Merge tag 'kvm-arm-for-v4.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/ARM fixes for v4.4-rc6

- Fix for the active interrupt detection code, affecting
  the timer interrupt injection.

The current handling of accesses to guest MSR_TSC_AUX returns error if
vcpu does not support rdtscp, though those accesses are initiated by
host. This can result in the reboot failure of some versions of
QEMU. This patch fixes this issue by passing those host initiated
accesses for further handling instead.
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

External inputs to the vgic from time to time need to poke into the
state of a virtual interrupt, the prime example is the architected timer
code.

Since the IRQ's active state can be represented in two places; the LR or
the distributor, we first loop over the LRs but if not active in the LRs
we just return if *any* IRQ is active on the VCPU in question.

This is of course bogus, as we should check if the specific IRQ in
quesiton is active on the distributor instead.
Reported-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Merge branch 'kvm-ppc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master

Invoking tracepoints within kvm_guest_enter/kvm_guest_exit causes a
lockdep splat.
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull VFIO fixes from Alex Williamson:

 - Various fixes for removing redundancy, const'ifying structs, avoiding
   stack usage, fixing WARN usage (Krzysztof Kozlowski, Julia Lawall,
   Kees Cook, Dan Carpenter)

 - Revert No-IOMMU mode as the intended user has not emerged (Alex
   Williamson)

* tag 'vfio-v4.4-rc5' of git://github.com/awilliam/linux-vfio:
  Revert: "vfio: Include No-IOMMU mode"
  vfio: fix a warning message
  vfio: platform: remove needless stack usage
  vfio-pci: constify pci_error_handlers structures
  vfio: Drop owner assignment from platform_driver

Merge tag 'devicetree-fixes-for-4.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull DT fixes from Rob Herring:
 "I think this should be all for 4.4:

   - Fix incorrect warning about overlapping memory regions

   - Export of_irq_find_parent again which was made static in 4.4, but
     has users pending for 4.5.

   - Fix of_msi_map_rid declaration location

   - Fix re-entrancy for of_fdt_unflatten_tree

   - Clean-up of phys_addr_t printks"

* tag 'devicetree-fixes-for-4.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  of/irq: move of_msi_map_rid declaration to the correct ifdef section
  of/irq: Export of_irq_find_parent again
  of/fdt: Add mutex protection for calls to __unflatten_device_tree()
  of/address: fix typo in comment block of of_translate_one()
  of: do not use 0x in front of %pa
  of: Fix comparison of reserved memory regions

Pull clk fixes from Stephen Boyd:
 "One small build fix, a couple do_div() fixes, and a fix for the gpio
  basic clock type are the major changes here.  There's also a couple
  fixes for the TI, sunxi, and scpi clock drivers"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: sunxi: pll2: Fix clock running too fast
  clk: scpi: add missing of_node_put
  clk: qoriq: fix memory leak
  imx/clk-pllv2: fix wrong do_div() usage
  imx/clk-pllv1: fix wrong do_div() usage
  clk: mmp: add linux/clk.h includes
  clk: ti: drop locking code from mux/divider drivers
  clk: ti816x: Add missing dmtimer clkdev entries
  clk: ti: fapll: fix wrong do_div() usage
  clk: ti: clkt_dpll: fix wrong do_div() usage
  clk: gpio: Get parent clk names in of_gpio_clk_setup()

Currently it is possible for userspace (e.g. QEMU) to set a value
for the MSR for a guest VCPU which has both of the TS bits set,
which is an illegal combination.  The result of this is that when
we execute a hrfid (hypervisor return from interrupt doubleword)
instruction to enter the guest, the CPU will take a TM Bad Thing
type of program interrupt (vector 0x700).

Now, if PR KVM is configured in the kernel along with HV KVM, we
actually handle this without crashing the host or giving hypervisor
privilege to the guest; instead what happens is that we deliver a
program interrupt to the guest, with SRR0 reflecting the address
of the hrfid instruction and SRR1 containing the MSR value at that
point.  If PR KVM is not configured in the kernel, then we try to
run the host's program interrupt handler with the MMU set to the
guest context, which almost certainly causes a host crash.

