Fix a possible use-after-free scenario in acpi_cppc_processor_probe()
that can happen if the function returns without cleaning up the
per-CPU pointer set by it previously.
Reported-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

First I had crashed what I bisected down to de966cf4 (sched/x86: Change
CONFIG_SCHED_ITMT to CONFIG_SCHED_MC_PRIO) because it made SCHED_ITMT the
default.

Then I run another bisect round and got here with the same backtrace:

|BUG: unable to handle kernel NULL pointer dereference at           (null)
|IP: [<ffffffff812aab6e>] acpi_cppc_processor_exit+0x40/0x60
|PGD 0 [    0.577616]
|Oops: 0000 [#1] SMP
|Modules linked in:
|CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.9.0-rc6-00146-g17669006 #51
|task: ffff88003f878000 task.stack: ffffc90000008000
|RIP: 0010:[<ffffffff812aab6e>]  [<ffffffff812aab6e>] acpi_cppc_processor_exit+0x40/0x60
|RSP: 0000:ffffc9000000bd48  EFLAGS: 00010296
|RAX: 00000000000137e0 RBX: 0000000000000000 RCX: 0000000000000001
|RDX: ffff88003fc00000 RSI: 0000000000000000 RDI: ffff88003fbca130
|RBP: ffffc9000000bd60 R08: 0000000000000514 R09: 0000000000000000
|R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002
|R13: 0000000000000020 R14: ffffffff8167cb00 R15: 0000000000000000
|FS:  0000000000000000(0000) GS:ffff88003fcc0000(0000) knlGS:0000000000000000
|CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
|CR2: 0000000000000000 CR3: 0000000001618000 CR4: 00000000000406e0
|Stack:
| ffff88003f939848 ffff88003fbca130 0000000000000001 ffffc9000000bd80
| ffffffff812a4ccb ffff88003fc0cee8 0000000000000000 ffffc9000000bdb8
| ffffffff812dc20d ffff88003fc0cee8 ffffffff8167cb00 ffff88003fc0cf48
|Call Trace:
| [<ffffffff812a4ccb>] acpi_processor_stop+0xb2/0xc5
| [<ffffffff812dc20d>] driver_probe_device+0x14d/0x2f0
| [<ffffffff812dc41e>] __driver_attach+0x6e/0x90
| [<ffffffff812da234>] bus_for_each_dev+0x54/0x90
| [<ffffffff812dbbf9>] driver_attach+0x19/0x20
| [<ffffffff812db6a6>] bus_add_driver+0xe6/0x200
| [<ffffffff812dcb23>] driver_register+0x83/0xc0
| [<ffffffff816f050a>] acpi_processor_driver_init+0x20/0x94
| [<ffffffff81000487>] do_one_initcall+0x97/0x180
| [<ffffffff816ccf5c>] kernel_init_freeable+0x112/0x1a6
| [<ffffffff813a0fc9>] kernel_init+0x9/0xf0
| [<ffffffff813acf35>] ret_from_fork+0x25/0x30
|Code: 02 00 00 00 48 8b 14 d5 e0 c3 55 81 48 8b 1c 02 4c 8d 6b 20 eb 15 49 8b 7d 00 48 85 ff 74 05 e8 39 8c d9 ff 41 ff c4 49 83 c5 20 <44> 3b 23 72 e6 48 8d bb a0 02 00 00 e8 b1 6f f9 ff 48 89 df e8
|RIP  [<ffffffff812aab6e>] acpi_cppc_processor_exit+0x40/0x60
| RSP <ffffc9000000bd48>
|CR2: 0000000000000000
|---[ end trace 917a625107b09711 ]---

Fix it.

Fixes: 17669006 (cpufreq/intel_pstate: Use CPPC to get max performance)
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
[ rjw: Subject ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We should return -EINVAL (instead of 0) if get_cpu_device() fails.

Fixes: 158c998e (ACPI / CPPC: add sysfs support to compute delivered performance)
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull IOMMU fixes from David Woodhouse:
 "Two minor fixes.

