The root complexes used to access off-chip PCIe devices (called PEM units
in the hardware manuals) on some Cavium ThunderX processors require quirky
access methods for the config space of the PCIe bridge.

Add a driver to provide these config space accessor functions.  Use the
pci-host-common code to configure the PCI machinery.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRob Herring <robh@kernel.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>

Move pci_host_common_probe() and associated functions to pci-host-common.c,
where it can be shared with other drivers.  Make it public (not static)
and update Kconfig and Makefile to build it.  No functional change
intended.

[bhelgaas: split into separate patch, changelog]
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NWill Deacon <will.deacon@arm.com>

Factor gen_pci_probe(), moving most of it into pci_host_common_probe()
where it can be shared with other drivers that have slightly different
config accessors.  No functional change intended.

[bhelgaas: split into separate patch, changelog]
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NWill Deacon <will.deacon@arm.com>

Move definitions for generic PCI host controller driver structures to a
separate header file so we can share them with other drivers.  No
functional change intended.

[bhelgaas: split into separate patch, changelog]
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NWill Deacon <will.deacon@arm.com>

Like the Yoga 900 models the Lenovo Yoga 700 does not have a
hw rfkill switch, and trying to read the hw rfkill switch through the
ideapad module causes it to always reported blocking breaking wifi.

This commit adds the Lenovo Yoga 700 to the no_hw_rfkill dmi list, fixing
the wifi breakage.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1295272
Tested-by: <dinyar.rabady+spam@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJosh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: NDarren Hart <dvhart@linux.intel.com>

This patch fixes compile time warnings when CONFIG_PM_SLEEP
is undefined. In this case sleep related counters are unused.
Signed-off-by: NSouvik Kumar Chakravarty <souvik.k.chakravarty@intel.com>
Signed-off-by: NDarren Hart <dvhart@linux.intel.com>

The extended flash address needs to be subtracted from bcm_tag flash
image offsets. Move this value to the bcm_tag header file.

Renamed define name to consistently use bcm963xx for flash layout
which should be considered a property of the board and not the SoC
(i.e. bcm63xx could theoretically be used on a board without CFE
or any flash).
Signed-off-by: NSimon Arlott <simon@fire.lp0.eu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: MIPS Mailing List <linux-mips@linux-mips.org>
Cc: MTD Maling List <linux-mtd@lists.infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11833/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Move Broadcom BCM963xx image tag data structure to include/linux/
so that drivers outside of mach-bcm63xx can use it.
Signed-off-by: NSimon Arlott <simon@fire.lp0.eu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: MIPS Mailing List <linux-mips@linux-mips.org>
Cc: MTD Maling List <linux-mtd@lists.infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11832/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This adds support for the interrupt controller present on PIC32 class
devices. It handles all internal and external interrupts. This controller
exists outside of the CPU core and is the arbitrator of all interrupts
(including interrupts from the CPU itself) before they are presented to
the CPU.

The following features are supported:
 - DT properties for EVIC and for devices/peripherals that use interrupt lines
 - Persistent and non-persistent interrupt handling
 - irqdomain and generic chip support
 - Configuration of external interrupt edge polarity
Signed-off-by: NCristian Birsan <cristian.birsan@microchip.com>
Signed-off-by: NJoshua Henderson <joshua.henderson@microchip.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12092/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

There are many locations that do

  if (memory_was_allocated_by_vmalloc)
    vfree(ptr);
  else
    kfree(ptr);

but kvfree() can handle both kmalloc()ed memory and vmalloc()ed memory
using is_vmalloc_addr().  Unless callers have special reasons, we can
replace this branch with kvfree().  Please check and reply if you found
problems.
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NJan Kara <jack@suse.com>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: NAndreas Dilger <andreas.dilger@intel.com>
Acked-by: N"Rafael J. Wysocki" <rjw@rjwysocki.net>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Boris Petkov <bp@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

gcc warns about the 'found' variable possibly being used uninitialized:

drivers/soc/qcom/spm.c: In function 'spm_dev_probe':
drivers/soc/qcom/spm.c:305:5: error: 'found' may be used uninitialized in this function [-Werror=maybe-uninitialized]

