switch compat_sys_sysctl to COMPAT_SYSCALL_DEFINE

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
kernel: fix new kernel-doc warning in wait.c

Fix new kernel-doc warnings in kernel/wait.c:

  Warning(kernel/wait.c:374): No description found for parameter 'p'
  Warning(kernel/wait.c:374): Excess function parameter 'word' description in 'wake_up_atomic_t'
  Warning(kernel/wait.c:374): Excess function parameter 'bit' description in 'wake_up_atomic_t'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix __wait_on_atomic_t() to call the action func if the counter != 0

Fix __wait_on_atomic_t() so that it calls the action func if the counter != 0
rather than if the counter is 0 so as to be analogous to __wait_on_bit().

Thanks to Yacine who found this by visual inspection.

This will affect FS-Cache in that it will could fail to sleep correctly when
trying to clean up after a netfs cookie is withdrawn.

Reported-by: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
cc: Milosz Tanski <milosz@adfin.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add new lockref infrastructure reference implementation

This introduces a new "lockref" structure that supports the concept of
lockless updates of reference counts that still honor an attached
spinlock.

NOTE! This reference implementation is not the optimized lockless
version, rather it is the fallback implementation using standard
spinlocks.  The actual optimized versions will be merged into 3.12, but
I wanted to get the infrastructure in place and document the new
interfaces.

[ Also note that this particular commit is drastically cut-down minimal
  version of the original patch by Waiman.  In order to properly credit
  the original author I'm marking Waiman as the author here, but in the
  end this patch bears little resemblance to the patch by Waiman.  So
  blame any errors on me editing things down to the point where I can
  introduce the infrastructure before the merge window for 3.12 actually
  opens.     - Linus ]

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/base/memory.c: fix show_mem_removable() to handle missing sections

"cat /sys/devices/system/memory/memory*/removable" crashed the system.

The problem is that show_mem_removable() is passing a
bad pfn to is_mem_section_removable(), which causes

    if (!node_online(page_to_nid(page)))

to blow up.  Why is it passing in a bad pfn?

The reason is that show_mem_removable() will loop sections_per_block
times.  sections_per_block is 16, but mem->section_count is 8,
indicating holes in this memory block.  Checking that the memory section
is present before checking to see if the memory section is removable
fixes the problem.

   harp5-sys:~ # cat /sys/devices/system/memory/memory*/removable
   0
   1
   1
   1
   1
   1
   1
   1
   1
   1
   1
   1
   1
   1
   BUG: unable to handle kernel paging request at ffffea00c3200000
   IP: [<ffffffff81117ed1>] is_pageblock_removable_nolock+0x1/0x90
   PGD 83ffd4067 PUD 37bdfce067 PMD 0
   Oops: 0000 [#1] SMP
   Modules linked in: autofs4 binfmt_misc rdma_ucm rdma_cm iw_cm ib_addr ib_srp scsi_transport_srp scsi_tgt ib_ipoib ib_cm ib_uverbs ib_umad iw_cxgb3 cxgb3 mdio mlx4_en mlx4_ib ib_sa mlx4_core ib_mthca ib_mad ib_core fuse nls_iso8859_1 nls_cp437 vfat fat joydev loop hid_generic usbhid hid hwperf(O) numatools(O) dm_mod iTCO_wdt ipv6 iTCO_vendor_support igb i2c_i801 ioatdma i2c_algo_bit ehci_pci pcspkr lpc_ich i2c_core ehci_hcd ptp sg mfd_core dca rtc_cmos pps_core mperf button xhci_hcd sd_mod crc_t10dif usbcore usb_common scsi_dh_emc scsi_dh_hp_sw scsi_dh_alua scsi_dh_rdac scsi_dh gru(O) xvma(O) xfs crc32c libcrc32c thermal sata_nv processor piix mptsas mptscsih scsi_transport_sas mptbase megaraid_sas fan thermal_sys hwmon ext3 jbd ata_piix ahci libahci libata scsi_mod
   CPU: 4 PID: 5991 Comm: cat Tainted: G           O 3.11.0-rc5-rja-uv+ #10
   Hardware name: SGI UV2000/ROMLEY, BIOS SGI UV 2000/3000 series BIOS 01/15/2013
   task: ffff88081f034580 ti: ffff880820022000 task.ti: ffff880820022000
   RIP: 0010:[<ffffffff81117ed1>]  [<ffffffff81117ed1>] is_pageblock_removable_nolock+0x1/0x90
   RSP: 0018:ffff880820023df8  EFLAGS: 00010287
   RAX: 0000000000040000 RBX: ffffea00c3200000 RCX: 0000000000000004
   RDX: ffffea00c30b0000 RSI: 00000000001c0000 RDI: ffffea00c3200000
   RBP: ffff880820023e38 R08: 0000000000000000 R09: 0000000000000001
   R10: 0000000000000000 R11: 0000000000000001 R12: ffffea00c33c0000
   R13: 0000160000000000 R14: 6db6db6db6db6db7 R15: 0000000000000001
   FS:  00007ffff7fb2700(0000) GS:ffff88083fc80000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: ffffea00c3200000 CR3: 000000081b954000 CR4: 00000000000407e0
   Call Trace:
     show_mem_removable+0x41/0x70
     dev_attr_show+0x2a/0x60
     sysfs_read_file+0xf7/0x1c0
     vfs_read+0xc8/0x130
     SyS_read+0x5d/0xa0
     system_call_fastpath+0x16/0x1b

Signed-off-by: Russ Anderson <rja@sgi.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ipc: remove forced assignment of selected message

This is a cleanup patch. The assignment is redundant.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>