  The first fixes the assignment of SR-IOV virtual functions to the
  correct IOMMU unit, and the second fixes the excessively large (and
  physically contiguous) PASID tables used with SVM"

* git://git.infradead.org/intel-iommu:
  iommu/vt-d: Fix PASID table allocation
  iommu/vt-d: Fix IOMMU lookup for SR-IOV Virtual Functions

Pull MIPS fixes from Ralf Baechle:
 "Another round of MIPS fixes for 4.9:

   - Fix unreadable output in __do_page_fault due to the KERN_CONT
     patchset

   - Correctly handle MIPS R6 fixes to the c0_wired register"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: mm: Fix output of __do_page_fault
  MIPS: Mask out limit field when calculating wired entry count

Pull vfs splice fix from Al Viro.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix default_file_splice_read()

Botched calculation of number of pages.  As the result,
we were dropping pieces when doing splice to pipe from
e.g. 9p.
Reported-by: NAlexei Starovoitov <ast@kernel.org>
Tested-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Pull i2c fixes from Wolfram Sang:
 "Here is a revert and two bugfixes for the I2C designware driver.

  Please note that we are still hunting down a regression for the
  i2c-octeon driver. While there is a fix pending, we have unclear
  feedback from the testers currently. An rc8 would be quite helpful
  for this case"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  Revert "i2c: designware: do not disable adapter after transfer"
  i2c: designware: fix rx fifo depth tracking
  i2c: designware: report short transfers

Pull ARM fix from Russell King:
 "This resolves the ksyms issues by reverting the commit which
  introduced the breakage"

There was what I consider to be a better fix, but it's late in the rc
game, so I'll take the revert.

* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
  Revert "arm: move exports to definitions"

Pull networking fixes from David Miller:

 1) Fix leak in fsl/fman driver, from Dan Carpenter.

 2) Call flow dissector initcall earlier than any networking driver can
    register and start to use it, from Eric Dumazet.

 3) Some dup header fixes from Geliang Tang.

 4) TIPC link monitoring compat fix from Jon Paul Maloy.

 5) Link changes require EEE re-negotiation in bcm_sf2 driver, from
    Florian Fainelli.

 6) Fix bogus handle ID passed into tfilter_notify_chain(), from Roman
    Mashak.

 7) Fix dump size calculation in rtnl_calcit(), from Zhang Shengju.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
  tipc: resolve connection flow control compatibility problem
  mvpp2: use correct size for memset
  net/mlx5: drop duplicate header delay.h
  net: ieee802154: drop duplicate header delay.h
  ibmvnic: drop duplicate header seq_file.h
  fsl/fman: fix a leak in tgec_free()
  net: ethtool: don't require CAP_NET_ADMIN for ETHTOOL_GLINKSETTINGS
  tipc: improve sanity check for received domain records
  tipc: fix compatibility bug in link monitoring
  net: ethernet: mvneta: Remove IFF_UNICAST_FLT which is not implemented
  dwc_eth_qos: drop duplicate headers
  net sched filters: fix filter handle ID in tfilter_notify_chain()
  net: dsa: bcm_sf2: Ensure we re-negotiate EEE during after link change
  bnxt: do not busy-poll when link is down
  udplite: call proper backlog handlers
  ipv6: bump genid when the IFA_F_TENTATIVE flag is clear
  net/mlx4_en: Free netdev resources under state lock
  net: revert "net: l2tp: Treat NET_XMIT_CN as success in l2tp_eth_dev_xmit"
  rtnetlink: fix the wrong minimal dump size getting from rtnl_calcit()
  bnxt_en: Fix a VXLAN vs GENEVE issue
  ...

Pull libnvdimm fixes from Dan Williams:

 - Fix a crash that occurs at driver initialization if the memory region
   is already busy (request_mem_region() fails).

 - Fix a vma validation check that mistakenly allows a private device-
   dax mapping to be established. Device-dax explicitly forbids private
   mappings so it can guarantee a given fault granularity and backing
   memory type.

 Both of these fixes have soaked in -next and are tagged for -stable.

