Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU changes from Paul E. McKenney:

 - Expedited grace-period changes, most notably avoiding having
   user threads drive expedited grace periods, using a workqueue
   instead.

 - Miscellaneous fixes, including a performance fix for lists
   that was sent with the lists modifications (second URL below).

 - CPU hotplug updates, most notably providing exact CPU-online
   tracking for RCU.  This will in turn allow removal of the
   checks supporting RCU's prior heuristic that was based on the
   assumption that CPUs would take no longer than one jiffy to
   come online.

 - Torture-test updates.

 - Documentation updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull kvm fix from Paolo Bonzini:
 "One fix for an x86 regression in VM migration, mostly visible with
  Windows because it uses RTC periodic interrupts"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: x86: correctly reset dest_map->vector when restoring LAPIC state

Kirill A Shutemov reports that the kernel doesn't try to cap dest_count
in any way, and uses the number to allocate kernel memory.  This causes
high order allocation warnings in the kernel log if someone passes in a
big enough value.  We should clamp the allocation at PAGE_SIZE to avoid
stressing the VM.

The two existing users of the dedupe ioctl never send more than 120
requests, so we can safely clamp dest_range at PAGE_SIZE, because with
4k pages we can handle up to 127 dedupe candidates.  Given the max
extent length of 16MB, we can end up doing 2GB of IO which is plenty.

[ Note: the "offsetof()" can't overflow, because 'count' is just a
  16-bit integer.  That's not obvious in the limited context of the
  patch, so I'm noting it here because it made me go look.  - Linus ]
Reported-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

All the VFS functions in the dedupe ioctl path return int status, so
the ioctl handler ought to as well.

Found by Coverity, CID 1350952.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull block fixes from Jens Axboe:
 "A set of fixes for the current series in the realm of block.

  Like the previous pull request, the meat of it are fixes for the nvme
  fabrics/target code.  Outside of that, just one fix from Gabriel for
  not doing a queue suspend if we didn't get the admin queue setup in
  the first place"

* 'for-linus' of git://git.kernel.dk/linux-block:
  nvme-rdma: add back dependency on CONFIG_BLOCK
  nvme-rdma: fix null pointer dereference on req->mr
  nvme-rdma: use ib_client API to detect device removal
  nvme-rdma: add DELETING queue flag
  nvme/quirk: Add a delay before checking device ready for memblaze device
  nvme: Don't suspend admin queue that wasn't created
  nvme-rdma: destroy nvme queue rdma resources on connect failure
  nvme_rdma: keep a ref on the ctrl during delete/flush
  iw_cxgb4: block module unload until all ep resources are released
  iw_cxgb4: call dev_put() on l2t allocation failure

get_user_ex(x, ptr) should zero x on failure.  It's not a lot of a leak
(at most we are leaking uninitialized 64bit value off the kernel stack,
and in a fairly constrained situation, at that), but the fix is trivial,
so...

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[ This sat in different branch from the uaccess fixes since mid-August ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When userspace sends KVM_SET_LAPIC, KVM schedules a check between
the vCPU's IRR and ISR and the IOAPIC redirection table, in order
to re-establish the IOAPIC's dest_map (the list of CPUs servicing
the real-time clock interrupt with the corresponding vectors).

However, __rtc_irq_eoi_tracking_restore_one was forgetting to
set dest_map->vectors.  Because of this, the IOAPIC did not process
the real-time clock interrupt EOI, ioapic->rtc_status.pending_eoi
got stuck at a non-zero value, and further RTC interrupts were
reported to userspace as coalesced.

Fixes: 9e4aabe2
Fixes: 4d99ba89
Cc: stable@vger.kernel.org
Cc: Joerg Roedel <jroedel@suse.de>
Cc: David Gilbert <dgilbert@redhat.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull PCI fixes from Bjorn Helgaas:
 "Here are two changes for v4.8.  The first fixes a "[Firmware Bug]: reg
  0x10: invalid BAR (can't size)" warning on Haswell, and the second
  fixes a problem in some new runtime suspend functionality we merged
  for v4.8.  Summary:

  Enumeration:
    Mark Haswell Power Control Unit as having non-compliant BARs (Bjorn Helgaas)

  Power management:
    Fix bridge_d3 update on device removal (Lukas Wunner)"

* tag 'pci-v4.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: Fix bridge_d3 update on device removal
  PCI: Mark Haswell Power Control Unit as having non-compliant BARs

Merge branches 'doc.2016.08.22c', 'exp.2016.08.22c', 'fixes.2016.09.14a', 'hotplug.2016.08.22c' and 'torture.2016.08.22c' into HEAD

doc.2016.08.22c: Documentation updates
exp.2016.08.22c: Expedited grace-period updates
fixes.2016.09.14a: Miscellaneous fixes
hotplug.2016.08.22c: CPU-hotplug changes
torture.2016.08.22c: Torture-test changes

Due to the use of READ_ONCE() in list_empty() the compiler cannot
optimise !list_empty() ? list_first_entry() : NULL very well. By
manually expanding list_first_entry_or_null() we can take advantage of
the READ_ONCE() to avoid the list element changing under the test while
the compiler can generate smaller code.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Josef Bacik <jbacik@fb.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Pull uaccess fixes from Al Viro:
 "Fixes for broken uaccess primitives - mostly lack of proper zeroing
  in copy_from_user()/get_user()/__get_user(), but for several
  architectures there's more (broken clear_user() on frv and
  strncpy_from_user() on hexagon)"

