rcu_read_(un)lock(), list_*_rcu(), and synchronize_rcu() are used for a secure
access and manipulation of the list of patches that modify the same function.
In particular, it is the variable func_stack that is accessible from the ftrace
handler via struct ftrace_ops and klp_ops.

Of course, it synchronizes also some states of the patch on the top of the
stack, e.g. func->transition in klp_ftrace_handler.

At the same time, this mechanism guards also the manipulation of
task->patch_state. It is modified according to the state of the transition and
the state of the process.

Now, all this works well as long as RCU works well. Sadly livepatching might
get into some corner cases when this is not true. For example, RCU is not
watching when rcu_read_lock() is taken in idle threads.  It is because they
might sleep and prevent reaching the grace period for too long.

There are ways how to make RCU watching even in idle threads, see
rcu_irq_enter(). But there is a small location inside RCU infrastructure when
even this does not work.

This small problematic location can be detected either before calling
rcu_irq_enter() by rcu_irq_enter_disabled() or later by rcu_is_watching().
Sadly, there is no safe way how to handle it.  Once we detect that RCU was not
watching, we might see inconsistent state of the function stack and the related
variables in klp_ftrace_handler(). Then we could do a wrong decision, use an
incompatible implementation of the function and break the consistency of the
system. We could warn but we could not avoid the damage.

Fortunately, ftrace has similar problems and they seem to be solved well there.
It uses a heavy weight implementation of some RCU operations. In particular, it
replaces:

  + rcu_read_lock() with preempt_disable_notrace()
  + rcu_read_unlock() with preempt_enable_notrace()
  + synchronize_rcu() with schedule_on_each_cpu(sync_work)

My understanding is that this is RCU implementation from a stone age. It meets
the core RCU requirements but it is rather ineffective. Especially, it does not
allow to batch or speed up the synchronize calls.

On the other hand, it is very trivial. It allows to safely trace and/or
livepatch even the RCU core infrastructure.  And the effectiveness is a not a
big issue because using ftrace or livepatches on productive systems is a rare
operation.  The safety is much more important than a negligible extra load.

Note that the alternative implementation follows the RCU principles. Therefore,
     we could and actually must use list_*_rcu() variants when manipulating the
     func_stack.  These functions allow to access the pointers in the right
     order and with the right barriers. But they do not use any other
     information that would be set only by rcu_read_lock().

Also note that there are actually two problems solved in ftrace:

First, it cares about the consistency of RCU read sections.  It is being solved
the way as described and used in this patch.

Second, ftrace needs to make sure that nobody is inside the dynamic trampoline
when it is being freed. For this, it also calls synchronize_rcu_tasks() in
preemptive kernel in ftrace_shutdown().

Livepatch has similar problem but it is solved by ftrace for free.
klp_ftrace_handler() is a good guy and never sleeps. In addition, it is
registered with FTRACE_OPS_FL_DYNAMIC. It causes that
unregister_ftrace_function() calls:

	* schedule_on_each_cpu(ftrace_sync) - always
	* synchronize_rcu_tasks() - in preemptive kernel

The effect is that nobody is neither inside the dynamic trampoline nor inside
the ftrace handler after unregister_ftrace_function() returns.

[jkosina@suse.cz: reformat changelog, fix comment]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

If TRIM_UNUSED_KSYMS is enabled, all unneeded exported symbols are made
unexported. Two-pass build of the kernel is done to find out which
symbols are needed based on a configuration. This effectively
complicates things for out-of-tree modules.

Livepatch exports functions to (un)register and enable/disable a live
patch. The only in-tree module which uses these functions is a sample in
samples/livepatch/. If the sample is disabled, the functions are
trimmed and out-of-tree live patches cannot be built.

Note that live patches are intended to be built out-of-tree.
Suggested-by: Michal Marek <mmarek@suse.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Pull livepatch updates from Jiri Kosina:

 - a per-task consistency model is being added for architectures that
   support reliable stack dumping (extending this, currently rather
   trivial set, is currently in the works).

   This extends the nature of the types of patches that can be applied
   by live patching infrastructure. The code stems from the design
   proposal made [1] back in November 2014. It's a hybrid of SUSE's
   kGraft and RH's kpatch, combining advantages of both: it uses
   kGraft's per-task consistency and syscall barrier switching combined
   with kpatch's stack trace switching. There are also a number of
   fallback options which make it quite flexible.