This closes the hole by making kvmppc_set_msr_hv() check for the
illegal combination and force the TS field to a safe value (00,
meaning non-transactional).

Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: Paul Mackerras <paulus@samba.org>

Pull IPMI fix from Corey Minyard:
 "Fix an Oops if an interrupt occurs at startup.  This can happen on
  some hardware"

* tag 'for-linus-4.4-1' of git://git.code.sf.net/p/openipmi/linux-ipmi:
  ipmi: move timer init to before irq is setup

We encountered a panic on boot in ipmi_si on a dell per320 due to an
uninitialized timer as follows.

static int smi_start_processing(void       *send_info,
                                ipmi_smi_t intf)
{
        /* Try to claim any interrupts. */
        if (new_smi->irq_setup)
                new_smi->irq_setup(new_smi);

 --> IRQ arrives here and irq handler tries to modify uninitialized timer

    which triggers BUG_ON(!timer->function) in __mod_timer().

 Call Trace:
   <IRQ>
   [<ffffffffa0532617>] start_new_msg+0x47/0x80 [ipmi_si]
   [<ffffffffa053269e>] start_check_enables+0x4e/0x60 [ipmi_si]
   [<ffffffffa0532bd8>] smi_event_handler+0x1e8/0x640 [ipmi_si]
   [<ffffffff810f5584>] ? __rcu_process_callbacks+0x54/0x350
   [<ffffffffa053327c>] si_irq_handler+0x3c/0x60 [ipmi_si]
   [<ffffffff810efaf0>] handle_IRQ_event+0x60/0x170
   [<ffffffff810f245e>] handle_edge_irq+0xde/0x180
   [<ffffffff8100fc59>] handle_irq+0x49/0xa0
   [<ffffffff8154643c>] do_IRQ+0x6c/0xf0
   [<ffffffff8100ba53>] ret_from_intr+0x0/0x11

        /* Set up the timer that drives the interface. */
        setup_timer(&new_smi->si_timer, smi_timeout, (long)new_smi);

The following patch fixes the problem.

To: Openipmi-developer@lists.sourceforge.net
To: Corey Minyard <minyard@acm.org>
CC: linux-kernel@vger.kernel.org
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Tony Camuso <tcamuso@redhat.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: stable@vger.kernel.org # Applies cleanly to 3.10-, needs small rework before

ROL on a 32 bit integer with a shift of 32 or more is undefined and the
result is arch-dependent. Avoid this by handling the trivial case of
roling by 0 correctly.

The trivial solution of checking if shift is 0 breaks gcc's detection
of this code as a ROL instruction, which is unacceptable.

This bug was reported and fixed in GCC
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57157):

	The standard rotate idiom,

	  (x << n) | (x >> (32 - n))

	is recognized by gcc (for concreteness, I discuss only the case that x
	is an uint32_t here).

	However, this is portable C only for n in the range 0 < n < 32. For n
	== 0, we get x >> 32 which gives undefined behaviour according to the
	C standard (6.5.7, Bitwise shift operators). To portably support n ==
	0, one has to write the rotate as something like

	  (x << n) | (x >> ((-n) & 31))

	And this is apparently not recognized by gcc.

Note that this is broken on older GCCs and will result in slower ROL.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull vfs fixes from Al Viro:
 "A couple of fixes, both -stable fodder (9p one all way back to 2.6.32,
  dio - to all branches where "Fix negative return from dio read beyond
  eof" will end up it; it's a fixup to commit marked for -stable)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix the regression from "direct-io: Fix negative return from dio read beyond eof"
  9p: ->evict_inode() should kick out ->i_data, not ->i_mapping

Pull PCI fixes from Bjorn Helgaas:
 "These are more fixes I'd like to have in v4.4.  Several for the Altera
  driver added for v4.4, and one for an MSI domain problem that affects
  several arm64 platforms:

  MSI:
   - Only use the generic MSI layer when domain is hierarchical (Marc
     Zyngier)

  Altera host bridge driver:
   - Fix loop in tlp_read_packet() (Dan Carpenter)
   - Fix Requester ID for config accesses (Ley Foon Tan)
   - Check TLP completion status (Ley Foon Tan)
   - Fix error when INTx is 4 (Ley Foon Tan)"

