This patch fixes an error in perf_event_open() when the pid
provided by the user is invalid. find_lively_task_by_vpid()
does not return NULL on error but an error code. Without the
fix the error code was silently passed to find_get_context()
which would eventually cause a invalid pointer dereference.
Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: paulus@samba.org
Cc: davem@davemloft.net
Cc: fweisbec@gmail.com
Cc: perfmon2-devel@lists.sf.net
Cc: eranian@gmail.com
Cc: robert.richter@amd.com
LKML-Reference: <4ca9a5d1.e8e9d80a.3dbb.ffff8f2e@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

The following build bug occurs on distcc builds:

   CC      arch/x86/kernel/asm-offsets.s
 In file included from include/linux/module.h:24,
                  from include/linux/crypto.h:22,
                  from arch/x86/kernel/asm-offsets_64.c:9,
                  from arch/x86/kernel/asm-offsets.c:5:
 include/trace/events/module.h: In function 'trace_module_load':
 include/trace/events/module.h:18: error: expected '(' before 'goto'
 include/trace/events/module.h:18: error: expected identifier or '*' before '(' token

It triggers because distcc is invoked by turning $CC into "distcc gcc",
but gcc-goto.sh check script was using $1 not $@ to expand parameters.

Cc: Jason Baron <jbaron@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100923034910.867858597@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core

Conflicts:
	arch/sparc/kernel/perf_event.c

Merge reason: Resolve the conflict.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

The !CC_OPTIMIZE_FOR_SIZE was added to enable the jump label functionality
because Jason noticed that the gcc option would not optimize the labels
and may even hurt performance.

But this is a gcc problem not a kernel one. Removing this condition should
add motivation to the gcc developers to actually fix it.

Cc: Jason Baron <jbaron@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

The structure in the x86 jump label code uses the typedef jump_label_t,
which is defined by the #ifdef arch type. The structure does not need
to be duplicated there.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Add jump label support for sparc64.
Signed-off-by: David S. Miller <davem@davemloft.net>
LKML-Reference: <3b5b071fcdb2afb7f67cacecfa78b14c740278a7.1284733808.git.jbaron@redhat.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>

[ cleaned up some formatting ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

add x86 support for jump label. I'm keeping this patch separate so its clear
to arch maintainers what was required for x86 support this new feature.
Hopefully, it wouldn't be too painful for other archs.
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <f838f49f40fbea0254036194be66dc48b598dcea.1284733808.git.jbaron@redhat.com>

[ cleaned up some formatting ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Convert the 'dynamic debug' infrastructure to use jump labels.
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <b77627358cea3e27d7be4386f45f66219afb8452.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Make use of the jump label infrastructure for tracepoints.
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <a9ba2056e2c9cf332c3c300b577463ce66ff23a8.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Add a jump_label_text_reserved(void *start, void *end), so that other
pieces of code that want to modify kernel text, can first verify that
jump label has not reserved the instruction.
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <06236663a3a7b1c1f13576bb9eccb6d9c17b7bfe.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Initialize the workqueue data structures *before* they are registered
so that they are ready for callbacks.
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <e3a3383fc370ac7086625bebe89d9480d7caf372.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

base patch to implement 'jump labeling'. Based on a new 'asm goto' inline
assembly gcc mechanism, we can now branch to labels from an 'asm goto'
statment. This allows us to create a 'no-op' fastpath, which can subsequently
be patched with a jump to the slowpath code. This is useful for code which
might be rarely used, but which we'd like to be able to call, if needed.
Tracepoints are the current usecase that these are being implemented for.
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <ee8b3595967989fdaf84e698dc7447d315ce972a.1284733808.git.jbaron@redhat.com>

[ cleaned up some formating ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sparc: Prevent no-handler signal syscall restart recursion.
  sparc: Don't mask signal when we can't setup signal frame.
  sparc64: Fix race in signal instruction flushing.
  sparc64: Support RAW perf events.

Conflicts:
	kernel/hw_breakpoint.c

Merge reason: resolve the conflict.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Make sigreturn zero regs->trap, make do_signal() do the same on all
paths.  As it is, signal interrupting e.g. read() from fd 512 (==
ERESTARTSYS) with another signal getting unblocked when the first
handler finishes will lead to restart one insn earlier than it ought
to.  Same for multiple signals with in-kernel handlers interrupting
that sucker at the same time.  Same for multiple signals of any kind
interrupting that sucker on 64bit...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  bdi: Fix warnings in __mark_inode_dirty for /dev/zero and friends
  char: Mark /dev/zero and /dev/kmem as not capable of writeback
  bdi: Initialize noop_backing_dev_info properly
  cfq-iosched: fix a kernel OOPs when usb key is inserted
  block: fix blk_rq_map_kern bio direction flag
  cciss: freeing uninitialized data on error path

Inodes of devices such as /dev/zero can get dirty for example via
utime(2) syscall or due to atime update. Backing device of such inodes
(zero_bdi, etc.) is however unable to handle dirty inodes and thus
__mark_inode_dirty complains.  In fact, inode should be rather dirtied
against backing device of the filesystem holding it. This is generally a
good rule except for filesystems such as 'bdev' or 'mtd_inodefs'. Inodes
in these pseudofilesystems are referenced from ordinary filesystem
inodes and carry mapping with real data of the device. Thus for these
inodes we have to use inode->i_mapping->backing_dev_info as we did so
far. We distinguish these filesystems by checking whether sb->s_bdi
points to a non-trivial backing device or not.