   Most of the heavy lifting done by Josh Poimboeuf with help from
   Miroslav Benes and Petr Mladek

   [1] https://lkml.kernel.org/r/20141107140458.GA21774@suse.cz

 - module load time patch optimization from Zhou Chengming

 - a few assorted small fixes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: add missing printk newlines
  livepatch: Cancel transition a safe way for immediate patches
  livepatch: Reduce the time of finding module symbols
  livepatch: make klp_mutex proper part of API
  livepatch: allow removal of a disabled patch
  livepatch: add /proc/<pid>/patch_state
  livepatch: change to a per-task consistency model
  livepatch: store function sizes
  livepatch: use kstrtobool() in enabled_store()
  livepatch: move patching functions into patch.c
  livepatch: remove unnecessary object loaded check
  livepatch: separate enabled and patched states
  livepatch/s390: add TIF_PATCH_PENDING thread flag
  livepatch/s390: reorganize TIF thread flag bits
  livepatch/powerpc: add TIF_PATCH_PENDING thread flag
  livepatch/x86: add TIF_PATCH_PENDING thread flag
  livepatch: create temporary klp_update_patch_state() stub
  x86/entry: define _TIF_ALLWORK_MASK flags explicitly
  stacktrace/x86: add function for detecting reliable stack traces

Pull HID subsystem updates from Jiri Kosina:

 - The need for HID_QUIRK_NO_INIT_REPORTS per-device quirk has been
   growing dramatically during past years, so the time has come to
   switch over the default, and perform the pro-active reading only in
   cases where it's really needed (multitouch, wacom).

   The only place where this behavior is (in some form) preserved is
   hiddev so that we don't introduce userspace-visible change of
   behavior.

   From Benjamin Tissoires

 - HID++ support for power_supply / baterry reporting.

   From Benjamin Tissoires and Bastien Nocera

 - Vast improvements / rework of DS3 and DS4 in Sony driver.

   From Roderick Colenbrander

 - Improvment (in terms of getting closer to the Microsoft's
   interpretation of slightly ambiguous specification) of logical range
   interpretation in case null-state is set in the rdesc.

   From Valtteri Heikkilä and Tomasz Kramkowski

 - A lot of newly supported device IDs and small assorted fixes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (71 commits)
  HID: usbhid: Add HID_QUIRK_NOGET for Aten CS-1758 KVM switch
  HID: asus: support backlight on USB keyboards
  HID: wacom: Move wacom_remote_irq and wacom_remote_status_irq
  HID: wacom: generic: sync pad events only for actual packets
  HID: sony: remove redundant check for -ve err
  HID: sony: Make sure to unregister sensors on failure
  HID: sony: Make DS4 bt poll interval adjustable
  HID: sony: Set proper bit flags on DS4 output report
  HID: sony: DS4 use brighter LED colors
  HID: sony: Improve navigation controller axis/button mapping
  HID: sony: Use DS3 MAC address as unique identifier on USB
  HID: logitech-hidpp: add a sysfs file to tell we support power_supply
  HID: logitech-hidpp: enable HID++ 1.0 battery reporting
  HID: logitech-hidpp: add support for battery status for the K750
  HID: logitech-hidpp: battery: provide CAPACITY_LEVEL
  HID: logitech-hidpp: rename battery level into capacity
  HID: logitech-hidpp: battery: provide ONLINE property
  HID: logitech-hidpp: notify battery on connect
  HID: logitech-hidpp: return an error if the queried feature is not present
  HID: logitech-hidpp: create the battery for all types of HID++ devices
  ...

Pull pin control updates from Linus Walleij:
 "This is the bulk of pin control changes for the v4.12 cycle.

  The extra week before the merge window actually resulted in some of
  the type of fixes that usually arrive after the merge window already
  starting to trickle in from eager developers using -next, I'm
  impressed.

  I have recruited a Samsung subsubsystem maintainer (Krzysztof) to deal
  with the onset of Samsung patches. It works great.

  Apart from that it is a boring round, just incremental updates and
  fixes all over the place, no serious core changes or anything exciting
  like that. The most pleasing to see is Julia Cartwrights work to audit
  the irqchip-providing drivers for realtime locking compliance. It's
  one of those "I should really get around to looking into that" things
  that have been on my TODO list since forever.

  Summary:

  Core changes:

   - add bi-directional and output-enable pin configurations to the
     generic bindings and generic pin controlling core.

  New drivers or subdrivers:

   - Armada 37xx SoC pin controller and GPIO support.

   - Axis ARTPEC-6 SoC pin controller support.

   - AllWinner A64 R_PIO controller support, and opening up the
     AllWinner sunxi driver for ARM64 use.

   - Rockchip RK3328 support.

   - Renesas R-Car H3 ES2.0 support.

   - STM32F469 support in the STM32 driver.

   - Aspeed G4 and G5 pin controller support.

  Improvements:

   - a whole slew of realtime improvements to drivers implementing
     irqchips: BCM, AMD, SiRF, sunxi, rockchip.

   - switch meson driver to get the GPIO ranges from the device tree.

   - input schmitt trigger support on the Rockchip driver.

   - enable the sunxi (AllWinner) driver to also be used on ARM64
     silicon.

   - name the Qualcomm QDF2xxx GPIO lines.

   - support GMMR GPIO regions on the Intel Cherryview. This fixes a
     serialization problem on these platforms.

   - pad retention support for the Samsung Exynos 5433.