However, the code is correct because we know that there is
always at least one online CPU. This initializes the 'found'
variable to zero before the loop so the compiler knows
it does not have to warn about it.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

If the parameter given to the macro is replaced throughout the macro as
it is evaluated.  The intent is that the macro parameter should replace
the only the first parameter to container_of().  However, the way the
macro was written, it would also inadvertantly replace a structure field
name.  If a parameter of any other name is given to the macro, it will
fail to compile, if the structure does not contain a field of the same
name.  At worst, it will compile, and hide improper access of an
unintended field in the structure.

Change the macro parameter name, so it does not conflict with the
structure field name.
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Acked-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

This adds support for AMD's PCI-Express Non-Transparent Bridge
(NTB) device on the Zeppelin platform. The driver connnects to the
standard NTB sub-system interface, with modification to add hooks
for power management in a separate patch. The AMD NTB device has 3
memory windows, 16 doorbell, 16 scratch-pad registers, and supports
up to 16 PCIe lanes running a Gen3 speeds.
Signed-off-by: NXiangliang Yu <Xiangliang.Yu@amd.com>
Reviewed-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

The rbd_dev_destroy() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

The create_cq() can receive creation flags which were used
differently by two commits which added create_cq extended
command and cross-channel. The merged code caused to not
accept any flags at all.

This patch unifies the check into one function and one return
error code.

Fixes: 972ecb82 ("IB/mlx5: Add create_cq extended command")
Fixes: 051f2630 ("IB/mlx5: Add driver cross-channel support")
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Added Raw Packet QP modify functionality which will enable user
space consumers to use it.

Since Raw Packet QP is built of SQ and RQ sub-objects, therefore
Raw Packet QP state changes are implemented by changing the state
of the sub-objects.
Signed-off-by: NMajd Dibbiny <majd@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

When modifying a QP, the desired operation was determined in
the mlx5_core using a transition table that takes the current
state, the final state, and returns the desired operation.

Since this logic will be used for Raw Packet QP, move the
operation table to the mlx5_ib.
Signed-off-by: NMajd Dibbiny <majd@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

When the user changes the Address Vector(AV) in the modify QP, he
provides an SL. This SL should be translated to Ethernet Priority
by taking the 3 LSB bits, and modify the QP's TIS according to this
Ethernet priority.
Signed-off-by: NMajd Dibbiny <majd@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Since Raw Packet QP is composed of RQ and SQ, the IB QP's
state is derived from the sub-objects. Therefore we need
to query each one of the sub-objects, and decide on the
IB QP's state.
Signed-off-by: NMajd Dibbiny <majd@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

This patch adds support for Raw Packet QP for the mlx5 device.

Raw Packet QP, unlike other QP types, has no matching mlx5_core_qp
object but rather it is built of RQ/SQ/TIR/TIS/TD mlx5_core object.

Since the SQ and RQ work-queue (WQ) buffers are not contiguous like
other QPs, we allocate separate buffers in the user-space and pass
the address of each one of them separately to the kernel.
Signed-off-by: NMajd Dibbiny <majd@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Extract specific IB QP fields to mlx5_ib_qp_trans structure.
The mlx5_core QP object resides in mlx5_ib_qp_base, which all QP types
inherit from. When we need to find mlx5_ib_qp using mlx5_core QP
(event handling and co), we use a pointer that resides in
mlx5_ib_qp_base.

In addition, we delete all redundant fields that weren't used anywhere
in the code:
-doorbell_qpn
-sq_max_wqes_per_wr
-sq_spare_wqes
Signed-off-by: NMajd Dibbiny <majd@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Transport Domain groups several TIS and TIR object. By grouping
these object, it defines wheather local loopback packets that
are sent from the TIS objects in the group are received by the
TIR objects in the same group.