* 'uaccess-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  avr32: fix copy_from_user()
  microblaze: fix __get_user()
  microblaze: fix copy_from_user()
  m32r: fix __get_user()
  blackfin: fix copy_from_user()
  sparc32: fix copy_from_user()
  sh: fix copy_from_user()
  sh64: failing __get_user() should zero
  score: fix copy_from_user() and friends
  score: fix __get_user/get_user
  s390: get_user() should zero on failure
  ppc32: fix copy_from_user()
  parisc: fix copy_from_user()
  openrisc: fix copy_from_user()
  nios2: fix __get_user()
  nios2: copy_from_user() should zero the tail of destination
  mn10300: copy_from_user() should zero on access_ok() failure...
  mn10300: failing __get_user() and get_user() should zero
  mips: copy_from_user() must zero the destination on access_ok() failure
  ARC: uaccess: get_user to zero out dest in cause of fault
  ...

Pull xen regression fix from David Vrabel:
 "Fix SMP boot in arm guests"

* tag 'for-linus-4.8b-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  arm/xen: fix SMP guests boot

Commit 88e957d6 ("xen: introduce xen_vcpu_id mapping") broke SMP
ARM guests on Xen. When FIFO-based event channels are in use (this is
the default), evtchn_fifo_alloc_control_block() is called on
CPU_UP_PREPARE event and this happens before we set up xen_vcpu_id
mapping in xen_starting_cpu. Temporary fix the issue by setting direct
Linux CPU id <-> Xen vCPU id mapping for all possible CPUs at boot. We
don't currently support kexec/kdump on Xen/ARM so these ids always
match.

In future, we have several ways to solve the issue, e.g.:

- Eliminate all hypercalls from CPU_UP_PREPARE, do them from the
  starting CPU. This can probably be done for both x86 and ARM and, if
  done, will allow us to get Xen's idea of vCPU id from CPUID/MPIDR on
  the starting CPU directly, no messing with ACPI/device tree
  required.

- Save vCPU id information from ACPI/device tree on ARM and use it to
  initialize xen_vcpu_id mapping. This is the same trick we currently
  do on x86.
Reported-by: Julien Grall <julien.grall@arm.com>
Tested-by: Wei Chen <Wei.Chen@arm.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

really ugly, but apparently avr32 compilers turns access_ok() into
something so bad that they want it in assembler.  Left that way,
zeroing added in inline wrapper.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

It could be done in exception-handling bits in __get_user_b() et.al.,
but the surgery involved would take more knowledge of sh64 details
than I have or _want_ to have.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

* should zero on any failure
* __get_user() should use __copy_from_user(), not copy_from_user()

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

should clear on access_ok() failures.  Also remove the useless
range truncation logics.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

... that should zero on faults.  Also remove the <censored> helpful
logics wrt range truncation copied from ppc32.  Where it had ever
been needed only in case of copy_from_user() *and* had not been merged
into the mainline until a month after the need had disappeared.
A decade before openrisc went into mainline, I might add...

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

a) should not leave crap on fault
b) should _not_ require access_ok() in any cases.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al reported potential issue with ARC get_user() as it wasn't clearing
out destination pointer in case of fault due to bad address etc.

Verified using following

| {
|  	u32 bogus1 = 0xdeadbeef;
|	u64 bogus2 = 0xdead;
|	int rc1, rc2;
|
|  	pr_info("Orig values %x %llx\n", bogus1, bogus2);
|	rc1 = get_user(bogus1, (u32 __user *)0x40000000);
|	rc2 = get_user(bogus2, (u64 __user *)0x50000000);
|	pr_info("access %d %d, new values %x %llx\n",
|		rc1, rc2, bogus1, bogus2);
| }

| [ARCLinux]# insmod /mnt/kernel-module/qtn.ko
| Orig values deadbeef dead
| access -14 -14, new values 0 0
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Acked-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

It's -EFAULT, not -1 (and contrary to the comment in there,
__strnlen_user() can return 0 - on faults).

Cc: stable@vger.kernel.org
Acked-by: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

It should check access_ok().  Otherwise a bunch of places turn into
trivially exploitable rootholes.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

* copy_from_user() on access_ok() failure ought to zero the destination
* none of those primitives should skip the access_ok() check in case of
small constant size.

Cc: stable@vger.kernel.org
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

both for access_ok() failures and for faults halfway through

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Starting with v4.8, we allow a PCIe port to runtime suspend to D3hot if the
port itself and its children satisfy a number of conditions.  Once a child
is removed, we recheck those conditions in case the removed device was
blocking the port from suspending.

The rechecking needs to happen *after* the device has been removed from the
bus it resides on.  Otherwise when walking the port's subordinate bus in
pci_bridge_d3_update(), the device being removed would erroneously still be
taken into account.

However the device is removed from the bus_list in pci_destroy_dev() and we
currently recheck *before* that.  Fix it.

Fixes: 9d26d3a8 ("PCI: Put PCIe ports into D3 during suspend")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <mika.westerberg@linux.intel.com>