   - handle suspend-to-ram in the AT91-pio4 driver.

   - pin configuration support in the Aspeed driver.

  Cleanups:

   - the final name of Rockchip RK1108 was RV1108 so rename the driver
     and variables to stay consistent"

* tag 'pinctrl-v4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (80 commits)
  pinctrl: mediatek: Add missing pinctrl bindings for mt7623
  pinctrl: artpec6: Fix return value check in artpec6_pmx_probe()
  pinctrl: artpec6: Remove .owner field for driver
  pinctrl: tegra: xusb: Silence sparse warnings
  ARM: at91/at91-pinctrl documentation: fix spelling mistake: "contoller" -> "controller"
  pinctrl: make artpec6 explicitly non-modular
  pinctrl: aspeed: g5: Add pinconf support
  pinctrl: aspeed: g4: Add pinconf support
  pinctrl: aspeed: Add core pinconf support
  pinctrl: aspeed: Document pinconf in devicetree bindings
  pinctrl: Add st,stm32f469-pinctrl compatible to stm32-pinctrl
  pinctrl: stm32: Add STM32F469 MCU support
  Documentation: dt: Remove ngpios from stm32-pinctrl binding
  pinctrl: stm32: replace device_initcall() with arch_initcall()
  pinctrl: stm32: add possibility to use gpio-ranges to declare bank range
  pinctrl: armada-37xx: Add gpio support
  pinctrl: armada-37xx: Add pin controller support for Armada 37xx
  pinctrl: dt-bindings: Add documentation for Armada 37xx pin controllers
  pinctrl: core: Make pinctrl_init_controller() static
  pinctrl: generic: Add bi-directional and output-enable
  ...

Pull MMC updates from Ulf Hansson:
 "MMC core:
   - Continue to re-factor code to prepare for eMMC CMDQ and blkmq support
   - Introduce queue semantics to prepare for eMMC CMDQ and blkmq support
   - Add helper functions to manage temporary enable/disable of eMMC CMDQ
   - Improve wait-busy detection for SDIO

  MMC host:
   - cavium: Add driver to support Cavium controllers
   - cavium: Extend Cavium driver to support Octeon and ThunderX SOCs
   - bcm2835: Add new driver for Broadcom BCM2835 controller
   - sdhci-xenon: Add driver to support Marvell Xenon SDHCI controller
   - sdhci-tegra: Add support for the Tegra186 variant
   - sdhci-of-esdhc: Support for UHS-I SD cards
   - sdhci-of-esdhc: Support for eMMC HS200 cards
   - sdhci-cadence: Add eMMC HS400 enhanced strobe support
   - sdhci-esdhc-imx: Reset tuning circuit when needed
   - sdhci-pci: Modernize and clean-up some PM related code
   - sdhci-pci: Avoid re-tuning at runtime PM for some Intel devices
   - sdhci-pci|acpi: Use aggressive PM for some Intel BYT controllers
   - sdhci: Re-factoring and modernizations
   - sdhci: Optimize delay loops
   - sdhci: Improve register dump print format
   - sdhci: Add support for the Command Queue Engine
   - meson-gx: Various improvements and clean-ups
   - meson-gx: Add support for CMD23
   - meson-gx: Basic tuning support to avoid CRC errors
   - s3cmci: Enable probing via DT
   - mediatek: Improve tuning support for eMMC HS200 and HS400 mode
   - tmio: Improve DMA support
   - tmio: Use correct response for CMD12
   - dw_mmc: Minor improvements and clean-ups"

* tag 'mmc-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: (148 commits)
  mmc: sdhci-of-esdhc: limit SD clock for ls1012a/ls1046a
  mmc: sdhci-of-esdhc: poll ESDHC_CLOCK_STABLE bit with udelay
  mmc: sdhci-xenon: Fix default value of LOGIC_TIMING_ADJUST for eMMC5.0 PHY
  mmc: sdhci-xenon: Fix the work flow in xenon_remove().
  MIPS: Octeon: cavium_octeon_defconfig: Enable Octeon MMC
  mmc: sdhci-xenon: Remove redundant dev_err call in get_dt_pad_ctrl_data()
  mmc: cavium: Use module_pci_driver to simplify the code
  mmc: cavium: Add MMC support for Octeon SOCs.
  mmc: cavium: Fix detection of block or byte addressing.
  mmc: core: Export API to allow hosts to get the card address
  mmc: sdio: Fix sdio wait busy implement limitation
  mmc: sdhci-esdhc-imx: reset tuning circuit when power on mmc card
  clk: apn806: fix spelling mistake: "mising" -> "missing"
  mmc: sdhci-of-esdhc: add delay between tuning cycles
  mmc: sdhci: Control the delay between tuning commands
  mmc: sdhci-of-esdhc: add tuning support
  mmc: sdhci-of-esdhc: add support for signal voltage switch
  mmc: sdhci-of-esdhc: add peripheral clock support
  mmc: sdhci-pci: Allow for 3 bytes from Intel DSM
  mmc: cavium: Fix a shift wrapping bug
  ...