Allocate a Transport Domain(TD) for each user context to be used
in the future by Raw Packet QP for Self-Loopback Control.
Signed-off-by: NMajd Dibbiny <majd@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

When an event arrives on QP/RQ/SQ, check whether it's supported,
and print a warning message otherwise.
Signed-off-by: NMajd Dibbiny <majd@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

RQ/SQ will be used to implement IB verbs QPs, so the IB QP affiliated
events are affiliated also with SQs and RQs.

Since SQ, RQ and QP resource numbers do not share the same name
space, a queue type field was added to the event data to specify
the SW object that the event is affiliated with.
Signed-off-by: NMajd Dibbiny <majd@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

To be used by mlx5_ib in the following patches for implementing
RAW PACKET QP.

Add mlx5_core_ prefix to alloc and delloc transport_domain since
they are exposed now.
Signed-off-by: NMajd Dibbiny <majd@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Per user context, work with CQE version that both the user-space
and the kernel support. Report this CQE version via the response of
the alloc_ucontext command.
Signed-off-by: NHaggai Abramovsky <hagaya@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Enforce working with CQE version 1 when the user supports CQE
version 1 and asked to work this way.

If the user still works with CQE version 0, then use the default
CQE version to tell the Firmware that the user still works in the
older mode.

After this patch, the kernel still reports CQE version 0.
Signed-off-by: NHaggai Abramovsky <hagaya@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

The wrong buffer size was passed to ib_is_udata_cleared.
Signed-off-by: NHaggai Abramovsky <hagaya@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

The rdma netlink local service registers a handler to handle RESOLVE
response and another handler to handle SET_TIMEOUT request. The first
thing these handlers do is to call netlink_capable() to check the
access right of the received skb to make sure that the sender has root
access. Under normal conditions, such responses and requests will be
directly forwarded to the handlers without going through the netlink_dump
pathway (see ibnl_rcv_msg() in drivers/infiniband/core/netlink.c).
However, a user application could send a RESOLVE request (not response)
to the local service, which will fall into the netlink_dump pathway,
where a new skb will be created without initializing the control block.
This new skb will be eventually forwarded to the local service RESOLVE
response handler. Unfortunately, netlink_capable() will cause general
protection fault if the skb's control block is not initialized. This
patch will address the problem by checking the skb first.
Signed-off-by: NKaike Wan <kaike.wan@intel.com>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Commit d1cd2142 ("pwm: Set enable state properly on failed call to
enable") introduced a mutex that is needed to protect internal state of
PWM devices. Since that mutex is acquired in pwm_set_polarity() and in
pwm_enable() and might potentially block, all PWM devices effectively
become "might sleep".

It's rather pointless to keep the .can_sleep field around, but given
that there are external users let's postpone the removal for the next
release cycle.
Signed-off-by: NThierry Reding <thierry.reding@gmail.com>

The DT binding doc says reset-gpios is an optional property but the code
currently bails out if it is omitted.

This is a regression since it breaks previously working device trees.
Fix it by restoring the original documented behaviour.

Fixes: ce037275 ("mmc: pwrseq_simple: use GPIO descriptors array API")
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NMartin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

do_div is the wrong way to divide a sector_t, as it is less efficient
when sector_t is 32-bit wide.  With the upcoming do_div optimizations,
the kernel starts warning about this:

  drivers/memstick/core/ms_block.c: In function 'msb_io_work':
  include/asm-generic/div64.h:207:28: warning: comparison of distinct pointer types lacks a cast

This changes the code to use sector_div instead, which always produces
optimal code.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This wasn't an asm-generic header to start with, and can be merged into
dma-mapping.h trivially.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Helge Deller <deller@gmx.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move the generic implementation to <linux/dma-mapping.h> now that all
architectures support it and remove the HAVE_DMA_ATTR Kconfig symbol now
that everyone supports them.