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  device-dax: fail all private mapping attempts
  device-dax: check devm_nsio_enable() return value

Pull KVM fixes from Radim Krčmář:
 "Four fixes for bugs found by syzkaller on x86, all for stable"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: check for pic and ioapic presence before use
  KVM: x86: fix out-of-bounds accesses of rtc_eoi map
  KVM: x86: drop error recovery in em_jmp_far and em_ret_far
  KVM: x86: fix out-of-bounds access in lapic

Pull powerpc fixes from Michael Ellerman:
 "Fixes marked for stable:
   - Set missing wakeup bit in LPCR on POWER9
   - Fix the early OPAL console wrappers
   - Fixup kernel read only mapping

  Fixes for code merged this cycle:
   - Fix missing CRCs, add more asm-prototypes.h declarations"

* tag 'powerpc-4.9-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm: Fixup kernel read only mapping
  powerpc/boot: Fix the early OPAL console wrappers
  powerpc: Fix missing CRCs, add more asm-prototypes.h declarations
  powerpc: Set missing wakeup bit in LPCR on POWER9

In commit 10724cc7 ("tipc: redesign connection-level flow control")
we replaced the previous message based flow control with one based on
1k blocks. In order to ensure backwards compatibility the mechanism
falls back to using message as base unit when it senses that the peer
doesn't support the new algorithm. The default flow control window,
i.e., how many units can be sent before the sender blocks and waits
for an acknowledge (aka advertisement) is 512. This was tested against
the previous version, which uses an acknowledge frequency of on ack per
256 received message, and found to work fine.

However, we missed the fact that versions older than Linux 3.15 use an
acknowledge frequency of 512, which is exactly the limit where a 4.6+
sender will stop and wait for acknowledge. This would also work fine if
it weren't for the fact that if the first sent message on a 4.6+ server
side is an empty SYNACK, this one is also is counted as a sent message,
while it is not counted as a received message on a legacy 3.15-receiver.
This leads to the sender always being one step ahead of the receiver, a
scenario causing the sender to block after 512 sent messages, while the
receiver only has registered 511 read messages. Hence, the legacy
receiver is not trigged to send an acknowledge, with a permanently
blocked sender as result.

We solve this deadlock by simply allowing the sender to send one more
message before it blocks, i.e., by a making minimal change to the
condition used for determining connection congestion.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

gcc-7 detects a short memset in mvpp2, introduced in the original
merge of the driver:

drivers/net/ethernet/marvell/mvpp2.c: In function 'mvpp2_cls_init':
drivers/net/ethernet/marvell/mvpp2.c:3296:2: error: 'memset' used with length equal to number of elements without multiplication by element size [-Werror=memset-elt-size]

The result seems to be that we write uninitialized data into the
flow table registers, although we did not get any warning about
that uninitialized data usage.

Using sizeof() lets us initialize then entire array instead.

Fixes: 3f518509 ("ethernet: Add new driver for Marvell Armada 375 network unit")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Drop duplicate header delay.h from mlx5/core/main.c.
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Acked-by: NMatan Barak <matanb@mellanox.com>
Acked-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Drop duplicate header delay.h from adf7242.c.
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Acked-by: NStefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Drop duplicate header seq_file.h from ibmvnic.c.
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We set "tgec->cfg" to NULL before passing it to kfree().  There is no
need to set it to NULL at all.  Let's just delete it.

Fixes: 57ba4c9b ("fsl/fman: Add FMan MAC support")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ETHTOOL_GLINKSETTINGS command is deprecating the ETHTOOL_GSET
command and likewise it shouldn't require the CAP_NET_ADMIN capability.
Signed-off-by: NMiroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 35c55c98 ("tipc: add neighbor monitoring framework") we
added a data area to the link monitor STATE messages under the
assumption that previous versions did not use any such data area.

For versions older than Linux 4.3 this assumption is not correct. In
those version, all STATE messages sent out from a node inadvertently
contain a 16 byte data area containing a string; -a leftover from
previous RESET messages which were using this during the setup phase.
This string serves no purpose in STATE messages, and should no be there.