Pull networking updates from David Millar:
 "Here are some highlights from the 2065 networking commits that
  happened this development cycle:

   1) XDP support for IXGBE (John Fastabend) and thunderx (Sunil Kowuri)

   2) Add a generic XDP driver, so that anyone can test XDP even if they
      lack a networking device whose driver has explicit XDP support
      (me).

   3) Sparc64 now has an eBPF JIT too (me)

   4) Add a BPF program testing framework via BPF_PROG_TEST_RUN (Alexei
      Starovoitov)

   5) Make netfitler network namespace teardown less expensive (Florian
      Westphal)

   6) Add symmetric hashing support to nft_hash (Laura Garcia Liebana)

   7) Implement NAPI and GRO in netvsc driver (Stephen Hemminger)

   8) Support TC flower offload statistics in mlxsw (Arkadi Sharshevsky)

   9) Multiqueue support in stmmac driver (Joao Pinto)

  10) Remove TCP timewait recycling, it never really could possibly work
      well in the real world and timestamp randomization really zaps any
      hint of usability this feature had (Soheil Hassas Yeganeh)

  11) Support level3 vs level4 ECMP route hashing in ipv4 (Nikolay
      Aleksandrov)

  12) Add socket busy poll support to epoll (Sridhar Samudrala)

  13) Netlink extended ACK support (Johannes Berg, Pablo Neira Ayuso,
      and several others)

  14) IPSEC hw offload infrastructure (Steffen Klassert)"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2065 commits)
  tipc: refactor function tipc_sk_recv_stream()
  tipc: refactor function tipc_sk_recvmsg()
  net: thunderx: Optimize page recycling for XDP
  net: thunderx: Support for XDP header adjustment
  net: thunderx: Add support for XDP_TX
  net: thunderx: Add support for XDP_DROP
  net: thunderx: Add basic XDP support
  net: thunderx: Cleanup receive buffer allocation
  net: thunderx: Optimize CQE_TX handling
  net: thunderx: Optimize RBDR descriptor handling
  net: thunderx: Support for page recycling
  ipx: call ipxitf_put() in ioctl error path
  net: sched: add helpers to handle extended actions
  qed*: Fix issues in the ptp filter config implementation.
  qede: Fix concurrency issue in PTP Tx path processing.
  stmmac: Add support for SIMATIC IOT2000 platform
  net: hns: fix ethtool_get_strings overflow in hns driver
  tcp: fix wraparound issue in tcp_lp
  bpf, arm64: fix jit branch offset related to ldimm64
  bpf, arm64: implement jiting of BPF_XADD
  ...

Pull crypto updates from Herbert Xu:
 "Here is the crypto update for 4.12:

  API:
   - Add batch registration for acomp/scomp
   - Change acomp testing to non-unique compressed result
   - Extend algorithm name limit to 128 bytes
   - Require setkey before accept(2) in algif_aead

  Algorithms:
   - Add support for deflate rfc1950 (zlib)

  Drivers:
   - Add accelerated crct10dif for powerpc
   - Add crc32 in stm32
   - Add sha384/sha512 in ccp
   - Add 3des/gcm(aes) for v5 devices in ccp
   - Add Queue Interface (QI) backend support in caam
   - Add new Exynos RNG driver
   - Add ThunderX ZIP driver
   - Add driver for hardware random generator on MT7623 SoC"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (101 commits)
  crypto: stm32 - Fix OF module alias information
  crypto: algif_aead - Require setkey before accept(2)
  crypto: scomp - add support for deflate rfc1950 (zlib)
  crypto: scomp - allow registration of multiple scomps
  crypto: ccp - Change ISR handler method for a v5 CCP
  crypto: ccp - Change ISR handler method for a v3 CCP
  crypto: crypto4xx - rename ce_ring_contol to ce_ring_control
  crypto: testmgr - Allow ecb(cipher_null) in FIPS mode
  Revert "crypto: arm64/sha - Add constant operand modifier to ASM_EXPORT"
  crypto: ccp - Disable interrupts early on unload
  crypto: ccp - Use only the relevant interrupt bits
  hwrng: mtk - Add driver for hardware random generator on MT7623 SoC
  dt-bindings: hwrng: Add Mediatek hardware random generator bindings
  crypto: crct10dif-vpmsum - Fix missing preempt_disable()
  crypto: testmgr - replace compression known answer test
  crypto: acomp - allow registration of multiple acomps
  hwrng: n2 - Use devm_kcalloc() in n2rng_probe()
  crypto: chcr - Fix error handling related to 'chcr_alloc_shash'
  padata: get_next is never NULL
  crypto: exynos - Add new Exynos RNG driver
  ...