Example: Assume we have an ext3 filesystem on /dev/sda1 mounted on /.
There's a device inode A described by a path "/dev/sdb" on this
filesystem. This inode will be dirtied against backing device "8:0"
after this patch. bdev filesystem contains block device inode B coupled
with our inode A. When someone modifies a page of /dev/sdb, it's B that
gets dirtied and the dirtying happens against the backing device "8:16".
Thus both inodes get filed to a correct bdi list.

Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

These devices don't do any writeback but their device inodes still can get
dirty so mark bdi appropriately so that bdi code does the right thing and files
inodes to lists of bdi carrying the device inodes.

Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

Properly initialize this backing dev info so that writeback code does not
barf when getting to it e.g. via sb->s_bdi.

Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

Explicitly clear the "in-syscall" bit when we have no signal
handler and back up the program counters to back up the system
call.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Don't invoke the signal handler tracehook in that situation
either.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

* 'for-linus/i2c/2636-rc5' of git://git.fluff.org/bjdooks/linux:
  i2c-omap: Make sure i2c bus is free before setting it to idle

The lock structs are currently protected by the BKL, but are accessed by
code in fs/locks.c and misc file system and DLM code.  These stubs will
allow all users to switch to the new interface before the implementation
is changed to a spinlock.
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If the i2c bus receives an interrupt with both BB (bus busy) and
ARDY (register access ready) statuses set during the tranfer of the last message
the bus was put to idle while still busy.

This caused bus to timeout.
Signed-off-by: Mathias Nyman <mathias.nyman@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

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 nohz balance kick
  sched: Fix user time incorrectly accounted as system time on 32-bit

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

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hw breakpoints: Fix pid namespace bug
  x86: Fix instruction breakpoint encoding
  oprofile: Add Support for Intel CPU Family 6 / Model 22 (Intel Celeron 540)
  kprobes: Fix Kconfig dependency

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: select CRYPTO
  ceph: check mapping to determine if FILE_CACHE cap is used
  ceph: only send one flushsnap per cap_snap per mds session
  ceph: fix cap_snap and realm split
  ceph: stop sending FLUSHSNAPs when we hit a dirty capsnap
  ceph: correctly set 'follows' in flushsnap messages
  ceph: fix dn offset during readdir_prepopulate
  ceph: fix file offset wrapping at 4GB on 32-bit archs
  ceph: fix reconnect encoding for old servers
  ceph: fix pagelist kunmap tail
  ceph: fix null pointer deref on anon root dentry release

* 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ickle/drm-intel:
  drm/i915: Hold a reference to the object whilst unbinding the eviction list
  drm/i915,agp/intel: Add second set of PCI-IDs for B43
  drm/i915: Fix Sandybridge fence registers
  drm/i915/crt: Downgrade warnings for hotplug failures
  drm/i915: Ensure that the crtcinfo is populated during mode_fixup()

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  lguest: update comments to reflect LHCALL_LOAD_GDT_ENTRY.
  virtio: console: Prevent userspace from submitting NULL buffers
  virtio: console: Fix poll blocking even though there is data to read

The per-pmu per-cpu context patch converted things from
get_cpu_var() to this_cpu_ptr(), but that only works if
rcu_read_lock() actually disables preemption, and since
there is no such guarantee, we need to fix that.

Use the newly introduced {get,put}_cpu_ptr().
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <20100917093009.308453028@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

These are similar to {get,put}_cpu_var() except for dynamically
allocated per-cpu memory.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <20100917093009.252867712@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Merge reason: Pick up the latest fixes in -rc5.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

There's a situation where the nohz balancer will try to wake itself:

cpu-x is idle which is also ilb_cpu
got a scheduler tick during idle
and the nohz_kick_needed() in trigger_load_balance() checks for
rq_x->nr_running which might not be zero (because of someone waking a
task on this rq etc) and this leads to the situation of the cpu-x
sending a kick to itself.

And this can cause a lockup.

Avoid this by not marking ourself eligible for kicking.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1284400941.2684.19.camel@sbsiddha-MOBL3.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Mike reported a kernel crash when a usb key hotplug is performed while all
kernel thrads are not in a root cgroup and are running in one of the child
cgroups of blkio controller.