Unfortunately, this data area is delivered to the link monitor
framework, where a sanity check catches that it is not a correct domain
record, and drops it. It also issues a rate limited warning about the
event.

Since such events occur much more frequently than anticipated, we now
choose to remove the warning in order to not fill the kernel log with
useless contents. We also make the sanity check stricter, to further
reduce the risk that such data is inavertently admitted.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 81729810 ("tipc: fix link priority propagation") introduced a
compatibility problem between TIPC versions newer than Linux 4.6 and
those older than Linux 4.4. In versions later than 4.4, link STATE
messages only contain a non-zero link priority value when the sender
wants the receiver to change its priority. This has the effect that the
receiver resets itself in order to apply the new priority. This works
well, and is consistent with the said commit.

However, in versions older than 4.4 a valid link priority is present in
all sent link STATE messages, leading to cyclic link establishment and
reset on the 4.6+ node.

We fix this by adding a test that the received value should not only
be valid, but also differ from the current value in order to cause the
receiving link endpoint to reset.
Reported-by: NAmar Nv <amar.nv005@gmail.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The mvneta driver advertises it supports IFF_UNICAST_FLT. However, it
actually does not. The hardware probably does support it, but there is
no code to configure the filter. As a quick and simple fix, remove the
flag. This will cause the core to fall back to promiscuous mode.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Fixes: b50b72de ("net: mvneta: enable features before registering the driver")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull parisc fixes from Helge Deller:
 "On parisc we were still seeing occasional random segmentation faults
  and memory corruption on SMP machines. Dave Anglin then looked again
  at the TLB related code and found two issues in the PCI DMA and
  generic TLB flush functions.

  Then, in our startup code we had some timing of the cache and TLB
  functions to calculate a threshold when to use a complete TLB/cache
  flush or just to flush a specific range. This code produced a race
  with newly started CPUs and thus lead to occasional kernel crashes
  (due to stale TLB/cache entries). The patch by Dave fixes this issue
  by flushing the local caches before starting secondary CPUs and by
  removing the race.

  The last problem fixed by this series is that we quite often suffered
  from hung tasks and self-detected stalls on the CPUs. It was somehow
  clear that this was related to the (in v4.7) newly introduced cr16
  clocksource and the own implementation of sched_clock(). I replaced
  the open-coded sched_clock() function and switched to the generic
  sched_clock() implementation which seems to have fixed this isse as
  well.

  All patches have been sucessfully tested on a variety of machines,
  including our debian buildd servers.

  All patches (beside the small pr_cont fix) are tagged for stable
  releases"

* 'parisc-4.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Also flush data TLB in flush_icache_page_asm
  parisc: Fix race in pci-dma.c
  parisc: Switch to generic sched_clock implementation
  parisc: Fix races in parisc_setup_cache_timing()
  parisc: Fix printk continuations in system detection

Pull keys fixes from James Morris:
 "From David:

   - Fix mpi_powm()'s handling of a number with a zero exponent
     [CVE-2016-8650].

     Integrate my and Andrey's patches for mpi_powm() and use
     mpi_resize() instead of RESIZE_IF_NEEDED() - the latter adds a
     duplicate check into the execution path of a trivial case we
     don't normally expect to be taken.

   - Fix double free in X.509 error handling"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  mpi: Fix NULL ptr dereference in mpi_powm() [ver #3]
  X.509: Fix double free in x509_cert_parse() [ver #3]

CONFIG_MODVERSIONS has been broken for pretty much the whole 4.9 series,
and quite frankly, nobody has cared very deeply.  We absolutely know how
to fix it, and it's not _complicated_, but it's not exactly pretty
either.

This oneliner fixes it without the ugliness, and allows for further
future cleanups.

  "We've secretly replaced their regular MODVERSIONS with nothing at
   all, let's see if they notice"
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull ACPI fixes from Rafael Wysocki:
 "Two ACPI fixes for 4.9-rc7.