Jon Maloy says:

====================
tipc: refactor socket receive functions

We try to make the functions tipc_sk_recvmsg() and
tipc_sk_recvstream() more readable.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

We try to make this function more readable by improving variable names
and comments, using more stack variables, and doing some smaller changes
to the logics. We also rename the function to make it consistent with
naming conventions used elsewhere in the code.
Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We try to make this function more readable by improving variable names
and comments, plus some minor changes to the logics.
Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sunil Goutham says:

====================
net: thunderx: Adds XDP support

This patch series adds support for XDP to ThunderX NIC driver
which is used on CN88xx, CN81xx and CN83xx platforms.

Patches 1-4 are performance improvement and cleanup patches
which are done keeping XDP performance bottlenecks in view.
Rest of the patches adds actual XDP support.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Driver follows a method of taking one extra reference on the
page for recycling which is fine in usual packet path where
each 64KB page is segmented into multiple receive buffers.

But in XDP mode since there is just one receive buffer per
page taking extra page reference itself becomes big bottleneck
consuming ~50% of CPU cycles due to atomic operations.

This patch adds a internal ref count in pgcache for each
page and additional page references are taken in a batch
instead of just one at a time. Internal i.e 'pgcache->ref_count'
and page's i.e 'page->_refcount' counters are compared to check
page's recyclability.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When in XDP mode reserve XDP_PACKET_HEADROOM bytes at the start
of receive buffer for XDP program to modify headers and adjust
packet start. Additional code changes done to handle such packets.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adds support for XDP_TX i.e transmits packet out of
the XDP TX queue mapped to the corresponding Rx queue
on which packet is received.

Since SQ for XDP TX will be used only on a single cpu i.e
SQ description creation and freeing, using atomic free count
is not necessary and will become a bottleneck. Hence added
a separate 'xdp_free_cnt' used for SQs designated for XDP
to track descriptor free count.

Changes also include
- A new entry 'xdp_page' is added to save transmitted packet's
  page pointer for later cleanup.
- XDP Tx SQ's doorbell is ringed once per NAPI instance.
- Retrieving designated SQ for packets being sent out by stack
  via 'nicvf_xmit'.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adds support for XDP_DROP.
Also since in XDP mode there is just a single buffer per page,
made changes to recycle DMA mapping info as well along with pages.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adds basic XDP support i.e attaching a BPF program to an
interface. Also takes care of allocating separate Tx queues
for XDP path and for network stack packet transmission.

This patch doesn't support handling of any of the XDP actions,
all are treated as XDP_PASS i.e packets will be handed over to
the network stack.

Changes also involve allocating one receive buffer per page in XDP
mode and multiple in normal mode i.e when no BPF program is attached.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Get rid of unnecessary double pointer references and type casting
in receive buffer allocation code.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Optimized CQE handling with below changes
- Feeing descriptors back to SQ in bulk i.e once per NAPI
  instance instead for every CQE_TX, this will reduce number
  of atomic updates to 'sq->free_cnt'.
- Checking errors in CQE_TX and CQE_RX before calling appropriate
  fn()s to update error stats i.e reduce branching.

Also removed debug messages in packet handling path which otherwise
causes issues if DEBUG is enabled.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Receive buffer's physical address or iova will anyway not
go beyond 49bits, since it is the max supported HW address.
As per perf, updating bitfields i.e buf_addr:42 in RBDR
descriptor entry consumes lots of cpu cycles, hence changed
it to a 64bit field with alignment requirements taken care of.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adds support for page recycling for allocating receive buffers
to reduce cost of refilling RBDR ring. Also got rid of using
compound pages when pagesize is 4K, only order-0 pages now.

Only page is recycled, DMA mappings still needs to be done for
every receive buffer allocated due to following constraints
- Cannot have just one receive buffer per 64KB page.
- There is just one buffer ring shared across 8 Rx queues, so
  buffers of same page can go to any Rx queue.
- HW gives buffer address where packet has been DMA'ed and not
  the index into buffer ring.
This makes it not possible to resue DMA mapping info. So unfortunately
have to go through costly mapping route for every buffer.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We should call ipxitf_put() if the copy_to_user() fails.
Reported-by: 李强 <liqiang6-s@360.cn>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jump is now the only one using value action opcode. This is going to
change soon. So introduce helpers to work with this. Convert TC_ACT_JUMP.

This also fixes the TC_ACT_JUMP check, which is incorrectly done as a
bit check, not a value check.

Fixes: e0ee84de ("net sched actions: Complete the JUMPX opcode")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sudarsana Reddy Kalluru says:

====================
qed*: PTP bug fixes.