	BUG: unable to handle kernel NULL pointer dereference at 0000002c
	IP: [<c11c7b08>] cfq_get_queue+0x232/0x412
	*pde = 00000000
	Oops: 0000 [#1] PREEMPT
	last sysfs file: /sys/devices/pci0000:00/0000:00:1d.7/usb2/2-1/2-1:1.0/host3/scsi_host/host3/uevent

	[..]
	Pid: 30039, comm: scsi_scan_3 Not tainted 2.6.35.2-fg.roam #1 Volvi2                         /Aspire 4315
	EIP: 0060:[<c11c7b08>] EFLAGS: 00010086 CPU: 0
	EIP is at cfq_get_queue+0x232/0x412
	EAX: f705f9c0 EBX: e977abac ECX: 00000000 EDX: 00000000
	ESI: f00da400 EDI: f00da4ec EBP: e977a800 ESP: dff8fd00
	 DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
	Process scsi_scan_3 (pid: 30039, ti=dff8e000 task=f6b6c9a0 task.ti=dff8e000)
	Stack:
	 00000000 00000000 00000001 01ff0000 f00da508 00000000 f00da524 f00da540
	<0> e7994940 dd631750 f705f9c0 e977a820 e977ac44 f00da4d0 00000001 f6b6c9a0
	<0> 00000010 00008010 0000000b 00000000 00000001 e977a800 dd76fac0 00000246
	Call Trace:
	 [<c11c7f10>] ? cfq_set_request+0x228/0x34c
	 [<c11c7ce8>] ? cfq_set_request+0x0/0x34c
	 [<c11bb3b9>] ? elv_set_request+0xf/0x1c
	 [<c11bdd51>] ? get_request+0x1ad/0x22f
	 [<c11bddf2>] ? get_request_wait+0x1f/0x11a
	 [<c11d013b>] ? kvasprintf+0x33/0x3b
	 [<c127b537>] ? scsi_execute+0x1d/0x103
	 [<c127b675>] ? scsi_execute_req+0x58/0x83
	 [<c127c391>] ? scsi_probe_and_add_lun+0x188/0x7c2
	 [<c12718c6>] ? attribute_container_add_device+0x15/0xfa
	 [<c11c95d1>] ? kobject_get+0xf/0x13
	 [<c126d1db>] ? get_device+0x10/0x14
	 [<c127be93>] ? scsi_alloc_target+0x217/0x24d
	 [<c127cbd8>] ? __scsi_scan_target+0x95/0x480
	 [<c10204eb>] ? dequeue_entity+0x14/0x1fe
	 [<c1020491>] ? update_curr+0x165/0x1ab
	 [<c1020491>] ? update_curr+0x165/0x1ab
	 [<c127d00d>] ? scsi_scan_channel+0x4a/0x76
	 [<c127d0b0>] ? scsi_scan_host_selected+0x77/0xad
	 [<c127d13c>] ? do_scan_async+0x0/0x11a
	 [<c127d137>] ? do_scsi_scan_host+0x51/0x56
	 [<c127d13c>] ? do_scan_async+0x0/0x11a
	 [<c127d14a>] ? do_scan_async+0xe/0x11a
	 [<c127d13c>] ? do_scan_async+0x0/0x11a
	 [<c10354c5>] ? kthread+0x5e/0x63
	 [<c1035467>] ? kthread+0x0/0x63
	 [<c1002af6>] ? kernel_thread_helper+0x6/0x10
	Code: 44 24 1c 54 83 44 24 18 54 83 fa 03 75 94 8b 06 c7 86 64 02 00 00 01 00 00 00 83 e0 03 09 f0 89 06 8b 44 24 28 8b 90 58 01 00 00 <8b> 42 2c 85 c0 75 03 8b 42 08 8d 54 24 48 52 8d 4c 24 50 51 68
	EIP: [<c11c7b08>] cfq_get_queue+0x232/0x412 SS:ESP 0068:dff8fd00
	CR2: 000000000000002c
	---[ end trace 9a88306573f69b12 ]---

The problem here is that we don't have bdi->dev information available when
thread does some IO.  Hence when dev_name() tries to access bdi->dev, it
crashes.

This problem does not happen if kernel threads are in root group as root
group is statically allocated at device initialization time and we don't
hit this piece of code.

Fix it by delaying the filling of major and minor number information of
device in blk_group.  Initially a blk_group is created with 0 as device
information and this information is filled later once some more IO comes
in from same group.
Reported-by: Mike Kazantsev <mk.fraggod@gmail.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

This bug was introduced in 7b6d91da
"block: unify flags for struct bio and struct request"

Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

The "h->scatter_list" is allocated inside a for loop.  If any of those
allocations fail, then the rest of the list is uninitialized data.  When
we free it we should start from the top and free backwards so that we
don't call kfree() on uninitialized pointers.

Also if the allocation for "h->scatter_list" fails then we would get an
Oops here.  I should have noticed this when I send: 4ee69851 "cciss:
handle allocation failure."  but I didn't.  Sorry about that.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

If another cpu does a very wide munmap() on the signal frame area,
it can tear down the page table hierarchy from underneath us.

Borrow an idea from the 64-bit fault path's get_user_insn(), and
disable cross call interrupts during the page table traversal
to lock them in place while we operate.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

We used to have a hypercall which reloaded the entire GDT, then we
switched to one which loaded a single entry (to match the IDT code).

Some comments were not updated, so fix them.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reported by: Eviatar Khen <eviatarkhen@gmail.com>