  One of them reverts a recent ACPI commit that attempted to improve
  reboot/power-off on some systems, but introduced problems elsewhere,
  and the other one fixes kernel builds with the new WDAT watchdog
  driver enabled in some configurations.

  Specifics:

   - Revert the recent commit that caused the ACPI _PTS method to be
     executed in the power-off/reboot code path (as per the
     specification) in an attempt to improve things on some systems
     (apparently expecting _PTS to be executed in that code path), but
     broke power-off/reboot on at least one other machine (Rafael
     Wysocki).

   - Fix kernel builds with the new WDAT watchdog driver enabled in some
     configurations by explicitly selecting WATCHDOG_CORE when enabling
     the WDAT watchdog driver (Mika Westerberg)"

* tag 'acpi-4.9-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  watchdog: wdat_wdt: Select WATCHDOG_CORE
  Revert "ACPI: Execute _PTS before system reboot"

Following the kernel Bugzilla discussion during the Kernel Summit
(https://lwn.net/Articles/705245/), add bug tracking system location
entry type (B) to MAINTAINERS and populate it for several subsystems
known to be using the kernel BZ actively (and add the upstream BZ for
ACPICA too).
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit 0317e6c0.

Srinivas reported recently touchscreen and touchpad stopped working in
Haswell based machine in Linux 4.9-rc series with timeout errors from
i2c_designware:

[   16.508013] i2c_designware INT33C3:00: controller timed out
[   16.508302] i2c_hid i2c-MSFT0001:02: failed to change power setting.
[   17.532016] i2c_designware INT33C3:00: controller timed out
[   18.556022] i2c_designware INT33C3:00: controller timed out
[   18.556315] i2c_hid i2c-ATML1000:00: failed to retrieve report from device.

I managed to reproduce similar errors on another Haswell based machine
where touchscreen initialization fails maybe in every 1/5 - 1/2 boots.
Since root cause for these errors is not clear yet and debugging is
ongoing it's better to revert this commit as we are near to release.
Reported-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

* acpi-sleep-fixes:
  Revert "ACPI: Execute _PTS before system reboot"

* acpi-wdat-fixes:
  watchdog: wdat_wdt: Select WATCHDOG_CORE

Merge tag 'linux-can-fixes-for-4.9-20161123' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2016-11-23

this is a pull request for net/master.

The patch by Oliver Hartkopp for the broadcast manager (bcm) fixes the
CAN-FD support, which may cause an out-of-bounds access otherwise.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Drop duplicate headers types.h and delay.h from dwc_eth_qos.c.
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull MFD fixes from Lee Jones:
 "Received a copule of last minute fixes for v4.9.

  The patches from Viresh are fixing issues displayed in KernelCI"

* tag 'mfd-fixes-4.9.1' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd:
  mfd: wm8994-core: Don't use managed regulator bulk get API
  mfd: wm8994-core: Disable regulators before removing them
  mfd: syscon: Support native-endian regmaps

Pull media fix from Mauro Carvalho Chehab:
 "Fix for the firmware load logic of the tuner-xc2028 driver"

* tag 'media/v4.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  xc2028: Fix use-after-free bug properly

Pull drm fixes from Dave Airlie:
 "Seems to be quietening down nicely, a few mediatek, one exynos and one
  hdlcd fix, along with two amd fixes"

* tag 'drm-fixes-for-v4.9-rc7' of git://people.freedesktop.org/~airlied/linux:
  gpu/drm/exynos/exynos_hdmi - Unmap region obtained by of_iomap
  drm/mediatek: fix null pointer dereference
  drm/mediatek: fixed the calc method of data rate per lane
  drm/mediatek: fix a typo of DISP_OD_CFG to OD_RELAYMODE
  drm/radeon: fix power state when port pm is unavailable (v2)
  drm/amdgpu: fix power state when port pm is unavailable
  drm/arm: hdlcd: fix plane base address update
  drm/amd/powerplay: avoid out of bounds access on array ps.

This is the second issue I noticed in reviewing the parisc TLB code.