The series addresses couple of issues in the PTP implementation.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

PTP hardware filter configuration performed by the driver for a given
user requested config is not correct for some of the PTP modes.
Following changes are needed for PTP config-filter implementation.
 1. NIG_REG_TX_PTP_EN register - Bits 0/1/2 respectively enables
    TimeSync/"V1 frame format support"/"V2 frame format support" on
    the TX side. Set the associated bits based on the user request.
 2. ptp4l application fails to operate in Peer Delay mode. Following
    changes are needed to fix this,
    a. Driver should enable (set to 0) DA #1-related bits for IPv4,
       IPv6 and MAC destination addresses in these registers:
         NIG_REG_TX_LLH_PTP_RULE_MASK
         NIG_REG_LLH_PTP_RULE_MASK
    b. NIG_REG_LLH_PTP_PARAM_MASK/NIG_REG_TX_LLH_PTP_PARAM_MASK should
       be set to 0x0 in all modes.
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

PTP Tx timestamping data structures are not protected against the
concurrent access in the Tx paths. Protecting the same using atomic
bit locks.
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The IOT2000 is industrial controller platform, derived from the Intel
Galileo Gen2 board. The variant IOT2020 comes with one LAN port, the
IOT2040 has two of them. They can be told apart based on the board asset
tag in the DMI table.

Based on patch by Sascha Weisenberger.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Sascha Weisenberger <sascha.weisenberger@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hns_get_sset_count() returns HNS_NET_STATS_CNT and the data space allocated
is not enough for ethtool_get_strings(), which will cause random memory
corruption.

When SLAB and DEBUG_SLAB are both enabled, memory corruptions like the
the following can be observed without this patch:
[   43.115200] Slab corruption (Not tainted): Acpi-ParseExt start=ffff801fb0b69030, len=80
[   43.115206] Redzone: 0x9f911029d006462/0x5f78745f31657070.
[   43.115208] Last user: [<5f7272655f746b70>](0x5f7272655f746b70)
[   43.115214] 010: 70 70 65 31 5f 74 78 5f 70 6b 74 00 6b 6b 6b 6b  ppe1_tx_pkt.kkkk
[   43.115217] 030: 70 70 65 31 5f 74 78 5f 70 6b 74 5f 6f 6b 00 6b  ppe1_tx_pkt_ok.k
[   43.115218] Next obj: start=ffff801fb0b69098, len=80
[   43.115220] Redzone: 0x706d655f6f666966/0x9f911029d74e35b.
[   43.115229] Last user: [<ffff0000084b11b0>](acpi_os_release_object+0x28/0x38)
[   43.115231] 000: 74 79 00 6b 6b 6b 6b 6b 70 70 65 31 5f 74 78 5f  ty.kkkkkppe1_tx_
[   43.115232] 010: 70 6b 74 5f 65 72 72 5f 63 73 75 6d 5f 66 61 69  pkt_err_csum_fai
Signed-off-by: Timmy Li <lixiaoping3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Be careful when comparing tcp_time_stamp to some u32 quantity,
otherwise result can be surprising.

Fixes: 7c106d7e ("[TCP]: TCP Low Priority congestion control")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When the instruction right before the branch destination is
a 64 bit load immediate, we currently calculate the wrong
jump offset in the ctx->offset[] array as we only account
one instruction slot for the 64 bit load immediate although
it uses two BPF instructions. Fix it up by setting the offset
into the right slot after we incremented the index.

Before (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // #3
  00000028:  d2800041  mov x1, #0x2 // #2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  54ffff82  b.cs 0x00000020
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl #48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl #48
  [...]

After (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // #3
  00000028:  d2800041  mov x1, #0x2 // #2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  540000a2  b.cs 0x00000044
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl #48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl #48
  [...]

Also, add a couple of test cases to make sure JITs pass
this test. Tested on Cavium ThunderX ARMv8. The added
test cases all pass after the fix.

Fixes: 8eee539d ("arm64: bpf: fix out-of-bounds read in bpf2a64_offset()")
Reported-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Xi Wang <xi.wang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This work adds BPF_XADD for BPF_W/BPF_DW to the arm64 JIT and therefore
completes JITing of all BPF instructions, meaning we can thus also remove
the 'notyet' label and do not need to fall back to the interpreter when
BPF_XADD is used in a program!

This now also brings arm64 JIT in line with x86_64, s390x, ppc64, sparc64,
where all current eBPF features are supported.

BPF_W example from test_bpf:

  .u.insns_int = {
    BPF_ALU32_IMM(BPF_MOV, R0, 0x12),
    BPF_ST_MEM(BPF_W, R10, -40, 0x10),
    BPF_STX_XADD(BPF_W, R10, R0, -40),
    BPF_LDX_MEM(BPF_W, R0, R10, -40),
    BPF_EXIT_INSN(),
  },

  [...]
  00000020:  52800247  mov w7, #0x12 // #18
  00000024:  928004eb  mov x11, #0xffffffffffffffd8 // #-40
  00000028:  d280020a  mov x10, #0x10 // #16
  0000002c:  b82b6b2a  str w10, [x25,x11]
  // start of xadd mapping:
  00000030:  928004ea  mov x10, #0xffffffffffffffd8 // #-40
  00000034:  8b19014a  add x10, x10, x25
  00000038:  f9800151  prfm pstl1strm, [x10]
  0000003c:  885f7d4b  ldxr w11, [x10]
  00000040:  0b07016b  add w11, w11, w7
  00000044:  880b7d4b  stxr w11, w11, [x10]
  00000048:  35ffffab  cbnz w11, 0x0000003c
  // end of xadd mapping:
  [...]