* tag 'pci-v4.4-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: altera: Fix error when INTx is 4
  PCI: altera: Check TLP completion status
  PCI: altera: Fix Requester ID for config accesses
  PCI: altera: Fix loop in tlp_read_packet()
  PCI/MSI: Only use the generic MSI layer when domain is hierarchical

In checking fixes for of_irq_find_parent declaration location, I found
that of_msi_map_rid is also wrong. of_msi_map_rid is not implemented for
Sparc, so it should not be in the Sparc specific section of the header.
Move it to just depend on OF_IRQ.

Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of_irq_find_parent was made static since it had no users outside of
of_irq.c. Export it again since we are going to use it again.
Signed-off-by: Carlo Caione <carlo@endlessm.com>
[robh: move of_irq_find_parent to correct ifdef section]
Signed-off-by: Rob Herring <robh@kernel.org>

Pull uml fixes from Richard Weinberger:
 "This contains various bug fixes, most of them are fall out from the
  merge window"

* 'for-linus-4.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: fix returns without va_end
  um: Fix fpstate handling
  arch: um: fix error when linking vmlinux.
  um: Fix get_signal() usage

Pull cgroup fixes from Tejun Heo:
 "More change than I'd have liked at this stage.  The pids controller
  and the changes made to cgroup core to support it introduced and
  revealed several important issues.

   - Assigning membership to a newly created task and migrating it can
     race leading to incorrect accounting.  Oleg fixed it by widening
     threadgroup synchronization.  It looks like we'll be able to merge
     it with a different percpu rwsem which is used in fork path making
     things simpler and cheaper.

   - The recent change to extend cgroup membership to zombies (so that
     pid accounting can extend till the pid is actually released) missed
     pinning the underlying data structures leading to use-after-free.
     Fixed.

   - v2 hierarchy was calling subsystem callbacks with the wrong target
     cgroup_subsys_state based on the incorrect assumption that they
     share the same target.  pids is the first controller affected by
     this.  Subsys callbacks updated so that they can deal with
     multi-target migrations"

* 'for-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup_pids: don't account for the root cgroup
  cgroup: fix handling of multi-destination migration from subtree_control enabling
  cgroup_freezer: simplify propagation of CGROUP_FROZEN clearing in freezer_attach()
  cgroup: pids: kill pids_fork(), simplify pids_can_fork() and pids_cancel_fork()
  cgroup: pids: fix race between cgroup_post_fork() and cgroup_migrate()
  cgroup: make css_set pin its css's to avoid use-afer-free
  cgroup: fix cftype->file_offset handling

Pull libata fixes from Tejun Heo:
 "Nothing too interesting.  All are device specific additions and
  workarounds"

* 'for-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  ata/sata_fsl.c: add ATA_FLAG_NO_LOG_PAGE to blacklist the controller for log page reads
  libata-eh.c: Introduce new ata port flag for controller which lockup on read log page
  sata_sil: disable trim
  AHCI: Fix softreset failed issue of Port Multiplier
  sata/mvebu: use #ifdef around suspend/resume code
  ahci: Order SATA device IDs for codename Lewisburg
  ahci: Add Device ID for Intel Sunrise Point PCH

When using va_list ensure that va_start will be followed by va_end.
Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

The x86 FPU cleanup changed fpstate to a plain integer.
UML on x86 has to deal with that too.
Signed-off-by: Richard Weinberger <richard@nod.at>

On gcc Ubuntu 4.8.4-2ubuntu1~14.04, linking vmlinux fails with:

arch/um/os-Linux/built-in.o: In function `os_timer_create':
/android/kernel/android/arch/um/os-Linux/time.c:51: undefined reference to `timer_create'
arch/um/os-Linux/built-in.o: In function `os_timer_set_interval':
/android/kernel/android/arch/um/os-Linux/time.c:84: undefined reference to `timer_settime'
arch/um/os-Linux/built-in.o: In function `os_timer_remain':
/android/kernel/android/arch/um/os-Linux/time.c:109: undefined reference to `timer_gettime'
arch/um/os-Linux/built-in.o: In function `os_timer_one_shot':
/android/kernel/android/arch/um/os-Linux/time.c:132: undefined reference to `timer_settime'
arch/um/os-Linux/built-in.o: In function `os_timer_disable':
/android/kernel/android/arch/um/os-Linux/time.c:145: undefined reference to `timer_settime'