The fic instruction may use either the instruction or data TLB in
flushing the instruction cache.  Thus, on machines with a split TLB, we
should also flush the data TLB after setting up the temporary alias
registers.

Although this has no functional impact, I changed the pdtlb and pitlb
instructions to consistently use the index register %r0.  These
instructions do not support integer displacements.

Tested on rp3440 and c8000.
Signed-off-by: NJohn David Anglin  <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: NHelge Deller <deller@gmx.de>

We are still troubled by occasional random segmentation faults and
memory memory corruption on SMP machines.  The causes quite a few
package builds to fail on the Debian buildd machines for parisc.  When
gcc-6 failed to build three times in a row, I looked again at the TLB
related code.  I found a couple of issues.  This is the first.

In general, we need to ensure page table updates and corresponding TLB
purges are atomic.  The attached patch fixes an instance in pci-dma.c
where the page table update was not guarded by the TLB lock.

Tested on rp3440 and c8000.  So far, no further random segmentation
faults have been observed.
Signed-off-by: NJohn David Anglin  <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: NHelge Deller <deller@gmx.de>

Drop the open-coded sched_clock() function and replace it by the provided
GENERIC_SCHED_CLOCK implementation.  We have seen quite some hung tasks in the
past, which seem to be fixed by this patch.
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.7+
Signed-off-by: NHelge Deller <deller@gmx.de>

Helge reported to me the following startup crash:

[    0.000000] Linux version 4.8.0-1-parisc64-smp (debian-kernel@lists.debian.org) (gcc version 5.4.1 20161019 (GCC) ) #1 SMP Debian 4.8.7-1 (2016-11-13)
[    0.000000] The 64-bit Kernel has started...
[    0.000000] Kernel default page size is 4 KB. Huge pages enabled with 1 MB physical and 2 MB virtual size.
[    0.000000] Determining PDC firmware type: System Map.
[    0.000000] model 9000/785/J5000
[    0.000000] Total Memory: 2048 MB
[    0.000000] Memory: 2018528K/2097152K available (9272K kernel code, 3053K rwdata, 1319K rodata, 1024K init, 840K bss, 78624K reserved, 0K cma-reserved)
[    0.000000] virtual kernel memory layout:
[    0.000000]     vmalloc : 0x0000000000008000 - 0x000000003f000000   (1007 MB)
[    0.000000]     memory  : 0x0000000040000000 - 0x00000000c0000000   (2048 MB)
[    0.000000]       .init : 0x0000000040100000 - 0x0000000040200000   (1024 kB)
[    0.000000]       .data : 0x0000000040b0e000 - 0x0000000040f533e0   (4372 kB)
[    0.000000]       .text : 0x0000000040200000 - 0x0000000040b0e000   (9272 kB)
[    0.768910] Brought up 1 CPUs
[    0.992465] NET: Registered protocol family 16
[    2.429981] Releasing cpu 1 now, hpa=fffffffffffa2000
[    2.635751] CPU(s): 2 out of 2 PA8500 (PCX-W) at 440.000000 MHz online
[    2.726692] Setting cache flush threshold to 1024 kB
[    2.729932] Not-handled unaligned insn 0x43ffff80
[    2.798114] Setting TLB flush threshold to 140 kB
[    2.928039] Unaligned handler failed, ret = -1
[    3.000419]       _______________________________
[    3.000419]      < Your System ate a SPARC! Gah! >
[    3.000419]       -------------------------------
[    3.000419]              \   ^__^
[    3.000419]                  (__)\       )\/\
[    3.000419]                   U  ||----w |
[    3.000419]                      ||     ||
[    9.340055] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.8.0-1-parisc64-smp #1 Debian 4.8.7-1
[    9.448082] task: 00000000bfd48060 task.stack: 00000000bfd50000
[    9.528040]
[   10.760029] IASQ: 0000000000000000 0000000000000000 IAOQ: 000000004025d154 000000004025d158
[   10.868052]  IIR: 43ffff80    ISR: 0000000000340000  IOR: 000001ff54150960
[   10.960029]  CPU:        1   CR30: 00000000bfd50000 CR31: 0000000011111111
[   11.052057]  ORIG_R28: 000000004021e3b4
[   11.100045]  IAOQ[0]: irq_exit+0x94/0x120
[   11.152062]  IAOQ[1]: irq_exit+0x98/0x120
[   11.208031]  RP(r2): irq_exit+0xb8/0x120
[   11.256074] Backtrace:
[   11.288067]  [<00000000402cd944>] cpu_startup_entry+0x1e4/0x598
[   11.368058]  [<0000000040109528>] smp_callin+0x2c0/0x2f0
[   11.436308]  [<00000000402b53fc>] update_curr+0x18c/0x2d0
[   11.508055]  [<00000000402b73b8>] dequeue_entity+0x2c0/0x1030
[   11.584040]  [<00000000402b3cc0>] set_next_entity+0x80/0xd30
[   11.660069]  [<00000000402c1594>] pick_next_task_fair+0x614/0x720
[   11.740085]  [<000000004020dd34>] __schedule+0x394/0xa60
[   11.808054]  [<000000004020e488>] schedule+0x88/0x118
[   11.876039]  [<0000000040283d3c>] rescuer_thread+0x4d4/0x5b0
[   11.948090]  [<000000004028fc4c>] kthread+0x1ec/0x248
[   12.016053]  [<0000000040205020>] end_fault_vector+0x20/0xc0
[   12.092239]  [<00000000402050c0>] _switch_to_ret+0x0/0xf40
[   12.164044]
[   12.184036] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.8.0-1-parisc64-smp #1 Debian 4.8.7-1
[   12.244040] Backtrace:
[   12.244040]  [<000000004021c480>] show_stack+0x68/0x80
[   12.244040]  [<00000000406f332c>] dump_stack+0xec/0x168
[   12.244040]  [<000000004021c74c>] die_if_kernel+0x25c/0x430
[   12.244040]  [<000000004022d320>] handle_unaligned+0xb48/0xb50
[   12.244040]
[   12.632066] ---[ end trace 9ca05a7215c7bbb2 ]---
[   12.692036] Kernel panic - not syncing: Attempted to kill the idle task!