BPF_DW example from test_bpf:

  .u.insns_int = {
    BPF_ALU32_IMM(BPF_MOV, R0, 0x12),
    BPF_ST_MEM(BPF_DW, R10, -40, 0x10),
    BPF_STX_XADD(BPF_DW, R10, R0, -40),
    BPF_LDX_MEM(BPF_DW, R0, R10, -40),
    BPF_EXIT_INSN(),
  },

  [...]
  00000020:  52800247  mov w7,  #0x12 // #18
  00000024:  928004eb  mov x11, #0xffffffffffffffd8 // #-40
  00000028:  d280020a  mov x10, #0x10 // #16
  0000002c:  f82b6b2a  str x10, [x25,x11]
  // start of xadd mapping:
  00000030:  928004ea  mov x10, #0xffffffffffffffd8 // #-40
  00000034:  8b19014a  add x10, x10, x25
  00000038:  f9800151  prfm pstl1strm, [x10]
  0000003c:  c85f7d4b  ldxr x11, [x10]
  00000040:  8b07016b  add x11, x11, x7
  00000044:  c80b7d4b  stxr w11, x11, [x10]
  00000048:  35ffffab  cbnz w11, 0x0000003c
  // end of xadd mapping:
  [...]

Tested on Cavium ThunderX ARMv8, test suite results after the patch:

  No JIT:   [ 3751.855362] test_bpf: Summary: 311 PASSED, 0 FAILED, [0/303 JIT'ed]
  With JIT: [ 3573.759527] test_bpf: Summary: 311 PASSED, 0 FAILED, [303/303 JIT'ed]
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull fs/compat.c cleanups from Al Viro:
 "More moving of compat syscalls from fs/compat.c to fs/*.c where the
  native counterparts live.

  And death to compat_sys_getdents64() - the only architecture that used
  to need it was ia64, and _that_ has lost biarch support quite a few
  years ago"

* 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs/compat.c: trim unused includes
  move compat_rw_copy_check_uvector() over to fs/read_write.c
  fhandle: move compat syscalls from compat.c
  open: move compat syscalls from compat.c
  stat: move compat syscalls from compat.c
  fcntl: move compat syscalls from compat.c
  readdir: move compat syscalls from compat.c
  statfs: move compat syscalls from compat.c
  utimes: move compat syscalls from compat.c
  move compat select-related syscalls to fs/select.c
  Remove compat_sys_getdents64()

Pull splice updates from Al Viro:
 "These actually missed the last cycle; the branch itself is from last
  December"

* 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  make nr_pages calculation in default_file_splice_read() a bit less ugly
  splice/tee/vmsplice: validate flags
  splice_pipe_desc: kill ->flags
  remove spd_release_page()

Pull iov_iter updates from Al Viro:
 "Cleanups that sat in -next + -stable fodder that has just missed 4.11.

  There's more iov_iter work in my local tree, but I'd prefer to push
  the stuff that had been in -next first"

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  iov_iter: don't revert iov buffer if csum error
  generic_file_read_iter(): make use of iov_iter_revert()
  generic_file_direct_write(): make use of iov_iter_revert()
  orangefs: use iov_iter_revert()
  sctp: switch to copy_from_iter_full()
  net/9p: switch to copy_from_iter_full()
  switch memcpy_from_msg() to copy_from_iter_full()
  rds: make use of iov_iter_revert()

Pull CIFS fixes from Steve French:
 "Three cifs/smb3 fixes - including two for stable"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: don't check for failure from mempool_alloc()
  Do not return number of bytes written for ioctl CIFS_IOC_COPYCHUNK_FILE
  Fix match_prepath()

Pull hardened usercopy updates from Kees Cook:
 "A couple hardened usercopy changes:

   - drop now unneeded is_vmalloc_or_module() check (Laura Abbott)

   - use enum instead of literals for stack frame API (Sahara)"

* tag 'usercopy-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  mm/usercopy: Drop extra is_vmalloc_or_module() check
  usercopy: Move enum for arch_within_stack_frames()

Pull pstore updates from Kees Cook:
 "This has a large internal refactoring along with several smaller
  fixes.