This is because -lrt appears in the generated link commandline
after arch/um/os-Linux/built-in.o. Fix this by removing -lrt from
arch/um/Makefile and adding it to the UM-specific section of
scripts/link-vmlinux.sh.
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

If get_signal() returns us a signal to post
we must not call it again, otherwise the already
posted signal will be overridden.
Before commit a610d6e6 this was the case as we stopped
the while after a successful handle_signal().

Cc: <stable@vger.kernel.org> # 3.10-
Fixes: a610d6e6 ("pull clearing RESTORE_SIGMASK into block_sigmask()")
Signed-off-by: Richard Weinberger <richard@nod.at>

Pull perf fixes from Ingo Molnar:
 "This tree includes four core perf fixes for misc bugs, three fixes to
  x86 PMU drivers, and two updates to old email addresses"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Do not send exit event twice
  perf/x86/intel: Fix INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_NA macro
  perf/x86/intel: Make L1D_PEND_MISS.FB_FULL not constrained on Haswell
  perf: Fix PERF_EVENT_IOC_PERIOD deadlock
  treewide: Remove old email address
  perf/x86: Fix LBR call stack save/restore
  perf: Update email address in MAINTAINERS
  perf/core: Robustify the perf_cgroup_from_task() RCU checks
  perf/core: Fix RCU problem with cgroup context switching code

Sure, it's better to bail out of past-the-eof read and return 0 than return
a bogus negative value on such.  Only we'd better make sure we are bailing out
with 0 and not -ENOMEM...

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

For block devices the pagecache is associated with the inode
on bdevfs, not with the aliasing ones on the mountable filesystems.
The latter have its own ->i_data empty and ->i_mapping pointing
to the (unique per major/minor) bdevfs inode.  That guarantees
cache coherence between all block device inodes with the same
device number.

Eviction of an alias inode has no business trying to evict the
pages belonging to bdevfs one; moreover, ->i_mapping is only
safe to access when the thing is opened.  At the time of
->evict_inode() the victim is definitely *not* opened.  We are
about to kill the address space embedded into struct inode
(inode->i_data) and that's what we need to empty of any pages.

9p instance tries to empty inode->i_mapping instead, which is
both unsafe and bogus - if we have several device nodes with
the same device number in different places, closing one of them
should not try to empty the (shared) page cache.

Fortunately, other instances in the tree are OK; they are
evicting from &inode->i_data instead, as 9p one should.

Cc: stable@vger.kernel.org # v2.6.32+, ones prior to 2.6.36 need only half of that
Reported-by: "Suzuki K. Poulose" <Suzuki.Poulose@arm.com>
Tested-by: "Suzuki K. Poulose" <Suzuki.Poulose@arm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

__unflatten_device_tree() calls unflatten_dt_node(), which declares
a static variable. It is therefore not reentrant.

One of the callers of __unflatten_device_tree(), unflatten_device_tree(),
is only called once during early initialization and does not need to be
protected. The other caller, of_fdt_unflatten_tree(), can be called at
any time, possibly multiple times in parallel. This can happen, for
example, if multiple devicetree overlays have to be loaded and installed.

Without this protection, errors such as the following may be seen.

kernel: End of tree marker overwritten: e6a3a458
kernel: find_target_node:
	Failed to find target-indirect node at /fragment@0
kernel: __of_overlay_create: of_build_overlay_info() failed for tree@/

Add a mutex to of_fdt_unflatten_tree() to make the call reentrant.

Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: Rob Herring <robh@kernel.org>

Pull virtio fixes from Michael Tsirkin:
 "This includes some fixes and cleanups in virtio and vhost code.