We have the insn 0x43ffff80 in IIR but from IAOQ we should have:
   4025d150:   0f f3 20 df     ldd,s r19(r31),r31
   4025d154:   0f 9f 00 9c     ldw r31(ret0),ret0
   4025d158:   bf 80 20 58     cmpb,*<> r0,ret0,4025d18c <irq_exit+0xcc>

Cpu0 has just completed running parisc_setup_cache_timing:

[    2.429981] Releasing cpu 1 now, hpa=fffffffffffa2000
[    2.635751] CPU(s): 2 out of 2 PA8500 (PCX-W) at 440.000000 MHz online
[    2.726692] Setting cache flush threshold to 1024 kB
[    2.729932] Not-handled unaligned insn 0x43ffff80
[    2.798114] Setting TLB flush threshold to 140 kB
[    2.928039] Unaligned handler failed, ret = -1

From the backtrace, cpu1 is in smp_callin:

void __init smp_callin(void)
{
       int slave_id = cpu_now_booting;

       smp_cpu_init(slave_id);
       preempt_disable();

       flush_cache_all_local(); /* start with known state */
       flush_tlb_all_local(NULL);

       local_irq_enable();  /* Interrupts have been off until now */

       cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

So, it has just flushed its caches and the TLB. It would seem either the
flushes in parisc_setup_cache_timing or smp_callin have corrupted kernel
memory.

The attached patch reworks parisc_setup_cache_timing to remove the races
in setting the cache and TLB flush thresholds. It also corrects the
number of bytes flushed in the TLB calculation.

The patch flushes the cache and TLB on cpu0 before starting the
secondary processors so that they are started from a known state.

Tested with a few reboots on c8000.
Signed-off-by: NJohn David Anglin  <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org> # v3.18+
Signed-off-by: NHelge Deller <deller@gmx.de>