   - constify compression structures; Bhumika Goyal

   - restore powerpc dumping; Ankit Kumar

   - fix more bugs in the rarely exercises module unloading logic

   - reorganize filesystem locking to fix problems noticed by lockdep

   - refactor internal pstore APIs to make development and review
     easier:
      - improve error reporting
      - add kernel-doc structure and function comments
      - avoid insane argument passing by using a common record
        structure"

* tag 'pstore-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (23 commits)
  pstore: Solve lockdep warning by moving inode locks
  pstore: Fix flags to enable dumps on powerpc
  pstore: Remove unused vmalloc.h in pmsg
  pstore: simplify write_user_compat()
  pstore: Remove write_buf() callback
  pstore: Replace arguments for write_buf_user() API
  pstore: Replace arguments for write_buf() API
  pstore: Replace arguments for erase() API
  pstore: Do not duplicate record metadata
  pstore: Allocate records on heap instead of stack
  pstore: Pass record contents instead of copying
  pstore: Always allocate buffer for decompression
  pstore: Replace arguments for write() API
  pstore: Replace arguments for read() API
  pstore: Switch pstore_mkfile to pass record
  pstore: Move record decompression to function
  pstore: Extract common arguments into structure
  pstore: Add kernel-doc for struct pstore_info
  pstore: Improve register_pstore() error reporting
  pstore: Avoid race in module unloading
  ...

Pull documentation update from Jonathan Corbet:
 "A reasonably busy cycle for documentation this time around. There is a
  new guide for user-space API documents, rather sparsely populated at
  the moment, but it's a start. Markus improved the infrastructure for
  converting diagrams. Mauro has converted much of the USB documentation
  over to RST. Plus the usual set of fixes, improvements, and tweaks.

  There's a bit more than the usual amount of reaching out of
  Documentation/ to fix comments elsewhere in the tree; I have acks for
  those where I could get them"

* tag 'docs-4.12' of git://git.lwn.net/linux: (74 commits)
  docs: Fix a couple typos
  docs: Fix a spelling error in vfio-mediated-device.txt
  docs: Fix a spelling error in ioctl-number.txt
  MAINTAINERS: update file entry for HSI subsystem
  Documentation: allow installing man pages to a user defined directory
  Doc/PM: Sync with intel_powerclamp code behavior
  zr364xx.rst: usb/devices is now at /sys/kernel/debug/
  usb.rst: move documentation from proc_usb_info.txt to USB ReST book
  convert philips.txt to ReST and add to media docs
  docs-rst: usb: update old usbfs-related documentation
  arm: Documentation: update a path name
  docs: process/4.Coding.rst: Fix a couple of document refs
  docs-rst: fix usb cross-references
  usb: gadget.h: be consistent at kernel doc macros
  usb: composite.h: fix two warnings when building docs
  usb: get rid of some ReST doc build errors
  usb.rst: get rid of some Sphinx errors
  usb/URB.txt: convert to ReST and update it
  usb/persist.txt: convert to ReST and add to driver-api book
  usb/hotplug.txt: convert to ReST and add to driver-api book
  ...

Pull m68k updates from Geert Uytterhoeven:

  - more kernel message modernizations and cleanups

  - Mac and Nubus improvements and cleanups.

* tag 'm68k-for-v4.12-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  nubus: Add MVC and VSC video card definitions
  nubus: Clean up whitespace
  nubus: Clean up printk calls
  nubus: Fix nubus_rewinddir
  m68k/mac: Clarify IOP message alloc/free confusion
  m68k/mac: Adopt platform_device_register_simple()
  m68k/mac: Modernize printing of kernel messages
  m68k/mac: IOP - Modernize printing of kernel messages

Pull s390 updates from Martin Schwidefsky:

 - three merges for KVM/s390 with changes for vfio-ccw and cpacf. The
   patches are included in the KVM tree as well, let git sort it out.

 - add the new 'trng' random number generator

 - provide the secure key verification API for the pkey interface

 - introduce the z13 cpu counters to perf

 - add a new system call to set up the guarded storage facility

 - simplify TASK_SIZE and arch_get_unmapped_area

 - export the raw STSI data related to CPU topology to user space

 - ... and the usual churn of bug-fixes and cleanups.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (74 commits)
  s390/crypt: use the correct module alias for paes_s390.
  s390/cpacf: Introduce kma instruction
  s390/cpacf: query instructions use unique parameters for compatibility with KMA
  s390/trng: Introduce s390 TRNG device driver.
  s390/crypto: Provide s390 specific arch random functionality.
  s390/crypto: Add new subfunctions to the cpacf PRNO function.
  s390/crypto: Renaming PPNO to PRNO.
  s390/pageattr: avoid unnecessary page table splitting
  s390/mm: simplify arch_get_unmapped_area[_topdown]
  s390/mm: make TASK_SIZE independent from the number of page table levels
  s390/gs: add regset for the guarded storage broadcast control block
  s390/kvm: Add use_cmma field to mm_context_t
  s390/kvm: Add PGSTE manipulation functions
  vfio: ccw: improve error handling for vfio_ccw_mdev_remove
  vfio: ccw: remove unnecessary NULL checks of a pointer
  s390/spinlock: remove compare and delay instruction
  s390/spinlock: use atomic primitives for spinlocks
  s390/cpumf: simplify detection of guest samples
  s390/pci: remove forward declaration
  s390/pci: increase the PCI_NR_FUNCTIONS default
  ...