  Most notably, shadowing the index fixes the excessive cacheline
  bouncing observed on AMD platforms"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio_ring: shadow available ring flags & index
  virtio: Do not drop __GFP_HIGH in alloc_indirect
  vhost: replace % with & on data path
  tools/virtio: fix byteswap logic
  tools/virtio: move list macro stubs
  virtio: fix memory leak of virtio ida cache layers
  vhost: relax log address alignment
  virtio-net: Stop doing DMA from the stack

Pull ext4 fixes from Ted Ts'o:
 "Ext4 bug fixes for v4.4, including fixes for post-2038 time encodings,
  some endian conversion problems with ext4 encryption, potential memory
  leaks after truncate in data=journal mode, and an ocfs2 regression
  caused by a jbd2 performance improvement"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  jbd2: fix null committed data return in undo_access
  ext4: add "static" to ext4_seq_##name##_fops struct
  ext4: fix an endianness bug in ext4_encrypted_follow_link()
  ext4: fix an endianness bug in ext4_encrypted_zeroout()
  jbd2: Fix unreclaimed pages after truncate in data=journal mode
  ext4: Fix handling of extended tv_sec

Improves cacheline transfer flow of available ring header.

Virtqueues are implemented as a pair of rings, one producer->consumer
avail ring and one consumer->producer used ring; preceding the
avail ring in memory are two contiguous u16 fields -- avail->flags
and avail->idx. A producer posts work by writing to avail->idx and
a consumer reads avail->idx.

The flags and idx fields only need to be written by a producer CPU
and only read by a consumer CPU; when the producer and consumer are
running on different CPUs and the virtio_ring code is structured to
only have source writes/sink reads, we can continuously transfer the
avail header cacheline between 'M' states between cores. This flow
optimizes core -> core bandwidth on certain CPUs.

(see: "Software Optimization Guide for AMD Family 15h Processors",
Section 11.6; similar language appears in the 10h guide and should
apply to CPUs w/ exclusive caches, using LLC as a transfer cache)

Unfortunately the existing virtio_ring code issued reads to the
avail->idx and read-modify-writes to avail->flags on the producer.

This change shadows the flags and index fields in producer memory;
the vring code now reads from the shadows and only ever writes to
avail->flags and avail->idx, allowing the cacheline to transfer
core -> core optimally.

In a concurrent version of vring_bench, the time required for
10,000,000 buffer checkout/returns was reduced by ~2% (average
across many runs) on an AMD Piledriver (15h) CPU:

(w/o shadowing):
 Performance counter stats for './vring_bench':
     5,451,082,016      L1-dcache-loads
     ...
       2.221477739 seconds time elapsed

(w/ shadowing):
 Performance counter stats for './vring_bench':
     5,405,701,361      L1-dcache-loads
     ...
       2.168405376 seconds time elapsed

The further away (in a NUMA sense) virtio producers and consumers are
from each other, the more we expect to benefit. Physical implementations
of virtio devices and implementations of virtio where the consumer polls
vring avail indexes (vhost) should also benefit.
Signed-off-by: Venkatesh Srinivas <venkateshs@google.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

b92b1b89 ("virtio: force vring descriptors to be allocated from
lowmem") tried to exclude highmem pages for descriptors so it cleared
__GFP_HIGHMEM from a given gfp mask. The patch also cleared __GFP_HIGH
which doesn't make much sense for this fix because __GFP_HIGH only
controls access to memory reserves and it doesn't have any influence
on the zone selection. Some of the call paths use GFP_ATOMIC and
dropping __GFP_HIGH will reduce their changes for success because the
lack of access to memory reserves.
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Mel Gorman <mgorman@techsingularity.net>

We know vring num is a power of 2, so use &
to mask the high bits.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

commit cf561f0d ("virtio: introduce
virtio_is_little_endian() helper") changed byteswap logic to
skip feature bit checks for LE platforms, but didn't
update tools/virtio, so vring_bench started failing.

Update the copy under tools/virtio/ (TODO: find a way to avoid this code
duplication).