[valentinrothberg@gmail.com: remove leftovers in Kconfig]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Helge Deller <deller@gmx.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NValentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NHelge Deller <deller@gmx.de>
Acked-by: NHelge Deller <deller@gmx.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This series converts all remaining architectures to use dma_map_ops and
the generic implementation of the DMA API.  This not only simplifies the
code a lot, but also prepares for possible future changes like more
generic non-iommu dma_ops implementations or generic per-device
dma_map_ops.

This patch (of 16):

We have a couple architectures that do not want to support this code, so
add another Kconfig symbol that disables the code similar to what we do
for the nommu case.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/iio/industrialio-sw-trigger.c:169:1-3: WARNING: PTR_ERR_OR_ZERO can be used

 Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Octavian Purdila <octavian.purdila@intel.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Adriana Reus <adriana.reus@intel.com>
Cc: Daniel Baluta <daniel.baluta@intel.com>
Cc: Cristina Opriceana <cristina.opriceana@gmail.com>
Cc: Peter Meerwald <pmeerw@pmeerw.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

UBSAN uses compile-time instrumentation to catch undefined behavior
(UB).  Compiler inserts code that perform certain kinds of checks before
operations that could cause UB.  If check fails (i.e.  UB detected)
__ubsan_handle_* function called to print error message.

So the most of the work is done by compiler.  This patch just implements
ubsan handlers printing errors.

GCC has this capability since 4.9.x [1] (see -fsanitize=undefined
option and its suboptions).
However GCC 5.x has more checkers implemented [2].
Article [3] has a bit more details about UBSAN in the GCC.

[1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
[2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
[3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/

Issues which UBSAN has found thus far are:

Found bugs:

 * out-of-bounds access - 97840cb6 ("netfilter: nfnetlink: fix
   insufficient validation in nfnetlink_bind")

undefined shifts:

 * d48458d4 ("jbd2: use a better hash function for the revoke
   table")

 * 10632008 ("clockevents: Prevent shift out of bounds")

 * 'x << -1' shift in ext4 -
   http://lkml.kernel.org/r/<5444EF21.8020501@samsung.com>

 * undefined rol32(0) -
   http://lkml.kernel.org/r/<1449198241-20654-1-git-send-email-sasha.levin@oracle.com>

 * undefined dirty_ratelimit calculation -
   http://lkml.kernel.org/r/<566594E2.3050306@odin.com>

 * undefined roundown_pow_of_two(0) -
   http://lkml.kernel.org/r/<1449156616-11474-1-git-send-email-sasha.levin@oracle.com>

 * [WONTFIX] undefined shift in __bpf_prog_run -
   http://lkml.kernel.org/r/<CACT4Y+ZxoR3UjLgcNdUm4fECLMx2VdtfrENMtRRCdgHB2n0bJA@mail.gmail.com>

   WONTFIX here because it should be fixed in bpf program, not in kernel.

signed overflows:

 * 32a8df4e ("sched: Fix odd values in effective_load()
   calculations")

 * mul overflow in ntp -
   http://lkml.kernel.org/r/<1449175608-1146-1-git-send-email-sasha.levin@oracle.com>

 * incorrect conversion into rtc_time in rtc_time64_to_tm() -
   http://lkml.kernel.org/r/<1449187944-11730-1-git-send-email-sasha.levin@oracle.com>

 * unvalidated timespec in io_getevents() -
   http://lkml.kernel.org/r/<CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com>

 * [NOTABUG] signed overflow in ktime_add_safe() -
   http://lkml.kernel.org/r/<CACT4Y+aJ4muRnWxsUe1CMnA6P8nooO33kwG-c8YZg=0Xc8rJqw@mail.gmail.com>

[akpm@linux-foundation.org: fix unused local warning]
[akpm@linux-foundation.org: fix __int128 build woes]
Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yury Gribov <y.gribov@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>