perf stat' for kernel tracepoints. The
implementation creates a 'for_each_subsystem' and 'for_each_event' for
easy iteration over the tracepoints.
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <426129bf9fcc8ee63bb094cf736e7316a7dcd77a.1248190728.git.jbaron@redhat.com>

[acme@doppio ~]$ perf report -s comm,dso,symbol -C firefox -d /usr/lib64/xulrunner-1.9.1/libxul.so | grep :: | head
     2.21%  [.] nsDeque::Push(void*)
     1.78%  [.] GraphWalker::DoWalk(nsDeque&)
     1.30%  [.] GCGraphBuilder::AddNode(void*, nsCycleCollectionParticipant*)
     1.27%  [.] XPCWrappedNative::CallMethod(XPCCallContext&, XPCWrappedNative::CallMode)
     1.18%  [.] imgContainer::DrawFrameTo(gfxIImageFrame*, gfxIImageFrame*, nsRect&)
     1.13%  [.] nsDeque::PopFront()
     1.11%  [.] nsGlobalWindow::RunTimeout(nsTimeout*)
     0.97%  [.] nsXPConnect::Traverse(void*, nsCycleCollectionTraversalCallback&)
     0.95%  [.] nsJSEventListener::cycleCollection::Traverse(void*, nsCycleCollectionTraversalCallback&)
     0.95%  [.] nsCOMPtr_base::~nsCOMPtr_base()
[acme@doppio ~]$

Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Suggested-by: Clark Williams <williams@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090720171412.GB10410@ghostprotocols.net>

for some reason, this structure gets compiled as 36 bytes in some files
(the ones that alloacte it) but 40 bytes in others (the ones that use it).
The cause is an off_t type that gets a different size in different
compilation units for some yet-to-be-explained reason.

But the effect is disasterous; the size/offset members of the struct
are at different offsets, and result in mostly complete garbage.
The parser in perf is so robust that this all gets hidden, and after
skipping an certain amount of samples, it recovers.... so this bug
is not normally noticed.

.... except when you want every sample to be exact.

Fix this by just using an explicitly sized type.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4A655917.9080504@linux.intel.com>

Right now we only print PERF_EVENT_THROTTLE + 1 (ie PERF_EVENT_UNTHROTTLE).
Fix this to print both a throttle and unthrottle event.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090722130546.GE9029@kryten>

perf stat and perf record currently look for all options on the command
line. This can lead to some confusion:

# perf stat ls -l
  Error: unknown switch `l'

While we can work around this by adding '--' before the command, the git
option parsing code can stop at the first non option:

# perf stat ls -l
 Performance counter stats for 'ls -l':
....
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090722130412.GD9029@kryten>

Anton noted that for inherited counters the counter-id as provided by
PERF_SAMPLE_ID isn't mappable to the id found through PERF_RECORD_ID
because each inherited counter gets its own id.

His suggestion was to always return the parent counter id, since that
is the primary counter id as exposed. However, these inherited
counters have a unique identifier so that events like
PERF_EVENT_PERIOD and PERF_EVENT_THROTTLE can be specific about which
counter gets modified, which is important when trying to normalize the
sample streams.

This patch removes PERF_EVENT_PERIOD in favour of PERF_SAMPLE_PERIOD,
which is more useful anyway, since changing periods became a lot more
common than initially thought -- rendering PERF_EVENT_PERIOD the less
useful solution (also, PERF_SAMPLE_PERIOD reports the more accurate
value, since it reports the value used to trigger the overflow,
whereas PERF_EVENT_PERIOD simply reports the requested period changed,
which might only take effect on the next cycle).

This still leaves us PERF_EVENT_THROTTLE to consider, but since that
_should_ be a rare occurrence, and linking it to a primary id is the
most useful bit to diagnose the problem, we introduce a
PERF_SAMPLE_STREAM_ID, for those few cases where the full
reconstruction is important.

[Does change the ABI a little, but I see no other way out]
Suggested-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1248095846.15751.8781.camel@twins>

Per example of Arjan's patch, I went through and found a few more.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>

the "reserved" field was not initialized to zero, resulting in 4 bytes
of stack data leaking to userspace....
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>

Fix a gcc unused variables warning.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>

There's some odd bug in gcc-4.2 where it miscompiles a simple loop whent
he loop counter is of type 'unsigned char' and it should count to 128.

The compiler will incorrectly decide that a trivial loop like this:

	unsigned char i, ...

	for (i = 0; i < 128; i++) {
		..

is endless, and will compile it to a single instruction that just
branches to itself.

This was triggered by the addition of '-fno-strict-overflow', and we
could play games with compiler versions and go back to '-fwrapv'
instead, but the trivial way to avoid it is to just make the loop
induction variable be an 'int' instead.

Thanks to Krzysztof Oledzki for reporting and testing and to Troy Moure
for digging through assembler differences and finding it.
Reported-and-tested-by: Krzysztof Oledzki <olel@ans.pl>
Found-by: Troy Moure <twmoure@szypr.net>
Gcc-bug-acked-by: Ian Lance Taylor <iant@google.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

commit ca109491 (hrtimer: removing all ur callback modes) moved all
hrtimer callbacks into hard interrupt context when high resolution
timers are active. That breaks code which relied on the assumption
that the callback happens in softirq context.

Provide a generic infrastructure which combines tasklets and hrtimers
together to provide an in-softirq hrtimer experience.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: torvalds@linux-foundation.org
Cc: kaber@trash.net
Cc: David Miller <davem@davemloft.net>
LKML-Reference: <1248265724.27058.1366.camel@twins>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Reset rx chain before trying to drain it.
Shut interrupts off last, incase there's something to report.
Signed-off-by: Mike McCormack <mikem@ring3k.org>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Don't leak kernel stack information through uninitialized structure members.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Acked-by: Borislav Petkov <petkovbb@gmail.com>.
Signed-off-by: David S. Miller <davem@davemloft.net>

I'm using ide on 2.6.30.1 with xfs filesystem. I noticed a kernel memory
leak after writing lots of data, the kmalloc-96 slab cache keeps
growing. It seems the struct ide_cmd kmalloced by idedisk_prepare_flush
is never kfreed.

Commit a09485df ("ide: move request
type specific code from ide_end_drive_cmd() to callers (v3)") and
f505d49f ("ide: fix barriers support")
cause this regression, cmd->rq must now be set for ide_complete_cmd to
honor the IDE_TFLAG_DYN flag.
Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We just had a case in which a buggy server occasionally returns the wrong
attributes during an OPEN call. While the client does catch this sort of
condition in nfs4_open_done(), and causes the nfs4_atomic_open() to return
-EISDIR, the logic in nfs_atomic_lookup() is broken, since it causes a
fallback to an ordinary lookup instead of just returning the error.

When the buggy server then returns a regular file for the fallback lookup,
the VFS allows the open, and bad things start to happen, since the open
file doesn't have any associated NFSv4 state.

The fix is firstly to return the EISDIR/ENOTDIR errors immediately, and
secondly to ensure that we are always careful when dereferencing the
nfs_open_context state pointer.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>