Cc: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Makes them more generally available.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

The virtio core uses a static ida named virtio_index_ida for
assigning index numbers to virtio devices during registration.
The ida core may allocate some internal idr cache layers and
an ida bitmap upon any ida allocation, and all these layers are
truely freed only upon the ida destruction. The virtio_index_ida
is not destroyed at present, leading to a memory leak when using
the virtio core as a module and atleast one virtio device is
registered and unregistered.

Fix this by invoking ida_destroy() in the virtio core module
exit.

Cc: stable@vger.kernel.org
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

commit 5d9a07b0 ("vhost: relax used
address alignment") fixed the alignment for the used virtual address,
but not for the physical address used for logging.

That's a mistake: alignment should clearly be the same for virtual and
physical addresses,

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Every attempt to issue a read log page command lockup the controller.
The command is currently sent if the sata device includes the devlsp feature
to read out the timing data.
This attempt to read the data, locks up the controller and the device
is not recognzied correctly (failed to set xfermode) and cannot be accessed.

This was found on Freescale P1013/P1022 and T4240 CPUs
using a ATP IG mSATA 4GB with the devslp feature.

fsl-sata ff718000.sata: Sata FSL Platform/CSB Driver init
[    1.254195] scsi0 : sata_fsl
[    1.256004] ata1: SATA max UDMA/133 irq 74
[    1.370666] fsl-gianfar ethernet.3: enabled errata workarounds, flags: 0x4
[    1.470671] fsl-gianfar ethernet.4: enabled errata workarounds, flags: 0x4
[    1.775584] ata1: Signature Update detected @ 504 msecs
[    1.947594] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[    1.948366] ata1.00: ATA-8: ATP IG mSATA, 20150311, max UDMA/133
[    1.948371] ata1.00: 7732368 sectors, multi 0: LBA
[    1.948843] ata1.00: failed to get Identify Device Data, Emask 0x1
[    1.948857] ata1.00: failed to set xfermode (err_mask=0x40)
[    7.467557] ata1: Signature Update detected @ 504 msecs
[    7.639560] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[    7.651320] ata1.00: failed to get Identify Device Data, Emask 0x1
[    7.651360] ata1.00: failed to set xfermode (err_mask=0x40)
[    7.655628] ata1: limiting SATA link speed to 1.5 Gbps
[    7.659458] ata1.00: limiting speed to UDMA/133:PIO3
[   13.163554] ata1: Signature Update detected @ 504 msecs
[   13.335558] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[   13.347298] ata1.00: failed to get Identify Device Data, Emask 0x1
[   13.347334] ata1.00: failed to set xfermode (err_mask=0x40)
[   13.351601] ata1.00: disabled
[   13.353278] ata1: exception Emask 0x50 SAct 0x0 SErr 0x800 action 0x6 frozen t4
[   13.359281] ata1: SError: { HostInt }
[   13.361644] ata1: hard resetting link
Signed-off-by: Andreas Werner <andreas.werner@men.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

Some controller lockup on a ata_read_log_page.
Add new ata port flag ATA_FLAG_NO_LOG_PAGE which can used
to blacklist a controller.

If this flag is set, any attempt to read a log page returns an error
without actually issuing the command.
Signed-off-by: Andreas Werner <andreas.werner@men.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

The following commit which went into mainline through networking tree

  3b13758f ("cgroups: Allow dynamically changing net_classid")

conflicts in net/core/netclassid_cgroup.c with the following pending
fix in cgroup/for-4.4-fixes.

  1f7dd3e5 ("cgroup: fix handling of multi-destination migration from subtree_control enabling")

The former separates out update_classid() from cgrp_attach() and
updates it to walk all fds of all tasks in the target css so that it
can be used from both migration and config change paths.  The latter
drops @css from cgrp_attach().

Resolve the conflict by making cgrp_attach() call update_classid()
with the css from the first task.  We can revive @tset walking in
cgrp_attach() but given that net_cls is v1 only where there always is
only one target css during migration, this is fine.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Nina Schiff <ninasc@fb.com>

Once virtio starts using the DMA API, we won't be able to safely DMA
from the stack.  virtio-net does a couple of config DMA requests
from small stack buffers -- switch to using dynamically-allocated
memory.

This should have no effect on any performance-critical code paths.
Reported-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Andy Lutomirski <luto@kernel.org>